/*
* Copyright (c) 2018-2022, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2020-2021, the SerenityOS developers.
* Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>
* Copyright (c) 2021, Tobias Christiansen <tobyase@serenityos.org>
* Copyright (c) 2022, MacDue <macdue@dueutil.tech>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/CharacterTypes.h>
#include <AK/Debug.h>
#include <AK/GenericLexer.h>
#include <AK/SourceLocation.h>
#include <LibWeb/Bindings/MainThreadVM.h>
#include <LibWeb/CSS/CSSFontFaceRule.h>
#include <LibWeb/CSS/CSSImportRule.h>
#include <LibWeb/CSS/CSSMediaRule.h>
#include <LibWeb/CSS/CSSStyleDeclaration.h>
#include <LibWeb/CSS/CSSStyleRule.h>
#include <LibWeb/CSS/CSSStyleSheet.h>
#include <LibWeb/CSS/CSSSupportsRule.h>
#include <LibWeb/CSS/CalculatedOr.h>
#include <LibWeb/CSS/EdgeRect.h>
#include <LibWeb/CSS/MediaList.h>
#include <LibWeb/CSS/Parser/Block.h>
#include <LibWeb/CSS/Parser/ComponentValue.h>
#include <LibWeb/CSS/Parser/DeclarationOrAtRule.h>
#include <LibWeb/CSS/Parser/Function.h>
#include <LibWeb/CSS/Parser/Parser.h>
#include <LibWeb/CSS/Parser/Rule.h>
#include <LibWeb/CSS/Selector.h>
#include <LibWeb/CSS/StyleValue.h>
#include <LibWeb/CSS/StyleValues/AngleStyleValue.h>
#include <LibWeb/CSS/StyleValues/BackgroundRepeatStyleValue.h>
#include <LibWeb/CSS/StyleValues/BackgroundSizeStyleValue.h>
#include <LibWeb/CSS/StyleValues/BackgroundStyleValue.h>
#include <LibWeb/CSS/StyleValues/BorderRadiusShorthandStyleValue.h>
#include <LibWeb/CSS/StyleValues/BorderRadiusStyleValue.h>
#include <LibWeb/CSS/StyleValues/BorderStyleValue.h>
#include <LibWeb/CSS/StyleValues/ColorStyleValue.h>
#include <LibWeb/CSS/StyleValues/ConicGradientStyleValue.h>
#include <LibWeb/CSS/StyleValues/ContentStyleValue.h>
#include <LibWeb/CSS/StyleValues/DisplayStyleValue.h>
#include <LibWeb/CSS/StyleValues/EdgeStyleValue.h>
#include <LibWeb/CSS/StyleValues/FilterValueListStyleValue.h>
#include <LibWeb/CSS/StyleValues/FlexFlowStyleValue.h>
#include <LibWeb/CSS/StyleValues/FlexStyleValue.h>
#include <LibWeb/CSS/StyleValues/FontStyleValue.h>
#include <LibWeb/CSS/StyleValues/FrequencyStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridAreaShorthandStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTemplateAreaStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTrackPlacementShorthandStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTrackPlacementStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTrackSizeListShorthandStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTrackSizeListStyleValue.h>
#include <LibWeb/CSS/StyleValues/IdentifierStyleValue.h>
#include <LibWeb/CSS/StyleValues/ImageStyleValue.h>
#include <LibWeb/CSS/StyleValues/InheritStyleValue.h>
#include <LibWeb/CSS/StyleValues/InitialStyleValue.h>
#include <LibWeb/CSS/StyleValues/LengthStyleValue.h>
#include <LibWeb/CSS/StyleValues/LinearGradientStyleValue.h>
#include <LibWeb/CSS/StyleValues/ListStyleStyleValue.h>
#include <LibWeb/CSS/StyleValues/NumericStyleValue.h>
#include <LibWeb/CSS/StyleValues/OverflowStyleValue.h>
#include <LibWeb/CSS/StyleValues/PercentageStyleValue.h>
#include <LibWeb/CSS/StyleValues/PositionStyleValue.h>
#include <LibWeb/CSS/StyleValues/RadialGradientStyleValue.h>
#include <LibWeb/CSS/StyleValues/RectStyleValue.h>
#include <LibWeb/CSS/StyleValues/ResolutionStyleValue.h>
#include <LibWeb/CSS/StyleValues/ShadowStyleValue.h>
#include <LibWeb/CSS/StyleValues/StringStyleValue.h>
#include <LibWeb/CSS/StyleValues/StyleValueList.h>
#include <LibWeb/CSS/StyleValues/TextDecorationStyleValue.h>
#include <LibWeb/CSS/StyleValues/TimeStyleValue.h>
#include <LibWeb/CSS/StyleValues/TransformationStyleValue.h>
#include <LibWeb/CSS/StyleValues/URLStyleValue.h>
#include <LibWeb/CSS/StyleValues/UnresolvedStyleValue.h>
#include <LibWeb/CSS/StyleValues/UnsetStyleValue.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/Dump.h>
#include <LibWeb/Infra/Strings.h>
static void log_parse_error(SourceLocation const& location = SourceLocation::current())
{
dbgln_if(CSS_PARSER_DEBUG, "Parse error (CSS) {}", location);
}
namespace Web::CSS::Parser {
ParsingContext::ParsingContext(JS::Realm& realm)
: m_realm(realm)
{
}
ParsingContext::ParsingContext(DOM::Document const& document, AK::URL url)
: m_realm(const_cast<JS::Realm&>(document.realm()))
, m_document(&document)
, m_url(move(url))
{
}
ParsingContext::ParsingContext(DOM::Document const& document)
: m_realm(const_cast<JS::Realm&>(document.realm()))
, m_document(&document)
, m_url(document.url())
{
}
ParsingContext::ParsingContext(DOM::ParentNode& parent_node)
: m_realm(parent_node.realm())
, m_document(&parent_node.document())
, m_url(parent_node.document().url())
{
}
bool ParsingContext::in_quirks_mode() const
{
return m_document ? m_document->in_quirks_mode() : false;
}
// https://www.w3.org/TR/css-values-4/#relative-urls
AK::URL ParsingContext::complete_url(StringView relative_url) const
{
return m_url.complete_url(relative_url);
}
ErrorOr<Parser> Parser::create(ParsingContext const& context, StringView input, StringView encoding)
{
auto tokens = TRY(Tokenizer::tokenize(input, encoding));
return Parser { context, move(tokens) };
}
Parser::Parser(ParsingContext const& context, Vector<Token> tokens)
: m_context(context)
, m_tokens(move(tokens))
, m_token_stream(m_tokens)
{
}
Parser::Parser(Parser&& other)
: m_context(other.m_context)
, m_tokens(move(other.m_tokens))
, m_token_stream(m_tokens)
{
// Moving the TokenStream directly from `other` would break it, because TokenStream holds
// a reference to the Vector<Token>, so it would be pointing at the old Parser's tokens.
// So instead, we create a new TokenStream from this Parser's tokens, and then tell it to
// copy the other TokenStream's state. This is quite hacky.
m_token_stream.copy_state({}, other.m_token_stream);
}
// 5.3.3. Parse a stylesheet
// https://www.w3.org/TR/css-syntax-3/#parse-stylesheet
template<typename T>
Parser::ParsedStyleSheet Parser::parse_a_stylesheet(TokenStream<T>& tokens, Optional<AK::URL> location)
{
// To parse a stylesheet from an input given an optional url location:
// 1. If input is a byte stream for stylesheet, decode bytes from input, and set input to the result.
// 2. Normalize input, and set input to the result.
// NOTE: These are done automatically when creating the Parser.
// 3. Create a new stylesheet, with its location set to location (or null, if location was not passed).
ParsedStyleSheet style_sheet;
style_sheet.location = move(location);
// 4. Consume a list of rules from input, with the top-level flag set, and set the stylesheet’s value to the result.
style_sheet.rules = consume_a_list_of_rules(tokens, TopLevel::Yes);
// 5. Return the stylesheet.
return style_sheet;
}
// https://www.w3.org/TR/css-syntax-3/#parse-a-css-stylesheet
CSSStyleSheet* Parser::parse_as_css_stylesheet(Optional<AK::URL> location)
{
// To parse a CSS stylesheet, first parse a stylesheet.
auto style_sheet = parse_a_stylesheet(m_token_stream, {});
// Interpret all of the resulting top-level qualified rules as style rules, defined below.
JS::MarkedVector<CSSRule*> rules(m_context.realm().heap());
for (auto& raw_rule : style_sheet.rules) {
auto* rule = convert_to_rule(raw_rule);
// If any style rule is invalid, or any at-rule is not recognized or is invalid according to its grammar or context, it’s a parse error. Discard that rule.
if (rule)
rules.append(rule);
}
auto rule_list = CSSRuleList::create(m_context.realm(), rules).release_value_but_fixme_should_propagate_errors();
auto media_list = MediaList::create(m_context.realm(), {}).release_value_but_fixme_should_propagate_errors();
return CSSStyleSheet::create(m_context.realm(), rule_list, media_list, move(location)).release_value_but_fixme_should_propagate_errors();
}
Optional<SelectorList> Parser::parse_as_selector(SelectorParsingMode parsing_mode)
{
auto selector_list = parse_a_selector_list(m_token_stream, SelectorType::Standalone, parsing_mode);
if (!selector_list.is_error())
return selector_list.release_value();
return {};
}
Optional<SelectorList> Parser::parse_as_relative_selector(SelectorParsingMode parsing_mode)
{
auto selector_list = parse_a_selector_list(m_token_stream, SelectorType::Relative, parsing_mode);
if (!selector_list.is_error())
return selector_list.release_value();
return {};
}
template<typename T>
Parser::ParseErrorOr<SelectorList> Parser::parse_a_selector_list(TokenStream<T>& tokens, SelectorType mode, SelectorParsingMode parsing_mode)
{
auto comma_separated_lists = parse_a_comma_separated_list_of_component_values(tokens);
Vector<NonnullRefPtr<Selector>> selectors;
for (auto& selector_parts : comma_separated_lists) {
auto stream = TokenStream(selector_parts);
auto selector = parse_complex_selector(stream, mode);
if (selector.is_error()) {
if (parsing_mode == SelectorParsingMode::Forgiving)
continue;
return selector.error();
}
selectors.append(selector.release_value());
}
if (selectors.is_empty() && parsing_mode != SelectorParsingMode::Forgiving)
return ParseError::SyntaxError;
return selectors;
}
Parser::ParseErrorOr<NonnullRefPtr<Selector>> Parser::parse_complex_selector(TokenStream<ComponentValue>& tokens, SelectorType mode)
{
Vector<Selector::CompoundSelector> compound_selectors;
auto first_selector = TRY(parse_compound_selector(tokens));
if (!first_selector.has_value())
return ParseError::SyntaxError;
if (mode == SelectorType::Standalone) {
if (first_selector->combinator != Selector::Combinator::Descendant)
return ParseError::SyntaxError;
first_selector->combinator = Selector::Combinator::None;
}
compound_selectors.append(first_selector.release_value());
while (tokens.has_next_token()) {
auto compound_selector = TRY(parse_compound_selector(tokens));
if (!compound_selector.has_value())
break;
compound_selectors.append(compound_selector.release_value());
}
if (compound_selectors.is_empty())
return ParseError::SyntaxError;
return Selector::create(move(compound_selectors));
}
Parser::ParseErrorOr<Optional<Selector::CompoundSelector>> Parser::parse_compound_selector(TokenStream<ComponentValue>& tokens)
{
tokens.skip_whitespace();
auto combinator = parse_selector_combinator(tokens).value_or(Selector::Combinator::Descendant);
tokens.skip_whitespace();
Vector<Selector::SimpleSelector> simple_selectors;
while (tokens.has_next_token()) {
auto component = TRY(parse_simple_selector(tokens));
if (!component.has_value())
break;
simple_selectors.append(component.release_value());
}
if (simple_selectors.is_empty())
return Optional<Selector::CompoundSelector> {};
return Selector::CompoundSelector { combinator, move(simple_selectors) };
}
Optional<Selector::Combinator> Parser::parse_selector_combinator(TokenStream<ComponentValue>& tokens)
{
auto const& current_value = tokens.next_token();
if (current_value.is(Token::Type::Delim)) {
switch (current_value.token().delim()) {
case '>':
return Selector::Combinator::ImmediateChild;
case '+':
return Selector::Combinator::NextSibling;
case '~':
return Selector::Combinator::SubsequentSibling;
case '|': {
auto const& next = tokens.peek_token();
if (next.is(Token::Type::EndOfFile))
return {};
if (next.is(Token::Type::Delim) && next.token().delim() == '|') {
tokens.next_token();
return Selector::Combinator::Column;
}
}
}
}
tokens.reconsume_current_input_token();
return {};
}
Parser::ParseErrorOr<Selector::SimpleSelector> Parser::parse_attribute_simple_selector(ComponentValue const& first_value)
{
auto attribute_tokens = TokenStream { first_value.block().values() };
attribute_tokens.skip_whitespace();
if (!attribute_tokens.has_next_token()) {
dbgln_if(CSS_PARSER_DEBUG, "CSS attribute selector is empty!");
return ParseError::SyntaxError;
}
// FIXME: Handle namespace prefix for attribute name.
auto const& attribute_part = attribute_tokens.next_token();
if (!attribute_part.is(Token::Type::Ident)) {
dbgln_if(CSS_PARSER_DEBUG, "Expected ident for attribute name, got: '{}'", attribute_part.to_debug_string());
return ParseError::SyntaxError;
}
Selector::SimpleSelector simple_selector {
.type = Selector::SimpleSelector::Type::Attribute,
.value = Selector::SimpleSelector::Attribute {
.match_type = Selector::SimpleSelector::Attribute::MatchType::HasAttribute,
// FIXME: Case-sensitivity is defined by the document language.
// HTML is insensitive with attribute names, and our code generally assumes
// they are converted to lowercase, so we do that here too. If we want to be
// correct with XML later, we'll need to keep the original case and then do
// a case-insensitive compare later.
.name = FlyString::from_deprecated_fly_string(attribute_part.token().ident().to_lowercase_string()).release_value_but_fixme_should_propagate_errors(),
.case_type = Selector::SimpleSelector::Attribute::CaseType::DefaultMatch,
}
};
attribute_tokens.skip_whitespace();
if (!attribute_tokens.has_next_token())
return simple_selector;
auto const& delim_part = attribute_tokens.next_token();
if (!delim_part.is(Token::Type::Delim)) {
dbgln_if(CSS_PARSER_DEBUG, "Expected a delim for attribute comparison, got: '{}'", delim_part.to_debug_string());
return ParseError::SyntaxError;
}
if (delim_part.token().delim() == '=') {
simple_selector.attribute().match_type = Selector::SimpleSelector::Attribute::MatchType::ExactValueMatch;
} else {
if (!attribute_tokens.has_next_token()) {
dbgln_if(CSS_PARSER_DEBUG, "Attribute selector ended part way through a match type.");
return ParseError::SyntaxError;
}
auto const& delim_second_part = attribute_tokens.next_token();
if (!(delim_second_part.is(Token::Type::Delim) && delim_second_part.token().delim() == '=')) {
dbgln_if(CSS_PARSER_DEBUG, "Expected a double delim for attribute comparison, got: '{}{}'", delim_part.to_debug_string(), delim_second_part.to_debug_string());
return ParseError::SyntaxError;
}
switch (delim_part.token().delim()) {
case '~':
simple_selector.attribute().match_type = Selector::SimpleSelector::Attribute::MatchType::ContainsWord;
break;
case '*':
simple_selector.attribute().match_type = Selector::SimpleSelector::Attribute::MatchType::ContainsString;
break;
case '|':
simple_selector.attribute().match_type = Selector::SimpleSelector::Attribute::MatchType::StartsWithSegment;
break;
case '^':
simple_selector.attribute().match_type = Selector::SimpleSelector::Attribute::MatchType::StartsWithString;
break;
case '$':
simple_selector.attribute().match_type = Selector::SimpleSelector::Attribute::MatchType::EndsWithString;
break;
default:
attribute_tokens.reconsume_current_input_token();
}
}
attribute_tokens.skip_whitespace();
if (!attribute_tokens.has_next_token()) {
dbgln_if(CSS_PARSER_DEBUG, "Attribute selector ended without a value to match.");
return ParseError::SyntaxError;
}
auto const& value_part = attribute_tokens.next_token();
if (!value_part.is(Token::Type::Ident) && !value_part.is(Token::Type::String)) {
dbgln_if(CSS_PARSER_DEBUG, "Expected a string or ident for the value to match attribute against, got: '{}'", value_part.to_debug_string());
return ParseError::SyntaxError;
}
auto value_string_view = value_part.token().is(Token::Type::Ident) ? value_part.token().ident() : value_part.token().string();
simple_selector.attribute().value = String::from_utf8(value_string_view).release_value_but_fixme_should_propagate_errors();
attribute_tokens.skip_whitespace();
// Handle case-sensitivity suffixes. https://www.w3.org/TR/selectors-4/#attribute-case
if (attribute_tokens.has_next_token()) {
auto const& case_sensitivity_part = attribute_tokens.next_token();
if (case_sensitivity_part.is(Token::Type::Ident)) {
auto case_sensitivity = case_sensitivity_part.token().ident();
if (case_sensitivity.equals_ignoring_ascii_case("i"sv)) {
simple_selector.attribute().case_type = Selector::SimpleSelector::Attribute::CaseType::CaseInsensitiveMatch;
} else if (case_sensitivity.equals_ignoring_ascii_case("s"sv)) {
simple_selector.attribute().case_type = Selector::SimpleSelector::Attribute::CaseType::CaseSensitiveMatch;
} else {
dbgln_if(CSS_PARSER_DEBUG, "Expected a \"i\" or \"s\" attribute selector case sensitivity identifier, got: '{}'", case_sensitivity_part.to_debug_string());
return ParseError::SyntaxError;
}
} else {
dbgln_if(CSS_PARSER_DEBUG, "Expected an attribute selector case sensitivity identifier, got: '{}'", case_sensitivity_part.to_debug_string());
return ParseError::SyntaxError;
}
}
if (attribute_tokens.has_next_token()) {
dbgln_if(CSS_PARSER_DEBUG, "Was not expecting anything else inside attribute selector.");
return ParseError::SyntaxError;
}
return simple_selector;
}
Parser::ParseErrorOr<Selector::SimpleSelector> Parser::parse_pseudo_simple_selector(TokenStream<ComponentValue>& tokens)
{
auto peek_token_ends_selector = [&]() -> bool {
auto const& value = tokens.peek_token();
return (value.is(Token::Type::EndOfFile) || value.is(Token::Type::Whitespace) || value.is(Token::Type::Comma));
};
if (peek_token_ends_selector())
return ParseError::SyntaxError;
bool is_pseudo = false;
if (tokens.peek_token().is(Token::Type::Colon)) {
is_pseudo = true;
tokens.next_token();
if (peek_token_ends_selector())
return ParseError::SyntaxError;
}
if (is_pseudo) {
auto const& name_token = tokens.next_token();
if (!name_token.is(Token::Type::Ident)) {
dbgln_if(CSS_PARSER_DEBUG, "Expected an ident for pseudo-element, got: '{}'", name_token.to_debug_string());
return ParseError::SyntaxError;
}
auto pseudo_name = name_token.token().ident();
auto pseudo_element = pseudo_element_from_string(pseudo_name);
// Note: We allow the "ignored" -webkit prefix here for -webkit-progress-bar/-webkit-progress-bar
if (!pseudo_element.has_value() && has_ignored_vendor_prefix(pseudo_name))
return ParseError::IncludesIgnoredVendorPrefix;
if (!pseudo_element.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "Unrecognized pseudo-element: '::{}'", pseudo_name);
return ParseError::SyntaxError;
}
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::PseudoElement,
.value = pseudo_element.value()
};
}
if (peek_token_ends_selector())
return ParseError::SyntaxError;
auto const& pseudo_class_token = tokens.next_token();
if (pseudo_class_token.is(Token::Type::Ident)) {
auto pseudo_name = pseudo_class_token.token().ident();
if (has_ignored_vendor_prefix(pseudo_name))
return ParseError::IncludesIgnoredVendorPrefix;
auto make_pseudo_class_selector = [](auto pseudo_class) {
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::PseudoClass,
.value = Selector::SimpleSelector::PseudoClass {
.type = pseudo_class }
};
};
if (pseudo_name.equals_ignoring_ascii_case("active"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Active);
if (pseudo_name.equals_ignoring_ascii_case("checked"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Checked);
if (pseudo_name.equals_ignoring_ascii_case("indeterminate"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Indeterminate);
if (pseudo_name.equals_ignoring_ascii_case("defined"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Defined);
if (pseudo_name.equals_ignoring_ascii_case("disabled"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Disabled);
if (pseudo_name.equals_ignoring_ascii_case("empty"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Empty);
if (pseudo_name.equals_ignoring_ascii_case("enabled"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Enabled);
if (pseudo_name.equals_ignoring_ascii_case("first-child"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::FirstChild);
if (pseudo_name.equals_ignoring_ascii_case("first-of-type"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::FirstOfType);
if (pseudo_name.equals_ignoring_ascii_case("focus"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Focus);
if (pseudo_name.equals_ignoring_ascii_case("focus-within"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::FocusWithin);
if (pseudo_name.equals_ignoring_ascii_case("hover"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Hover);
if (pseudo_name.equals_ignoring_ascii_case("last-child"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::LastChild);
if (pseudo_name.equals_ignoring_ascii_case("last-of-type"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::LastOfType);
if (pseudo_name.equals_ignoring_ascii_case("link"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Link);
if (pseudo_name.equals_ignoring_ascii_case("only-child"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::OnlyChild);
if (pseudo_name.equals_ignoring_ascii_case("only-of-type"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::OnlyOfType);
if (pseudo_name.equals_ignoring_ascii_case("root"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Root);
if (pseudo_name.equals_ignoring_ascii_case("visited"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Visited);
if (pseudo_name.equals_ignoring_ascii_case("scope"sv))
return make_pseudo_class_selector(Selector::SimpleSelector::PseudoClass::Type::Scope);
// Single-colon syntax allowed for ::after, ::before, ::first-letter and ::first-line for compatibility.
// https://www.w3.org/TR/selectors/#pseudo-element-syntax
if (auto pseudo_element = pseudo_element_from_string(pseudo_name); pseudo_element.has_value()) {
switch (pseudo_element.value()) {
case Selector::PseudoElement::After:
case Selector::PseudoElement::Before:
case Selector::PseudoElement::FirstLetter:
case Selector::PseudoElement::FirstLine:
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::PseudoElement,
.value = pseudo_element.value()
};
default:
break;
}
}
dbgln_if(CSS_PARSER_DEBUG, "Unrecognized pseudo-class: ':{}'", pseudo_name);
return ParseError::SyntaxError;
}
if (pseudo_class_token.is_function()) {
auto parse_nth_child_selector = [this](auto pseudo_class, Vector<ComponentValue> const& function_values, bool allow_of = false) -> ParseErrorOr<Selector::SimpleSelector> {
auto tokens = TokenStream<ComponentValue>(function_values);
auto nth_child_pattern = parse_a_n_plus_b_pattern(tokens);
if (!nth_child_pattern.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "!!! Invalid An+B format for {}", pseudo_class_name(pseudo_class));
return ParseError::SyntaxError;
}
tokens.skip_whitespace();
if (!tokens.has_next_token()) {
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::PseudoClass,
.value = Selector::SimpleSelector::PseudoClass {
.type = pseudo_class,
.nth_child_pattern = nth_child_pattern.release_value() }
};
}
if (!allow_of)
return ParseError::SyntaxError;
// Parse the `of <selector-list>` syntax
auto const& maybe_of = tokens.next_token();
if (!(maybe_of.is(Token::Type::Ident) && maybe_of.token().ident().equals_ignoring_ascii_case("of"sv)))
return ParseError::SyntaxError;
tokens.skip_whitespace();
auto selector_list = TRY(parse_a_selector_list(tokens, SelectorType::Standalone));
tokens.skip_whitespace();
if (tokens.has_next_token())
return ParseError::SyntaxError;
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::PseudoClass,
.value = Selector::SimpleSelector::PseudoClass {
.type = pseudo_class,
.nth_child_pattern = nth_child_pattern.release_value(),
.argument_selector_list = move(selector_list) }
};
};
auto const& pseudo_function = pseudo_class_token.function();
if (pseudo_function.name().equals_ignoring_ascii_case("is"sv)
|| pseudo_function.name().equals_ignoring_ascii_case("where"sv)) {
auto function_token_stream = TokenStream(pseudo_function.values());
// NOTE: Because it's forgiving, even complete garbage will parse OK as an empty selector-list.
auto argument_selector_list = MUST(parse_a_selector_list(function_token_stream, SelectorType::Standalone, SelectorParsingMode::Forgiving));
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::PseudoClass,
.value = Selector::SimpleSelector::PseudoClass {
.type = pseudo_function.name().equals_ignoring_ascii_case("is"sv)
? Selector::SimpleSelector::PseudoClass::Type::Is
: Selector::SimpleSelector::PseudoClass::Type::Where,
.argument_selector_list = move(argument_selector_list) }
};
}
if (pseudo_function.name().equals_ignoring_ascii_case("not"sv)) {
auto function_token_stream = TokenStream(pseudo_function.values());
auto not_selector = TRY(parse_a_selector_list(function_token_stream, SelectorType::Standalone));
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::PseudoClass,
.value = Selector::SimpleSelector::PseudoClass {
.type = Selector::SimpleSelector::PseudoClass::Type::Not,
.argument_selector_list = move(not_selector) }
};
}
if (pseudo_function.name().equals_ignoring_ascii_case("lang"sv)) {
if (pseudo_function.values().is_empty()) {
dbgln_if(CSS_PARSER_DEBUG, "Empty :lang() selector");
return ParseError::SyntaxError;
}
// FIXME: Support multiple, comma-separated, language ranges.
Vector<FlyString> languages;
languages.append(pseudo_function.values().first().token().to_string().release_value_but_fixme_should_propagate_errors());
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::PseudoClass,
.value = Selector::SimpleSelector::PseudoClass {
.type = Selector::SimpleSelector::PseudoClass::Type::Lang,
.languages = move(languages) }
};
}
if (pseudo_function.name().equals_ignoring_ascii_case("nth-child"sv))
return parse_nth_child_selector(Selector::SimpleSelector::PseudoClass::Type::NthChild, pseudo_function.values(), true);
if (pseudo_function.name().equals_ignoring_ascii_case("nth-last-child"sv))
return parse_nth_child_selector(Selector::SimpleSelector::PseudoClass::Type::NthLastChild, pseudo_function.values(), true);
if (pseudo_function.name().equals_ignoring_ascii_case("nth-of-type"sv))
return parse_nth_child_selector(Selector::SimpleSelector::PseudoClass::Type::NthOfType, pseudo_function.values(), false);
if (pseudo_function.name().equals_ignoring_ascii_case("nth-last-of-type"sv))
return parse_nth_child_selector(Selector::SimpleSelector::PseudoClass::Type::NthLastOfType, pseudo_function.values(), false);
dbgln_if(CSS_PARSER_DEBUG, "Unrecognized pseudo-class function: ':{}'()", pseudo_function.name());
return ParseError::SyntaxError;
}
dbgln_if(CSS_PARSER_DEBUG, "Unexpected Block in pseudo-class name, expected a function or identifier. '{}'", pseudo_class_token.to_debug_string());
return ParseError::SyntaxError;
}
Parser::ParseErrorOr<Optional<Selector::SimpleSelector>> Parser::parse_simple_selector(TokenStream<ComponentValue>& tokens)
{
auto peek_token_ends_selector = [&]() -> bool {
auto const& value = tokens.peek_token();
return (value.is(Token::Type::EndOfFile) || value.is(Token::Type::Whitespace) || value.is(Token::Type::Comma));
};
if (peek_token_ends_selector())
return Optional<Selector::SimpleSelector> {};
auto const& first_value = tokens.next_token();
if (first_value.is(Token::Type::Delim)) {
u32 delim = first_value.token().delim();
switch (delim) {
case '*':
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::Universal
};
case '.': {
if (peek_token_ends_selector())
return ParseError::SyntaxError;
auto const& class_name_value = tokens.next_token();
if (!class_name_value.is(Token::Type::Ident)) {
dbgln_if(CSS_PARSER_DEBUG, "Expected an ident after '.', got: {}", class_name_value.to_debug_string());
return ParseError::SyntaxError;
}
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::Class,
.value = Selector::SimpleSelector::Name { FlyString::from_utf8(class_name_value.token().ident()).release_value_but_fixme_should_propagate_errors() }
};
}
case '>':
case '+':
case '~':
case '|':
// Whitespace is not required between the compound-selector and a combinator.
// So, if we see a combinator, return that this compound-selector is done, instead of a syntax error.
tokens.reconsume_current_input_token();
return Optional<Selector::SimpleSelector> {};
default:
dbgln_if(CSS_PARSER_DEBUG, "!!! Invalid simple selector!");
return ParseError::SyntaxError;
}
}
if (first_value.is(Token::Type::Hash)) {
if (first_value.token().hash_type() != Token::HashType::Id) {
dbgln_if(CSS_PARSER_DEBUG, "Selector contains hash token that is not an id: {}", first_value.to_debug_string());
return ParseError::SyntaxError;
}
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::Id,
.value = Selector::SimpleSelector::Name { FlyString::from_utf8(first_value.token().hash_value()).release_value_but_fixme_should_propagate_errors() }
};
}
if (first_value.is(Token::Type::Ident)) {
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::TagName,
// FIXME: XML requires case-sensitivity for identifiers, while HTML does not. As such, this should be reworked if XML support is added.
.value = Selector::SimpleSelector::Name { FlyString::from_utf8(first_value.token().ident().to_lowercase_string()).release_value_but_fixme_should_propagate_errors() }
};
}
if (first_value.is_block() && first_value.block().is_square())
return TRY(parse_attribute_simple_selector(first_value));
if (first_value.is(Token::Type::Colon))
return TRY(parse_pseudo_simple_selector(tokens));
dbgln_if(CSS_PARSER_DEBUG, "!!! Invalid simple selector!");
return ParseError::SyntaxError;
}
Vector<NonnullRefPtr<MediaQuery>> Parser::parse_as_media_query_list()
{
return parse_a_media_query_list(m_token_stream);
}
template<typename T>
Vector<NonnullRefPtr<MediaQuery>> Parser::parse_a_media_query_list(TokenStream<T>& tokens)
{
// https://www.w3.org/TR/mediaqueries-4/#mq-list
auto comma_separated_lists = parse_a_comma_separated_list_of_component_values(tokens);
AK::Vector<NonnullRefPtr<MediaQuery>> media_queries;
for (auto& media_query_parts : comma_separated_lists) {
auto stream = TokenStream(media_query_parts);
media_queries.append(parse_media_query(stream));
}
return media_queries;
}
RefPtr<MediaQuery> Parser::parse_as_media_query()
{
// https://www.w3.org/TR/cssom-1/#parse-a-media-query
auto media_query_list = parse_as_media_query_list();
if (media_query_list.is_empty())
return MediaQuery::create_not_all();
if (media_query_list.size() == 1)
return media_query_list.first();
return nullptr;
}
// `<media-query>`, https://www.w3.org/TR/mediaqueries-4/#typedef-media-query
NonnullRefPtr<MediaQuery> Parser::parse_media_query(TokenStream<ComponentValue>& tokens)
{
// `<media-query> = <media-condition>
// | [ not | only ]? <media-type> [ and <media-condition-without-or> ]?`
// `[ not | only ]?`, Returns whether to negate the query
auto parse_initial_modifier = [](auto& tokens) -> Optional<bool> {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto& token = tokens.next_token();
if (!token.is(Token::Type::Ident))
return {};
auto ident = token.token().ident();
if (ident.equals_ignoring_ascii_case("not"sv)) {
transaction.commit();
return true;
}
if (ident.equals_ignoring_ascii_case("only"sv)) {
transaction.commit();
return false;
}
return {};
};
auto invalid_media_query = [&]() {
// "A media query that does not match the grammar in the previous section must be replaced by `not all`
// during parsing." - https://www.w3.org/TR/mediaqueries-5/#error-handling
if constexpr (CSS_PARSER_DEBUG) {
dbgln("Invalid media query:");
tokens.dump_all_tokens();
}
return MediaQuery::create_not_all();
};
auto media_query = MediaQuery::create();
tokens.skip_whitespace();
// `<media-condition>`
if (auto media_condition = parse_media_condition(tokens, MediaCondition::AllowOr::Yes)) {
tokens.skip_whitespace();
if (tokens.has_next_token())
return invalid_media_query();
media_query->m_media_condition = move(media_condition);
return media_query;
}
// `[ not | only ]?`
if (auto modifier = parse_initial_modifier(tokens); modifier.has_value()) {
media_query->m_negated = modifier.value();
tokens.skip_whitespace();
}
// `<media-type>`
if (auto media_type = parse_media_type(tokens); media_type.has_value()) {
media_query->m_media_type = media_type.value();
tokens.skip_whitespace();
} else {
return invalid_media_query();
}
if (!tokens.has_next_token())
return media_query;
// `[ and <media-condition-without-or> ]?`
if (auto maybe_and = tokens.next_token(); maybe_and.is(Token::Type::Ident) && maybe_and.token().ident().equals_ignoring_ascii_case("and"sv)) {
if (auto media_condition = parse_media_condition(tokens, MediaCondition::AllowOr::No)) {
tokens.skip_whitespace();
if (tokens.has_next_token())
return invalid_media_query();
media_query->m_media_condition = move(media_condition);
return media_query;
}
return invalid_media_query();
}
return invalid_media_query();
}
// `<media-condition>`, https://www.w3.org/TR/mediaqueries-4/#typedef-media-condition
// `<media-condition-widthout-or>`, https://www.w3.org/TR/mediaqueries-4/#typedef-media-condition-without-or
// (We distinguish between these two with the `allow_or` parameter.)
OwnPtr<MediaCondition> Parser::parse_media_condition(TokenStream<ComponentValue>& tokens, MediaCondition::AllowOr allow_or)
{
// `<media-not> | <media-in-parens> [ <media-and>* | <media-or>* ]`
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
// `<media-not> = not <media-in-parens>`
auto parse_media_not = [&](auto& tokens) -> OwnPtr<MediaCondition> {
auto local_transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto& first_token = tokens.next_token();
if (first_token.is(Token::Type::Ident) && first_token.token().ident().equals_ignoring_ascii_case("not"sv)) {
if (auto child_condition = parse_media_condition(tokens, MediaCondition::AllowOr::Yes)) {
local_transaction.commit();
return MediaCondition::from_not(child_condition.release_nonnull());
}
}
return {};
};
auto parse_media_with_combinator = [&](auto& tokens, StringView combinator) -> OwnPtr<MediaCondition> {
auto local_transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto& first = tokens.next_token();
if (first.is(Token::Type::Ident) && first.token().ident().equals_ignoring_ascii_case(combinator)) {
tokens.skip_whitespace();
if (auto media_in_parens = parse_media_in_parens(tokens)) {
local_transaction.commit();
return media_in_parens;
}
}
return {};
};
// `<media-and> = and <media-in-parens>`
auto parse_media_and = [&](auto& tokens) { return parse_media_with_combinator(tokens, "and"sv); };
// `<media-or> = or <media-in-parens>`
auto parse_media_or = [&](auto& tokens) { return parse_media_with_combinator(tokens, "or"sv); };
// `<media-not>`
if (auto maybe_media_not = parse_media_not(tokens)) {
transaction.commit();
return maybe_media_not.release_nonnull();
}
// `<media-in-parens> [ <media-and>* | <media-or>* ]`
if (auto maybe_media_in_parens = parse_media_in_parens(tokens)) {
tokens.skip_whitespace();
// Only `<media-in-parens>`
if (!tokens.has_next_token()) {
transaction.commit();
return maybe_media_in_parens.release_nonnull();
}
Vector<NonnullOwnPtr<MediaCondition>> child_conditions;
child_conditions.append(maybe_media_in_parens.release_nonnull());
// `<media-and>*`
if (auto media_and = parse_media_and(tokens)) {
child_conditions.append(media_and.release_nonnull());
tokens.skip_whitespace();
while (tokens.has_next_token()) {
if (auto next_media_and = parse_media_and(tokens)) {
child_conditions.append(next_media_and.release_nonnull());
tokens.skip_whitespace();
continue;
}
// We failed - invalid syntax!
return {};
}
transaction.commit();
return MediaCondition::from_and_list(move(child_conditions));
}
// `<media-or>*`
if (allow_or == MediaCondition::AllowOr::Yes) {
if (auto media_or = parse_media_or(tokens)) {
child_conditions.append(media_or.release_nonnull());
tokens.skip_whitespace();
while (tokens.has_next_token()) {
if (auto next_media_or = parse_media_or(tokens)) {
child_conditions.append(next_media_or.release_nonnull());
tokens.skip_whitespace();
continue;
}
// We failed - invalid syntax!
return {};
}
transaction.commit();
return MediaCondition::from_or_list(move(child_conditions));
}
}
}
return {};
}
// `<media-feature>`, https://www.w3.org/TR/mediaqueries-4/#typedef-media-feature
Optional<MediaFeature> Parser::parse_media_feature(TokenStream<ComponentValue>& tokens)
{
// `[ <mf-plain> | <mf-boolean> | <mf-range> ]`
tokens.skip_whitespace();
// `<mf-name> = <ident>`
struct MediaFeatureName {
enum Type {
Normal,
Min,
Max
} type;
MediaFeatureID id;
};
auto parse_mf_name = [](auto& tokens, bool allow_min_max_prefix) -> Optional<MediaFeatureName> {
auto transaction = tokens.begin_transaction();
auto& token = tokens.next_token();
if (token.is(Token::Type::Ident)) {
auto name = token.token().ident();
if (auto id = media_feature_id_from_string(name); id.has_value()) {
transaction.commit();
return MediaFeatureName { MediaFeatureName::Type::Normal, id.value() };
}
if (allow_min_max_prefix && (name.starts_with("min-"sv, CaseSensitivity::CaseInsensitive) || name.starts_with("max-"sv, CaseSensitivity::CaseInsensitive))) {
auto adjusted_name = name.substring_view(4);
if (auto id = media_feature_id_from_string(adjusted_name); id.has_value() && media_feature_type_is_range(id.value())) {
transaction.commit();
return MediaFeatureName {
name.starts_with("min-"sv, CaseSensitivity::CaseInsensitive) ? MediaFeatureName::Type::Min : MediaFeatureName::Type::Max,
id.value()
};
}
}
}
return {};
};
// `<mf-boolean> = <mf-name>`
auto parse_mf_boolean = [&](auto& tokens) -> Optional<MediaFeature> {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
if (auto maybe_name = parse_mf_name(tokens, false); maybe_name.has_value()) {
tokens.skip_whitespace();
if (!tokens.has_next_token()) {
transaction.commit();
return MediaFeature::boolean(maybe_name->id);
}
}
return {};
};
// `<mf-plain> = <mf-name> : <mf-value>`
auto parse_mf_plain = [&](auto& tokens) -> Optional<MediaFeature> {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
if (auto maybe_name = parse_mf_name(tokens, true); maybe_name.has_value()) {
tokens.skip_whitespace();
if (tokens.next_token().is(Token::Type::Colon)) {
tokens.skip_whitespace();
if (auto maybe_value = parse_media_feature_value(maybe_name->id, tokens); maybe_value.has_value()) {
tokens.skip_whitespace();
if (!tokens.has_next_token()) {
transaction.commit();
switch (maybe_name->type) {
case MediaFeatureName::Type::Normal:
return MediaFeature::plain(maybe_name->id, maybe_value.release_value());
case MediaFeatureName::Type::Min:
return MediaFeature::min(maybe_name->id, maybe_value.release_value());
case MediaFeatureName::Type::Max:
return MediaFeature::max(maybe_name->id, maybe_value.release_value());
}
VERIFY_NOT_REACHED();
}
}
}
}
return {};
};
// `<mf-lt> = '<' '='?
// <mf-gt> = '>' '='?
// <mf-eq> = '='
// <mf-comparison> = <mf-lt> | <mf-gt> | <mf-eq>`
auto parse_comparison = [](auto& tokens) -> Optional<MediaFeature::Comparison> {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto& first = tokens.next_token();
if (first.is(Token::Type::Delim)) {
auto first_delim = first.token().delim();
if (first_delim == '=') {
transaction.commit();
return MediaFeature::Comparison::Equal;
}
if (first_delim == '<') {
auto& second = tokens.peek_token();
if (second.is(Token::Type::Delim) && second.token().delim() == '=') {
tokens.next_token();
transaction.commit();
return MediaFeature::Comparison::LessThanOrEqual;
}
transaction.commit();
return MediaFeature::Comparison::LessThan;
}
if (first_delim == '>') {
auto& second = tokens.peek_token();
if (second.is(Token::Type::Delim) && second.token().delim() == '=') {
tokens.next_token();
transaction.commit();
return MediaFeature::Comparison::GreaterThanOrEqual;
}
transaction.commit();
return MediaFeature::Comparison::GreaterThan;
}
}
return {};
};
auto flip = [](MediaFeature::Comparison comparison) {
switch (comparison) {
case MediaFeature::Comparison::Equal:
return MediaFeature::Comparison::Equal;
case MediaFeature::Comparison::LessThan:
return MediaFeature::Comparison::GreaterThan;
case MediaFeature::Comparison::LessThanOrEqual:
return MediaFeature::Comparison::GreaterThanOrEqual;
case MediaFeature::Comparison::GreaterThan:
return MediaFeature::Comparison::LessThan;
case MediaFeature::Comparison::GreaterThanOrEqual:
return MediaFeature::Comparison::LessThanOrEqual;
}
VERIFY_NOT_REACHED();
};
auto comparisons_match = [](MediaFeature::Comparison a, MediaFeature::Comparison b) -> bool {
switch (a) {
case MediaFeature::Comparison::Equal:
return b == MediaFeature::Comparison::Equal;
case MediaFeature::Comparison::LessThan:
case MediaFeature::Comparison::LessThanOrEqual:
return b == MediaFeature::Comparison::LessThan || b == MediaFeature::Comparison::LessThanOrEqual;
case MediaFeature::Comparison::GreaterThan:
case MediaFeature::Comparison::GreaterThanOrEqual:
return b == MediaFeature::Comparison::GreaterThan || b == MediaFeature::Comparison::GreaterThanOrEqual;
}
VERIFY_NOT_REACHED();
};
// `<mf-range> = <mf-name> <mf-comparison> <mf-value>
// | <mf-value> <mf-comparison> <mf-name>
// | <mf-value> <mf-lt> <mf-name> <mf-lt> <mf-value>
// | <mf-value> <mf-gt> <mf-name> <mf-gt> <mf-value>`
auto parse_mf_range = [&](auto& tokens) -> Optional<MediaFeature> {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
// `<mf-name> <mf-comparison> <mf-value>`
// NOTE: We have to check for <mf-name> first, since all <mf-name>s will also parse as <mf-value>.
if (auto maybe_name = parse_mf_name(tokens, false); maybe_name.has_value() && media_feature_type_is_range(maybe_name->id)) {
tokens.skip_whitespace();
if (auto maybe_comparison = parse_comparison(tokens); maybe_comparison.has_value()) {
tokens.skip_whitespace();
if (auto maybe_value = parse_media_feature_value(maybe_name->id, tokens); maybe_value.has_value()) {
tokens.skip_whitespace();
if (!tokens.has_next_token() && !maybe_value->is_ident()) {
transaction.commit();
return MediaFeature::half_range(maybe_value.release_value(), flip(maybe_comparison.release_value()), maybe_name->id);
}
}
}
}
// `<mf-value> <mf-comparison> <mf-name>
// | <mf-value> <mf-lt> <mf-name> <mf-lt> <mf-value>
// | <mf-value> <mf-gt> <mf-name> <mf-gt> <mf-value>`
// NOTE: To parse the first value, we need to first find and parse the <mf-name> so we know what value types to parse.
// To allow for <mf-value> to be any number of tokens long, we scan forward until we find a comparison, and then
// treat the next non-whitespace token as the <mf-name>, which should be correct as long as they don't add a value
// type that can include a comparison in it. :^)
Optional<MediaFeatureName> maybe_name;
{
// This transaction is never committed, we just use it to rewind automatically.
auto temp_transaction = tokens.begin_transaction();
while (tokens.has_next_token() && !maybe_name.has_value()) {
if (auto maybe_comparison = parse_comparison(tokens); maybe_comparison.has_value()) {
// We found a comparison, so the next non-whitespace token should be the <mf-name>
tokens.skip_whitespace();
maybe_name = parse_mf_name(tokens, false);
break;
}
tokens.next_token();
tokens.skip_whitespace();
}
}
// Now, we can parse the range properly.
if (maybe_name.has_value() && media_feature_type_is_range(maybe_name->id)) {
if (auto maybe_left_value = parse_media_feature_value(maybe_name->id, tokens); maybe_left_value.has_value()) {
tokens.skip_whitespace();
if (auto maybe_left_comparison = parse_comparison(tokens); maybe_left_comparison.has_value()) {
tokens.skip_whitespace();
tokens.next_token(); // The <mf-name> which we already parsed above.
tokens.skip_whitespace();
if (!tokens.has_next_token()) {
transaction.commit();
return MediaFeature::half_range(maybe_left_value.release_value(), maybe_left_comparison.release_value(), maybe_name->id);
}
if (auto maybe_right_comparison = parse_comparison(tokens); maybe_right_comparison.has_value()) {
tokens.skip_whitespace();
if (auto maybe_right_value = parse_media_feature_value(maybe_name->id, tokens); maybe_right_value.has_value()) {
tokens.skip_whitespace();
// For this to be valid, the following must be true:
// - Comparisons must either both be >/>= or both be </<=.
// - Neither comparison can be `=`.
// - Neither value can be an ident.
auto left_comparison = maybe_left_comparison.release_value();
auto right_comparison = maybe_right_comparison.release_value();
if (!tokens.has_next_token()
&& comparisons_match(left_comparison, right_comparison)
&& left_comparison != MediaFeature::Comparison::Equal
&& !maybe_left_value->is_ident() && !maybe_right_value->is_ident()) {
transaction.commit();
return MediaFeature::range(maybe_left_value.release_value(), left_comparison, maybe_name->id, right_comparison, maybe_right_value.release_value());
}
}
}
}
}
}
return {};
};
if (auto maybe_mf_boolean = parse_mf_boolean(tokens); maybe_mf_boolean.has_value())
return maybe_mf_boolean.release_value();
if (auto maybe_mf_plain = parse_mf_plain(tokens); maybe_mf_plain.has_value())
return maybe_mf_plain.release_value();
if (auto maybe_mf_range = parse_mf_range(tokens); maybe_mf_range.has_value())
return maybe_mf_range.release_value();
return {};
}
Optional<MediaQuery::MediaType> Parser::parse_media_type(TokenStream<ComponentValue>& tokens)
{
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto const& token = tokens.next_token();
if (!token.is(Token::Type::Ident))
return {};
transaction.commit();
auto ident = token.token().ident();
return media_type_from_string(ident);
}
// `<media-in-parens>`, https://www.w3.org/TR/mediaqueries-4/#typedef-media-in-parens
OwnPtr<MediaCondition> Parser::parse_media_in_parens(TokenStream<ComponentValue>& tokens)
{
// `<media-in-parens> = ( <media-condition> ) | ( <media-feature> ) | <general-enclosed>`
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
// `( <media-condition> ) | ( <media-feature> )`
auto const& first_token = tokens.peek_token();
if (first_token.is_block() && first_token.block().is_paren()) {
TokenStream inner_token_stream { first_token.block().values() };
if (auto maybe_media_condition = parse_media_condition(inner_token_stream, MediaCondition::AllowOr::Yes)) {
tokens.next_token();
transaction.commit();
return maybe_media_condition.release_nonnull();
}
if (auto maybe_media_feature = parse_media_feature(inner_token_stream); maybe_media_feature.has_value()) {
tokens.next_token();
transaction.commit();
return MediaCondition::from_feature(maybe_media_feature.release_value());
}
}
// `<general-enclosed>`
// FIXME: We should only be taking this branch if the grammar doesn't match the above options.
// Currently we take it if the above fail to parse, which is different.
// eg, `@media (min-width: 76yaks)` is valid grammar, but does not parse because `yaks` isn't a unit.
if (auto maybe_general_enclosed = parse_general_enclosed(tokens); maybe_general_enclosed.has_value()) {
transaction.commit();
return MediaCondition::from_general_enclosed(maybe_general_enclosed.release_value());
}
return {};
}
// `<mf-value>`, https://www.w3.org/TR/mediaqueries-4/#typedef-mf-value
Optional<MediaFeatureValue> Parser::parse_media_feature_value(MediaFeatureID media_feature, TokenStream<ComponentValue>& tokens)
{
// Identifiers
if (tokens.peek_token().is(Token::Type::Ident)) {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto ident = value_id_from_string(tokens.next_token().token().ident());
if (ident.has_value() && media_feature_accepts_identifier(media_feature, ident.value())) {
transaction.commit();
return MediaFeatureValue(ident.value());
}
}
// One branch for each member of the MediaFeatureValueType enum:
// Boolean (<mq-boolean> in the spec: a 1 or 0)
if (media_feature_accepts_type(media_feature, MediaFeatureValueType::Boolean)) {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto const& first = tokens.next_token();
if (first.is(Token::Type::Number) && first.token().number().is_integer()
&& (first.token().number_value() == 0 || first.token().number_value() == 1)) {
transaction.commit();
return MediaFeatureValue(first.token().number_value());
}
}
// Integer
if (media_feature_accepts_type(media_feature, MediaFeatureValueType::Integer)) {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto const& first = tokens.next_token();
if (first.is(Token::Type::Number) && first.token().number().is_integer()) {
transaction.commit();
return MediaFeatureValue(first.token().number_value());
}
}
// Length
if (media_feature_accepts_type(media_feature, MediaFeatureValueType::Length)) {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto const& first = tokens.next_token();
if (auto length = parse_length(first); length.has_value()) {
transaction.commit();
return MediaFeatureValue(length.release_value());
}
}
// Ratio
if (media_feature_accepts_type(media_feature, MediaFeatureValueType::Ratio)) {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
if (auto ratio = parse_ratio(tokens); ratio.has_value()) {
transaction.commit();
return MediaFeatureValue(ratio.release_value());
}
}
// Resolution
if (media_feature_accepts_type(media_feature, MediaFeatureValueType::Resolution)) {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto const& first = tokens.next_token();
if (auto resolution = parse_dimension(first); resolution.has_value() && resolution->is_resolution()) {
transaction.commit();
return MediaFeatureValue(resolution->resolution());
}
}
return {};
}
RefPtr<Supports> Parser::parse_as_supports()
{
return parse_a_supports(m_token_stream);
}
template<typename T>
RefPtr<Supports> Parser::parse_a_supports(TokenStream<T>& tokens)
{
auto component_values = parse_a_list_of_component_values(tokens);
TokenStream<ComponentValue> token_stream { component_values };
auto maybe_condition = parse_supports_condition(token_stream);
token_stream.skip_whitespace();
if (maybe_condition && !token_stream.has_next_token())
return Supports::create(maybe_condition.release_nonnull());
return {};
}
OwnPtr<Supports::Condition> Parser::parse_supports_condition(TokenStream<ComponentValue>& tokens)
{
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto const& peeked_token = tokens.peek_token();
// `not <supports-in-parens>`
if (peeked_token.is(Token::Type::Ident) && peeked_token.token().ident().equals_ignoring_ascii_case("not"sv)) {
tokens.next_token();
tokens.skip_whitespace();
auto child = parse_supports_in_parens(tokens);
if (!child.has_value())
return {};
transaction.commit();
auto condition = make<Supports::Condition>();
condition->type = Supports::Condition::Type::Not;
condition->children.append(child.release_value());
return condition;
}
// ` <supports-in-parens> [ and <supports-in-parens> ]*
// | <supports-in-parens> [ or <supports-in-parens> ]*`
Vector<Supports::InParens> children;
Optional<Supports::Condition::Type> condition_type {};
auto as_condition_type = [](auto& token) -> Optional<Supports::Condition::Type> {
if (!token.is(Token::Type::Ident))
return {};
auto ident = token.token().ident();
if (ident.equals_ignoring_ascii_case("and"sv))
return Supports::Condition::Type::And;
if (ident.equals_ignoring_ascii_case("or"sv))
return Supports::Condition::Type::Or;
return {};
};
while (tokens.has_next_token()) {
if (!children.is_empty()) {
// Expect `and` or `or` here
auto maybe_combination = as_condition_type(tokens.next_token());
if (!maybe_combination.has_value())
return {};
if (!condition_type.has_value()) {
condition_type = maybe_combination.value();
} else if (maybe_combination != condition_type) {
return {};
}
}
tokens.skip_whitespace();
if (auto in_parens = parse_supports_in_parens(tokens); in_parens.has_value()) {
children.append(in_parens.release_value());
} else {
return {};
}
tokens.skip_whitespace();
}
if (children.is_empty())
return {};
transaction.commit();
auto condition = make<Supports::Condition>();
condition->type = condition_type.value_or(Supports::Condition::Type::Or);
condition->children = move(children);
return condition;
}
Optional<Supports::InParens> Parser::parse_supports_in_parens(TokenStream<ComponentValue>& tokens)
{
// `( <supports-condition> )`
auto const& first_token = tokens.peek_token();
if (first_token.is_block() && first_token.block().is_paren()) {
auto transaction = tokens.begin_transaction();
tokens.next_token();
tokens.skip_whitespace();
TokenStream child_tokens { first_token.block().values() };
if (auto condition = parse_supports_condition(child_tokens)) {
if (child_tokens.has_next_token())
return {};
transaction.commit();
return Supports::InParens {
.value = { condition.release_nonnull() }
};
}
}
// `<supports-feature>`
if (auto feature = parse_supports_feature(tokens); feature.has_value()) {
return Supports::InParens {
.value = { feature.release_value() }
};
}
// `<general-enclosed>`
if (auto general_enclosed = parse_general_enclosed(tokens); general_enclosed.has_value()) {
return Supports::InParens {
.value = general_enclosed.release_value()
};
}
return {};
}
Optional<Supports::Feature> Parser::parse_supports_feature(TokenStream<ComponentValue>& tokens)
{
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto const& first_token = tokens.next_token();
// `<supports-decl>`
if (first_token.is_block() && first_token.block().is_paren()) {
TokenStream block_tokens { first_token.block().values() };
// FIXME: Parsing and then converting back to a string is weird.
if (auto declaration = consume_a_declaration(block_tokens); declaration.has_value()) {
transaction.commit();
return Supports::Feature {
Supports::Declaration { declaration->to_string().release_value_but_fixme_should_propagate_errors(), JS::make_handle(m_context.realm()) }
};
}
}
// `<supports-selector-fn>`
if (first_token.is_function() && first_token.function().name().equals_ignoring_ascii_case("selector"sv)) {
// FIXME: Parsing and then converting back to a string is weird.
StringBuilder builder;
for (auto const& item : first_token.function().values())
builder.append(item.to_string().release_value_but_fixme_should_propagate_errors());
transaction.commit();
return Supports::Feature {
Supports::Selector { builder.to_string().release_value_but_fixme_should_propagate_errors(), JS::make_handle(m_context.realm()) }
};
}
return {};
}
// https://www.w3.org/TR/mediaqueries-4/#typedef-general-enclosed
Optional<GeneralEnclosed> Parser::parse_general_enclosed(TokenStream<ComponentValue>& tokens)
{
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto const& first_token = tokens.next_token();
// `[ <function-token> <any-value>? ) ]`
if (first_token.is_function()) {
transaction.commit();
return GeneralEnclosed { first_token.to_string().release_value_but_fixme_should_propagate_errors() };
}
// `( <any-value>? )`
if (first_token.is_block() && first_token.block().is_paren()) {
transaction.commit();
return GeneralEnclosed { first_token.to_string().release_value_but_fixme_should_propagate_errors() };
}
return {};
}
// 5.4.1. Consume a list of rules
// https://www.w3.org/TR/css-syntax-3/#consume-list-of-rules
template<typename T>
Vector<NonnullRefPtr<Rule>> Parser::consume_a_list_of_rules(TokenStream<T>& tokens, TopLevel top_level)
{
// To consume a list of rules, given a top-level flag:
// Create an initially empty list of rules.
Vector<NonnullRefPtr<Rule>> rules;
// Repeatedly consume the next input token:
for (;;) {
auto& token = tokens.next_token();
// <whitespace-token>
if (token.is(Token::Type::Whitespace)) {
// Do nothing.
continue;
}
// <EOF-token>
if (token.is(Token::Type::EndOfFile)) {
// Return the list of rules.
return rules;
}
// <CDO-token>
// <CDC-token>
if (token.is(Token::Type::CDO) || token.is(Token::Type::CDC)) {
// If the top-level flag is set, do nothing.
if (top_level == TopLevel::Yes)
continue;
// Otherwise, reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume a qualified rule. If anything is returned, append it to the list of rules.
if (auto maybe_qualified = consume_a_qualified_rule(tokens))
rules.append(maybe_qualified.release_nonnull());
continue;
}
// <at-keyword-token>
if (token.is(Token::Type::AtKeyword)) {
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume an at-rule, and append the returned value to the list of rules.
rules.append(consume_an_at_rule(tokens));
continue;
}
// anything else
{
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume a qualified rule. If anything is returned, append it to the list of rules.
if (auto maybe_qualified = consume_a_qualified_rule(tokens))
rules.append(maybe_qualified.release_nonnull());
continue;
}
}
}
// 5.4.2. Consume an at-rule
// https://www.w3.org/TR/css-syntax-3/#consume-at-rule
template<typename T>
NonnullRefPtr<Rule> Parser::consume_an_at_rule(TokenStream<T>& tokens)
{
// To consume an at-rule:
// Consume the next input token.
auto& name_ident = tokens.next_token();
VERIFY(name_ident.is(Token::Type::AtKeyword));
// Create a new at-rule with its name set to the value of the current input token, its prelude initially set to an empty list, and its value initially set to nothing.
// NOTE: We create the Rule fully initialized when we return it instead.
auto at_rule_name = FlyString::from_utf8(((Token)name_ident).at_keyword()).release_value_but_fixme_should_propagate_errors();
Vector<ComponentValue> prelude;
RefPtr<Block> block;
// Repeatedly consume the next input token:
for (;;) {
auto& token = tokens.next_token();
// <semicolon-token>
if (token.is(Token::Type::Semicolon)) {
// Return the at-rule.
return Rule::make_at_rule(move(at_rule_name), move(prelude), move(block));
}
// <EOF-token>
if (token.is(Token::Type::EndOfFile)) {
// This is a parse error. Return the at-rule.
log_parse_error();
return Rule::make_at_rule(move(at_rule_name), move(prelude), move(block));
}
// <{-token>
if (token.is(Token::Type::OpenCurly)) {
// Consume a simple block and assign it to the at-rule’s block. Return the at-rule.
block = consume_a_simple_block(tokens);
return Rule::make_at_rule(move(at_rule_name), move(prelude), move(block));
}
// simple block with an associated token of <{-token>
if constexpr (IsSame<T, ComponentValue>) {
ComponentValue const& component_value = token;
if (component_value.is_block() && component_value.block().is_curly()) {
// Assign the block to the at-rule’s block. Return the at-rule.
block = component_value.block();
return Rule::make_at_rule(move(at_rule_name), move(prelude), move(block));
}
}
// anything else
{
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume a component value. Append the returned value to the at-rule’s prelude.
prelude.append(consume_a_component_value(tokens));
}
}
}
// 5.4.3. Consume a qualified rule
// https://www.w3.org/TR/css-syntax-3/#consume-qualified-rule
template<typename T>
RefPtr<Rule> Parser::consume_a_qualified_rule(TokenStream<T>& tokens)
{
// To consume a qualified rule:
// Create a new qualified rule with its prelude initially set to an empty list, and its value initially set to nothing.
// NOTE: We create the Rule fully initialized when we return it instead.
Vector<ComponentValue> prelude;
RefPtr<Block> block;
// Repeatedly consume the next input token:
for (;;) {
auto& token = tokens.next_token();
// <EOF-token>
if (token.is(Token::Type::EndOfFile)) {
// This is a parse error. Return nothing.
log_parse_error();
return {};
}
// <{-token>
if (token.is(Token::Type::OpenCurly)) {
// Consume a simple block and assign it to the qualified rule’s block. Return the qualified rule.
block = consume_a_simple_block(tokens);
return Rule::make_qualified_rule(move(prelude), move(block));
}
// simple block with an associated token of <{-token>
if constexpr (IsSame<T, ComponentValue>) {
ComponentValue const& component_value = token;
if (component_value.is_block() && component_value.block().is_curly()) {
// Assign the block to the qualified rule’s block. Return the qualified rule.
block = component_value.block();
return Rule::make_qualified_rule(move(prelude), move(block));
}
}
// anything else
{
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume a component value. Append the returned value to the qualified rule’s prelude.
prelude.append(consume_a_component_value(tokens));
}
}
}
// 5.4.4. Consume a style block’s contents
// https://www.w3.org/TR/css-syntax-3/#consume-a-style-blocks-contents
template<typename T>
Vector<DeclarationOrAtRule> Parser::consume_a_style_blocks_contents(TokenStream<T>& tokens)
{
// To consume a style block’s contents:
// Create an initially empty list of declarations decls, and an initially empty list of rules rules.
Vector<DeclarationOrAtRule> declarations;
Vector<DeclarationOrAtRule> rules;
// Repeatedly consume the next input token:
for (;;) {
auto& token = tokens.next_token();
// <whitespace-token>
// <semicolon-token>
if (token.is(Token::Type::Whitespace) || token.is(Token::Type::Semicolon)) {
// Do nothing.
continue;
}
// <EOF-token>
if (token.is(Token::Type::EndOfFile)) {
// Extend decls with rules, then return decls.
declarations.extend(move(rules));
return declarations;
}
// <at-keyword-token>
if (token.is(Token::Type::AtKeyword)) {
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume an at-rule, and append the result to rules.
rules.empend(consume_an_at_rule(tokens));
continue;
}
// <ident-token>
if (token.is(Token::Type::Ident)) {
// Initialize a temporary list initially filled with the current input token.
Vector<ComponentValue> temporary_list;
temporary_list.append(token);
// As long as the next input token is anything other than a <semicolon-token> or <EOF-token>,
// consume a component value and append it to the temporary list.
for (;;) {
auto& next_input_token = tokens.peek_token();
if (next_input_token.is(Token::Type::Semicolon) || next_input_token.is(Token::Type::EndOfFile))
break;
temporary_list.append(consume_a_component_value(tokens));
}
// Consume a declaration from the temporary list. If anything was returned, append it to decls.
auto token_stream = TokenStream(temporary_list);
if (auto maybe_declaration = consume_a_declaration(token_stream); maybe_declaration.has_value())
declarations.empend(maybe_declaration.release_value());
continue;
}
// <delim-token> with a value of "&" (U+0026 AMPERSAND)
if (token.is(Token::Type::Delim) && token.token().delim() == '&') {
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume a qualified rule. If anything was returned, append it to rules.
if (auto qualified_rule = consume_a_qualified_rule(tokens))
rules.empend(qualified_rule);
continue;
}
// anything else
{
// This is a parse error.
log_parse_error();
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// As long as the next input token is anything other than a <semicolon-token> or <EOF-token>,
// consume a component value and throw away the returned value.
for (;;) {
auto& peek = tokens.peek_token();
if (peek.is(Token::Type::Semicolon) || peek.is(Token::Type::EndOfFile))
break;
(void)consume_a_component_value(tokens);
}
}
}
}
template<>
ComponentValue Parser::consume_a_component_value(TokenStream<ComponentValue>& tokens)
{
// Note: This overload is called once tokens have already been converted into component values,
// so we do not need to do the work in the more general overload.
return tokens.next_token();
}
// 5.4.7. Consume a component value
// https://www.w3.org/TR/css-syntax-3/#consume-component-value
template<typename T>
ComponentValue Parser::consume_a_component_value(TokenStream<T>& tokens)
{
// To consume a component value:
// Consume the next input token.
auto& token = tokens.next_token();
// If the current input token is a <{-token>, <[-token>, or <(-token>, consume a simple block and return it.
if (token.is(Token::Type::OpenCurly) || token.is(Token::Type::OpenSquare) || token.is(Token::Type::OpenParen))
return ComponentValue(consume_a_simple_block(tokens));
// Otherwise, if the current input token is a <function-token>, consume a function and return it.
if (token.is(Token::Type::Function))
return ComponentValue(consume_a_function(tokens));
// Otherwise, return the current input token.
return ComponentValue(token);
}
// 5.4.8. Consume a simple block
// https://www.w3.org/TR/css-syntax-3/#consume-simple-block
template<typename T>
NonnullRefPtr<Block> Parser::consume_a_simple_block(TokenStream<T>& tokens)
{
// Note: This algorithm assumes that the current input token has already been checked
// to be an <{-token>, <[-token>, or <(-token>.
// To consume a simple block:
// The ending token is the mirror variant of the current input token.
// (E.g. if it was called with <[-token>, the ending token is <]-token>.)
auto ending_token = ((Token)tokens.current_token()).mirror_variant();
// Create a simple block with its associated token set to the current input token
// and with its value initially set to an empty list.
// NOTE: We create the Block fully initialized when we return it instead.
Token block_token = tokens.current_token();
Vector<ComponentValue> block_values;
// Repeatedly consume the next input token and process it as follows:
for (;;) {
auto& token = tokens.next_token();
// ending token
if (token.is(ending_token)) {
// Return the block.
return Block::create(move(block_token), move(block_values));
}
// <EOF-token>
if (token.is(Token::Type::EndOfFile)) {
// This is a parse error. Return the block.
log_parse_error();
return Block::create(move(block_token), move(block_values));
}
// anything else
{
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume a component value and append it to the value of the block.
block_values.empend(consume_a_component_value(tokens));
}
}
}
// 5.4.9. Consume a function
// https://www.w3.org/TR/css-syntax-3/#consume-function
template<typename T>
NonnullRefPtr<Function> Parser::consume_a_function(TokenStream<T>& tokens)
{
// Note: This algorithm assumes that the current input token has already been checked to be a <function-token>.
auto name_ident = tokens.current_token();
VERIFY(name_ident.is(Token::Type::Function));
// To consume a function:
// Create a function with its name equal to the value of the current input token
// and with its value initially set to an empty list.
// NOTE: We create the Function fully initialized when we return it instead.
auto function_name = FlyString::from_utf8(((Token)name_ident).function()).release_value_but_fixme_should_propagate_errors();
Vector<ComponentValue> function_values;
// Repeatedly consume the next input token and process it as follows:
for (;;) {
auto& token = tokens.next_token();
// <)-token>
if (token.is(Token::Type::CloseParen)) {
// Return the function.
return Function::create(move(function_name), move(function_values));
}
// <EOF-token>
if (token.is(Token::Type::EndOfFile)) {
// This is a parse error. Return the function.
log_parse_error();
return Function::create(move(function_name), move(function_values));
}
// anything else
{
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume a component value and append the returned value to the function’s value.
function_values.append(consume_a_component_value(tokens));
}
}
}
// 5.4.6. Consume a declaration
// https://www.w3.org/TR/css-syntax-3/#consume-declaration
template<typename T>
Optional<Declaration> Parser::consume_a_declaration(TokenStream<T>& tokens)
{
// Note: This algorithm assumes that the next input token has already been checked to
// be an <ident-token>.
// NOTE: This is not true in our implementation! For convenience, we both skip whitespace
// and gracefully handle the first token not being an <ident-token>.
// To consume a declaration:
// Consume the next input token.
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto& token = tokens.next_token();
// NOTE: Not to spec, handle the case where the input token *isn't* an <ident-token>.
if (!token.is(Token::Type::Ident))
return {};
// Create a new declaration with its name set to the value of the current input token
// and its value initially set to the empty list.
// NOTE: We create a fully-initialized Declaration just before returning it instead.
auto declaration_name = FlyString::from_utf8(((Token)token).ident()).release_value_but_fixme_should_propagate_errors();
Vector<ComponentValue> declaration_values;
Important declaration_important = Important::No;
// 1. While the next input token is a <whitespace-token>, consume the next input token.
tokens.skip_whitespace();
// 2. If the next input token is anything other than a <colon-token>, this is a parse error.
// Return nothing.
auto& maybe_colon = tokens.peek_token();
if (!maybe_colon.is(Token::Type::Colon)) {
log_parse_error();
return {};
}
// Otherwise, consume the next input token.
tokens.next_token();
// 3. While the next input token is a <whitespace-token>, consume the next input token.
tokens.skip_whitespace();
// 4. As long as the next input token is anything other than an <EOF-token>, consume a
// component value and append it to the declaration’s value.
for (;;) {
if (tokens.peek_token().is(Token::Type::EndOfFile)) {
break;
}
declaration_values.append(consume_a_component_value(tokens));
}
// 5. If the last two non-<whitespace-token>s in the declaration’s value are a <delim-token>
// with the value "!" followed by an <ident-token> with a value that is an ASCII case-insensitive
// match for "important", remove them from the declaration’s value and set the declaration’s
// important flag to true.
if (declaration_values.size() >= 2) {
// Walk backwards from the end until we find "important"
Optional<size_t> important_index;
for (size_t i = declaration_values.size() - 1; i > 0; i--) {
auto value = declaration_values[i];
if (value.is(Token::Type::Ident) && Infra::is_ascii_case_insensitive_match(value.token().ident(), "important"sv)) {
important_index = i;
break;
}
if (value.is(Token::Type::Whitespace))
continue;
break;
}
// Walk backwards from important until we find "!"
if (important_index.has_value()) {
Optional<size_t> bang_index;
for (size_t i = important_index.value() - 1; i > 0; i--) {
auto value = declaration_values[i];
if (value.is(Token::Type::Delim) && value.token().delim() == '!') {
bang_index = i;
break;
}
if (value.is(Token::Type::Whitespace))
continue;
break;
}
if (bang_index.has_value()) {
declaration_values.remove(important_index.value());
declaration_values.remove(bang_index.value());
declaration_important = Important::Yes;
}
}
}
// 6. While the last token in the declaration’s value is a <whitespace-token>, remove that token.
while (!declaration_values.is_empty()) {
auto maybe_whitespace = declaration_values.last();
if (!(maybe_whitespace.is(Token::Type::Whitespace))) {
break;
}
declaration_values.take_last();
}
// 7. Return the declaration.
transaction.commit();
return Declaration { move(declaration_name), move(declaration_values), declaration_important };
}
// 5.4.5. Consume a list of declarations
// https://www.w3.org/TR/css-syntax-3/#consume-list-of-declarations
template<typename T>
Vector<DeclarationOrAtRule> Parser::consume_a_list_of_declarations(TokenStream<T>& tokens)
{
// To consume a list of declarations:
// Create an initially empty list of declarations.
Vector<DeclarationOrAtRule> list_of_declarations;
// Repeatedly consume the next input token:
for (;;) {
auto& token = tokens.next_token();
// <whitespace-token>
// <semicolon-token>
if (token.is(Token::Type::Whitespace) || token.is(Token::Type::Semicolon)) {
// Do nothing.
continue;
}
// <EOF-token>
if (token.is(Token::Type::EndOfFile)) {
// Return the list of declarations.
return list_of_declarations;
}
// <at-keyword-token>
if (token.is(Token::Type::AtKeyword)) {
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// Consume an at-rule. Append the returned rule to the list of declarations.
list_of_declarations.empend(consume_an_at_rule(tokens));
continue;
}
// <ident-token>
if (token.is(Token::Type::Ident)) {
// Initialize a temporary list initially filled with the current input token.
Vector<ComponentValue> temporary_list;
temporary_list.append(token);
// As long as the next input token is anything other than a <semicolon-token> or <EOF-token>,
// consume a component value and append it to the temporary list.
for (;;) {
auto& peek = tokens.peek_token();
if (peek.is(Token::Type::Semicolon) || peek.is(Token::Type::EndOfFile))
break;
temporary_list.append(consume_a_component_value(tokens));
}
// Consume a declaration from the temporary list. If anything was returned, append it to the list of declarations.
auto token_stream = TokenStream(temporary_list);
if (auto maybe_declaration = consume_a_declaration(token_stream); maybe_declaration.has_value())
list_of_declarations.empend(maybe_declaration.value());
continue;
}
// anything else
{
// This is a parse error.
log_parse_error();
// Reconsume the current input token.
tokens.reconsume_current_input_token();
// As long as the next input token is anything other than a <semicolon-token> or <EOF-token>,
// consume a component value and throw away the returned value.
for (;;) {
auto& peek = tokens.peek_token();
if (peek.is(Token::Type::Semicolon) || peek.is(Token::Type::EndOfFile))
break;
dbgln_if(CSS_PARSER_DEBUG, "Discarding token: '{}'", peek.to_debug_string());
(void)consume_a_component_value(tokens);
}
}
}
}
CSSRule* Parser::parse_as_css_rule()
{
auto maybe_rule = parse_a_rule(m_token_stream);
if (maybe_rule)
return convert_to_rule(maybe_rule.release_nonnull());
return {};
}
// 5.3.5. Parse a rule
// https://www.w3.org/TR/css-syntax-3/#parse-rule
template<typename T>
RefPtr<Rule> Parser::parse_a_rule(TokenStream<T>& tokens)
{
// To parse a rule from input:
RefPtr<Rule> rule;
// 1. Normalize input, and set input to the result.
// Note: This is done when initializing the Parser.
// 2. While the next input token from input is a <whitespace-token>, consume the next input token from input.
tokens.skip_whitespace();
// 3. If the next input token from input is an <EOF-token>, return a syntax error.
auto& token = tokens.peek_token();
if (token.is(Token::Type::EndOfFile)) {
return {};
}
// Otherwise, if the next input token from input is an <at-keyword-token>, consume an at-rule from input, and let rule be the return value.
else if (token.is(Token::Type::AtKeyword)) {
rule = consume_an_at_rule(m_token_stream);
}
// Otherwise, consume a qualified rule from input and let rule be the return value. If nothing was returned, return a syntax error.
else {
auto qualified_rule = consume_a_qualified_rule(tokens);
if (!qualified_rule)
return {};
rule = qualified_rule;
}
// 4. While the next input token from input is a <whitespace-token>, consume the next input token from input.
tokens.skip_whitespace();
// 5. If the next input token from input is an <EOF-token>, return rule. Otherwise, return a syntax error.
if (tokens.peek_token().is(Token::Type::EndOfFile))
return rule;
return {};
}
// 5.3.4. Parse a list of rules
// https://www.w3.org/TR/css-syntax-3/#parse-list-of-rules
template<typename T>
Vector<NonnullRefPtr<Rule>> Parser::parse_a_list_of_rules(TokenStream<T>& tokens)
{
// To parse a list of rules from input:
// 1. Normalize input, and set input to the result.
// Note: This is done when initializing the Parser.
// 2. Consume a list of rules from the input, with the top-level flag unset.
auto list_of_rules = consume_a_list_of_rules(tokens, TopLevel::No);
// 3. Return the returned list.
return list_of_rules;
}
Optional<StyleProperty> Parser::parse_as_supports_condition()
{
auto maybe_declaration = parse_a_declaration(m_token_stream);
if (maybe_declaration.has_value())
return convert_to_style_property(maybe_declaration.release_value());
return {};
}
// 5.3.6. Parse a declaration
// https://www.w3.org/TR/css-syntax-3/#parse-a-declaration
template<typename T>
Optional<Declaration> Parser::parse_a_declaration(TokenStream<T>& tokens)
{
// To parse a declaration from input:
// 1. Normalize input, and set input to the result.
// Note: This is done when initializing the Parser.
// 2. While the next input token from input is a <whitespace-token>, consume the next input token.
tokens.skip_whitespace();
// 3. If the next input token from input is not an <ident-token>, return a syntax error.
auto& token = tokens.peek_token();
if (!token.is(Token::Type::Ident)) {
return {};
}
// 4. Consume a declaration from input. If anything was returned, return it. Otherwise, return a syntax error.
if (auto declaration = consume_a_declaration(tokens); declaration.has_value())
return declaration.release_value();
return {};
}
// 5.3.7. Parse a style block’s contents
// https://www.w3.org/TR/css-syntax-3/#parse-style-blocks-contents
template<typename T>
Vector<DeclarationOrAtRule> Parser::parse_a_style_blocks_contents(TokenStream<T>& tokens)
{
// To parse a style block’s contents from input:
// 1. Normalize input, and set input to the result.
// Note: This is done when initializing the Parser.
// 2. Consume a style block’s contents from input, and return the result.
return consume_a_style_blocks_contents(tokens);
}
// 5.3.8. Parse a list of declarations
// https://www.w3.org/TR/css-syntax-3/#parse-list-of-declarations
template<typename T>
Vector<DeclarationOrAtRule> Parser::parse_a_list_of_declarations(TokenStream<T>& tokens)
{
// To parse a list of declarations from input:
// 1. Normalize input, and set input to the result.
// Note: This is done when initializing the Parser.
// 2. Consume a list of declarations from input, and return the result.
return consume_a_list_of_declarations(tokens);
}
// 5.3.9. Parse a component value
// https://www.w3.org/TR/css-syntax-3/#parse-component-value
template<typename T>
Optional<ComponentValue> Parser::parse_a_component_value(TokenStream<T>& tokens)
{
// To parse a component value from input:
// 1. Normalize input, and set input to the result.
// Note: This is done when initializing the Parser.
// 2. While the next input token from input is a <whitespace-token>, consume the next input token from input.
tokens.skip_whitespace();
// 3. If the next input token from input is an <EOF-token>, return a syntax error.
if (tokens.peek_token().is(Token::Type::EndOfFile))
return {};
// 4. Consume a component value from input and let value be the return value.
auto value = consume_a_component_value(tokens);
// 5. While the next input token from input is a <whitespace-token>, consume the next input token.
tokens.skip_whitespace();
// 6. If the next input token from input is an <EOF-token>, return value. Otherwise, return a syntax error.
if (tokens.peek_token().is(Token::Type::EndOfFile))
return value;
return {};
}
// 5.3.10. Parse a list of component values
// https://www.w3.org/TR/css-syntax-3/#parse-list-of-component-values
template<typename T>
Vector<ComponentValue> Parser::parse_a_list_of_component_values(TokenStream<T>& tokens)
{
// To parse a list of component values from input:
// 1. Normalize input, and set input to the result.
// Note: This is done when initializing the Parser.
// 2. Repeatedly consume a component value from input until an <EOF-token> is returned, appending the returned values (except the final <EOF-token>) into a list. Return the list.
Vector<ComponentValue> component_values;
for (;;) {
if (tokens.peek_token().is(Token::Type::EndOfFile)) {
break;
}
component_values.append(consume_a_component_value(tokens));
}
return component_values;
}
// 5.3.11. Parse a comma-separated list of component values
// https://www.w3.org/TR/css-syntax-3/#parse-comma-separated-list-of-component-values
template<typename T>
Vector<Vector<ComponentValue>> Parser::parse_a_comma_separated_list_of_component_values(TokenStream<T>& tokens)
{
// To parse a comma-separated list of component values from input:
// 1. Normalize input, and set input to the result.
// Note: This is done when initializing the Parser.
// 2. Let list of cvls be an initially empty list of component value lists.
Vector<Vector<ComponentValue>> list_of_component_value_lists;
// 3. Repeatedly consume a component value from input until an <EOF-token> or <comma-token> is returned,
// appending the returned values (except the final <EOF-token> or <comma-token>) into a list.
// Append the list to list of cvls.
// If it was a <comma-token> that was returned, repeat this step.
Vector<ComponentValue> current_list;
for (;;) {
auto component_value = consume_a_component_value(tokens);
if (component_value.is(Token::Type::EndOfFile)) {
list_of_component_value_lists.append(move(current_list));
break;
}
if (component_value.is(Token::Type::Comma)) {
list_of_component_value_lists.append(move(current_list));
current_list = {};
continue;
}
current_list.append(component_value);
}
// 4. Return list of cvls.
return list_of_component_value_lists;
}
ElementInlineCSSStyleDeclaration* Parser::parse_as_style_attribute(DOM::Element& element)
{
auto declarations_and_at_rules = parse_a_list_of_declarations(m_token_stream);
auto [properties, custom_properties] = extract_properties(declarations_and_at_rules);
return ElementInlineCSSStyleDeclaration::create(element, move(properties), move(custom_properties)).release_value_but_fixme_should_propagate_errors();
}
Optional<AK::URL> Parser::parse_url_function(ComponentValue const& component_value, AllowedDataUrlType allowed_data_url_type)
{
// FIXME: Handle list of media queries. https://www.w3.org/TR/css-cascade-3/#conditional-import
// FIXME: Handle data: urls (RFC2397)
auto convert_string_to_url = [&](StringView& url_string) -> Optional<AK::URL> {
if (url_string.starts_with("data:"sv, CaseSensitivity::CaseInsensitive)) {
auto data_url = AK::URL(url_string);
switch (allowed_data_url_type) {
case AllowedDataUrlType::Image:
if (data_url.data_mime_type().starts_with("image"sv, CaseSensitivity::CaseInsensitive))
return data_url;
break;
case AllowedDataUrlType::Font:
if (data_url.data_mime_type().starts_with("font"sv, CaseSensitivity::CaseInsensitive))
return data_url;
break;
default:
break;
}
return {};
}
return m_context.complete_url(url_string);
};
if (component_value.is(Token::Type::Url)) {
auto url_string = component_value.token().url();
return convert_string_to_url(url_string);
}
if (component_value.is_function() && component_value.function().name().equals_ignoring_ascii_case("url"sv)) {
auto const& function_values = component_value.function().values();
// FIXME: Handle url-modifiers. https://www.w3.org/TR/css-values-4/#url-modifiers
for (size_t i = 0; i < function_values.size(); ++i) {
auto const& value = function_values[i];
if (value.is(Token::Type::Whitespace))
continue;
if (value.is(Token::Type::String)) {
auto url_string = value.token().string();
return convert_string_to_url(url_string);
}
break;
}
}
return {};
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_url_value(ComponentValue const& component_value, AllowedDataUrlType allowed_data_url_type)
{
auto url = parse_url_function(component_value, allowed_data_url_type);
if (!url.has_value())
return nullptr;
return URLStyleValue::create(*url);
}
template<typename TElement>
static Optional<Vector<TElement>> parse_color_stop_list(auto& tokens, auto is_position, auto get_position, auto parse_color, auto parse_dimension)
{
enum class ElementType {
Garbage,
ColorStop,
ColorHint
};
auto parse_color_stop_list_element = [&](TElement& element) -> ElementType {
tokens.skip_whitespace();
if (!tokens.has_next_token())
return ElementType::Garbage;
auto const& token = tokens.next_token();
Gfx::Color color;
Optional<typename TElement::PositionType> position;
Optional<typename TElement::PositionType> second_position;
auto dimension = parse_dimension(token);
if (dimension.has_value() && is_position(*dimension)) {
// [<T-percentage> <color>] or [<T-percentage>]
position = get_position(*dimension);
tokens.skip_whitespace();
// <T-percentage>
if (!tokens.has_next_token() || tokens.peek_token().is(Token::Type::Comma)) {
element.transition_hint = typename TElement::ColorHint { *position };
return ElementType::ColorHint;
}
// <T-percentage> <color>
auto maybe_color = parse_color(tokens.next_token());
if (!maybe_color.has_value())
return ElementType::Garbage;
color = *maybe_color;
} else {
// [<color> <T-percentage>?]
auto maybe_color = parse_color(token);
if (!maybe_color.has_value())
return ElementType::Garbage;
color = *maybe_color;
tokens.skip_whitespace();
// Allow up to [<color> <T-percentage> <T-percentage>] (double-position color stops)
// Note: Double-position color stops only appear to be valid in this order.
for (auto stop_position : Array { &position, &second_position }) {
if (tokens.has_next_token() && !tokens.peek_token().is(Token::Type::Comma)) {
auto token = tokens.next_token();
auto dimension = parse_dimension(token);
if (!dimension.has_value() || !is_position(*dimension))
return ElementType::Garbage;
*stop_position = get_position(*dimension);
tokens.skip_whitespace();
}
}
}
element.color_stop = typename TElement::ColorStop { color, position, second_position };
return ElementType::ColorStop;
};
TElement first_element {};
if (parse_color_stop_list_element(first_element) != ElementType::ColorStop)
return {};
if (!tokens.has_next_token())
return {};
Vector<TElement> color_stops { first_element };
while (tokens.has_next_token()) {
TElement list_element {};
tokens.skip_whitespace();
if (!tokens.next_token().is(Token::Type::Comma))
return {};
auto element_type = parse_color_stop_list_element(list_element);
if (element_type == ElementType::ColorHint) {
// <color-hint>, <color-stop>
tokens.skip_whitespace();
if (!tokens.next_token().is(Token::Type::Comma))
return {};
// Note: This fills in the color stop on the same list_element as the color hint (it does not overwrite it).
if (parse_color_stop_list_element(list_element) != ElementType::ColorStop)
return {};
} else if (element_type == ElementType::ColorStop) {
// <color-stop>
} else {
return {};
}
color_stops.append(list_element);
}
return color_stops;
}
Optional<Vector<LinearColorStopListElement>> Parser::parse_linear_color_stop_list(TokenStream<ComponentValue>& tokens)
{
// <color-stop-list> =
// <linear-color-stop> , [ <linear-color-hint>? , <linear-color-stop> ]#
return parse_color_stop_list<LinearColorStopListElement>(
tokens,
[](Dimension& dimension) { return dimension.is_length_percentage(); },
[](Dimension& dimension) { return dimension.length_percentage(); },
[&](auto& token) { return parse_color(token); },
[&](auto& token) { return parse_dimension(token); });
}
Optional<Vector<AngularColorStopListElement>> Parser::parse_angular_color_stop_list(TokenStream<ComponentValue>& tokens)
{
// <angular-color-stop-list> =
// <angular-color-stop> , [ <angular-color-hint>? , <angular-color-stop> ]#
return parse_color_stop_list<AngularColorStopListElement>(
tokens,
[](Dimension& dimension) { return dimension.is_angle_percentage(); },
[](Dimension& dimension) { return dimension.angle_percentage(); },
[&](auto& token) { return parse_color(token); },
[&](auto& token) { return parse_dimension(token); });
}
static StringView consume_if_starts_with(StringView str, StringView start, auto found_callback)
{
if (str.starts_with(start, CaseSensitivity::CaseInsensitive)) {
found_callback();
return str.substring_view(start.length());
}
return str;
};
ErrorOr<RefPtr<StyleValue>> Parser::parse_linear_gradient_function(ComponentValue const& component_value)
{
using GradientType = LinearGradientStyleValue::GradientType;
if (!component_value.is_function())
return nullptr;
GradientRepeating repeating_gradient = GradientRepeating::No;
GradientType gradient_type { GradientType::Standard };
auto function_name = component_value.function().name();
function_name = consume_if_starts_with(function_name, "-webkit-"sv, [&] {
gradient_type = GradientType::WebKit;
});
function_name = consume_if_starts_with(function_name, "repeating-"sv, [&] {
repeating_gradient = GradientRepeating::Yes;
});
if (!function_name.equals_ignoring_ascii_case("linear-gradient"sv))
return nullptr;
// linear-gradient() = linear-gradient([ <angle> | to <side-or-corner> ]?, <color-stop-list>)
TokenStream tokens { component_value.function().values() };
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
bool has_direction_param = true;
LinearGradientStyleValue::GradientDirection gradient_direction = gradient_type == GradientType::Standard
? SideOrCorner::Bottom
: SideOrCorner::Top;
auto to_side = [](StringView value) -> Optional<SideOrCorner> {
if (value.equals_ignoring_ascii_case("top"sv))
return SideOrCorner::Top;
if (value.equals_ignoring_ascii_case("bottom"sv))
return SideOrCorner::Bottom;
if (value.equals_ignoring_ascii_case("left"sv))
return SideOrCorner::Left;
if (value.equals_ignoring_ascii_case("right"sv))
return SideOrCorner::Right;
return {};
};
auto is_to_side_or_corner = [&](auto const& token) {
if (!token.is(Token::Type::Ident))
return false;
if (gradient_type == GradientType::WebKit)
return to_side(token.token().ident()).has_value();
return token.token().ident().equals_ignoring_ascii_case("to"sv);
};
auto const& first_param = tokens.peek_token();
if (first_param.is(Token::Type::Dimension)) {
// <angle>
tokens.next_token();
float angle_value = first_param.token().dimension_value();
auto unit_string = first_param.token().dimension_unit();
auto angle_type = Angle::unit_from_name(unit_string);
if (!angle_type.has_value())
return nullptr;
gradient_direction = Angle { angle_value, angle_type.release_value() };
} else if (is_to_side_or_corner(first_param)) {
// <side-or-corner> = [left | right] || [top | bottom]
// Note: -webkit-linear-gradient does not include to the "to" prefix on the side or corner
if (gradient_type == GradientType::Standard) {
tokens.next_token();
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
}
// [left | right] || [top | bottom]
auto const& first_side = tokens.next_token();
if (!first_side.is(Token::Type::Ident))
return nullptr;
auto side_a = to_side(first_side.token().ident());
tokens.skip_whitespace();
Optional<SideOrCorner> side_b;
if (tokens.has_next_token() && tokens.peek_token().is(Token::Type::Ident))
side_b = to_side(tokens.next_token().token().ident());
if (side_a.has_value() && !side_b.has_value()) {
gradient_direction = *side_a;
} else if (side_a.has_value() && side_b.has_value()) {
// Convert two sides to a corner
if (to_underlying(*side_b) < to_underlying(*side_a))
swap(side_a, side_b);
if (side_a == SideOrCorner::Top && side_b == SideOrCorner::Left)
gradient_direction = SideOrCorner::TopLeft;
else if (side_a == SideOrCorner::Top && side_b == SideOrCorner::Right)
gradient_direction = SideOrCorner::TopRight;
else if (side_a == SideOrCorner::Bottom && side_b == SideOrCorner::Left)
gradient_direction = SideOrCorner::BottomLeft;
else if (side_a == SideOrCorner::Bottom && side_b == SideOrCorner::Right)
gradient_direction = SideOrCorner::BottomRight;
else
return nullptr;
} else {
return nullptr;
}
} else {
has_direction_param = false;
}
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
if (has_direction_param && !tokens.next_token().is(Token::Type::Comma))
return nullptr;
auto color_stops = parse_linear_color_stop_list(tokens);
if (!color_stops.has_value())
return nullptr;
return LinearGradientStyleValue::create(gradient_direction, move(*color_stops), gradient_type, repeating_gradient);
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_conic_gradient_function(ComponentValue const& component_value)
{
if (!component_value.is_function())
return nullptr;
GradientRepeating repeating_gradient = GradientRepeating::No;
auto function_name = component_value.function().name();
function_name = consume_if_starts_with(function_name, "repeating-"sv, [&] {
repeating_gradient = GradientRepeating::Yes;
});
if (!function_name.equals_ignoring_ascii_case("conic-gradient"sv))
return nullptr;
TokenStream tokens { component_value.function().values() };
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
Angle from_angle(0, Angle::Type::Deg);
PositionValue at_position = PositionValue::center();
// conic-gradient( [ [ from <angle> ]? [ at <position> ]? ] ||
// <color-interpolation-method> , <angular-color-stop-list> )
auto token = tokens.peek_token();
bool got_from_angle = false;
bool got_color_interpolation_method = false;
bool got_at_position = false;
while (token.is(Token::Type::Ident)) {
auto consume_identifier = [&](auto identifier) {
auto token_string = token.token().ident();
if (token_string.equals_ignoring_ascii_case(identifier)) {
(void)tokens.next_token();
tokens.skip_whitespace();
return true;
}
return false;
};
if (consume_identifier("from"sv)) {
// from <angle>
if (got_from_angle || got_at_position)
return nullptr;
if (!tokens.has_next_token())
return nullptr;
auto angle_token = tokens.next_token();
if (!angle_token.is(Token::Type::Dimension))
return nullptr;
float angle = angle_token.token().dimension_value();
auto angle_unit = angle_token.token().dimension_unit();
auto angle_type = Angle::unit_from_name(angle_unit);
if (!angle_type.has_value())
return nullptr;
from_angle = Angle(angle, *angle_type);
got_from_angle = true;
} else if (consume_identifier("at"sv)) {
// at <position>
if (got_at_position)
return nullptr;
auto position = parse_position(tokens);
if (!position.has_value())
return nullptr;
at_position = *position;
got_at_position = true;
} else if (consume_identifier("in"sv)) {
// <color-interpolation-method>
if (got_color_interpolation_method)
return nullptr;
dbgln("FIXME: Parse color interpolation method for conic-gradient()");
got_color_interpolation_method = true;
} else {
break;
}
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
token = tokens.peek_token();
}
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
if ((got_from_angle || got_at_position || got_color_interpolation_method) && !tokens.next_token().is(Token::Type::Comma))
return nullptr;
auto color_stops = parse_angular_color_stop_list(tokens);
if (!color_stops.has_value())
return nullptr;
return ConicGradientStyleValue::create(from_angle, at_position, move(*color_stops), repeating_gradient);
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_radial_gradient_function(ComponentValue const& component_value)
{
using EndingShape = RadialGradientStyleValue::EndingShape;
using Extent = RadialGradientStyleValue::Extent;
using CircleSize = RadialGradientStyleValue::CircleSize;
using EllipseSize = RadialGradientStyleValue::EllipseSize;
using Size = RadialGradientStyleValue::Size;
if (!component_value.is_function())
return nullptr;
auto repeating_gradient = GradientRepeating::No;
auto function_name = component_value.function().name();
function_name = consume_if_starts_with(function_name, "repeating-"sv, [&] {
repeating_gradient = GradientRepeating::Yes;
});
if (!function_name.equals_ignoring_ascii_case("radial-gradient"sv))
return nullptr;
TokenStream tokens { component_value.function().values() };
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
bool expect_comma = false;
auto commit_value = [&]<typename... T>(auto value, T&... transactions) {
(transactions.commit(), ...);
return value;
};
// radial-gradient( [ <ending-shape> || <size> ]? [ at <position> ]? , <color-stop-list> )
Size size = Extent::FarthestCorner;
EndingShape ending_shape = EndingShape::Circle;
PositionValue at_position = PositionValue::center();
auto parse_ending_shape = [&]() -> Optional<EndingShape> {
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto& token = tokens.next_token();
if (!token.is(Token::Type::Ident))
return {};
auto ident = token.token().ident();
if (ident.equals_ignoring_ascii_case("circle"sv))
return commit_value(EndingShape::Circle, transaction);
if (ident.equals_ignoring_ascii_case("ellipse"sv))
return commit_value(EndingShape::Ellipse, transaction);
return {};
};
auto parse_extent_keyword = [](StringView keyword) -> Optional<Extent> {
if (keyword.equals_ignoring_ascii_case("closest-corner"sv))
return Extent::ClosestCorner;
if (keyword.equals_ignoring_ascii_case("closest-side"sv))
return Extent::ClosestSide;
if (keyword.equals_ignoring_ascii_case("farthest-corner"sv))
return Extent::FarthestCorner;
if (keyword.equals_ignoring_ascii_case("farthest-side"sv))
return Extent::FarthestSide;
return {};
};
auto parse_size = [&]() -> Optional<Size> {
// <size> =
// <extent-keyword> |
// <length [0,∞]> |
// <length-percentage [0,∞]>{2}
auto transaction_size = tokens.begin_transaction();
tokens.skip_whitespace();
if (!tokens.has_next_token())
return {};
auto& token = tokens.next_token();
if (token.is(Token::Type::Ident)) {
auto extent = parse_extent_keyword(token.token().ident());
if (!extent.has_value())
return {};
return commit_value(*extent, transaction_size);
}
auto first_dimension = parse_dimension(token);
if (!first_dimension.has_value())
return {};
if (!first_dimension->is_length_percentage())
return {};
auto transaction_second_dimension = tokens.begin_transaction();
tokens.skip_whitespace();
if (tokens.has_next_token()) {
auto& second_token = tokens.next_token();
auto second_dimension = parse_dimension(second_token);
if (second_dimension.has_value() && second_dimension->is_length_percentage())
return commit_value(EllipseSize { first_dimension->length_percentage(), second_dimension->length_percentage() },
transaction_size, transaction_second_dimension);
}
if (first_dimension->is_length())
return commit_value(CircleSize { first_dimension->length() }, transaction_size);
return {};
};
{
// [ <ending-shape> || <size> ]?
auto maybe_ending_shape = parse_ending_shape();
auto maybe_size = parse_size();
if (!maybe_ending_shape.has_value() && maybe_size.has_value())
maybe_ending_shape = parse_ending_shape();
if (maybe_size.has_value()) {
size = *maybe_size;
expect_comma = true;
}
if (maybe_ending_shape.has_value()) {
expect_comma = true;
ending_shape = *maybe_ending_shape;
if (ending_shape == EndingShape::Circle && size.has<EllipseSize>())
return nullptr;
if (ending_shape == EndingShape::Ellipse && size.has<CircleSize>())
return nullptr;
} else {
ending_shape = size.has<CircleSize>() ? EndingShape::Circle : EndingShape::Ellipse;
}
}
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
auto& token = tokens.peek_token();
if (token.is(Token::Type::Ident) && token.token().ident().equals_ignoring_ascii_case("at"sv)) {
(void)tokens.next_token();
auto position = parse_position(tokens);
if (!position.has_value())
return nullptr;
at_position = *position;
expect_comma = true;
}
tokens.skip_whitespace();
if (!tokens.has_next_token())
return nullptr;
if (expect_comma && !tokens.next_token().is(Token::Type::Comma))
return nullptr;
// <color-stop-list>
auto color_stops = parse_linear_color_stop_list(tokens);
if (!color_stops.has_value())
return nullptr;
return RadialGradientStyleValue::create(ending_shape, size, at_position, move(*color_stops), repeating_gradient);
}
Optional<PositionValue> Parser::parse_position(TokenStream<ComponentValue>& tokens, PositionValue initial_value)
{
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
if (!tokens.has_next_token())
return {};
auto parse_horizontal_preset = [&](auto ident) -> Optional<PositionValue::HorizontalPreset> {
if (ident.equals_ignoring_ascii_case("left"sv))
return PositionValue::HorizontalPreset::Left;
if (ident.equals_ignoring_ascii_case("center"sv))
return PositionValue::HorizontalPreset::Center;
if (ident.equals_ignoring_ascii_case("right"sv))
return PositionValue::HorizontalPreset::Right;
return {};
};
auto parse_vertical_preset = [&](auto ident) -> Optional<PositionValue::VerticalPreset> {
if (ident.equals_ignoring_ascii_case("top"sv))
return PositionValue::VerticalPreset::Top;
if (ident.equals_ignoring_ascii_case("center"sv))
return PositionValue::VerticalPreset::Center;
if (ident.equals_ignoring_ascii_case("bottom"sv))
return PositionValue::VerticalPreset::Bottom;
return {};
};
auto parse_horizontal_edge = [&](auto ident) -> Optional<PositionValue::HorizontalEdge> {
if (ident.equals_ignoring_ascii_case("left"sv))
return PositionValue::HorizontalEdge::Left;
if (ident.equals_ignoring_ascii_case("right"sv))
return PositionValue::HorizontalEdge::Right;
return {};
};
auto parse_vertical_edge = [&](auto ident) -> Optional<PositionValue::VerticalEdge> {
if (ident.equals_ignoring_ascii_case("top"sv))
return PositionValue::VerticalEdge::Top;
if (ident.equals_ignoring_ascii_case("bottom"sv))
return PositionValue::VerticalEdge::Bottom;
return {};
};
// <position> = [
// [ left | center | right ] || [ top | center | bottom ]
// |
// [ left | center | right | <length-percentage> ]
// [ top | center | bottom | <length-percentage> ]?
// |
// [ [ left | right ] <length-percentage> ] &&
// [ [ top | bottom ] <length-percentage> ]
// ]
// [ left | center | right ] || [ top | center | bottom ]
auto alternation_1 = [&]() -> Optional<PositionValue> {
auto transaction = tokens.begin_transaction();
PositionValue position = initial_value;
auto& first_token = tokens.next_token();
if (!first_token.is(Token::Type::Ident))
return {};
auto ident = first_token.token().ident();
// <horizontal-position> <vertical-position>?
auto horizontal_position = parse_horizontal_preset(ident);
if (horizontal_position.has_value()) {
position.horizontal_position = *horizontal_position;
auto transaction_optional_parse = tokens.begin_transaction();
tokens.skip_whitespace();
if (tokens.has_next_token()) {
auto& second_token = tokens.next_token();
if (second_token.is(Token::Type::Ident)) {
auto vertical_position = parse_vertical_preset(second_token.token().ident());
if (vertical_position.has_value()) {
transaction_optional_parse.commit();
position.vertical_position = *vertical_position;
}
}
}
} else {
// <vertical-position> <horizontal-position>?
auto vertical_position = parse_vertical_preset(ident);
if (!vertical_position.has_value())
return {};
position.vertical_position = *vertical_position;
auto transaction_optional_parse = tokens.begin_transaction();
tokens.skip_whitespace();
if (tokens.has_next_token()) {
auto& second_token = tokens.next_token();
if (second_token.is(Token::Type::Ident)) {
auto horizontal_position = parse_horizontal_preset(second_token.token().ident());
if (horizontal_position.has_value()) {
transaction_optional_parse.commit();
position.horizontal_position = *horizontal_position;
}
}
}
}
transaction.commit();
return position;
};
// [ left | center | right | <length-percentage> ]
// [ top | center | bottom | <length-percentage> ]?
auto alternation_2 = [&]() -> Optional<PositionValue> {
auto transaction = tokens.begin_transaction();
PositionValue position = initial_value;
auto& first_token = tokens.next_token();
if (first_token.is(Token::Type::Ident)) {
auto horizontal_position = parse_horizontal_preset(first_token.token().ident());
if (!horizontal_position.has_value())
return {};
position.horizontal_position = *horizontal_position;
} else {
auto dimension = parse_dimension(first_token);
if (!dimension.has_value() || !dimension->is_length_percentage())
return {};
position.horizontal_position = dimension->length_percentage();
}
auto transaction_optional_parse = tokens.begin_transaction();
tokens.skip_whitespace();
if (tokens.has_next_token()) {
auto& second_token = tokens.next_token();
if (second_token.is(Token::Type::Ident)) {
auto vertical_position = parse_vertical_preset(second_token.token().ident());
if (vertical_position.has_value()) {
transaction_optional_parse.commit();
position.vertical_position = *vertical_position;
}
} else {
auto dimension = parse_dimension(second_token);
if (dimension.has_value() && dimension->is_length_percentage()) {
transaction_optional_parse.commit();
position.vertical_position = dimension->length_percentage();
}
}
}
transaction.commit();
return position;
};
// [ [ left | right ] <length-percentage> ] &&
// [ [ top | bottom ] <length-percentage> ]
auto alternation_3 = [&]() -> Optional<PositionValue> {
auto transaction = tokens.begin_transaction();
PositionValue position {};
auto parse_horizontal = [&] {
// [ left | right ] <length-percentage> ]
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
if (!tokens.has_next_token())
return false;
auto& first_token = tokens.next_token();
if (!first_token.is(Token::Type::Ident))
return false;
auto horizontal_egde = parse_horizontal_edge(first_token.token().ident());
if (!horizontal_egde.has_value())
return false;
position.x_relative_to = *horizontal_egde;
tokens.skip_whitespace();
if (!tokens.has_next_token())
return false;
auto& second_token = tokens.next_token();
auto dimension = parse_dimension(second_token);
if (!dimension.has_value() || !dimension->is_length_percentage())
return false;
position.horizontal_position = dimension->length_percentage();
transaction.commit();
return true;
};
auto parse_vertical = [&] {
// [ top | bottom ] <length-percentage> ]
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
if (!tokens.has_next_token())
return false;
auto& first_token = tokens.next_token();
if (!first_token.is(Token::Type::Ident))
return false;
auto vertical_edge = parse_vertical_edge(first_token.token().ident());
if (!vertical_edge.has_value())
return false;
position.y_relative_to = *vertical_edge;
tokens.skip_whitespace();
if (!tokens.has_next_token())
return false;
auto& second_token = tokens.next_token();
auto dimension = parse_dimension(second_token);
if (!dimension.has_value() || !dimension->is_length_percentage())
return false;
position.vertical_position = dimension->length_percentage();
transaction.commit();
return true;
};
if ((parse_horizontal() && parse_vertical()) || (parse_vertical() && parse_horizontal())) {
transaction.commit();
return position;
}
return {};
};
// Note: The alternatives must be attempted in this order since `alternation_2' can match a prefix of `alternation_3'
auto position = alternation_3();
if (!position.has_value())
position = alternation_2();
if (!position.has_value())
position = alternation_1();
if (position.has_value())
transaction.commit();
return position;
}
CSSRule* Parser::convert_to_rule(NonnullRefPtr<Rule> rule)
{
if (rule->is_at_rule()) {
if (has_ignored_vendor_prefix(rule->at_rule_name()))
return {};
if (rule->at_rule_name().equals_ignoring_ascii_case("font-face"sv)) {
if (!rule->block() || !rule->block()->is_curly()) {
dbgln_if(CSS_PARSER_DEBUG, "@font-face rule is malformed.");
return {};
}
TokenStream tokens { rule->block()->values() };
return parse_font_face_rule(tokens);
}
if (rule->at_rule_name().equals_ignoring_ascii_case("import"sv) && !rule->prelude().is_empty()) {
Optional<AK::URL> url;
for (auto const& token : rule->prelude()) {
if (token.is(Token::Type::Whitespace))
continue;
if (token.is(Token::Type::String)) {
url = m_context.complete_url(token.token().string());
} else {
url = parse_url_function(token);
}
// FIXME: Handle list of media queries. https://www.w3.org/TR/css-cascade-3/#conditional-import
if (url.has_value())
break;
}
if (url.has_value())
return CSSImportRule::create(url.value(), const_cast<DOM::Document&>(*m_context.document())).release_value_but_fixme_should_propagate_errors();
dbgln_if(CSS_PARSER_DEBUG, "Unable to parse url from @import rule");
return {};
}
if (rule->at_rule_name().equals_ignoring_ascii_case("media"sv)) {
auto media_query_tokens = TokenStream { rule->prelude() };
auto media_query_list = parse_a_media_query_list(media_query_tokens);
if (media_query_list.is_empty() || !rule->block())
return {};
auto child_tokens = TokenStream { rule->block()->values() };
auto parser_rules = parse_a_list_of_rules(child_tokens);
JS::MarkedVector<CSSRule*> child_rules(m_context.realm().heap());
for (auto& raw_rule : parser_rules) {
if (auto* child_rule = convert_to_rule(raw_rule))
child_rules.append(child_rule);
}
auto media_list = MediaList::create(m_context.realm(), move(media_query_list)).release_value_but_fixme_should_propagate_errors();
auto rule_list = CSSRuleList::create(m_context.realm(), child_rules).release_value_but_fixme_should_propagate_errors();
return CSSMediaRule::create(m_context.realm(), media_list, rule_list).release_value_but_fixme_should_propagate_errors();
}
if (rule->at_rule_name().equals_ignoring_ascii_case("supports"sv)) {
auto supports_tokens = TokenStream { rule->prelude() };
auto supports = parse_a_supports(supports_tokens);
if (!supports) {
if constexpr (CSS_PARSER_DEBUG) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @supports rule invalid; discarding.");
supports_tokens.dump_all_tokens();
}
return {};
}
if (!rule->block())
return {};
auto child_tokens = TokenStream { rule->block()->values() };
auto parser_rules = parse_a_list_of_rules(child_tokens);
JS::MarkedVector<CSSRule*> child_rules(m_context.realm().heap());
for (auto& raw_rule : parser_rules) {
if (auto* child_rule = convert_to_rule(raw_rule))
child_rules.append(child_rule);
}
auto rule_list = CSSRuleList::create(m_context.realm(), child_rules).release_value_but_fixme_should_propagate_errors();
return CSSSupportsRule::create(m_context.realm(), supports.release_nonnull(), rule_list).release_value_but_fixme_should_propagate_errors();
}
// FIXME: More at rules!
dbgln_if(CSS_PARSER_DEBUG, "Unrecognized CSS at-rule: @{}", rule->at_rule_name());
return {};
}
auto prelude_stream = TokenStream(rule->prelude());
auto selectors = parse_a_selector_list(prelude_stream, SelectorType::Standalone);
if (selectors.is_error()) {
if (selectors.error() == ParseError::SyntaxError) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: style rule selectors invalid; discarding.");
if constexpr (CSS_PARSER_DEBUG) {
prelude_stream.dump_all_tokens();
}
}
return {};
}
if (selectors.value().is_empty()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: empty selector; discarding.");
return {};
}
if (!rule->block()->is_curly())
return {};
auto stream = TokenStream(rule->block()->values());
auto declarations_and_at_rules = parse_a_style_blocks_contents(stream);
auto* declaration = convert_to_style_declaration(declarations_and_at_rules);
if (!declaration) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: style rule declaration invalid; discarding.");
return {};
}
return CSSStyleRule::create(m_context.realm(), move(selectors.value()), *declaration).release_value_but_fixme_should_propagate_errors();
}
auto Parser::extract_properties(Vector<DeclarationOrAtRule> const& declarations_and_at_rules) -> PropertiesAndCustomProperties
{
PropertiesAndCustomProperties result;
for (auto const& declaration_or_at_rule : declarations_and_at_rules) {
if (declaration_or_at_rule.is_at_rule()) {
dbgln_if(CSS_PARSER_DEBUG, "!!! CSS at-rule is not allowed here!");
continue;
}
auto const& declaration = declaration_or_at_rule.declaration();
if (auto maybe_property = convert_to_style_property(declaration); maybe_property.has_value()) {
auto property = maybe_property.release_value();
if (property.property_id == PropertyID::Custom) {
result.custom_properties.set(property.custom_name, property);
} else {
result.properties.append(move(property));
}
}
}
return result;
}
PropertyOwningCSSStyleDeclaration* Parser::convert_to_style_declaration(Vector<DeclarationOrAtRule> const& declarations_and_at_rules)
{
auto [properties, custom_properties] = extract_properties(declarations_and_at_rules);
return PropertyOwningCSSStyleDeclaration::create(m_context.realm(), move(properties), move(custom_properties)).release_value_but_fixme_should_propagate_errors();
}
Optional<StyleProperty> Parser::convert_to_style_property(Declaration const& declaration)
{
auto property_name = declaration.name();
auto property_id = property_id_from_string(property_name);
if (!property_id.has_value()) {
if (property_name.starts_with("--"sv)) {
property_id = PropertyID::Custom;
} else if (has_ignored_vendor_prefix(property_name)) {
return {};
} else if (!property_name.starts_with('-')) {
dbgln_if(CSS_PARSER_DEBUG, "Unrecognized CSS property '{}'", property_name);
return {};
}
}
auto value_token_stream = TokenStream(declaration.values());
auto value = parse_css_value(property_id.value(), value_token_stream);
if (value.is_error()) {
if (value.error() == ParseError::SyntaxError) {
dbgln_if(CSS_PARSER_DEBUG, "Unable to parse value for CSS property '{}'.", property_name);
if constexpr (CSS_PARSER_DEBUG) {
value_token_stream.dump_all_tokens();
}
}
return {};
}
if (property_id.value() == PropertyID::Custom)
return StyleProperty { declaration.importance(), property_id.value(), value.release_value(), declaration.name() };
return StyleProperty { declaration.importance(), property_id.value(), value.release_value(), {} };
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_builtin_value(ComponentValue const& component_value)
{
if (component_value.is(Token::Type::Ident)) {
auto ident = component_value.token().ident();
if (ident.equals_ignoring_ascii_case("inherit"sv))
return InheritStyleValue::the();
if (ident.equals_ignoring_ascii_case("initial"sv))
return InitialStyleValue::the();
if (ident.equals_ignoring_ascii_case("unset"sv))
return UnsetStyleValue::the();
// FIXME: Implement `revert` and `revert-layer` keywords, from Cascade4 and Cascade5 respectively
}
return nullptr;
}
ErrorOr<RefPtr<CalculatedStyleValue>> Parser::parse_calculated_value(Vector<ComponentValue> const& component_values)
{
auto calculation_tree = TRY(parse_a_calculation(component_values));
if (calculation_tree == nullptr) {
dbgln_if(CSS_PARSER_DEBUG, "Failed to parse calculation tree");
return nullptr;
} else {
if constexpr (CSS_PARSER_DEBUG) {
dbgln("Parsed calculation tree:");
StringBuilder builder;
TRY(calculation_tree->dump(builder, 0));
dbgln(builder.string_view());
}
}
auto calc_type = calculation_tree->resolved_type();
if (!calc_type.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "calc() resolved as invalid!!!");
return nullptr;
}
[[maybe_unused]] auto to_string = [](CalculatedStyleValue::ResolvedType type) {
switch (type) {
case CalculatedStyleValue::ResolvedType::Angle:
return "Angle"sv;
case CalculatedStyleValue::ResolvedType::Frequency:
return "Frequency"sv;
case CalculatedStyleValue::ResolvedType::Integer:
return "Integer"sv;
case CalculatedStyleValue::ResolvedType::Length:
return "Length"sv;
case CalculatedStyleValue::ResolvedType::Number:
return "Number"sv;
case CalculatedStyleValue::ResolvedType::Percentage:
return "Percentage"sv;
case CalculatedStyleValue::ResolvedType::Time:
return "Time"sv;
}
VERIFY_NOT_REACHED();
};
dbgln_if(CSS_PARSER_DEBUG, "Deduced calc() resolved type as: {}", to_string(calc_type.value()));
return CalculatedStyleValue::create(calculation_tree.release_nonnull(), calc_type.release_value());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_dynamic_value(ComponentValue const& component_value)
{
if (component_value.is_function()) {
auto const& function = component_value.function();
if (function.name().equals_ignoring_ascii_case("calc"sv))
return parse_calculated_value(function.values());
if (function.name().equals_ignoring_ascii_case("var"sv)) {
// Declarations using `var()` should already be parsed as an UnresolvedStyleValue before this point.
VERIFY_NOT_REACHED();
}
}
return nullptr;
}
Optional<Parser::Dimension> Parser::parse_dimension(ComponentValue const& component_value)
{
if (component_value.is(Token::Type::Dimension)) {
float numeric_value = component_value.token().dimension_value();
auto unit_string = component_value.token().dimension_unit();
if (auto length_type = Length::unit_from_name(unit_string); length_type.has_value())
return Length { numeric_value, length_type.release_value() };
if (auto angle_type = Angle::unit_from_name(unit_string); angle_type.has_value())
return Angle { numeric_value, angle_type.release_value() };
if (auto frequency_type = Frequency::unit_from_name(unit_string); frequency_type.has_value())
return Frequency { numeric_value, frequency_type.release_value() };
if (auto resolution_type = Resolution::unit_from_name(unit_string); resolution_type.has_value())
return Resolution { numeric_value, resolution_type.release_value() };
if (auto time_type = Time::unit_from_name(unit_string); time_type.has_value())
return Time { numeric_value, time_type.release_value() };
}
if (component_value.is(Token::Type::Percentage))
return Percentage { static_cast<float>(component_value.token().percentage()) };
if (component_value.is(Token::Type::Number)) {
float numeric_value = component_value.token().number_value();
if (numeric_value == 0)
return Length::make_px(0);
if (m_context.in_quirks_mode() && property_has_quirk(m_context.current_property_id(), Quirk::UnitlessLength)) {
// https://quirks.spec.whatwg.org/#quirky-length-value
// FIXME: Disallow quirk when inside a CSS sub-expression (like `calc()`)
// "The <quirky-length> value must not be supported in arguments to CSS expressions other than the rect()
// expression, and must not be supported in the supports() static method of the CSS interface."
return Length::make_px(numeric_value);
}
}
return {};
}
Optional<Length> Parser::parse_length(ComponentValue const& component_value)
{
auto dimension = parse_dimension(component_value);
if (!dimension.has_value())
return {};
if (dimension->is_length())
return dimension->length();
return {};
}
Optional<Ratio> Parser::parse_ratio(TokenStream<ComponentValue>& tokens)
{
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
// `<ratio> = <number [0,∞]> [ / <number [0,∞]> ]?`
// FIXME: I think either part is allowed to be calc(), which makes everything complicated.
auto first_number = tokens.next_token();
if (!first_number.is(Token::Type::Number) || first_number.token().number_value() < 0)
return {};
{
auto two_value_transaction = tokens.begin_transaction();
tokens.skip_whitespace();
auto solidus = tokens.next_token();
tokens.skip_whitespace();
auto second_number = tokens.next_token();
if (solidus.is(Token::Type::Delim) && solidus.token().delim() == '/'
&& second_number.is(Token::Type::Number) && second_number.token().number_value() > 0) {
// Two-value ratio
two_value_transaction.commit();
transaction.commit();
return Ratio { static_cast<float>(first_number.token().number_value()), static_cast<float>(second_number.token().number_value()) };
}
}
// Single-value ratio
transaction.commit();
return Ratio { static_cast<float>(first_number.token().number_value()) };
}
// https://www.w3.org/TR/css-syntax-3/#urange-syntax
Optional<UnicodeRange> Parser::parse_unicode_range(TokenStream<ComponentValue>& tokens)
{
auto transaction = tokens.begin_transaction();
tokens.skip_whitespace();
// <urange> =
// u '+' <ident-token> '?'* |
// u <dimension-token> '?'* |
// u <number-token> '?'* |
// u <number-token> <dimension-token> |
// u <number-token> <number-token> |
// u '+' '?'+
// (All with no whitespace in between tokens.)
// NOTE: Parsing this is different from usual. We take these steps:
// 1. Match the grammar above against the tokens, concatenating them into a string using their original representation.
// 2. Then, parse that string according to the spec algorithm.
// Step 2 is performed by calling the other parse_unicode_range() overload.
auto is_question_mark = [](ComponentValue const& component_value) {
return component_value.is(Token::Type::Delim) && component_value.token().delim() == '?';
};
auto is_ending_token = [](ComponentValue const& component_value) {
return component_value.is(Token::Type::EndOfFile)
|| component_value.is(Token::Type::Comma)
|| component_value.is(Token::Type::Semicolon)
|| component_value.is(Token::Type::Whitespace);
};
auto create_unicode_range = [&](StringView text, auto& local_transaction) -> Optional<UnicodeRange> {
auto maybe_unicode_range = parse_unicode_range(text);
if (maybe_unicode_range.has_value()) {
local_transaction.commit();
transaction.commit();
}
return maybe_unicode_range;
};
// All options start with 'u'/'U'.
auto const& u = tokens.next_token();
if (!(u.is(Token::Type::Ident) && u.token().ident().equals_ignoring_ascii_case("u"sv))) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> does not start with 'u'");
return {};
}
auto const& second_token = tokens.next_token();
// u '+' <ident-token> '?'* |
// u '+' '?'+
if (second_token.is(Token::Type::Delim) && second_token.token().delim() == '+') {
auto local_transaction = tokens.begin_transaction();
StringBuilder string_builder;
string_builder.append(second_token.token().representation());
auto const& third_token = tokens.next_token();
if (third_token.is(Token::Type::Ident) || is_question_mark(third_token)) {
string_builder.append(third_token.token().representation());
while (is_question_mark(tokens.peek_token()))
string_builder.append(tokens.next_token().token().representation());
if (is_ending_token(tokens.peek_token()))
return create_unicode_range(string_builder.string_view(), local_transaction);
}
}
// u <dimension-token> '?'*
if (second_token.is(Token::Type::Dimension)) {
auto local_transaction = tokens.begin_transaction();
StringBuilder string_builder;
string_builder.append(second_token.token().representation());
while (is_question_mark(tokens.peek_token()))
string_builder.append(tokens.next_token().token().representation());
if (is_ending_token(tokens.peek_token()))
return create_unicode_range(string_builder.string_view(), local_transaction);
}
// u <number-token> '?'* |
// u <number-token> <dimension-token> |
// u <number-token> <number-token>
if (second_token.is(Token::Type::Number)) {
auto local_transaction = tokens.begin_transaction();
StringBuilder string_builder;
string_builder.append(second_token.token().representation());
if (is_ending_token(tokens.peek_token()))
return create_unicode_range(string_builder.string_view(), local_transaction);
auto const& third_token = tokens.next_token();
if (is_question_mark(third_token)) {
string_builder.append(third_token.token().representation());
while (is_question_mark(tokens.peek_token()))
string_builder.append(tokens.next_token().token().representation());
if (is_ending_token(tokens.peek_token()))
return create_unicode_range(string_builder.string_view(), local_transaction);
} else if (third_token.is(Token::Type::Dimension)) {
string_builder.append(third_token.token().representation());
if (is_ending_token(tokens.peek_token()))
return create_unicode_range(string_builder.string_view(), local_transaction);
} else if (third_token.is(Token::Type::Number)) {
string_builder.append(third_token.token().representation());
if (is_ending_token(tokens.peek_token()))
return create_unicode_range(string_builder.string_view(), local_transaction);
}
}
if constexpr (CSS_PARSER_DEBUG) {
dbgln("CSSParser: Tokens did not match <urange> grammar.");
tokens.dump_all_tokens();
}
return {};
}
Optional<UnicodeRange> Parser::parse_unicode_range(StringView text)
{
auto make_valid_unicode_range = [&](u32 start_value, u32 end_value) -> Optional<UnicodeRange> {
// https://www.w3.org/TR/css-syntax-3/#maximum-allowed-code-point
constexpr u32 maximum_allowed_code_point = 0x10FFFF;
// To determine what codepoints the <urange> represents:
// 1. If end value is greater than the maximum allowed code point,
// the <urange> is invalid and a syntax error.
if (end_value > maximum_allowed_code_point) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: Invalid <urange>: end_value ({}) > maximum ({})", end_value, maximum_allowed_code_point);
return {};
}
// 2. If start value is greater than end value, the <urange> is invalid and a syntax error.
if (start_value > end_value) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: Invalid <urange>: start_value ({}) > end_value ({})", start_value, end_value);
return {};
}
// 3. Otherwise, the <urange> represents a contiguous range of codepoints from start value to end value, inclusive.
return UnicodeRange { start_value, end_value };
};
// 1. Skipping the first u token, concatenate the representations of all the tokens in the production together.
// Let this be text.
// NOTE: The concatenation is already done by the caller.
GenericLexer lexer { text };
// 2. If the first character of text is U+002B PLUS SIGN, consume it.
// Otherwise, this is an invalid <urange>, and this algorithm must exit.
if (lexer.next_is('+')) {
lexer.consume();
} else {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: Second character of <urange> was not '+'; got: '{}'", lexer.consume());
return {};
}
// 3. Consume as many hex digits from text as possible.
// then consume as many U+003F QUESTION MARK (?) code points as possible.
auto hex_digits = lexer.consume_while(is_ascii_hex_digit);
auto question_marks = lexer.consume_while([](auto it) { return it == '?'; });
// If zero code points were consumed, or more than six code points were consumed,
// this is an invalid <urange>, and this algorithm must exit.
size_t consumed_code_points = hex_digits.length() + question_marks.length();
if (consumed_code_points == 0 || consumed_code_points > 6) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> start value had {} digits/?s, expected between 1 and 6.", consumed_code_points);
return {};
}
StringView start_value_code_points { hex_digits.characters_without_null_termination(), consumed_code_points };
// If any U+003F QUESTION MARK (?) code points were consumed, then:
if (question_marks.length() > 0) {
// 1. If there are any code points left in text, this is an invalid <urange>,
// and this algorithm must exit.
if (lexer.tell_remaining() != 0) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> invalid; had {} code points left over.", lexer.tell_remaining());
return {};
}
// 2. Interpret the consumed code points as a hexadecimal number,
// with the U+003F QUESTION MARK (?) code points replaced by U+0030 DIGIT ZERO (0) code points.
// This is the start value.
auto start_value_string = start_value_code_points.replace("?"sv, "0"sv, ReplaceMode::All);
auto maybe_start_value = AK::StringUtils::convert_to_uint_from_hex<u32>(start_value_string);
if (!maybe_start_value.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> ?-converted start value did not parse as hex number.");
return {};
}
u32 start_value = maybe_start_value.release_value();
// 3. Interpret the consumed code points as a hexadecimal number again,
// with the U+003F QUESTION MARK (?) code points replaced by U+0046 LATIN CAPITAL LETTER F (F) code points.
// This is the end value.
auto end_value_string = start_value_code_points.replace("?"sv, "F"sv, ReplaceMode::All);
auto maybe_end_value = AK::StringUtils::convert_to_uint_from_hex<u32>(end_value_string);
if (!maybe_end_value.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> ?-converted end value did not parse as hex number.");
return {};
}
u32 end_value = maybe_end_value.release_value();
// 4. Exit this algorithm.
return make_valid_unicode_range(start_value, end_value);
}
// Otherwise, interpret the consumed code points as a hexadecimal number. This is the start value.
auto maybe_start_value = AK::StringUtils::convert_to_uint_from_hex<u32>(start_value_code_points);
if (!maybe_start_value.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> start value did not parse as hex number.");
return {};
}
u32 start_value = maybe_start_value.release_value();
// 4. If there are no code points left in text, The end value is the same as the start value.
// Exit this algorithm.
if (lexer.tell_remaining() == 0)
return make_valid_unicode_range(start_value, start_value);
// 5. If the next code point in text is U+002D HYPHEN-MINUS (-), consume it.
if (lexer.next_is('-')) {
lexer.consume();
}
// Otherwise, this is an invalid <urange>, and this algorithm must exit.
else {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> start and end values not separated by '-'.");
return {};
}
// 6. Consume as many hex digits as possible from text.
auto end_hex_digits = lexer.consume_while(is_ascii_hex_digit);
// If zero hex digits were consumed, or more than 6 hex digits were consumed,
// this is an invalid <urange>, and this algorithm must exit.
if (end_hex_digits.length() == 0 || end_hex_digits.length() > 6) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> end value had {} digits, expected between 1 and 6.", end_hex_digits.length());
return {};
}
// If there are any code points left in text, this is an invalid <urange>, and this algorithm must exit.
if (lexer.tell_remaining() != 0) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> invalid; had {} code points left over.", lexer.tell_remaining());
return {};
}
// 7. Interpret the consumed code points as a hexadecimal number. This is the end value.
auto maybe_end_value = AK::StringUtils::convert_to_uint_from_hex<u32>(end_hex_digits);
if (!maybe_end_value.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: <urange> end value did not parse as hex number.");
return {};
}
u32 end_value = maybe_end_value.release_value();
return make_valid_unicode_range(start_value, end_value);
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_dimension_value(ComponentValue const& component_value)
{
// Numbers with no units can be lengths, in two situations:
// 1) We're in quirks mode, and it's an integer.
// 2) It's a 0.
// We handle case 1 here. Case 2 is handled by NumericStyleValue pretending to be a LengthStyleValue if it is 0.
if (component_value.is(Token::Type::Number) && !(m_context.in_quirks_mode() && property_has_quirk(m_context.current_property_id(), Quirk::UnitlessLength)))
return nullptr;
auto dimension = parse_dimension(component_value);
if (!dimension.has_value())
return nullptr;
if (dimension->is_angle())
return AngleStyleValue::create(dimension->angle());
if (dimension->is_frequency())
return FrequencyStyleValue::create(dimension->frequency());
if (dimension->is_length())
return LengthStyleValue::create(dimension->length());
if (dimension->is_percentage())
return PercentageStyleValue::create(dimension->percentage());
if (dimension->is_resolution())
return ResolutionStyleValue::create(dimension->resolution());
if (dimension->is_time())
return TimeStyleValue::create(dimension->time());
VERIFY_NOT_REACHED();
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_numeric_value(ComponentValue const& component_value)
{
if (component_value.is(Token::Type::Number)) {
auto const& number = component_value.token();
if (number.number().is_integer())
return NumericStyleValue::create_integer(number.to_integer());
return NumericStyleValue::create_float(number.number_value());
}
return nullptr;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_identifier_value(ComponentValue const& component_value)
{
if (component_value.is(Token::Type::Ident)) {
auto value_id = value_id_from_string(component_value.token().ident());
if (value_id.has_value())
return IdentifierStyleValue::create(value_id.value());
}
return nullptr;
}
Optional<Color> Parser::parse_rgb_or_hsl_color(StringView function_name, Vector<ComponentValue> const& component_values)
{
Token params[4];
bool legacy_syntax = false;
auto tokens = TokenStream { component_values };
tokens.skip_whitespace();
auto const& component1 = tokens.next_token();
if (!component1.is(Token::Type::Number)
&& !component1.is(Token::Type::Percentage)
&& !component1.is(Token::Type::Dimension))
return {};
params[0] = component1.token();
tokens.skip_whitespace();
if (tokens.peek_token().is(Token::Type::Comma)) {
legacy_syntax = true;
tokens.next_token();
}
tokens.skip_whitespace();
auto const& component2 = tokens.next_token();
if (!component2.is(Token::Type::Number) && !component2.is(Token::Type::Percentage))
return {};
params[1] = component2.token();
tokens.skip_whitespace();
if (legacy_syntax && !tokens.next_token().is(Token::Type::Comma))
return {};
tokens.skip_whitespace();
auto const& component3 = tokens.next_token();
if (!component3.is(Token::Type::Number) && !component3.is(Token::Type::Percentage))
return {};
params[2] = component3.token();
tokens.skip_whitespace();
auto const& alpha_separator = tokens.peek_token();
bool has_comma = alpha_separator.is(Token::Type::Comma);
bool has_slash = alpha_separator.is(Token::Type::Delim) && alpha_separator.token().delim() == '/';
if (legacy_syntax ? has_comma : has_slash) {
tokens.next_token();
tokens.skip_whitespace();
auto const& component4 = tokens.next_token();
if (!component4.is(Token::Type::Number) && !component4.is(Token::Type::Percentage))
return {};
params[3] = component4.token();
}
tokens.skip_whitespace();
if (tokens.has_next_token())
return {};
if (function_name.equals_ignoring_ascii_case("rgb"sv)
|| function_name.equals_ignoring_ascii_case("rgba"sv)) {
// https://www.w3.org/TR/css-color-4/#rgb-functions
u8 a_val = 255;
if (params[3].is(Token::Type::Number))
a_val = clamp(lroundf(params[3].number_value() * 255.0f), 0, 255);
else if (params[3].is(Token::Type::Percentage))
a_val = clamp(lroundf(params[3].percentage() * 2.55f), 0, 255);
if (params[0].is(Token::Type::Number)
&& params[1].is(Token::Type::Number)
&& params[2].is(Token::Type::Number)) {
u8 r_val = clamp(llroundf(params[0].number_value()), 0, 255);
u8 g_val = clamp(llroundf(params[1].number_value()), 0, 255);
u8 b_val = clamp(llroundf(params[2].number_value()), 0, 255);
return Color(r_val, g_val, b_val, a_val);
}
if (params[0].is(Token::Type::Percentage)
&& params[1].is(Token::Type::Percentage)
&& params[2].is(Token::Type::Percentage)) {
u8 r_val = lroundf(clamp(params[0].percentage() * 2.55f, 0, 255));
u8 g_val = lroundf(clamp(params[1].percentage() * 2.55f, 0, 255));
u8 b_val = lroundf(clamp(params[2].percentage() * 2.55f, 0, 255));
return Color(r_val, g_val, b_val, a_val);
}
} else if (function_name.equals_ignoring_ascii_case("hsl"sv)
|| function_name.equals_ignoring_ascii_case("hsla"sv)) {
// https://www.w3.org/TR/css-color-4/#the-hsl-notation
float a_val = 1.0f;
if (params[3].is(Token::Type::Number))
a_val = params[3].number_value();
else if (params[3].is(Token::Type::Percentage))
a_val = params[3].percentage() / 100.0f;
if (params[0].is(Token::Type::Dimension)
&& params[1].is(Token::Type::Percentage)
&& params[2].is(Token::Type::Percentage)) {
float numeric_value = params[0].dimension_value();
auto unit_string = params[0].dimension_unit();
auto angle_type = Angle::unit_from_name(unit_string);
if (!angle_type.has_value())
return {};
auto angle = Angle { numeric_value, angle_type.release_value() };
float h_val = fmodf(angle.to_degrees(), 360.0f);
float s_val = params[1].percentage() / 100.0f;
float l_val = params[2].percentage() / 100.0f;
return Color::from_hsla(h_val, s_val, l_val, a_val);
}
if (params[0].is(Token::Type::Number)
&& params[1].is(Token::Type::Percentage)
&& params[2].is(Token::Type::Percentage)) {
float h_val = fmodf(params[0].number_value(), 360.0f);
float s_val = params[1].percentage() / 100.0f;
float l_val = params[2].percentage() / 100.0f;
return Color::from_hsla(h_val, s_val, l_val, a_val);
}
}
return {};
}
// https://www.w3.org/TR/CSS2/visufx.html#value-def-shape
ErrorOr<RefPtr<StyleValue>> Parser::parse_rect_value(ComponentValue const& component_value)
{
if (!component_value.is_function())
return nullptr;
auto const& function = component_value.function();
if (!function.name().equals_ignoring_ascii_case("rect"sv))
return nullptr;
Vector<Length, 4> params;
auto tokens = TokenStream { function.values() };
enum class CommaRequirement {
Unknown,
RequiresCommas,
RequiresNoCommas
};
enum class Side {
Top = 0,
Right = 1,
Bottom = 2,
Left = 3
};
auto comma_requirement = CommaRequirement::Unknown;
// In CSS 2.1, the only valid <shape> value is: rect(<top>, <right>, <bottom>, <left>) where
// <top> and <bottom> specify offsets from the top border edge of the box, and <right>, and
// <left> specify offsets from the left border edge of the box.
for (size_t side = 0; side < 4; side++) {
tokens.skip_whitespace();
// <top>, <right>, <bottom>, and <left> may either have a <length> value or 'auto'.
// Negative lengths are permitted.
auto current_token = tokens.next_token().token();
if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_ascii_case("auto"sv)) {
params.append(Length::make_auto());
} else {
auto maybe_length = parse_length(current_token);
if (!maybe_length.has_value())
return nullptr;
params.append(maybe_length.value());
}
tokens.skip_whitespace();
// The last side, should be no more tokens following it.
if (static_cast<Side>(side) == Side::Left) {
if (tokens.has_next_token())
return nullptr;
break;
}
bool next_is_comma = tokens.peek_token().is(Token::Type::Comma);
// Authors should separate offset values with commas. User agents must support separation
// with commas, but may also support separation without commas (but not a combination),
// because a previous revision of this specification was ambiguous in this respect.
if (comma_requirement == CommaRequirement::Unknown)
comma_requirement = next_is_comma ? CommaRequirement::RequiresCommas : CommaRequirement::RequiresNoCommas;
if (comma_requirement == CommaRequirement::RequiresCommas) {
if (next_is_comma)
tokens.next_token();
else
return nullptr;
} else if (comma_requirement == CommaRequirement::RequiresNoCommas) {
if (next_is_comma)
return nullptr;
} else {
VERIFY_NOT_REACHED();
}
}
return RectStyleValue::create(EdgeRect { params[0], params[1], params[2], params[3] });
}
Optional<Color> Parser::parse_color(ComponentValue const& component_value)
{
// https://www.w3.org/TR/css-color-4/
if (component_value.is(Token::Type::Ident)) {
auto ident = component_value.token().ident();
auto color = Color::from_string(ident);
if (color.has_value())
return color;
} else if (component_value.is(Token::Type::Hash)) {
auto color = Color::from_string(DeprecatedString::formatted("#{}", component_value.token().hash_value()));
if (color.has_value())
return color;
return {};
} else if (component_value.is_function()) {
auto const& function = component_value.function();
auto const& values = function.values();
return parse_rgb_or_hsl_color(function.name(), values);
}
// https://quirks.spec.whatwg.org/#the-hashless-hex-color-quirk
if (m_context.in_quirks_mode() && property_has_quirk(m_context.current_property_id(), Quirk::HashlessHexColor)) {
// The value of a quirky color is obtained from the possible component values using the following algorithm,
// aborting on the first step that returns a value:
// 1. Let cv be the component value.
auto const& cv = component_value;
DeprecatedString serialization;
// 2. If cv is a <number-token> or a <dimension-token>, follow these substeps:
if (cv.is(Token::Type::Number) || cv.is(Token::Type::Dimension)) {
// 1. If cv’s type flag is not "integer", return an error.
// This means that values that happen to use scientific notation, e.g., 5e5e5e, will fail to parse.
if (!cv.token().number().is_integer())
return {};
// 2. If cv’s value is less than zero, return an error.
auto value = cv.is(Token::Type::Number) ? cv.token().to_integer() : cv.token().dimension_value_int();
if (value < 0)
return {};
// 3. Let serialization be the serialization of cv’s value, as a base-ten integer using digits 0-9 (U+0030 to U+0039) in the shortest form possible.
StringBuilder serialization_builder;
serialization_builder.appendff("{}", value);
// 4. If cv is a <dimension-token>, append the unit to serialization.
if (cv.is(Token::Type::Dimension))
serialization_builder.append(cv.token().dimension_unit());
// 5. If serialization consists of fewer than six characters, prepend zeros (U+0030) so that it becomes six characters.
serialization = serialization_builder.to_deprecated_string();
if (serialization_builder.length() < 6) {
StringBuilder builder;
for (size_t i = 0; i < (6 - serialization_builder.length()); i++)
builder.append('0');
builder.append(serialization_builder.string_view());
serialization = builder.to_deprecated_string();
}
}
// 3. Otherwise, cv is an <ident-token>; let serialization be cv’s value.
else {
if (!cv.is(Token::Type::Ident))
return {};
serialization = cv.token().ident();
}
// 4. If serialization does not consist of three or six characters, return an error.
if (serialization.length() != 3 && serialization.length() != 6)
return {};
// 5. If serialization contains any characters not in the range [0-9A-Fa-f] (U+0030 to U+0039, U+0041 to U+0046, U+0061 to U+0066), return an error.
for (auto c : serialization) {
if (!((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f')))
return {};
}
// 6. Return the concatenation of "#" (U+0023) and serialization.
DeprecatedString concatenation = DeprecatedString::formatted("#{}", serialization);
return Color::from_string(concatenation);
}
return {};
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_color_value(ComponentValue const& component_value)
{
auto color = parse_color(component_value);
if (color.has_value())
return ColorStyleValue::create(color.value());
if (component_value.is(Token::Type::Ident)) {
if (auto ident = value_id_from_string(component_value.token().ident()); ident.has_value()) {
switch (ident.value()) {
case ValueID::Currentcolor:
case ValueID::LibwebLink:
case ValueID::LibwebPaletteActiveLink:
case ValueID::LibwebPaletteActiveWindowBorder1:
case ValueID::LibwebPaletteActiveWindowBorder2:
case ValueID::LibwebPaletteActiveWindowTitle:
case ValueID::LibwebPaletteBase:
case ValueID::LibwebPaletteBaseText:
case ValueID::LibwebPaletteButton:
case ValueID::LibwebPaletteButtonText:
case ValueID::LibwebPaletteDesktopBackground:
case ValueID::LibwebPaletteFocusOutline:
case ValueID::LibwebPaletteHighlightWindowBorder1:
case ValueID::LibwebPaletteHighlightWindowBorder2:
case ValueID::LibwebPaletteHighlightWindowTitle:
case ValueID::LibwebPaletteHoverHighlight:
case ValueID::LibwebPaletteInactiveSelection:
case ValueID::LibwebPaletteInactiveSelectionText:
case ValueID::LibwebPaletteInactiveWindowBorder1:
case ValueID::LibwebPaletteInactiveWindowBorder2:
case ValueID::LibwebPaletteInactiveWindowTitle:
case ValueID::LibwebPaletteLink:
case ValueID::LibwebPaletteMenuBase:
case ValueID::LibwebPaletteMenuBaseText:
case ValueID::LibwebPaletteMenuSelection:
case ValueID::LibwebPaletteMenuSelectionText:
case ValueID::LibwebPaletteMenuStripe:
case ValueID::LibwebPaletteMovingWindowBorder1:
case ValueID::LibwebPaletteMovingWindowBorder2:
case ValueID::LibwebPaletteMovingWindowTitle:
case ValueID::LibwebPaletteRubberBandBorder:
case ValueID::LibwebPaletteRubberBandFill:
case ValueID::LibwebPaletteRuler:
case ValueID::LibwebPaletteRulerActiveText:
case ValueID::LibwebPaletteRulerBorder:
case ValueID::LibwebPaletteRulerInactiveText:
case ValueID::LibwebPaletteSelection:
case ValueID::LibwebPaletteSelectionText:
case ValueID::LibwebPaletteSyntaxComment:
case ValueID::LibwebPaletteSyntaxControlKeyword:
case ValueID::LibwebPaletteSyntaxIdentifier:
case ValueID::LibwebPaletteSyntaxKeyword:
case ValueID::LibwebPaletteSyntaxNumber:
case ValueID::LibwebPaletteSyntaxOperator:
case ValueID::LibwebPaletteSyntaxPreprocessorStatement:
case ValueID::LibwebPaletteSyntaxPreprocessorValue:
case ValueID::LibwebPaletteSyntaxPunctuation:
case ValueID::LibwebPaletteSyntaxString:
case ValueID::LibwebPaletteSyntaxType:
case ValueID::LibwebPaletteTextCursor:
case ValueID::LibwebPaletteThreedHighlight:
case ValueID::LibwebPaletteThreedShadow1:
case ValueID::LibwebPaletteThreedShadow2:
case ValueID::LibwebPaletteVisitedLink:
case ValueID::LibwebPaletteWindow:
case ValueID::LibwebPaletteWindowText:
return IdentifierStyleValue::create(ident.value());
default:
break;
}
}
}
return nullptr;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_string_value(ComponentValue const& component_value)
{
if (component_value.is(Token::Type::String))
return StringStyleValue::create(TRY(String::from_utf8(component_value.token().string())));
return nullptr;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_image_value(ComponentValue const& component_value)
{
auto url = parse_url_function(component_value, AllowedDataUrlType::Image);
if (url.has_value())
return ImageStyleValue::create(url.value());
auto linear_gradient = TRY(parse_linear_gradient_function(component_value));
if (linear_gradient)
return linear_gradient;
auto conic_gradient = TRY(parse_conic_gradient_function(component_value));
if (conic_gradient)
return conic_gradient;
return parse_radial_gradient_function(component_value);
}
template<typename ParseFunction>
ErrorOr<RefPtr<StyleValue>> Parser::parse_comma_separated_value_list(Vector<ComponentValue> const& component_values, ParseFunction parse_one_value)
{
auto tokens = TokenStream { component_values };
auto first = TRY(parse_one_value(tokens));
if (!first || !tokens.has_next_token())
return first;
StyleValueVector values;
values.append(first.release_nonnull());
while (tokens.has_next_token()) {
if (!tokens.next_token().is(Token::Type::Comma))
return nullptr;
if (auto maybe_value = TRY(parse_one_value(tokens))) {
values.append(maybe_value.release_nonnull());
continue;
}
return nullptr;
}
return StyleValueList::create(move(values), StyleValueList::Separator::Comma);
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_simple_comma_separated_value_list(Vector<ComponentValue> const& component_values)
{
return parse_comma_separated_value_list(component_values, [=, this](auto& tokens) -> ErrorOr<RefPtr<StyleValue>> {
auto& token = tokens.next_token();
if (auto value = TRY(parse_css_value(token)); value && property_accepts_value(m_context.current_property_id(), *value))
return value;
tokens.reconsume_current_input_token();
return nullptr;
});
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_background_value(Vector<ComponentValue> const& component_values)
{
StyleValueVector background_images;
StyleValueVector background_positions;
StyleValueVector background_sizes;
StyleValueVector background_repeats;
StyleValueVector background_attachments;
StyleValueVector background_clips;
StyleValueVector background_origins;
RefPtr<StyleValue> background_color;
auto initial_background_image = TRY(property_initial_value(m_context.realm(), PropertyID::BackgroundImage));
auto initial_background_position = TRY(property_initial_value(m_context.realm(), PropertyID::BackgroundPosition));
auto initial_background_size = TRY(property_initial_value(m_context.realm(), PropertyID::BackgroundSize));
auto initial_background_repeat = TRY(property_initial_value(m_context.realm(), PropertyID::BackgroundRepeat));
auto initial_background_attachment = TRY(property_initial_value(m_context.realm(), PropertyID::BackgroundAttachment));
auto initial_background_clip = TRY(property_initial_value(m_context.realm(), PropertyID::BackgroundClip));
auto initial_background_origin = TRY(property_initial_value(m_context.realm(), PropertyID::BackgroundOrigin));
auto initial_background_color = TRY(property_initial_value(m_context.realm(), PropertyID::BackgroundColor));
// Per-layer values
RefPtr<StyleValue> background_image;
RefPtr<StyleValue> background_position;
RefPtr<StyleValue> background_size;
RefPtr<StyleValue> background_repeat;
RefPtr<StyleValue> background_attachment;
RefPtr<StyleValue> background_clip;
RefPtr<StyleValue> background_origin;
bool has_multiple_layers = false;
auto background_layer_is_valid = [&](bool allow_background_color) -> bool {
if (allow_background_color) {
if (background_color)
return true;
} else {
if (background_color)
return false;
}
return background_image || background_position || background_size || background_repeat || background_attachment || background_clip || background_origin;
};
auto complete_background_layer = [&]() -> ErrorOr<void> {
TRY(background_images.try_append(background_image ? background_image.release_nonnull() : initial_background_image));
TRY(background_positions.try_append(background_position ? background_position.release_nonnull() : initial_background_position));
TRY(background_sizes.try_append(background_size ? background_size.release_nonnull() : initial_background_size));
TRY(background_repeats.try_append(background_repeat ? background_repeat.release_nonnull() : initial_background_repeat));
TRY(background_attachments.try_append(background_attachment ? background_attachment.release_nonnull() : initial_background_attachment));
if (!background_origin && !background_clip) {
background_origin = initial_background_origin;
background_clip = initial_background_clip;
} else if (!background_clip) {
background_clip = background_origin;
}
TRY(background_origins.try_append(background_origin.release_nonnull()));
TRY(background_clips.try_append(background_clip.release_nonnull()));
background_image = nullptr;
background_position = nullptr;
background_size = nullptr;
background_repeat = nullptr;
background_attachment = nullptr;
background_clip = nullptr;
background_origin = nullptr;
return {};
};
auto tokens = TokenStream { component_values };
while (tokens.has_next_token()) {
auto const& part = tokens.next_token();
if (part.is(Token::Type::Comma)) {
has_multiple_layers = true;
if (!background_layer_is_valid(false))
return nullptr;
TRY(complete_background_layer());
continue;
}
auto value = TRY(parse_css_value(part));
if (!value)
return nullptr;
if (property_accepts_value(PropertyID::BackgroundAttachment, *value)) {
if (background_attachment)
return nullptr;
background_attachment = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::BackgroundColor, *value)) {
if (background_color)
return nullptr;
background_color = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::BackgroundImage, *value)) {
if (background_image)
return nullptr;
background_image = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::BackgroundOrigin, *value)) {
// background-origin and background-clip accept the same values. From the spec:
// "If one <box> value is present then it sets both background-origin and background-clip to that value.
// If two values are present, then the first sets background-origin and the second background-clip."
// - https://www.w3.org/TR/css-backgrounds-3/#background
// So, we put the first one in background-origin, then if we get a second, we put it in background-clip.
// If we only get one, we copy the value before creating the BackgroundStyleValue.
if (!background_origin) {
background_origin = value.release_nonnull();
continue;
}
if (!background_clip) {
background_clip = value.release_nonnull();
continue;
}
return nullptr;
}
if (property_accepts_value(PropertyID::BackgroundPosition, *value)) {
if (background_position)
return nullptr;
tokens.reconsume_current_input_token();
if (auto maybe_background_position = TRY(parse_single_background_position_value(tokens))) {
background_position = maybe_background_position.release_nonnull();
// Attempt to parse `/ <background-size>`
auto transaction = tokens.begin_transaction();
auto& maybe_slash = tokens.next_token();
if (maybe_slash.is(Token::Type::Delim) && maybe_slash.token().delim() == '/') {
if (auto maybe_background_size = TRY(parse_single_background_size_value(tokens))) {
transaction.commit();
background_size = maybe_background_size.release_nonnull();
continue;
}
return nullptr;
}
continue;
}
return nullptr;
}
if (property_accepts_value(PropertyID::BackgroundRepeat, *value)) {
if (background_repeat)
return nullptr;
tokens.reconsume_current_input_token();
if (auto maybe_repeat = TRY(parse_single_background_repeat_value(tokens))) {
background_repeat = maybe_repeat.release_nonnull();
continue;
}
return nullptr;
}
return nullptr;
}
if (!background_layer_is_valid(true))
return nullptr;
// We only need to create StyleValueLists if there are multiple layers.
// Otherwise, we can pass the single StyleValues directly.
if (has_multiple_layers) {
TRY(complete_background_layer());
if (!background_color)
background_color = initial_background_color;
return BackgroundStyleValue::create(
background_color.release_nonnull(),
TRY(StyleValueList::create(move(background_images), StyleValueList::Separator::Comma)),
TRY(StyleValueList::create(move(background_positions), StyleValueList::Separator::Comma)),
TRY(StyleValueList::create(move(background_sizes), StyleValueList::Separator::Comma)),
TRY(StyleValueList::create(move(background_repeats), StyleValueList::Separator::Comma)),
TRY(StyleValueList::create(move(background_attachments), StyleValueList::Separator::Comma)),
TRY(StyleValueList::create(move(background_origins), StyleValueList::Separator::Comma)),
TRY(StyleValueList::create(move(background_clips), StyleValueList::Separator::Comma)));
}
if (!background_color)
background_color = initial_background_color;
if (!background_image)
background_image = initial_background_image;
if (!background_position)
background_position = initial_background_position;
if (!background_size)
background_size = initial_background_size;
if (!background_repeat)
background_repeat = initial_background_repeat;
if (!background_attachment)
background_attachment = initial_background_attachment;
if (!background_origin && !background_clip) {
background_origin = initial_background_origin;
background_clip = initial_background_clip;
} else if (!background_clip) {
background_clip = background_origin;
}
return BackgroundStyleValue::create(
background_color.release_nonnull(),
background_image.release_nonnull(),
background_position.release_nonnull(),
background_size.release_nonnull(),
background_repeat.release_nonnull(),
background_attachment.release_nonnull(),
background_origin.release_nonnull(),
background_clip.release_nonnull());
}
static Optional<PositionEdge> identifier_to_edge(ValueID identifier)
{
switch (identifier) {
case ValueID::Top:
return PositionEdge::Top;
case ValueID::Bottom:
return PositionEdge::Bottom;
case ValueID::Left:
return PositionEdge::Left;
case ValueID::Right:
return PositionEdge::Right;
default:
return {};
}
};
static Optional<LengthPercentage> style_value_to_length_percentage(auto value)
{
if (value->is_percentage())
return LengthPercentage { value->as_percentage().percentage() };
if (value->has_length())
return LengthPercentage { value->to_length() };
if (value->is_calculated())
return LengthPercentage { value->as_calculated() };
return {};
};
ErrorOr<RefPtr<StyleValue>> Parser::parse_single_background_position_value(TokenStream<ComponentValue>& tokens)
{
// NOTE: This *looks* like it parses a <position>, but it doesn't. From the spec:
// "Note: The background-position property also accepts a three-value syntax.
// This has been disallowed generically because it creates parsing ambiguities
// when combined with other length or percentage components in a property value."
// - https://www.w3.org/TR/css-values-4/#typedef-position
// So, we'll need a separate function to parse <position> later.
auto transaction = tokens.begin_transaction();
auto is_horizontal = [](ValueID identifier) -> bool {
switch (identifier) {
case ValueID::Left:
case ValueID::Right:
return true;
default:
return false;
}
};
auto is_vertical = [](ValueID identifier) -> bool {
switch (identifier) {
case ValueID::Top:
case ValueID::Bottom:
return true;
default:
return false;
}
};
struct EdgeOffset {
PositionEdge edge;
LengthPercentage offset;
bool edge_provided;
bool offset_provided;
};
Optional<EdgeOffset> horizontal;
Optional<EdgeOffset> vertical;
bool found_center = false;
auto const center_offset = Percentage { 50 };
auto const zero_offset = Length::make_px(0);
while (tokens.has_next_token()) {
// Check if we're done
auto seen_items = (horizontal.has_value() ? 1 : 0) + (vertical.has_value() ? 1 : 0) + (found_center ? 1 : 0);
if (seen_items == 2)
break;
auto const& token = tokens.peek_token();
auto maybe_value = TRY(parse_css_value(token));
if (!maybe_value || !property_accepts_value(PropertyID::BackgroundPosition, *maybe_value))
break;
tokens.next_token();
auto value = maybe_value.release_nonnull();
auto offset = style_value_to_length_percentage(value);
if (offset.has_value()) {
if (!horizontal.has_value()) {
horizontal = EdgeOffset { PositionEdge::Left, *offset, false, true };
} else if (!vertical.has_value()) {
vertical = EdgeOffset { PositionEdge::Top, *offset, false, true };
} else {
return nullptr;
}
continue;
}
auto try_parse_offset = [&](bool& offset_provided) -> ErrorOr<LengthPercentage> {
if (tokens.has_next_token()) {
auto& token = tokens.peek_token();
auto maybe_value = TRY(parse_css_value(token));
if (!maybe_value)
return zero_offset;
auto offset = style_value_to_length_percentage(maybe_value.release_nonnull());
if (offset.has_value()) {
offset_provided = true;
tokens.next_token();
return *offset;
}
}
return zero_offset;
};
if (value->is_identifier()) {
auto identifier = value->to_identifier();
if (is_horizontal(identifier)) {
bool offset_provided = false;
auto offset = TRY(try_parse_offset(offset_provided));
horizontal = EdgeOffset { *identifier_to_edge(identifier), offset, true, offset_provided };
} else if (is_vertical(identifier)) {
bool offset_provided = false;
auto offset = TRY(try_parse_offset(offset_provided));
vertical = EdgeOffset { *identifier_to_edge(identifier), offset, true, offset_provided };
} else if (identifier == ValueID::Center) {
found_center = true;
} else {
return nullptr;
}
continue;
}
tokens.reconsume_current_input_token();
break;
}
if (found_center) {
if (horizontal.has_value() && vertical.has_value())
return nullptr;
if (!horizontal.has_value())
horizontal = EdgeOffset { PositionEdge::Left, center_offset, true, false };
if (!vertical.has_value())
vertical = EdgeOffset { PositionEdge::Top, center_offset, true, false };
}
if (!horizontal.has_value() && !vertical.has_value())
return nullptr;
// Unpack `<edge> <length>`:
// The loop above reads this pattern as a single EdgeOffset, when actually, it should be treated
// as `x y` if the edge is horizontal, and `y` (with the second token reconsumed) otherwise.
if (!vertical.has_value() && horizontal->edge_provided && horizontal->offset_provided) {
// Split into `x y`
vertical = EdgeOffset { PositionEdge::Top, horizontal->offset, false, true };
horizontal->offset = zero_offset;
horizontal->offset_provided = false;
} else if (!horizontal.has_value() && vertical->edge_provided && vertical->offset_provided) {
// `y`, reconsume
vertical->offset = zero_offset;
vertical->offset_provided = false;
tokens.reconsume_current_input_token();
}
// If only one value is specified, the second value is assumed to be center.
if (!horizontal.has_value())
horizontal = EdgeOffset { PositionEdge::Left, center_offset, false, false };
if (!vertical.has_value())
vertical = EdgeOffset { PositionEdge::Top, center_offset, false, false };
transaction.commit();
return PositionStyleValue::create(
TRY(EdgeStyleValue::create(horizontal->edge, horizontal->offset)),
TRY(EdgeStyleValue::create(vertical->edge, vertical->offset)));
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_single_background_position_x_or_y_value(TokenStream<ComponentValue>& tokens, PropertyID property)
{
PositionEdge relative_edge {};
if (property == PropertyID::BackgroundPositionX) {
// [ center | [ [ left | right | x-start | x-end ]? <length-percentage>? ]! ]#
relative_edge = PositionEdge::Left;
} else if (property == PropertyID::BackgroundPositionY) {
// [ center | [ [ top | bottom | y-start | y-end ]? <length-percentage>? ]! ]#
relative_edge = PositionEdge::Top;
} else {
VERIFY_NOT_REACHED();
}
auto transaction = tokens.begin_transaction();
if (!tokens.has_next_token())
return nullptr;
auto parse_value = [&](auto& token) -> ErrorOr<RefPtr<StyleValue>> {
auto maybe_value = TRY(parse_css_value(token));
if (!maybe_value || !property_accepts_value(property, *maybe_value))
return nullptr;
return maybe_value.release_nonnull();
};
auto value = TRY(parse_value(tokens.next_token()));
if (value->is_identifier()) {
auto identifier = value->to_identifier();
if (identifier == ValueID::Center) {
transaction.commit();
return EdgeStyleValue::create(relative_edge, Percentage { 50 });
}
if (auto edge = identifier_to_edge(identifier); edge.has_value()) {
relative_edge = *edge;
} else {
return nullptr;
}
if (tokens.has_next_token()) {
value = TRY(parse_value(tokens.peek_token()));
if (!value) {
transaction.commit();
return EdgeStyleValue::create(relative_edge, Length::make_px(0));
}
tokens.next_token();
}
}
auto offset = style_value_to_length_percentage(value);
if (offset.has_value()) {
transaction.commit();
return EdgeStyleValue::create(relative_edge, *offset);
}
return nullptr;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_single_background_repeat_value(TokenStream<ComponentValue>& tokens)
{
auto transaction = tokens.begin_transaction();
auto is_directional_repeat = [](StyleValue const& value) -> bool {
auto value_id = value.to_identifier();
return value_id == ValueID::RepeatX || value_id == ValueID::RepeatY;
};
auto as_repeat = [](ValueID identifier) -> Optional<Repeat> {
switch (identifier) {
case ValueID::NoRepeat:
return Repeat::NoRepeat;
case ValueID::Repeat:
return Repeat::Repeat;
case ValueID::Round:
return Repeat::Round;
case ValueID::Space:
return Repeat::Space;
default:
return {};
}
};
auto const& token = tokens.next_token();
auto maybe_x_value = TRY(parse_css_value(token));
if (!maybe_x_value || !property_accepts_value(PropertyID::BackgroundRepeat, *maybe_x_value))
return nullptr;
auto x_value = maybe_x_value.release_nonnull();
if (is_directional_repeat(*x_value)) {
auto value_id = x_value->to_identifier();
transaction.commit();
return BackgroundRepeatStyleValue::create(
value_id == ValueID::RepeatX ? Repeat::Repeat : Repeat::NoRepeat,
value_id == ValueID::RepeatX ? Repeat::NoRepeat : Repeat::Repeat);
}
auto x_repeat = as_repeat(x_value->to_identifier());
if (!x_repeat.has_value())
return nullptr;
// See if we have a second value for Y
auto const& second_token = tokens.peek_token();
auto maybe_y_value = TRY(parse_css_value(second_token));
if (!maybe_y_value || !property_accepts_value(PropertyID::BackgroundRepeat, *maybe_y_value)) {
// We don't have a second value, so use x for both
transaction.commit();
return BackgroundRepeatStyleValue::create(x_repeat.value(), x_repeat.value());
}
tokens.next_token();
auto y_value = maybe_y_value.release_nonnull();
if (is_directional_repeat(*y_value))
return nullptr;
auto y_repeat = as_repeat(y_value->to_identifier());
if (!y_repeat.has_value())
return nullptr;
transaction.commit();
return BackgroundRepeatStyleValue::create(x_repeat.value(), y_repeat.value());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_single_background_size_value(TokenStream<ComponentValue>& tokens)
{
auto transaction = tokens.begin_transaction();
auto get_length_percentage = [](StyleValue& style_value) -> Optional<LengthPercentage> {
if (style_value.has_auto())
return LengthPercentage { Length::make_auto() };
if (style_value.is_percentage())
return LengthPercentage { style_value.as_percentage().percentage() };
if (style_value.has_length())
return LengthPercentage { style_value.to_length() };
return {};
};
auto maybe_x_value = TRY(parse_css_value(tokens.next_token()));
if (!maybe_x_value || !property_accepts_value(PropertyID::BackgroundSize, *maybe_x_value))
return nullptr;
auto x_value = maybe_x_value.release_nonnull();
if (x_value->to_identifier() == ValueID::Cover || x_value->to_identifier() == ValueID::Contain) {
transaction.commit();
return x_value;
}
auto maybe_y_value = TRY(parse_css_value(tokens.peek_token()));
if (!maybe_y_value || !property_accepts_value(PropertyID::BackgroundSize, *maybe_y_value)) {
auto y_value = LengthPercentage { Length::make_auto() };
auto x_size = get_length_percentage(*x_value);
if (!x_size.has_value())
return nullptr;
transaction.commit();
return BackgroundSizeStyleValue::create(x_size.value(), y_value);
}
tokens.next_token();
auto y_value = maybe_y_value.release_nonnull();
auto x_size = get_length_percentage(*x_value);
auto y_size = get_length_percentage(*y_value);
if (!x_size.has_value() || !y_size.has_value())
return nullptr;
transaction.commit();
return BackgroundSizeStyleValue::create(x_size.release_value(), y_size.release_value());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_border_value(Vector<ComponentValue> const& component_values)
{
if (component_values.size() > 3)
return nullptr;
RefPtr<StyleValue> border_width;
RefPtr<StyleValue> border_color;
RefPtr<StyleValue> border_style;
for (auto const& part : component_values) {
auto value = TRY(parse_css_value(part));
if (!value)
return nullptr;
if (property_accepts_value(PropertyID::BorderWidth, *value)) {
if (border_width)
return nullptr;
border_width = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::BorderColor, *value)) {
if (border_color)
return nullptr;
border_color = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::BorderStyle, *value)) {
if (border_style)
return nullptr;
border_style = value.release_nonnull();
continue;
}
return nullptr;
}
if (!border_width)
border_width = TRY(property_initial_value(m_context.realm(), PropertyID::BorderWidth));
if (!border_style)
border_style = TRY(property_initial_value(m_context.realm(), PropertyID::BorderStyle));
if (!border_color)
border_color = TRY(property_initial_value(m_context.realm(), PropertyID::BorderColor));
return BorderStyleValue::create(border_width.release_nonnull(), border_style.release_nonnull(), border_color.release_nonnull());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_border_radius_value(Vector<ComponentValue> const& component_values)
{
if (component_values.size() == 2) {
auto horizontal = parse_dimension(component_values[0]);
auto vertical = parse_dimension(component_values[1]);
if (horizontal.has_value() && horizontal->is_length_percentage() && vertical.has_value() && vertical->is_length_percentage())
return BorderRadiusStyleValue::create(horizontal->length_percentage(), vertical->length_percentage());
return nullptr;
}
if (component_values.size() == 1) {
auto radius = parse_dimension(component_values[0]);
if (radius.has_value() && radius->is_length_percentage())
return BorderRadiusStyleValue::create(radius->length_percentage(), radius->length_percentage());
return nullptr;
}
return nullptr;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_border_radius_shorthand_value(Vector<ComponentValue> const& component_values)
{
auto top_left = [&](Vector<LengthPercentage>& radii) { return radii[0]; };
auto top_right = [&](Vector<LengthPercentage>& radii) {
switch (radii.size()) {
case 4:
case 3:
case 2:
return radii[1];
case 1:
return radii[0];
default:
VERIFY_NOT_REACHED();
}
};
auto bottom_right = [&](Vector<LengthPercentage>& radii) {
switch (radii.size()) {
case 4:
case 3:
return radii[2];
case 2:
case 1:
return radii[0];
default:
VERIFY_NOT_REACHED();
}
};
auto bottom_left = [&](Vector<LengthPercentage>& radii) {
switch (radii.size()) {
case 4:
return radii[3];
case 3:
case 2:
return radii[1];
case 1:
return radii[0];
default:
VERIFY_NOT_REACHED();
}
};
Vector<LengthPercentage> horizontal_radii;
Vector<LengthPercentage> vertical_radii;
bool reading_vertical = false;
for (auto const& value : component_values) {
if (value.is(Token::Type::Delim) && value.token().delim() == '/') {
if (reading_vertical || horizontal_radii.is_empty())
return nullptr;
reading_vertical = true;
continue;
}
auto maybe_dimension = parse_dimension(value);
if (!maybe_dimension.has_value() || !maybe_dimension->is_length_percentage())
return nullptr;
if (reading_vertical) {
vertical_radii.append(maybe_dimension->length_percentage());
} else {
horizontal_radii.append(maybe_dimension->length_percentage());
}
}
if (horizontal_radii.size() > 4 || vertical_radii.size() > 4
|| horizontal_radii.is_empty()
|| (reading_vertical && vertical_radii.is_empty()))
return nullptr;
auto top_left_radius = TRY(BorderRadiusStyleValue::create(top_left(horizontal_radii),
vertical_radii.is_empty() ? top_left(horizontal_radii) : top_left(vertical_radii)));
auto top_right_radius = TRY(BorderRadiusStyleValue::create(top_right(horizontal_radii),
vertical_radii.is_empty() ? top_right(horizontal_radii) : top_right(vertical_radii)));
auto bottom_right_radius = TRY(BorderRadiusStyleValue::create(bottom_right(horizontal_radii),
vertical_radii.is_empty() ? bottom_right(horizontal_radii) : bottom_right(vertical_radii)));
auto bottom_left_radius = TRY(BorderRadiusStyleValue::create(bottom_left(horizontal_radii),
vertical_radii.is_empty() ? bottom_left(horizontal_radii) : bottom_left(vertical_radii)));
return BorderRadiusShorthandStyleValue::create(move(top_left_radius), move(top_right_radius), move(bottom_right_radius), move(bottom_left_radius));
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_shadow_value(Vector<ComponentValue> const& component_values, AllowInsetKeyword allow_inset_keyword)
{
// "none"
if (component_values.size() == 1 && component_values.first().is(Token::Type::Ident)) {
auto ident = TRY(parse_identifier_value(component_values.first()));
if (ident && ident->to_identifier() == ValueID::None)
return ident;
}
return parse_comma_separated_value_list(component_values, [this, allow_inset_keyword](auto& tokens) {
return parse_single_shadow_value(tokens, allow_inset_keyword);
});
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_single_shadow_value(TokenStream<ComponentValue>& tokens, AllowInsetKeyword allow_inset_keyword)
{
auto transaction = tokens.begin_transaction();
Optional<Color> color;
Optional<Length> offset_x;
Optional<Length> offset_y;
Optional<Length> blur_radius;
Optional<Length> spread_distance;
Optional<ShadowPlacement> placement;
while (tokens.has_next_token()) {
auto const& token = tokens.peek_token();
if (auto maybe_color = parse_color(token); maybe_color.has_value()) {
if (color.has_value())
return nullptr;
color = maybe_color.release_value();
tokens.next_token();
continue;
}
if (auto maybe_offset_x = parse_length(token); maybe_offset_x.has_value()) {
// horizontal offset
if (offset_x.has_value())
return nullptr;
offset_x = maybe_offset_x.release_value();
tokens.next_token();
// vertical offset
if (!tokens.has_next_token())
return nullptr;
auto maybe_offset_y = parse_length(tokens.peek_token());
if (!maybe_offset_y.has_value())
return nullptr;
offset_y = maybe_offset_y.release_value();
tokens.next_token();
// blur radius (optional)
if (!tokens.has_next_token())
break;
auto maybe_blur_radius = parse_length(tokens.peek_token());
if (!maybe_blur_radius.has_value())
continue;
blur_radius = maybe_blur_radius.release_value();
tokens.next_token();
// spread distance (optional)
if (!tokens.has_next_token())
break;
auto maybe_spread_distance = parse_length(tokens.peek_token());
if (!maybe_spread_distance.has_value())
continue;
spread_distance = maybe_spread_distance.release_value();
tokens.next_token();
continue;
}
if (allow_inset_keyword == AllowInsetKeyword::Yes
&& token.is(Token::Type::Ident) && token.token().ident().equals_ignoring_ascii_case("inset"sv)) {
if (placement.has_value())
return nullptr;
placement = ShadowPlacement::Inner;
tokens.next_token();
continue;
}
if (token.is(Token::Type::Comma))
break;
return nullptr;
}
// FIXME: If color is absent, default to `currentColor`
if (!color.has_value())
color = Color::NamedColor::Black;
// x/y offsets are required
if (!offset_x.has_value() || !offset_y.has_value())
return nullptr;
// Other lengths default to 0
if (!blur_radius.has_value())
blur_radius = Length::make_px(0);
if (!spread_distance.has_value())
spread_distance = Length::make_px(0);
// Placement is outer by default
if (!placement.has_value())
placement = ShadowPlacement::Outer;
transaction.commit();
return ShadowStyleValue::create(color.release_value(), offset_x.release_value(), offset_y.release_value(), blur_radius.release_value(), spread_distance.release_value(), placement.release_value());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_content_value(Vector<ComponentValue> const& component_values)
{
// FIXME: `content` accepts several kinds of function() type, which we don't handle in property_accepts_value() yet.
auto is_single_value_identifier = [](ValueID identifier) -> bool {
switch (identifier) {
case ValueID::None:
case ValueID::Normal:
return true;
default:
return false;
}
};
if (component_values.size() == 1) {
if (auto identifier = TRY(parse_identifier_value(component_values.first()))) {
if (is_single_value_identifier(identifier->to_identifier()))
return identifier;
}
}
StyleValueVector content_values;
StyleValueVector alt_text_values;
bool in_alt_text = false;
for (auto const& value : component_values) {
if (value.is(Token::Type::Delim) && value.token().delim() == '/') {
if (in_alt_text || content_values.is_empty())
return nullptr;
in_alt_text = true;
continue;
}
auto style_value = TRY(parse_css_value(value));
if (style_value && property_accepts_value(PropertyID::Content, *style_value)) {
if (is_single_value_identifier(style_value->to_identifier()))
return nullptr;
if (in_alt_text) {
alt_text_values.append(style_value.release_nonnull());
} else {
content_values.append(style_value.release_nonnull());
}
continue;
}
return nullptr;
}
if (content_values.is_empty())
return nullptr;
if (in_alt_text && alt_text_values.is_empty())
return nullptr;
RefPtr<StyleValueList> alt_text;
if (!alt_text_values.is_empty())
alt_text = TRY(StyleValueList::create(move(alt_text_values), StyleValueList::Separator::Space));
return ContentStyleValue::create(TRY(StyleValueList::create(move(content_values), StyleValueList::Separator::Space)), move(alt_text));
}
// https://www.w3.org/TR/css-display-3/#the-display-properties
ErrorOr<RefPtr<StyleValue>> Parser::parse_display_value(Vector<ComponentValue> const& component_values)
{
auto parse_inside = [](ValueID identifier) -> Optional<Display::Inside> {
switch (identifier) {
case ValueID::Flow:
return Display::Inside::Flow;
case ValueID::FlowRoot:
return Display::Inside::FlowRoot;
case ValueID::Table:
return Display::Inside::Table;
case ValueID::Flex:
return Display::Inside::Flex;
case ValueID::Grid:
return Display::Inside::Grid;
case ValueID::Ruby:
return Display::Inside::Ruby;
default:
return {};
}
};
auto parse_outside = [](ValueID identifier) -> Optional<Display::Outside> {
switch (identifier) {
case ValueID::Block:
return Display::Outside::Block;
case ValueID::Inline:
return Display::Outside::Inline;
case ValueID::RunIn:
return Display::Outside::RunIn;
default:
return {};
}
};
auto parse_single_component_display = [&](Vector<ComponentValue> const& component_values) -> ErrorOr<Optional<Display>> {
if (auto identifier = TRY(parse_identifier_value(component_values.first()))) {
switch (identifier->to_identifier()) {
// display-outside
case ValueID::Block:
return Display::from_short(Display::Short::Block);
case ValueID::Inline:
return Display::from_short(Display::Short::Inline);
case ValueID::RunIn:
return Display::from_short(Display::Short::RunIn);
// display-inside
case ValueID::Flow:
return Display::from_short(Display::Short::Flow);
case ValueID::FlowRoot:
return Display::from_short(Display::Short::FlowRoot);
case ValueID::Table:
return Display::from_short(Display::Short::Table);
case ValueID::Flex:
return Display::from_short(Display::Short::Flex);
case ValueID::Grid:
return Display::from_short(Display::Short::Grid);
case ValueID::Ruby:
return Display::from_short(Display::Short::Ruby);
// display-listitem
case ValueID::ListItem:
return Display::from_short(Display::Short::ListItem);
// display-internal
case ValueID::TableRowGroup:
return Display { Display::Internal::TableRowGroup };
case ValueID::TableHeaderGroup:
return Display { Display::Internal::TableHeaderGroup };
case ValueID::TableFooterGroup:
return Display { Display::Internal::TableFooterGroup };
case ValueID::TableRow:
return Display { Display::Internal::TableRow };
case ValueID::TableCell:
return Display { Display::Internal::TableCell };
case ValueID::TableColumnGroup:
return Display { Display::Internal::TableColumnGroup };
case ValueID::TableColumn:
return Display { Display::Internal::TableColumn };
case ValueID::TableCaption:
return Display { Display::Internal::TableCaption };
case ValueID::RubyBase:
return Display { Display::Internal::RubyBase };
case ValueID::RubyText:
return Display { Display::Internal::RubyText };
case ValueID::RubyBaseContainer:
return Display { Display::Internal::RubyBaseContainer };
case ValueID::RubyTextContainer:
return Display { Display::Internal::RubyTextContainer };
// display-box
case ValueID::Contents:
// FIXME this should be Display::Short::Contents but contents is currently not implemented
return Display::from_short(Display::Short::Flow);
case ValueID::None:
return Display::from_short(Display::Short::None);
// display-legacy
case ValueID::InlineBlock:
return Display::from_short(Display::Short::InlineBlock);
case ValueID::InlineTable:
return Display::from_short(Display::Short::InlineTable);
case ValueID::InlineFlex:
return Display::from_short(Display::Short::InlineFlex);
case ValueID::InlineGrid:
return Display::from_short(Display::Short::InlineGrid);
default:
return OptionalNone {};
}
}
return OptionalNone {};
};
auto parse_multi_component_display = [&](Vector<ComponentValue> const& component_values) -> ErrorOr<Optional<Display>> {
auto list_item = Display::ListItem::No;
Display::Inside inside = Display::Inside::Flow;
Display::Outside outside = Display::Outside::Block;
for (size_t i = 0; i < component_values.size(); ++i) {
if (auto value = TRY(parse_identifier_value(component_values[i]))) {
auto identifier = value->to_identifier();
if (ValueID::ListItem == identifier) {
list_item = Display::ListItem::Yes;
continue;
}
auto inside_value = parse_inside(identifier);
if (inside_value.has_value()) {
inside = inside_value.value();
continue;
}
auto outside_value = parse_outside(identifier);
if (outside_value.has_value()) {
outside = outside_value.value();
}
}
}
// The spec does not allow any other inside values to be combined with list-item
// <display-outside>? && [ flow | flow-root ]? && list-item
if (list_item == Display::ListItem::Yes && inside != Display::Inside::Flow && inside != Display::Inside::FlowRoot)
return OptionalNone {};
return Display { outside, inside, list_item };
};
Optional<Display> display;
if (component_values.size() == 1)
display = TRY(parse_single_component_display(component_values));
else
display = TRY(parse_multi_component_display(component_values));
if (display.has_value())
return DisplayStyleValue::create(display.value());
return nullptr;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_filter_value_list_value(Vector<ComponentValue> const& component_values)
{
if (component_values.size() == 1 && component_values.first().is(Token::Type::Ident)) {
auto ident = TRY(parse_identifier_value(component_values.first()));
if (ident && ident->to_identifier() == ValueID::None)
return ident;
}
TokenStream tokens { component_values };
// FIXME: <url>s are ignored for now
// <filter-value-list> = [ <filter-function> | <url> ]+
enum class FilterToken {
// Color filters:
Brightness,
Contrast,
Grayscale,
Invert,
Opacity,
Saturate,
Sepia,
// Special filters:
Blur,
DropShadow,
HueRotate
};
auto filter_token_to_operation = [&](auto filter) {
VERIFY(to_underlying(filter) < to_underlying(FilterToken::Blur));
return static_cast<Filter::Color::Operation>(filter);
};
auto parse_number_percentage = [&](auto& token) -> Optional<NumberPercentage> {
if (token.is(Token::Type::Percentage))
return NumberPercentage(Percentage(token.token().percentage()));
if (token.is(Token::Type::Number))
return NumberPercentage(Number(Number::Type::Number, token.token().number_value()));
return {};
};
auto parse_filter_function_name = [&](auto name) -> Optional<FilterToken> {
if (name.equals_ignoring_ascii_case("blur"sv))
return FilterToken::Blur;
if (name.equals_ignoring_ascii_case("brightness"sv))
return FilterToken::Brightness;
if (name.equals_ignoring_ascii_case("contrast"sv))
return FilterToken::Contrast;
if (name.equals_ignoring_ascii_case("drop-shadow"sv))
return FilterToken::DropShadow;
if (name.equals_ignoring_ascii_case("grayscale"sv))
return FilterToken::Grayscale;
if (name.equals_ignoring_ascii_case("hue-rotate"sv))
return FilterToken::HueRotate;
if (name.equals_ignoring_ascii_case("invert"sv))
return FilterToken::Invert;
if (name.equals_ignoring_ascii_case("opacity"sv))
return FilterToken::Opacity;
if (name.equals_ignoring_ascii_case("saturate"sv))
return FilterToken::Saturate;
if (name.equals_ignoring_ascii_case("sepia"sv))
return FilterToken::Sepia;
return {};
};
auto parse_filter_function = [&](auto filter_token, auto function_values) -> Optional<FilterFunction> {
TokenStream tokens { function_values };
tokens.skip_whitespace();
auto if_no_more_tokens_return = [&](auto filter) -> Optional<FilterFunction> {
tokens.skip_whitespace();
if (tokens.has_next_token())
return {};
return filter;
};
if (filter_token == FilterToken::Blur) {
// blur( <length>? )
if (!tokens.has_next_token())
return Filter::Blur {};
auto blur_radius = parse_length(tokens.next_token());
if (!blur_radius.has_value())
return {};
return if_no_more_tokens_return(Filter::Blur { *blur_radius });
} else if (filter_token == FilterToken::DropShadow) {
if (!tokens.has_next_token())
return {};
auto next_token = [&]() -> auto&
{
auto& token = tokens.next_token();
tokens.skip_whitespace();
return token;
};
// drop-shadow( [ <color>? && <length>{2,3} ] )
// Note: The following code is a little awkward to allow the color to be before or after the lengths.
auto& first_param = next_token();
Optional<Length> maybe_radius = {};
auto maybe_color = parse_color(first_param);
auto x_offset = parse_length(maybe_color.has_value() ? next_token() : first_param);
if (!x_offset.has_value() || !tokens.has_next_token()) {
return {};
}
auto y_offset = parse_length(next_token());
if (!y_offset.has_value()) {
return {};
}
if (tokens.has_next_token()) {
auto& token = next_token();
maybe_radius = parse_length(token);
if (!maybe_color.has_value() && (!maybe_radius.has_value() || tokens.has_next_token())) {
maybe_color = parse_color(!maybe_radius.has_value() ? token : next_token());
if (!maybe_color.has_value()) {
return {};
}
} else if (!maybe_radius.has_value()) {
return {};
}
}
return if_no_more_tokens_return(Filter::DropShadow { *x_offset, *y_offset, maybe_radius, maybe_color });
} else if (filter_token == FilterToken::HueRotate) {
// hue-rotate( [ <angle> | <zero> ]? )
if (!tokens.has_next_token())
return Filter::HueRotate {};
auto& token = tokens.next_token();
if (token.is(Token::Type::Number)) {
// hue-rotate(0)
auto number = token.token().number();
if (number.is_integer() && number.integer_value() == 0)
return if_no_more_tokens_return(Filter::HueRotate { Filter::HueRotate::Zero {} });
return {};
}
if (!token.is(Token::Type::Dimension))
return {};
float angle_value = token.token().dimension_value();
auto angle_unit_name = token.token().dimension_unit();
auto angle_unit = Angle::unit_from_name(angle_unit_name);
if (!angle_unit.has_value())
return {};
Angle angle { angle_value, angle_unit.release_value() };
return if_no_more_tokens_return(Filter::HueRotate { angle });
} else {
// Simple filters:
// brightness( <number-percentage>? )
// contrast( <number-percentage>? )
// grayscale( <number-percentage>? )
// invert( <number-percentage>? )
// opacity( <number-percentage>? )
// sepia( <number-percentage>? )
// saturate( <number-percentage>? )
if (!tokens.has_next_token())
return Filter::Color { filter_token_to_operation(filter_token) };
auto amount = parse_number_percentage(tokens.next_token());
if (!amount.has_value())
return {};
return if_no_more_tokens_return(Filter::Color { filter_token_to_operation(filter_token), *amount });
}
};
Vector<FilterFunction> filter_value_list {};
while (tokens.has_next_token()) {
tokens.skip_whitespace();
if (!tokens.has_next_token())
break;
auto& token = tokens.next_token();
if (!token.is_function())
return nullptr;
auto filter_token = parse_filter_function_name(token.function().name());
if (!filter_token.has_value())
return nullptr;
auto filter_function = parse_filter_function(*filter_token, token.function().values());
if (!filter_function.has_value())
return nullptr;
filter_value_list.append(*filter_function);
}
if (filter_value_list.is_empty())
return nullptr;
return FilterValueListStyleValue::create(move(filter_value_list));
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_flex_value(Vector<ComponentValue> const& component_values)
{
if (component_values.size() == 1) {
// One-value syntax: <flex-grow> | <flex-basis> | none
auto value = TRY(parse_css_value(component_values[0]));
if (!value)
return nullptr;
if (property_accepts_value(PropertyID::FlexGrow, *value)) {
// NOTE: The spec says that flex-basis should be 0 here, but other engines currently use 0%.
// https://github.com/w3c/csswg-drafts/issues/5742
auto zero_percent = TRY(NumericStyleValue::create_integer(0));
auto one = TRY(NumericStyleValue::create_integer(1));
return FlexStyleValue::create(*value, one, zero_percent);
}
if (property_accepts_value(PropertyID::FlexBasis, *value)) {
auto one = TRY(NumericStyleValue::create_integer(1));
return FlexStyleValue::create(one, one, *value);
}
if (value->is_identifier() && property_accepts_value(PropertyID::Flex, *value)) {
switch (value->to_identifier()) {
case ValueID::None: {
auto zero = TRY(NumericStyleValue::create_integer(0));
return FlexStyleValue::create(zero, zero, TRY(IdentifierStyleValue::create(ValueID::Auto)));
}
default:
return value;
}
}
return nullptr;
}
RefPtr<StyleValue> flex_grow;
RefPtr<StyleValue> flex_shrink;
RefPtr<StyleValue> flex_basis;
for (size_t i = 0; i < component_values.size(); ++i) {
auto value = TRY(parse_css_value(component_values[i]));
if (!value)
return nullptr;
// Zero is a valid value for basis, but only if grow and shrink are already specified.
if (value->has_number() && value->to_number() == 0) {
if (flex_grow && flex_shrink && !flex_basis) {
flex_basis = TRY(LengthStyleValue::create(Length::make_px(0)));
continue;
}
}
if (property_accepts_value(PropertyID::FlexGrow, *value)) {
if (flex_grow)
return nullptr;
flex_grow = value.release_nonnull();
// Flex-shrink may optionally follow directly after.
if (i + 1 < component_values.size()) {
auto second_value = TRY(parse_css_value(component_values[i + 1]));
if (second_value && property_accepts_value(PropertyID::FlexShrink, *second_value)) {
flex_shrink = second_value.release_nonnull();
i++;
}
}
continue;
}
if (property_accepts_value(PropertyID::FlexBasis, *value)) {
if (flex_basis)
return nullptr;
flex_basis = value.release_nonnull();
continue;
}
return nullptr;
}
if (!flex_grow)
flex_grow = TRY(property_initial_value(m_context.realm(), PropertyID::FlexGrow));
if (!flex_shrink)
flex_shrink = TRY(property_initial_value(m_context.realm(), PropertyID::FlexShrink));
if (!flex_basis)
flex_basis = TRY(property_initial_value(m_context.realm(), PropertyID::FlexBasis));
return FlexStyleValue::create(flex_grow.release_nonnull(), flex_shrink.release_nonnull(), flex_basis.release_nonnull());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_flex_flow_value(Vector<ComponentValue> const& component_values)
{
if (component_values.size() > 2)
return nullptr;
RefPtr<StyleValue> flex_direction;
RefPtr<StyleValue> flex_wrap;
for (auto const& part : component_values) {
auto value = TRY(parse_css_value(part));
if (!value)
return nullptr;
if (property_accepts_value(PropertyID::FlexDirection, *value)) {
if (flex_direction)
return nullptr;
flex_direction = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::FlexWrap, *value)) {
if (flex_wrap)
return nullptr;
flex_wrap = value.release_nonnull();
continue;
}
}
if (!flex_direction)
flex_direction = TRY(property_initial_value(m_context.realm(), PropertyID::FlexDirection));
if (!flex_wrap)
flex_wrap = TRY(property_initial_value(m_context.realm(), PropertyID::FlexWrap));
return FlexFlowStyleValue::create(flex_direction.release_nonnull(), flex_wrap.release_nonnull());
}
static bool is_generic_font_family(ValueID identifier)
{
switch (identifier) {
case ValueID::Cursive:
case ValueID::Fantasy:
case ValueID::Monospace:
case ValueID::Serif:
case ValueID::SansSerif:
case ValueID::UiMonospace:
case ValueID::UiRounded:
case ValueID::UiSerif:
case ValueID::UiSansSerif:
return true;
default:
return false;
}
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_font_value(Vector<ComponentValue> const& component_values)
{
RefPtr<StyleValue> font_stretch;
RefPtr<StyleValue> font_style;
RefPtr<StyleValue> font_weight;
RefPtr<StyleValue> font_size;
RefPtr<StyleValue> line_height;
RefPtr<StyleValue> font_families;
RefPtr<StyleValue> font_variant;
// FIXME: Handle system fonts. (caption, icon, menu, message-box, small-caption, status-bar)
// Several sub-properties can be "normal", and appear in any order: style, variant, weight, stretch
// So, we have to handle that separately.
int normal_count = 0;
for (size_t i = 0; i < component_values.size(); ++i) {
auto value = TRY(parse_css_value(component_values[i]));
if (!value)
return nullptr;
if (value->to_identifier() == ValueID::Normal) {
normal_count++;
continue;
}
// FIXME: Handle angle parameter to `oblique`: https://www.w3.org/TR/css-fonts-4/#font-style-prop
if (property_accepts_value(PropertyID::FontStyle, *value)) {
if (font_style)
return nullptr;
font_style = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::FontWeight, *value)) {
if (font_weight)
return nullptr;
font_weight = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::FontVariant, *value)) {
if (font_variant)
return nullptr;
font_variant = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::FontSize, *value)) {
if (font_size)
return nullptr;
font_size = value.release_nonnull();
// Consume `/ line-height` if present
if (i + 2 < component_values.size()) {
auto const& maybe_solidus = component_values[i + 1];
if (maybe_solidus.is(Token::Type::Delim) && maybe_solidus.token().delim() == '/') {
auto maybe_line_height = TRY(parse_css_value(component_values[i + 2]));
if (!(maybe_line_height && property_accepts_value(PropertyID::LineHeight, *maybe_line_height)))
return nullptr;
line_height = maybe_line_height.release_nonnull();
i += 2;
}
}
// Consume font-families
auto maybe_font_families = TRY(parse_font_family_value(component_values, i + 1));
if (!maybe_font_families)
return nullptr;
font_families = maybe_font_families.release_nonnull();
break;
}
if (property_accepts_value(PropertyID::FontStretch, *value)) {
if (font_stretch)
return nullptr;
font_stretch = value.release_nonnull();
continue;
}
return nullptr;
}
// Since normal is the default value for all the properties that can have it, we don't have to actually
// set anything to normal here. It'll be set when we create the FontStyleValue below.
// We just need to make sure we were not given more normals than will fit.
int unset_value_count = (font_style ? 0 : 1) + (font_weight ? 0 : 1);
if (unset_value_count < normal_count)
return nullptr;
if (!font_size || !font_families)
return nullptr;
if (!font_stretch)
font_stretch = TRY(property_initial_value(m_context.realm(), PropertyID::FontStretch));
if (!font_style)
font_style = TRY(property_initial_value(m_context.realm(), PropertyID::FontStyle));
if (!font_weight)
font_weight = TRY(property_initial_value(m_context.realm(), PropertyID::FontWeight));
if (!line_height)
line_height = TRY(property_initial_value(m_context.realm(), PropertyID::LineHeight));
return FontStyleValue::create(font_stretch.release_nonnull(), font_style.release_nonnull(), font_weight.release_nonnull(), font_size.release_nonnull(), line_height.release_nonnull(), font_families.release_nonnull());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_font_family_value(Vector<ComponentValue> const& component_values, size_t start_index)
{
auto is_comma_or_eof = [&](size_t i) -> bool {
if (i < component_values.size()) {
auto const& maybe_comma = component_values[i];
if (!maybe_comma.is(Token::Type::Comma))
return false;
}
return true;
};
// Note: Font-family names can either be a quoted string, or a keyword, or a series of custom-idents.
// eg, these are equivalent:
// font-family: my cool font\!, serif;
// font-family: "my cool font!", serif;
StyleValueVector font_families;
Vector<DeprecatedString> current_name_parts;
for (size_t i = start_index; i < component_values.size(); ++i) {
auto const& part = component_values[i];
if (part.is(Token::Type::String)) {
// `font-family: my cool "font";` is invalid.
if (!current_name_parts.is_empty())
return nullptr;
if (!is_comma_or_eof(i + 1))
return nullptr;
font_families.append(TRY(StringStyleValue::create(TRY(String::from_utf8(part.token().string())))));
i++;
continue;
}
if (part.is(Token::Type::Ident)) {
// If this is a valid identifier, it's NOT a custom-ident and can't be part of a larger name.
auto maybe_ident = TRY(parse_css_value(part));
if (maybe_ident) {
// CSS-wide keywords are not allowed
if (maybe_ident->is_builtin())
return nullptr;
if (is_generic_font_family(maybe_ident->to_identifier())) {
// Can't have a generic-font-name as a token in an unquoted font name.
if (!current_name_parts.is_empty())
return nullptr;
if (!is_comma_or_eof(i + 1))
return nullptr;
font_families.append(maybe_ident.release_nonnull());
i++;
continue;
}
}
current_name_parts.append(part.token().ident());
continue;
}
if (part.is(Token::Type::Comma)) {
if (current_name_parts.is_empty())
return nullptr;
font_families.append(TRY(StringStyleValue::create(TRY(String::from_utf8(DeprecatedString::join(' ', current_name_parts))))));
current_name_parts.clear();
// Can't have a trailing comma
if (i + 1 == component_values.size())
return nullptr;
continue;
}
}
if (!current_name_parts.is_empty()) {
font_families.append(TRY(StringStyleValue::create(TRY(String::from_utf8(DeprecatedString::join(' ', current_name_parts))))));
current_name_parts.clear();
}
if (font_families.is_empty())
return nullptr;
return StyleValueList::create(move(font_families), StyleValueList::Separator::Comma);
}
CSSRule* Parser::parse_font_face_rule(TokenStream<ComponentValue>& tokens)
{
auto declarations_and_at_rules = parse_a_list_of_declarations(tokens);
Optional<FlyString> font_family;
Vector<FontFace::Source> src;
Vector<UnicodeRange> unicode_range;
Optional<int> weight;
Optional<int> slope;
for (auto& declaration_or_at_rule : declarations_and_at_rules) {
if (declaration_or_at_rule.is_at_rule()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: CSS at-rules are not allowed in @font-family; discarding.");
continue;
}
auto const& declaration = declaration_or_at_rule.declaration();
if (declaration.name().equals_ignoring_ascii_case("font-weight"sv)) {
TokenStream token_stream { declaration.values() };
if (auto value = parse_css_value(CSS::PropertyID::FontWeight, token_stream); !value.is_error()) {
weight = value.value()->to_font_weight();
}
continue;
}
if (declaration.name().equals_ignoring_ascii_case("font-style"sv)) {
TokenStream token_stream { declaration.values() };
if (auto value = parse_css_value(CSS::PropertyID::FontStyle, token_stream); !value.is_error()) {
slope = value.value()->to_font_slope();
}
continue;
}
if (declaration.name().equals_ignoring_ascii_case("font-family"sv)) {
// FIXME: This is very similar to, but different from, the logic in parse_font_family_value().
// Ideally they could share code.
Vector<DeprecatedString> font_family_parts;
bool had_syntax_error = false;
for (size_t i = 0; i < declaration.values().size(); ++i) {
auto const& part = declaration.values()[i];
if (part.is(Token::Type::Whitespace))
continue;
if (part.is(Token::Type::String)) {
if (!font_family_parts.is_empty()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face font-family format invalid; discarding.");
had_syntax_error = true;
break;
}
font_family_parts.append(part.token().string());
continue;
}
if (part.is(Token::Type::Ident)) {
if (is_builtin(part.token().ident())) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face font-family format invalid; discarding.");
had_syntax_error = true;
break;
}
auto value_id = value_id_from_string(part.token().ident());
if (value_id.has_value() && is_generic_font_family(value_id.value())) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face font-family format invalid; discarding.");
had_syntax_error = true;
break;
}
font_family_parts.append(part.token().ident());
continue;
}
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face font-family format invalid; discarding.");
had_syntax_error = true;
break;
}
if (had_syntax_error || font_family_parts.is_empty())
continue;
font_family = String::join(' ', font_family_parts).release_value_but_fixme_should_propagate_errors();
continue;
}
if (declaration.name().equals_ignoring_ascii_case("src"sv)) {
TokenStream token_stream { declaration.values() };
Vector<FontFace::Source> supported_sources = parse_font_face_src(token_stream);
if (!supported_sources.is_empty())
src = move(supported_sources);
continue;
}
if (declaration.name().equals_ignoring_ascii_case("unicode-range"sv)) {
Vector<UnicodeRange> unicode_ranges;
bool unicode_range_invalid = false;
TokenStream all_tokens { declaration.values() };
auto range_token_lists = parse_a_comma_separated_list_of_component_values(all_tokens);
for (auto& range_tokens : range_token_lists) {
TokenStream range_token_stream { range_tokens };
auto maybe_unicode_range = parse_unicode_range(range_token_stream);
if (!maybe_unicode_range.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face unicode-range format invalid; discarding.");
unicode_range_invalid = true;
break;
}
unicode_ranges.append(maybe_unicode_range.release_value());
}
if (unicode_range_invalid || unicode_ranges.is_empty())
continue;
unicode_range = move(unicode_ranges);
continue;
}
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: Unrecognized descriptor '{}' in @font-family; discarding.", declaration.name());
}
if (!font_family.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: Failed to parse @font-face: no font-family!");
return {};
}
if (unicode_range.is_empty()) {
unicode_range.empend(0x0u, 0x10FFFFu);
}
return CSSFontFaceRule::create(m_context.realm(), FontFace { font_family.release_value(), weight, slope, move(src), move(unicode_range) }).release_value_but_fixme_should_propagate_errors();
}
Vector<FontFace::Source> Parser::parse_font_face_src(TokenStream<ComponentValue>& component_values)
{
// FIXME: Get this information from the system somehow?
// Format-name table: https://www.w3.org/TR/css-fonts-4/#font-format-definitions
auto font_format_is_supported = [](StringView name) {
// The spec requires us to treat opentype and truetype as synonymous.
if (name.is_one_of_ignoring_ascii_case("opentype"sv, "truetype"sv, "woff"sv))
return true;
return false;
};
Vector<FontFace::Source> supported_sources;
auto list_of_source_token_lists = parse_a_comma_separated_list_of_component_values(component_values);
for (auto const& source_token_list : list_of_source_token_lists) {
TokenStream source_tokens { source_token_list };
source_tokens.skip_whitespace();
auto const& first = source_tokens.next_token();
// <url> [ format(<font-format>)]?
// FIXME: Implement optional tech() function from CSS-Fonts-4.
if (auto maybe_url = parse_url_function(first, AllowedDataUrlType::Font); maybe_url.has_value()) {
auto url = maybe_url.release_value();
if (!url.is_valid()) {
continue;
}
Optional<FlyString> format;
source_tokens.skip_whitespace();
if (!source_tokens.has_next_token()) {
supported_sources.empend(move(url), format);
continue;
}
auto maybe_function = source_tokens.next_token();
if (!maybe_function.is_function()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face src invalid (token after `url()` that isn't a function: {}); discarding.", maybe_function.to_debug_string());
return {};
}
auto const& function = maybe_function.function();
if (function.name().equals_ignoring_ascii_case("format"sv)) {
TokenStream format_tokens { function.values() };
format_tokens.skip_whitespace();
auto const& format_name_token = format_tokens.next_token();
StringView format_name;
if (format_name_token.is(Token::Type::Ident)) {
format_name = format_name_token.token().ident();
} else if (format_name_token.is(Token::Type::String)) {
format_name = format_name_token.token().string();
} else {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face src invalid (`format()` parameter not an ident or string; is: {}); discarding.", format_name_token.to_debug_string());
return {};
}
if (!font_format_is_supported(format_name)) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face src format({}) not supported; skipping.", format_name);
continue;
}
format = FlyString::from_utf8(format_name).release_value_but_fixme_should_propagate_errors();
} else {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face src invalid (unrecognized function token `{}`); discarding.", function.name());
return {};
}
source_tokens.skip_whitespace();
if (source_tokens.has_next_token()) {
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face src invalid (extra token `{}`); discarding.", source_tokens.peek_token().to_debug_string());
return {};
}
supported_sources.empend(move(url), format);
continue;
}
// FIXME: Implement `local()`.
dbgln_if(CSS_PARSER_DEBUG, "CSSParser: @font-face src invalid (failed to parse url from: {}); discarding.", first.to_debug_string());
return {};
}
return supported_sources;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_list_style_value(Vector<ComponentValue> const& component_values)
{
if (component_values.size() > 3)
return nullptr;
RefPtr<StyleValue> list_position;
RefPtr<StyleValue> list_image;
RefPtr<StyleValue> list_type;
int found_nones = 0;
for (auto const& part : component_values) {
auto value = TRY(parse_css_value(part));
if (!value)
return nullptr;
if (value->to_identifier() == ValueID::None) {
found_nones++;
continue;
}
if (property_accepts_value(PropertyID::ListStylePosition, *value)) {
if (list_position)
return nullptr;
list_position = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::ListStyleImage, *value)) {
if (list_image)
return nullptr;
list_image = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::ListStyleType, *value)) {
if (list_type)
return nullptr;
list_type = value.release_nonnull();
continue;
}
}
if (found_nones > 2)
return nullptr;
if (found_nones == 2) {
if (list_image || list_type)
return nullptr;
auto none = TRY(IdentifierStyleValue::create(ValueID::None));
list_image = none;
list_type = none;
} else if (found_nones == 1) {
if (list_image && list_type)
return nullptr;
auto none = TRY(IdentifierStyleValue::create(ValueID::None));
if (!list_image)
list_image = none;
if (!list_type)
list_type = none;
}
if (!list_position)
list_position = TRY(property_initial_value(m_context.realm(), PropertyID::ListStylePosition));
if (!list_image)
list_image = TRY(property_initial_value(m_context.realm(), PropertyID::ListStyleImage));
if (!list_type)
list_type = TRY(property_initial_value(m_context.realm(), PropertyID::ListStyleType));
return ListStyleStyleValue::create(list_position.release_nonnull(), list_image.release_nonnull(), list_type.release_nonnull());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_overflow_value(Vector<ComponentValue> const& component_values)
{
if (component_values.size() == 1) {
auto maybe_value = TRY(parse_css_value(component_values.first()));
if (!maybe_value)
return nullptr;
auto value = maybe_value.release_nonnull();
if (property_accepts_value(PropertyID::Overflow, *value))
return OverflowStyleValue::create(value, value);
return nullptr;
}
if (component_values.size() == 2) {
auto maybe_x_value = TRY(parse_css_value(component_values[0]));
auto maybe_y_value = TRY(parse_css_value(component_values[1]));
if (!maybe_x_value || !maybe_y_value)
return nullptr;
auto x_value = maybe_x_value.release_nonnull();
auto y_value = maybe_y_value.release_nonnull();
if (!property_accepts_value(PropertyID::OverflowX, x_value) || !property_accepts_value(PropertyID::OverflowY, y_value)) {
return nullptr;
}
return OverflowStyleValue::create(x_value, y_value);
}
return nullptr;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_text_decoration_value(Vector<ComponentValue> const& component_values)
{
RefPtr<StyleValue> decoration_line;
RefPtr<StyleValue> decoration_thickness;
RefPtr<StyleValue> decoration_style;
RefPtr<StyleValue> decoration_color;
auto tokens = TokenStream { component_values };
while (tokens.has_next_token()) {
auto const& part = tokens.next_token();
auto value = TRY(parse_css_value(part));
if (!value)
return nullptr;
if (property_accepts_value(PropertyID::TextDecorationColor, *value)) {
if (decoration_color)
return nullptr;
decoration_color = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::TextDecorationLine, *value)) {
if (decoration_line)
return nullptr;
tokens.reconsume_current_input_token();
auto parsed_decoration_line = TRY(parse_text_decoration_line_value(tokens));
if (!parsed_decoration_line)
return nullptr;
decoration_line = parsed_decoration_line.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::TextDecorationThickness, *value)) {
if (decoration_thickness)
return nullptr;
decoration_thickness = value.release_nonnull();
continue;
}
if (property_accepts_value(PropertyID::TextDecorationStyle, *value)) {
if (decoration_style)
return nullptr;
decoration_style = value.release_nonnull();
continue;
}
return nullptr;
}
if (!decoration_line)
decoration_line = TRY(property_initial_value(m_context.realm(), PropertyID::TextDecorationLine));
if (!decoration_thickness)
decoration_thickness = TRY(property_initial_value(m_context.realm(), PropertyID::TextDecorationThickness));
if (!decoration_style)
decoration_style = TRY(property_initial_value(m_context.realm(), PropertyID::TextDecorationStyle));
if (!decoration_color)
decoration_color = TRY(property_initial_value(m_context.realm(), PropertyID::TextDecorationColor));
return TextDecorationStyleValue::create(decoration_line.release_nonnull(), decoration_thickness.release_nonnull(), decoration_style.release_nonnull(), decoration_color.release_nonnull());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_text_decoration_line_value(TokenStream<ComponentValue>& tokens)
{
StyleValueVector style_values;
while (tokens.has_next_token()) {
auto const& token = tokens.next_token();
auto maybe_value = TRY(parse_css_value(token));
if (!maybe_value || !property_accepts_value(PropertyID::TextDecorationLine, *maybe_value)) {
tokens.reconsume_current_input_token();
break;
}
auto value = maybe_value.release_nonnull();
if (auto maybe_line = value_id_to_text_decoration_line(value->to_identifier()); maybe_line.has_value()) {
auto line = maybe_line.release_value();
if (line == TextDecorationLine::None) {
if (!style_values.is_empty()) {
tokens.reconsume_current_input_token();
break;
}
return value;
}
if (style_values.contains_slow(value)) {
tokens.reconsume_current_input_token();
break;
}
style_values.append(move(value));
continue;
}
tokens.reconsume_current_input_token();
break;
}
if (style_values.is_empty())
return nullptr;
return StyleValueList::create(move(style_values), StyleValueList::Separator::Space);
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_transform_value(Vector<ComponentValue> const& component_values)
{
StyleValueVector transformations;
auto tokens = TokenStream { component_values };
tokens.skip_whitespace();
while (tokens.has_next_token()) {
tokens.skip_whitespace();
auto const& part = tokens.next_token();
if (part.is(Token::Type::Ident) && part.token().ident().equals_ignoring_ascii_case("none"sv)) {
if (!transformations.is_empty())
return nullptr;
tokens.skip_whitespace();
if (tokens.has_next_token())
return nullptr;
return IdentifierStyleValue::create(ValueID::None);
}
if (!part.is_function())
return nullptr;
auto maybe_function = transform_function_from_string(part.function().name());
if (!maybe_function.has_value())
return nullptr;
auto function = maybe_function.release_value();
auto function_metadata = transform_function_metadata(function);
StyleValueVector values;
auto argument_tokens = TokenStream { part.function().values() };
argument_tokens.skip_whitespace();
size_t argument_index = 0;
while (argument_tokens.has_next_token()) {
if (argument_index == function_metadata.parameters.size()) {
dbgln_if(CSS_PARSER_DEBUG, "Too many arguments to {}. max: {}", part.function().name(), function_metadata.parameters.size());
return nullptr;
}
auto const& value = argument_tokens.next_token();
RefPtr<CalculatedStyleValue> maybe_calc_value;
if (auto maybe_dynamic_value = TRY(parse_dynamic_value(value))) {
// TODO: calc() is the only dynamic value we support for now, but more will come later.
// FIXME: Actually, calc() should probably be parsed inside parse_dimension_value() etc,
// so that it affects every use instead of us having to manually implement it.
VERIFY(maybe_dynamic_value->is_calculated());
maybe_calc_value = maybe_dynamic_value->as_calculated();
}
switch (function_metadata.parameters[argument_index].type) {
case TransformFunctionParameterType::Angle: {
// These are `<angle> | <zero>` in the spec, so we have to check for both kinds.
if (maybe_calc_value && maybe_calc_value->resolves_to_angle()) {
values.append(maybe_calc_value.release_nonnull());
} else if (value.is(Token::Type::Number) && value.token().number_value() == 0) {
values.append(TRY(AngleStyleValue::create(Angle::make_degrees(0))));
} else {
auto dimension_value = TRY(parse_dimension_value(value));
if (!dimension_value || !dimension_value->is_angle())
return nullptr;
values.append(dimension_value.release_nonnull());
}
break;
}
case TransformFunctionParameterType::Length: {
if (maybe_calc_value && maybe_calc_value->resolves_to_length()) {
values.append(maybe_calc_value.release_nonnull());
} else {
auto dimension_value = TRY(parse_dimension_value(value));
if (!dimension_value)
return nullptr;
if (dimension_value->is_length())
values.append(dimension_value.release_nonnull());
else
return nullptr;
}
break;
}
case TransformFunctionParameterType::LengthPercentage: {
if (maybe_calc_value && maybe_calc_value->resolves_to_length()) {
values.append(maybe_calc_value.release_nonnull());
} else {
auto dimension_value = TRY(parse_dimension_value(value));
if (!dimension_value)
return nullptr;
if (dimension_value->is_percentage() || dimension_value->is_length())
values.append(dimension_value.release_nonnull());
else
return nullptr;
}
break;
}
case TransformFunctionParameterType::Number: {
if (maybe_calc_value && maybe_calc_value->resolves_to_number()) {
values.append(maybe_calc_value.release_nonnull());
} else {
auto number = TRY(parse_numeric_value(value));
if (!number)
return nullptr;
values.append(number.release_nonnull());
}
break;
}
}
argument_tokens.skip_whitespace();
if (argument_tokens.has_next_token()) {
// Arguments must be separated by commas.
if (!argument_tokens.next_token().is(Token::Type::Comma))
return nullptr;
argument_tokens.skip_whitespace();
// If there are no more parameters after the comma, this is invalid.
if (!argument_tokens.has_next_token())
return nullptr;
}
argument_index++;
}
if (argument_index < function_metadata.parameters.size() && function_metadata.parameters[argument_index].required) {
dbgln_if(CSS_PARSER_DEBUG, "Required parameter at position {} is missing", argument_index);
return nullptr;
}
transformations.append(TRY(TransformationStyleValue::create(function, move(values))));
}
return StyleValueList::create(move(transformations), StyleValueList::Separator::Space);
}
// https://www.w3.org/TR/css-transforms-1/#propdef-transform-origin
// FIXME: This only supports a 2D position
ErrorOr<RefPtr<StyleValue>> Parser::parse_transform_origin_value(Vector<ComponentValue> const& component_values)
{
enum class Axis {
None,
X,
Y,
};
struct AxisOffset {
Axis axis;
NonnullRefPtr<StyleValue> offset;
};
auto to_axis_offset = [](RefPtr<StyleValue> value) -> ErrorOr<Optional<AxisOffset>> {
if (value->is_percentage())
return AxisOffset { Axis::None, value->as_percentage() };
if (value->is_length())
return AxisOffset { Axis::None, value->as_length() };
if (value->has_length())
return AxisOffset { Axis::None, TRY(LengthStyleValue::create(value->to_length())) };
if (value->is_identifier()) {
switch (value->to_identifier()) {
case ValueID::Top:
return AxisOffset { Axis::Y, TRY(PercentageStyleValue::create(Percentage(0))) };
case ValueID::Left:
return AxisOffset { Axis::X, TRY(PercentageStyleValue::create(Percentage(0))) };
case ValueID::Center:
return AxisOffset { Axis::None, TRY(PercentageStyleValue::create(Percentage(50))) };
case ValueID::Bottom:
return AxisOffset { Axis::Y, TRY(PercentageStyleValue::create(Percentage(100))) };
case ValueID::Right:
return AxisOffset { Axis::X, TRY(PercentageStyleValue::create(Percentage(100))) };
default:
return OptionalNone {};
}
}
return OptionalNone {};
};
auto make_list = [](NonnullRefPtr<StyleValue> const& x_value, NonnullRefPtr<StyleValue> const& y_value) -> ErrorOr<NonnullRefPtr<StyleValueList>> {
StyleValueVector values;
values.append(x_value);
values.append(y_value);
return StyleValueList::create(move(values), StyleValueList::Separator::Space);
};
switch (component_values.size()) {
case 1: {
auto single_value = TRY(to_axis_offset(TRY(parse_css_value(component_values[0]))));
if (!single_value.has_value())
return nullptr;
// If only one value is specified, the second value is assumed to be center.
// FIXME: If one or two values are specified, the third value is assumed to be 0px.
switch (single_value->axis) {
case Axis::None:
case Axis::X:
return make_list(single_value->offset, TRY(PercentageStyleValue::create(Percentage(50))));
case Axis::Y:
return make_list(TRY(PercentageStyleValue::create(Percentage(50))), single_value->offset);
}
VERIFY_NOT_REACHED();
}
case 2: {
auto first_value = TRY(to_axis_offset(TRY(parse_css_value(component_values[0]))));
auto second_value = TRY(to_axis_offset(TRY(parse_css_value(component_values[1]))));
if (!first_value.has_value() || !second_value.has_value())
return nullptr;
RefPtr<StyleValue> x_value;
RefPtr<StyleValue> y_value;
if (first_value->axis == Axis::X) {
x_value = first_value->offset;
} else if (first_value->axis == Axis::Y) {
y_value = first_value->offset;
}
if (second_value->axis == Axis::X) {
if (x_value)
return nullptr;
x_value = second_value->offset;
// Put the other in Y since its axis can't have been X
y_value = first_value->offset;
} else if (second_value->axis == Axis::Y) {
if (y_value)
return nullptr;
y_value = second_value->offset;
// Put the other in X since its axis can't have been Y
x_value = first_value->offset;
} else {
if (x_value) {
VERIFY(!y_value);
y_value = second_value->offset;
} else {
VERIFY(!x_value);
x_value = second_value->offset;
}
}
// If two or more values are defined and either no value is a keyword, or the only used keyword is center,
// then the first value represents the horizontal position (or offset) and the second represents the vertical position (or offset).
// FIXME: A third value always represents the Z position (or offset) and must be of type <length>.
if (first_value->axis == Axis::None && second_value->axis == Axis::None) {
x_value = first_value->offset;
y_value = second_value->offset;
}
return make_list(x_value.release_nonnull(), y_value.release_nonnull());
}
}
return nullptr;
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_as_css_value(PropertyID property_id)
{
auto component_values = parse_a_list_of_component_values(m_token_stream);
auto tokens = TokenStream(component_values);
auto parsed_value = parse_css_value(property_id, tokens);
if (parsed_value.is_error())
return nullptr;
return parsed_value.release_value();
}
Optional<CSS::GridSize> Parser::parse_grid_size(ComponentValue const& component_value)
{
if (component_value.is_function()) {
auto const& function = component_value.function();
if (function.name().equals_ignoring_ascii_case("calc"sv)) {
auto calculated_style_value = parse_calculated_value(function.values());
if (calculated_style_value.is_error()) {
// FIXME: Propagate error
return {};
}
return GridSize(LengthPercentage { *calculated_style_value.release_value() });
}
return {};
}
auto token = component_value.token();
if (token.is(Token::Type::Dimension) && token.dimension_unit().equals_ignoring_ascii_case("fr"sv)) {
float numeric_value = token.dimension_value();
if (numeric_value)
return GridSize(numeric_value);
}
if (token.is(Token::Type::Ident) && token.ident().equals_ignoring_ascii_case("auto"sv))
return GridSize::make_auto();
if (token.is(Token::Type::Ident) && token.ident().equals_ignoring_ascii_case("max-content"sv))
return GridSize(GridSize::Type::MaxContent);
if (token.is(Token::Type::Ident) && token.ident().equals_ignoring_ascii_case("min-content"sv))
return GridSize(GridSize::Type::MinContent);
auto dimension = parse_dimension(token);
if (!dimension.has_value())
return {};
if (dimension->is_length())
return GridSize(dimension->length());
else if (dimension->is_percentage())
return GridSize(dimension->percentage());
return {};
}
Optional<CSS::GridMinMax> Parser::parse_min_max(Vector<ComponentValue> const& component_values)
{
// https://www.w3.org/TR/css-grid-2/#valdef-grid-template-columns-minmax
// 'minmax(min, max)'
// Defines a size range greater than or equal to min and less than or equal to max. If the max is
// less than the min, then the max will be floored by the min (essentially yielding minmax(min,
// min)). As a maximum, a <flex> value sets the track’s flex factor; it is invalid as a minimum.
auto function_tokens = TokenStream(component_values);
auto comma_separated_list = parse_a_comma_separated_list_of_component_values(function_tokens);
if (comma_separated_list.size() != 2)
return {};
TokenStream part_one_tokens { comma_separated_list[0] };
part_one_tokens.skip_whitespace();
if (!part_one_tokens.has_next_token())
return {};
auto current_token = part_one_tokens.next_token();
auto min_grid_size = parse_grid_size(current_token);
TokenStream part_two_tokens { comma_separated_list[1] };
part_two_tokens.skip_whitespace();
if (!part_two_tokens.has_next_token())
return {};
current_token = part_two_tokens.next_token();
auto max_grid_size = parse_grid_size(current_token);
if (min_grid_size.has_value() && max_grid_size.has_value()) {
// https://www.w3.org/TR/css-grid-2/#valdef-grid-template-columns-minmax
// As a maximum, a <flex> value sets the track’s flex factor; it is invalid as a minimum.
if (min_grid_size.value().is_flexible_length())
return {};
return CSS::GridMinMax(min_grid_size.value(), max_grid_size.value());
}
return {};
}
Optional<CSS::GridRepeat> Parser::parse_repeat(Vector<ComponentValue> const& component_values)
{
// https://www.w3.org/TR/css-grid-2/#repeat-syntax
// 7.2.3.1. Syntax of repeat()
// The generic form of the repeat() syntax is, approximately,
// repeat( [ <integer [1,∞]> | auto-fill | auto-fit ] , <track-list> )
auto is_auto_fill = false;
auto is_auto_fit = false;
auto function_tokens = TokenStream(component_values);
auto comma_separated_list = parse_a_comma_separated_list_of_component_values(function_tokens);
if (comma_separated_list.size() != 2)
return {};
// The first argument specifies the number of repetitions.
TokenStream part_one_tokens { comma_separated_list[0] };
part_one_tokens.skip_whitespace();
if (!part_one_tokens.has_next_token())
return {};
auto current_token = part_one_tokens.next_token().token();
auto repeat_count = 0;
if (current_token.is(Token::Type::Number) && current_token.number().is_integer() && current_token.number_value() > 0)
repeat_count = current_token.number_value();
else if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_ascii_case("auto-fill"sv))
is_auto_fill = true;
else if (current_token.is(Token::Type::Ident) && current_token.ident().equals_ignoring_ascii_case("auto-fit"sv))
is_auto_fit = true;
// The second argument is a track list, which is repeated that number of times.
TokenStream part_two_tokens { comma_separated_list[1] };
part_two_tokens.skip_whitespace();
if (!part_two_tokens.has_next_token())
return {};
Vector<CSS::ExplicitGridTrack> repeat_params;
Vector<Vector<String>> line_names_list;
auto last_object_was_line_names = false;
while (part_two_tokens.has_next_token()) {
auto token = part_two_tokens.next_token();
Vector<String> line_names;
if (token.is_block()) {
if (last_object_was_line_names)
return {};
last_object_was_line_names = true;
if (!token.block().is_square())
return {};
TokenStream block_tokens { token.block().values() };
while (block_tokens.has_next_token()) {
auto current_block_token = block_tokens.next_token();
auto maybe_string = String::from_utf8(current_block_token.token().ident());
if (maybe_string.is_error())
return {};
line_names.append(maybe_string.value());
block_tokens.skip_whitespace();
}
line_names_list.append(line_names);
part_two_tokens.skip_whitespace();
} else {
last_object_was_line_names = false;
auto track_sizing_function = parse_track_sizing_function(token);
if (!track_sizing_function.has_value())
return {};
// However, there are some restrictions:
// The repeat() notation can’t be nested.
if (track_sizing_function.value().is_repeat())
return {};
// Automatic repetitions (auto-fill or auto-fit) cannot be combined with intrinsic or flexible sizes.
if (track_sizing_function.value().is_default() && track_sizing_function.value().grid_size().is_flexible_length() && (is_auto_fill || is_auto_fit))
return {};
repeat_params.append(track_sizing_function.value());
part_two_tokens.skip_whitespace();
}
}
while (line_names_list.size() <= repeat_params.size())
line_names_list.append({});
// Thus the precise syntax of the repeat() notation has several forms:
// <track-repeat> = repeat( [ <integer [1,∞]> ] , [ <line-names>? <track-size> ]+ <line-names>? )
// <auto-repeat> = repeat( [ auto-fill | auto-fit ] , [ <line-names>? <fixed-size> ]+ <line-names>? )
// <fixed-repeat> = repeat( [ <integer [1,∞]> ] , [ <line-names>? <fixed-size> ]+ <line-names>? )
// <name-repeat> = repeat( [ <integer [1,∞]> | auto-fill ], <line-names>+)
// The <track-repeat> variant can represent the repetition of any <track-size>, but is limited to a
// fixed number of repetitions.
// The <auto-repeat> variant can repeat automatically to fill a space, but requires definite track
// sizes so that the number of repetitions can be calculated. It can only appear once in the track
// list, but the same track list can also contain <fixed-repeat>s.
// The <name-repeat> variant is for adding line names to subgrids. It can only be used with the
// subgrid keyword and cannot specify track sizes, only line names.
// If a repeat() function that is not a <name-repeat> ends up placing two <line-names> adjacent to
// each other, the name lists are merged. For example, repeat(2, [a] 1fr [b]) is equivalent to [a]
// 1fr [b a] 1fr [b].
if (is_auto_fill)
return CSS::GridRepeat(CSS::GridTrackSizeList(repeat_params, line_names_list), CSS::GridRepeat::Type::AutoFill);
else if (is_auto_fit)
return CSS::GridRepeat(CSS::GridTrackSizeList(repeat_params, line_names_list), CSS::GridRepeat::Type::AutoFit);
else
return CSS::GridRepeat(CSS::GridTrackSizeList(repeat_params, line_names_list), repeat_count);
}
Optional<CSS::ExplicitGridTrack> Parser::parse_track_sizing_function(ComponentValue const& token)
{
if (token.is_function()) {
auto const& function_token = token.function();
if (function_token.name().equals_ignoring_ascii_case("repeat"sv)) {
auto maybe_repeat = parse_repeat(function_token.values());
if (maybe_repeat.has_value())
return CSS::ExplicitGridTrack(maybe_repeat.value());
else
return {};
} else if (function_token.name().equals_ignoring_ascii_case("minmax"sv)) {
auto maybe_min_max_value = parse_min_max(function_token.values());
if (maybe_min_max_value.has_value())
return CSS::ExplicitGridTrack(maybe_min_max_value.value());
else
return {};
} else if (function_token.name().equals_ignoring_ascii_case("calc"sv)) {
auto grid_size = parse_grid_size(token);
if (!grid_size.has_value())
return {};
return CSS::ExplicitGridTrack(grid_size.value());
}
return {};
} else if (token.is(Token::Type::Ident) && token.token().ident().equals_ignoring_ascii_case("auto"sv)) {
return CSS::ExplicitGridTrack(GridSize(Length::make_auto()));
} else if (token.is_block()) {
return {};
} else {
auto grid_size = parse_grid_size(token);
if (!grid_size.has_value())
return {};
return CSS::ExplicitGridTrack(grid_size.value());
}
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_grid_track_size_list(Vector<ComponentValue> const& component_values, bool allow_separate_line_name_blocks)
{
Vector<CSS::ExplicitGridTrack> track_list;
Vector<Vector<String>> line_names_list;
auto last_object_was_line_names = false;
TokenStream tokens { component_values };
while (tokens.has_next_token()) {
auto token = tokens.next_token();
if (token.is_block()) {
if (last_object_was_line_names && !allow_separate_line_name_blocks)
return GridTrackSizeListStyleValue::make_auto();
last_object_was_line_names = true;
Vector<String> line_names;
if (!token.block().is_square())
return GridTrackSizeListStyleValue::make_auto();
TokenStream block_tokens { token.block().values() };
while (block_tokens.has_next_token()) {
auto current_block_token = block_tokens.next_token();
auto maybe_string = String::from_utf8(current_block_token.token().ident());
if (maybe_string.is_error())
return nullptr;
line_names.append(maybe_string.value());
block_tokens.skip_whitespace();
}
line_names_list.append(line_names);
} else {
last_object_was_line_names = false;
auto track_sizing_function = parse_track_sizing_function(token);
if (!track_sizing_function.has_value())
return GridTrackSizeListStyleValue::make_auto();
// FIXME: Handle multiple repeat values (should combine them here, or remove
// any other ones if the first one is auto-fill, etc.)
track_list.append(track_sizing_function.value());
}
}
while (line_names_list.size() <= track_list.size())
line_names_list.append({});
return GridTrackSizeListStyleValue::create(CSS::GridTrackSizeList(track_list, line_names_list));
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_grid_auto_track_sizes(Vector<ComponentValue> const& component_values)
{
// https://www.w3.org/TR/css-grid-2/#auto-tracks
// <track-size>+
Vector<CSS::ExplicitGridTrack> track_list;
TokenStream tokens { component_values };
while (tokens.has_next_token()) {
auto token = tokens.next_token();
auto track_sizing_function = parse_track_sizing_function(token);
if (!track_sizing_function.has_value())
return GridTrackSizeListStyleValue::make_auto();
// FIXME: Handle multiple repeat values (should combine them here, or remove
// any other ones if the first one is auto-fill, etc.)
track_list.append(track_sizing_function.value());
}
return GridTrackSizeListStyleValue::create(CSS::GridTrackSizeList(track_list, {}));
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_grid_track_placement(Vector<ComponentValue> const& component_values)
{
// https://www.w3.org/TR/css-grid-2/#line-placement
// Line-based Placement: the grid-row-start, grid-column-start, grid-row-end, and grid-column-end properties
// <grid-line> =
// auto |
// <custom-ident> |
// [ <integer> && <custom-ident>? ] |
// [ span && [ <integer> || <custom-ident> ] ]
auto is_auto = [](Token token) -> bool {
if (token.is(Token::Type::Ident) && token.ident().equals_ignoring_ascii_case("auto"sv))
return true;
return false;
};
auto is_span = [](Token token) -> bool {
if (token.is(Token::Type::Ident) && token.ident().equals_ignoring_ascii_case("span"sv))
return true;
return false;
};
auto is_valid_integer = [](Token token) -> bool {
// An <integer> value of zero makes the declaration invalid.
if (token.is(Token::Type::Number) && token.number().is_integer() && token.number_value() != 0)
return true;
return false;
};
auto is_line_name = [](Token token) -> bool {
// The <custom-ident> additionally excludes the keywords span and auto.
if (token.is(Token::Type::Ident) && !token.ident().equals_ignoring_ascii_case("span"sv) && !token.ident().equals_ignoring_ascii_case("auto"sv))
return true;
return false;
};
auto tokens = TokenStream { component_values };
tokens.skip_whitespace();
auto current_token = tokens.next_token().token();
if (!tokens.has_next_token()) {
if (is_auto(current_token))
return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement());
if (is_span(current_token))
return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(1, true));
if (is_valid_integer(current_token))
return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(static_cast<int>(current_token.number_value())));
if (is_line_name(current_token)) {
auto maybe_string = String::from_utf8(current_token.ident());
if (!maybe_string.is_error())
return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(maybe_string.value()));
}
return nullptr;
}
auto span_value = false;
auto span_or_position_value = 0;
String line_name_value;
while (true) {
if (is_auto(current_token))
return nullptr;
if (is_span(current_token)) {
if (span_value == false)
span_value = true;
else
return nullptr;
}
if (is_valid_integer(current_token)) {
if (span_or_position_value == 0)
span_or_position_value = static_cast<int>(current_token.number_value());
else
return nullptr;
}
if (is_line_name(current_token)) {
if (line_name_value.is_empty()) {
auto maybe_string = String::from_utf8(current_token.ident());
if (maybe_string.is_error())
return nullptr;
line_name_value = maybe_string.release_value();
} else {
return nullptr;
}
}
tokens.skip_whitespace();
if (tokens.has_next_token())
current_token = tokens.next_token().token();
else
break;
}
// Negative integers or zero are invalid.
if (span_value && span_or_position_value < 1)
return nullptr;
// If the <integer> is omitted, it defaults to 1.
if (span_or_position_value == 0)
span_or_position_value = 1;
if (!line_name_value.is_empty())
return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(line_name_value, span_or_position_value, span_value));
return GridTrackPlacementStyleValue::create(CSS::GridTrackPlacement(span_or_position_value, span_value));
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_grid_track_placement_shorthand_value(Vector<ComponentValue> const& component_values)
{
auto tokens = TokenStream { component_values };
auto current_token = tokens.next_token().token();
Vector<ComponentValue> track_start_placement_tokens;
while (true) {
if (current_token.is(Token::Type::Delim) && current_token.delim() == "/"sv)
break;
track_start_placement_tokens.append(current_token);
if (!tokens.has_next_token())
break;
current_token = tokens.next_token().token();
}
Vector<ComponentValue> track_end_placement_tokens;
if (tokens.has_next_token()) {
current_token = tokens.next_token().token();
while (true) {
track_end_placement_tokens.append(current_token);
if (!tokens.has_next_token())
break;
current_token = tokens.next_token().token();
}
}
auto parsed_start_value = TRY(parse_grid_track_placement(track_start_placement_tokens));
if (parsed_start_value && track_end_placement_tokens.is_empty())
return GridTrackPlacementShorthandStyleValue::create(parsed_start_value.release_nonnull()->as_grid_track_placement().grid_track_placement());
auto parsed_end_value = TRY(parse_grid_track_placement(track_end_placement_tokens));
if (parsed_start_value && parsed_end_value)
return GridTrackPlacementShorthandStyleValue::create(parsed_start_value.release_nonnull()->as_grid_track_placement(), parsed_end_value.release_nonnull()->as_grid_track_placement());
return nullptr;
}
// https://www.w3.org/TR/css-grid-2/#explicit-grid-shorthand
// 7.4. Explicit Grid Shorthand: the grid-template property
ErrorOr<RefPtr<StyleValue>> Parser::parse_grid_track_size_list_shorthand_value(Vector<ComponentValue> const& component_values)
{
// The grid-template property is a shorthand for setting grid-template-columns, grid-template-rows,
// and grid-template-areas in a single declaration. It has several distinct syntax forms:
// none
// - Sets all three properties to their initial values (none).
// <'grid-template-rows'> / <'grid-template-columns'>
// - Sets grid-template-rows and grid-template-columns to the specified values, respectively, and sets grid-template-areas to none.
// [ <line-names>? <string> <track-size>? <line-names>? ]+ [ / <explicit-track-list> ]?
// - Sets grid-template-areas to the strings listed.
// - Sets grid-template-rows to the <track-size>s following each string (filling in auto for any missing sizes),
// and splicing in the named lines defined before/after each size.
// - Sets grid-template-columns to the track listing specified after the slash (or none, if not specified).
Vector<ComponentValue> template_rows_tokens;
Vector<ComponentValue> template_columns_tokens;
Vector<ComponentValue> template_area_tokens;
int forward_slash_index = -1;
for (size_t x = 0; x < component_values.size(); x++) {
if (component_values[x].is_token() && component_values[x].token().is(Token::Type::Delim) && component_values[x].token().delim() == "/"sv) {
forward_slash_index = x;
break;
}
}
for (size_t x = 0; x < (forward_slash_index > -1 ? forward_slash_index : component_values.size()); x++) {
if (component_values[x].is_token() && component_values[x].token().is(Token::Type::String))
template_area_tokens.append(component_values[x]);
else
template_rows_tokens.append(component_values[x]);
}
if (forward_slash_index > -1) {
for (size_t x = forward_slash_index + 1; x < component_values.size(); x++)
template_columns_tokens.append(component_values[x]);
}
auto parsed_template_areas_values = TRY(parse_grid_template_areas_value(template_area_tokens));
auto parsed_template_rows_values = TRY(parse_grid_track_size_list(template_rows_tokens, true));
auto parsed_template_columns_values = TRY(parse_grid_track_size_list(template_columns_tokens));
return GridTrackSizeListShorthandStyleValue::create(
parsed_template_areas_values.release_nonnull()->as_grid_template_area(),
parsed_template_rows_values.release_nonnull()->as_grid_track_size_list(),
parsed_template_columns_values.release_nonnull()->as_grid_track_size_list());
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_grid_area_shorthand_value(Vector<ComponentValue> const& component_values)
{
auto tokens = TokenStream { component_values };
Token current_token;
auto parse_placement_tokens = [&](Vector<ComponentValue>& placement_tokens, bool check_for_delimiter = true) -> void {
current_token = tokens.next_token().token();
while (true) {
if (check_for_delimiter && current_token.is(Token::Type::Delim) && current_token.delim() == "/"sv)
break;
placement_tokens.append(current_token);
tokens.skip_whitespace();
if (!tokens.has_next_token())
break;
current_token = tokens.next_token().token();
}
};
Vector<ComponentValue> row_start_placement_tokens;
parse_placement_tokens(row_start_placement_tokens);
Vector<ComponentValue> column_start_placement_tokens;
if (tokens.has_next_token())
parse_placement_tokens(column_start_placement_tokens);
Vector<ComponentValue> row_end_placement_tokens;
if (tokens.has_next_token())
parse_placement_tokens(row_end_placement_tokens);
Vector<ComponentValue> column_end_placement_tokens;
if (tokens.has_next_token())
parse_placement_tokens(column_end_placement_tokens, false);
// https://www.w3.org/TR/css-grid-2/#placement-shorthands
// The grid-area property is a shorthand for grid-row-start, grid-column-start, grid-row-end and
// grid-column-end.
auto row_start_style_value = TRY(parse_grid_track_placement(row_start_placement_tokens));
auto column_start_style_value = TRY(parse_grid_track_placement(column_start_placement_tokens));
auto row_end_style_value = TRY(parse_grid_track_placement(row_end_placement_tokens));
auto column_end_style_value = TRY(parse_grid_track_placement(column_end_placement_tokens));
// If four <grid-line> values are specified, grid-row-start is set to the first value, grid-column-start
// is set to the second value, grid-row-end is set to the third value, and grid-column-end is set to the
// fourth value.
auto row_start = GridTrackPlacement::make_auto();
auto column_start = GridTrackPlacement::make_auto();
auto row_end = GridTrackPlacement::make_auto();
auto column_end = GridTrackPlacement::make_auto();
if (row_start_style_value)
row_start = row_start_style_value.release_nonnull()->as_grid_track_placement().grid_track_placement();
// When grid-column-start is omitted, if grid-row-start is a <custom-ident>, all four longhands are set to
// that value. Otherwise, it is set to auto.
if (column_start_style_value)
column_start = column_start_style_value.release_nonnull()->as_grid_track_placement().grid_track_placement();
else
column_start = row_start;
// When grid-row-end is omitted, if grid-row-start is a <custom-ident>, grid-row-end is set to that
// <custom-ident>; otherwise, it is set to auto.
if (row_end_style_value)
row_end = row_end_style_value.release_nonnull()->as_grid_track_placement().grid_track_placement();
else
row_end = column_start;
// When grid-column-end is omitted, if grid-column-start is a <custom-ident>, grid-column-end is set to
// that <custom-ident>; otherwise, it is set to auto.
if (column_end_style_value)
column_end = column_end_style_value.release_nonnull()->as_grid_track_placement().grid_track_placement();
else
column_end = row_end;
return GridAreaShorthandStyleValue::create(row_start, column_start, row_end, column_end);
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_grid_template_areas_value(Vector<ComponentValue> const& component_values)
{
Vector<Vector<String>> grid_area_rows;
for (auto& component_value : component_values) {
Vector<String> grid_area_columns;
if (component_value.is(Token::Type::String)) {
auto const parts = TRY(TRY(String::from_utf8(component_value.token().string())).split(' '));
for (auto& part : parts) {
grid_area_columns.append(part);
}
}
grid_area_rows.append(move(grid_area_columns));
}
return GridTemplateAreaStyleValue::create(grid_area_rows);
}
Parser::ParseErrorOr<NonnullRefPtr<StyleValue>> Parser::parse_css_value(PropertyID property_id, TokenStream<ComponentValue>& tokens)
{
// FIXME: This is a hack. Until we can reasonably combine the error types, just log the error
// and return ParseError::InternalError if we get an AK::Error result.
#define FIXME_TRY(expression) \
({ \
/* Ignore -Wshadow to allow nesting the macro. */ \
AK_IGNORE_DIAGNOSTIC("-Wshadow", \
auto&& _temporary_result = (expression)); \
if (_temporary_result.is_error()) [[unlikely]] { \
dbgln("System error when parsing style value: {}", _temporary_result.release_error()); \
return ParseError::InternalError; \
} \
_temporary_result.release_value(); \
})
auto function_contains_var_or_attr = [](Function const& function, auto&& recurse) -> bool {
if (function.name().equals_ignoring_ascii_case("var"sv) || function.name().equals_ignoring_ascii_case("attr"sv))
return true;
for (auto const& token : function.values()) {
if (token.is_function() && recurse(token.function(), recurse))
return true;
}
return false;
};
auto block_contains_var_or_attr = [function_contains_var_or_attr](Block const& block, auto&& recurse) -> bool {
for (auto const& token : block.values()) {
if (token.is_function() && function_contains_var_or_attr(token.function(), function_contains_var_or_attr))
return true;
if (token.is_block() && recurse(token.block(), recurse))
return true;
}
return false;
};
m_context.set_current_property_id(property_id);
Vector<ComponentValue> component_values;
bool contains_var_or_attr = false;
while (tokens.has_next_token()) {
auto const& token = tokens.next_token();
if (token.is(Token::Type::Semicolon)) {
tokens.reconsume_current_input_token();
break;
}
if (property_id != PropertyID::Custom) {
if (token.is(Token::Type::Whitespace))
continue;
if (token.is(Token::Type::Ident) && has_ignored_vendor_prefix(token.token().ident()))
return ParseError::IncludesIgnoredVendorPrefix;
}
if (!contains_var_or_attr) {
if (token.is_function() && function_contains_var_or_attr(token.function(), function_contains_var_or_attr))
contains_var_or_attr = true;
else if (token.is_block() && block_contains_var_or_attr(token.block(), block_contains_var_or_attr))
contains_var_or_attr = true;
}
component_values.append(token);
}
if (property_id == PropertyID::Custom || contains_var_or_attr)
return FIXME_TRY(UnresolvedStyleValue::create(move(component_values), contains_var_or_attr));
if (component_values.is_empty())
return ParseError::SyntaxError;
if (component_values.size() == 1) {
if (auto parsed_value = FIXME_TRY(parse_builtin_value(component_values.first())))
return parsed_value.release_nonnull();
}
// Special-case property handling
switch (property_id) {
case PropertyID::BackdropFilter:
if (auto parsed_value = FIXME_TRY(parse_filter_value_list_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Background:
if (auto parsed_value = FIXME_TRY(parse_background_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::BackgroundAttachment:
case PropertyID::BackgroundClip:
case PropertyID::BackgroundImage:
case PropertyID::BackgroundOrigin:
if (auto parsed_value = FIXME_TRY(parse_simple_comma_separated_value_list(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::BackgroundPosition:
if (auto parsed_value = FIXME_TRY(parse_comma_separated_value_list(component_values, [this](auto& tokens) { return parse_single_background_position_value(tokens); })))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::BackgroundPositionX:
case PropertyID::BackgroundPositionY:
if (auto parsed_value = FIXME_TRY(parse_comma_separated_value_list(component_values, [this, property_id](auto& tokens) { return parse_single_background_position_x_or_y_value(tokens, property_id); })))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::BackgroundRepeat:
if (auto parsed_value = FIXME_TRY(parse_comma_separated_value_list(component_values, [this](auto& tokens) { return parse_single_background_repeat_value(tokens); })))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::BackgroundSize:
if (auto parsed_value = FIXME_TRY(parse_comma_separated_value_list(component_values, [this](auto& tokens) { return parse_single_background_size_value(tokens); })))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Border:
case PropertyID::BorderBottom:
case PropertyID::BorderLeft:
case PropertyID::BorderRight:
case PropertyID::BorderTop:
if (auto parsed_value = FIXME_TRY(parse_border_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::BorderTopLeftRadius:
case PropertyID::BorderTopRightRadius:
case PropertyID::BorderBottomRightRadius:
case PropertyID::BorderBottomLeftRadius:
if (auto parsed_value = FIXME_TRY(parse_border_radius_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::BorderRadius:
if (auto parsed_value = FIXME_TRY(parse_border_radius_shorthand_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::BoxShadow:
if (auto parsed_value = FIXME_TRY(parse_shadow_value(component_values, AllowInsetKeyword::Yes)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Content:
if (auto parsed_value = FIXME_TRY(parse_content_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Display:
if (auto parsed_value = FIXME_TRY(parse_display_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Flex:
if (auto parsed_value = FIXME_TRY(parse_flex_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::FlexFlow:
if (auto parsed_value = FIXME_TRY(parse_flex_flow_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Font:
if (auto parsed_value = FIXME_TRY(parse_font_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::FontFamily:
if (auto parsed_value = FIXME_TRY(parse_font_family_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridColumn:
if (auto parsed_value = FIXME_TRY(parse_grid_track_placement_shorthand_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridArea:
if (auto parsed_value = FIXME_TRY(parse_grid_area_shorthand_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridTemplateAreas:
if (auto parsed_value = FIXME_TRY(parse_grid_template_areas_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridColumnEnd:
if (auto parsed_value = FIXME_TRY(parse_grid_track_placement(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridColumnStart:
if (auto parsed_value = FIXME_TRY(parse_grid_track_placement(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridRow:
if (auto parsed_value = FIXME_TRY(parse_grid_track_placement_shorthand_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridRowEnd:
if (auto parsed_value = FIXME_TRY(parse_grid_track_placement(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridRowStart:
if (auto parsed_value = FIXME_TRY(parse_grid_track_placement(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridTemplate:
if (auto parsed_value = FIXME_TRY(parse_grid_track_size_list_shorthand_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridTemplateColumns:
if (auto parsed_value = FIXME_TRY(parse_grid_track_size_list(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridTemplateRows:
if (auto parsed_value = FIXME_TRY(parse_grid_track_size_list(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridAutoColumns:
if (auto parsed_value = FIXME_TRY(parse_grid_auto_track_sizes(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::GridAutoRows:
if (auto parsed_value = FIXME_TRY(parse_grid_auto_track_sizes(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::ListStyle:
if (auto parsed_value = FIXME_TRY(parse_list_style_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Overflow:
if (auto parsed_value = FIXME_TRY(parse_overflow_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::TextDecoration:
if (auto parsed_value = FIXME_TRY(parse_text_decoration_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::TextDecorationLine: {
TokenStream value_tokens { component_values };
auto parsed_value = FIXME_TRY(parse_text_decoration_line_value(value_tokens));
if (parsed_value && !value_tokens.has_next_token())
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
}
case PropertyID::TextShadow:
if (auto parsed_value = FIXME_TRY(parse_shadow_value(component_values, AllowInsetKeyword::No)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::Transform:
if (auto parsed_value = FIXME_TRY(parse_transform_value(component_values)))
return parsed_value.release_nonnull();
return ParseError::SyntaxError;
case PropertyID::TransformOrigin:
if (auto parsed_value = FIXME_TRY(parse_transform_origin_value(component_values)))
return parsed_value.release_nonnull();
return ParseError ::SyntaxError;
case PropertyID::Fill:
if (component_values.size() == 1) {
if (auto parsed_url = FIXME_TRY(parse_url_value(component_values.first())))
return parsed_url.release_nonnull();
}
// Allow normal value parsing to continue.
// URL is done here to avoid ambiguity with images.
break;
default:
break;
}
if (component_values.size() == 1) {
if (auto parsed_value = FIXME_TRY(parse_css_value(component_values.first()))) {
if (property_accepts_value(property_id, *parsed_value))
return parsed_value.release_nonnull();
}
return ParseError::SyntaxError;
}
// We have multiple values, so treat them as a StyleValueList.
if (property_maximum_value_count(property_id) > 1) {
StyleValueVector parsed_values;
for (auto& component_value : component_values) {
auto parsed_value = FIXME_TRY(parse_css_value(component_value));
if (!parsed_value || !property_accepts_value(property_id, *parsed_value))
return ParseError::SyntaxError;
parsed_values.append(parsed_value.release_nonnull());
}
if (!parsed_values.is_empty() && parsed_values.size() <= property_maximum_value_count(property_id))
return FIXME_TRY(StyleValueList::create(move(parsed_values), StyleValueList::Separator::Space));
}
return ParseError::SyntaxError;
#undef FIXME_TRY
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_css_value_for_property(PropertyID property_id, TokenStream<ComponentValue>& tokens)
{
auto result = parse_css_value_for_properties({ &property_id, 1 }, tokens);
if (result.is_error())
return result.release_error();
return result.value().style_value;
}
ErrorOr<Parser::PropertyAndValue> Parser::parse_css_value_for_properties(ReadonlySpan<PropertyID> property_ids, TokenStream<ComponentValue>& tokens)
{
auto any_property_accepts_type = [](ReadonlySpan<PropertyID> property_ids, ValueType value_type) -> Optional<PropertyID> {
for (auto const& property : property_ids) {
if (property_accepts_type(property, value_type))
return property;
}
return {};
};
auto any_property_accepts_identifier = [](ReadonlySpan<PropertyID> property_ids, ValueID identifier) -> Optional<PropertyID> {
for (auto const& property : property_ids) {
if (property_accepts_identifier(property, identifier))
return property;
}
return {};
};
auto& peek_token = tokens.peek_token();
if (peek_token.is(Token::Type::Ident)) {
// NOTE: We do not try to parse "CSS-wide keywords" here. https://www.w3.org/TR/css-values-4/#common-keywords
// These are only valid on their own, and so should be parsed directly in `parse_css_value()`.
auto ident = value_id_from_string(peek_token.token().ident());
if (ident.has_value()) {
if (auto property = any_property_accepts_identifier(property_ids, ident.value()); property.has_value()) {
(void)tokens.next_token();
return PropertyAndValue { *property, TRY(IdentifierStyleValue::create(ident.value())) };
}
}
// FIXME: Custom idents. https://www.w3.org/TR/css-values-4/#identifier-value
}
if (auto property = any_property_accepts_type(property_ids, ValueType::Color); property.has_value()) {
if (auto maybe_color = TRY(parse_color_value(peek_token))) {
(void)tokens.next_token();
return PropertyAndValue { *property, maybe_color };
}
}
if (auto property = any_property_accepts_type(property_ids, ValueType::Image); property.has_value()) {
if (auto maybe_image = TRY(parse_image_value(peek_token))) {
(void)tokens.next_token();
return PropertyAndValue { *property, maybe_image };
}
}
auto property_accepting_integer = any_property_accepts_type(property_ids, ValueType::Integer);
auto property_accepting_number = any_property_accepts_type(property_ids, ValueType::Number);
bool property_accepts_numeric = property_accepting_integer.has_value() || property_accepting_number.has_value();
if (peek_token.is(Token::Type::Number) && property_accepts_numeric) {
auto numeric = TRY(parse_numeric_value(peek_token));
(void)tokens.next_token();
if (numeric->as_numeric().has_integer() && property_accepting_integer.has_value())
return PropertyAndValue { *property_accepting_integer, numeric };
return PropertyAndValue { property_accepting_integer.value_or(property_accepting_number.value()), numeric };
}
if (peek_token.is(Token::Type::Percentage)) {
if (auto property = any_property_accepts_type(property_ids, ValueType::Percentage); property.has_value()) {
(void)tokens.next_token();
return PropertyAndValue { *property, TRY(PercentageStyleValue::create(Percentage(peek_token.token().percentage()))) };
}
}
if (auto property = any_property_accepts_type(property_ids, ValueType::Rect); property.has_value()) {
if (auto maybe_rect = TRY(parse_rect_value(peek_token))) {
(void)tokens.next_token();
return PropertyAndValue { *property, maybe_rect };
}
}
if (peek_token.is(Token::Type::String)) {
if (auto property = any_property_accepts_type(property_ids, ValueType::String); property.has_value())
return PropertyAndValue { *property, TRY(StringStyleValue::create(TRY(String::from_utf8(tokens.next_token().token().string())))) };
}
if (auto property = any_property_accepts_type(property_ids, ValueType::Url); property.has_value()) {
if (auto url = TRY(parse_url_value(peek_token))) {
(void)tokens.next_token();
return PropertyAndValue { *property, url };
}
}
bool property_accepts_dimension = any_property_accepts_type(property_ids, ValueType::Angle).has_value()
|| any_property_accepts_type(property_ids, ValueType::Length).has_value()
|| any_property_accepts_type(property_ids, ValueType::Percentage).has_value()
|| any_property_accepts_type(property_ids, ValueType::Resolution).has_value()
|| any_property_accepts_type(property_ids, ValueType::Time).has_value();
if (property_accepts_dimension) {
if (auto maybe_dimension = parse_dimension(peek_token); maybe_dimension.has_value()) {
(void)tokens.next_token();
auto dimension = maybe_dimension.release_value();
if (dimension.is_angle()) {
if (auto property = any_property_accepts_type(property_ids, ValueType::Angle); property.has_value())
return PropertyAndValue { *property, TRY(AngleStyleValue::create(dimension.angle())) };
}
if (dimension.is_frequency()) {
if (auto property = any_property_accepts_type(property_ids, ValueType::Frequency); property.has_value())
return PropertyAndValue { *property, TRY(FrequencyStyleValue::create(dimension.frequency())) };
}
if (dimension.is_length()) {
if (auto property = any_property_accepts_type(property_ids, ValueType::Length); property.has_value())
return PropertyAndValue { *property, TRY(LengthStyleValue::create(dimension.length())) };
}
if (dimension.is_resolution()) {
if (auto property = any_property_accepts_type(property_ids, ValueType::Resolution); property.has_value())
return PropertyAndValue { *property, TRY(ResolutionStyleValue::create(dimension.resolution())) };
}
if (dimension.is_time()) {
if (auto property = any_property_accepts_type(property_ids, ValueType::Time); property.has_value())
return PropertyAndValue { *property, TRY(TimeStyleValue::create(dimension.time())) };
}
}
}
// In order to not end up parsing `calc()` and other math expressions multiple times,
// we parse it once, and then see if its resolved type matches what the property accepts.
if (peek_token.is_function() && (property_accepts_dimension || property_accepts_numeric)) {
if (auto maybe_dynamic = TRY(parse_dynamic_value(peek_token)); maybe_dynamic && maybe_dynamic->is_calculated()) {
(void)tokens.next_token();
auto& calculated = maybe_dynamic->as_calculated();
switch (calculated.resolved_type()) {
case CalculatedStyleValue::ResolvedType::Angle:
if (auto property = any_property_accepts_type(property_ids, ValueType::Angle); property.has_value())
return PropertyAndValue { *property, calculated };
break;
case CalculatedStyleValue::ResolvedType::Frequency:
if (auto property = any_property_accepts_type(property_ids, ValueType::Frequency); property.has_value())
return PropertyAndValue { *property, calculated };
break;
case CalculatedStyleValue::ResolvedType::Integer:
case CalculatedStyleValue::ResolvedType::Number:
if (property_accepts_numeric)
return PropertyAndValue { property_accepting_integer.value_or(property_accepting_number.value()), calculated };
break;
case CalculatedStyleValue::ResolvedType::Length:
if (auto property = any_property_accepts_type(property_ids, ValueType::Length); property.has_value())
return PropertyAndValue { *property, calculated };
break;
case CalculatedStyleValue::ResolvedType::Percentage:
if (auto property = any_property_accepts_type(property_ids, ValueType::Percentage); property.has_value())
return PropertyAndValue { *property, calculated };
break;
case CalculatedStyleValue::ResolvedType::Time:
if (auto property = any_property_accepts_type(property_ids, ValueType::Time); property.has_value())
return PropertyAndValue { *property, calculated };
break;
}
}
}
return PropertyAndValue { property_ids.first(), nullptr };
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_css_value(ComponentValue const& component_value)
{
if (auto builtin = TRY(parse_builtin_value(component_value)))
return builtin;
if (auto dynamic = TRY(parse_dynamic_value(component_value)))
return dynamic;
// We parse colors before numbers, to catch hashless hex colors.
if (auto color = TRY(parse_color_value(component_value)))
return color;
if (auto dimension = TRY(parse_dimension_value(component_value)))
return dimension;
if (auto numeric = TRY(parse_numeric_value(component_value)))
return numeric;
if (auto identifier = TRY(parse_identifier_value(component_value)))
return identifier;
if (auto string = TRY(parse_string_value(component_value)))
return string;
if (auto image = TRY(parse_image_value(component_value)))
return image;
if (auto rect = TRY(parse_rect_value(component_value)))
return rect;
return nullptr;
}
Optional<Selector::SimpleSelector::ANPlusBPattern> Parser::parse_a_n_plus_b_pattern(TokenStream<ComponentValue>& values)
{
auto transaction = values.begin_transaction();
auto syntax_error = [&]() -> Optional<Selector::SimpleSelector::ANPlusBPattern> {
if constexpr (CSS_PARSER_DEBUG) {
dbgln_if(CSS_PARSER_DEBUG, "Invalid An+B value:");
values.dump_all_tokens();
}
return {};
};
auto is_n = [](ComponentValue const& value) -> bool {
return value.is(Token::Type::Ident) && value.token().ident().equals_ignoring_ascii_case("n"sv);
};
auto is_ndash = [](ComponentValue const& value) -> bool {
return value.is(Token::Type::Ident) && value.token().ident().equals_ignoring_ascii_case("n-"sv);
};
auto is_dashn = [](ComponentValue const& value) -> bool {
return value.is(Token::Type::Ident) && value.token().ident().equals_ignoring_ascii_case("-n"sv);
};
auto is_dashndash = [](ComponentValue const& value) -> bool {
return value.is(Token::Type::Ident) && value.token().ident().equals_ignoring_ascii_case("-n-"sv);
};
auto is_delim = [](ComponentValue const& value, u32 delim) -> bool {
return value.is(Token::Type::Delim) && value.token().delim() == delim;
};
auto is_sign = [](ComponentValue const& value) -> bool {
return value.is(Token::Type::Delim) && (value.token().delim() == '+' || value.token().delim() == '-');
};
auto is_n_dimension = [](ComponentValue const& value) -> bool {
if (!value.is(Token::Type::Dimension))
return false;
if (!value.token().number().is_integer())
return false;
if (!value.token().dimension_unit().equals_ignoring_ascii_case("n"sv))
return false;
return true;
};
auto is_ndash_dimension = [](ComponentValue const& value) -> bool {
if (!value.is(Token::Type::Dimension))
return false;
if (!value.token().number().is_integer())
return false;
if (!value.token().dimension_unit().equals_ignoring_ascii_case("n-"sv))
return false;
return true;
};
auto is_ndashdigit_dimension = [](ComponentValue const& value) -> bool {
if (!value.is(Token::Type::Dimension))
return false;
if (!value.token().number().is_integer())
return false;
auto dimension_unit = value.token().dimension_unit();
if (!dimension_unit.starts_with("n-"sv, CaseSensitivity::CaseInsensitive))
return false;
for (size_t i = 2; i < dimension_unit.length(); ++i) {
if (!is_ascii_digit(dimension_unit[i]))
return false;
}
return true;
};
auto is_ndashdigit_ident = [](ComponentValue const& value) -> bool {
if (!value.is(Token::Type::Ident))
return false;
auto ident = value.token().ident();
if (!ident.starts_with("n-"sv, CaseSensitivity::CaseInsensitive))
return false;
for (size_t i = 2; i < ident.length(); ++i) {
if (!is_ascii_digit(ident[i]))
return false;
}
return true;
};
auto is_dashndashdigit_ident = [](ComponentValue const& value) -> bool {
if (!value.is(Token::Type::Ident))
return false;
auto ident = value.token().ident();
if (!ident.starts_with("-n-"sv, CaseSensitivity::CaseInsensitive))
return false;
if (ident.length() == 3)
return false;
for (size_t i = 3; i < ident.length(); ++i) {
if (!is_ascii_digit(ident[i]))
return false;
}
return true;
};
auto is_integer = [](ComponentValue const& value) -> bool {
return value.is(Token::Type::Number) && value.token().number().is_integer();
};
auto is_signed_integer = [](ComponentValue const& value) -> bool {
return value.is(Token::Type::Number) && value.token().number().is_integer_with_explicit_sign();
};
auto is_signless_integer = [](ComponentValue const& value) -> bool {
return value.is(Token::Type::Number) && !value.token().number().is_integer_with_explicit_sign();
};
// https://www.w3.org/TR/css-syntax-3/#the-anb-type
// Unfortunately these can't be in the same order as in the spec.
values.skip_whitespace();
auto const& first_value = values.next_token();
// odd | even
if (first_value.is(Token::Type::Ident)) {
auto ident = first_value.token().ident();
if (ident.equals_ignoring_ascii_case("odd"sv)) {
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { 2, 1 };
}
if (ident.equals_ignoring_ascii_case("even"sv)) {
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { 2, 0 };
}
}
// <integer>
if (is_integer(first_value)) {
int b = first_value.token().to_integer();
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { 0, b };
}
// <n-dimension>
// <n-dimension> <signed-integer>
// <n-dimension> ['+' | '-'] <signless-integer>
if (is_n_dimension(first_value)) {
int a = first_value.token().dimension_value_int();
values.skip_whitespace();
// <n-dimension> <signed-integer>
if (is_signed_integer(values.peek_token())) {
int b = values.next_token().token().to_integer();
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { a, b };
}
// <n-dimension> ['+' | '-'] <signless-integer>
{
auto child_transaction = transaction.create_child();
auto const& second_value = values.next_token();
values.skip_whitespace();
auto const& third_value = values.next_token();
if (is_sign(second_value) && is_signless_integer(third_value)) {
int b = third_value.token().to_integer() * (is_delim(second_value, '+') ? 1 : -1);
child_transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { a, b };
}
}
// <n-dimension>
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { a, 0 };
}
// <ndash-dimension> <signless-integer>
if (is_ndash_dimension(first_value)) {
values.skip_whitespace();
auto const& second_value = values.next_token();
if (is_signless_integer(second_value)) {
int a = first_value.token().dimension_value_int();
int b = -second_value.token().to_integer();
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { a, b };
}
return syntax_error();
}
// <ndashdigit-dimension>
if (is_ndashdigit_dimension(first_value)) {
auto const& dimension = first_value.token();
int a = dimension.dimension_value_int();
auto maybe_b = dimension.dimension_unit().substring_view(1).to_int();
if (maybe_b.has_value()) {
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { a, maybe_b.value() };
}
return syntax_error();
}
// <dashndashdigit-ident>
if (is_dashndashdigit_ident(first_value)) {
auto maybe_b = first_value.token().ident().substring_view(2).to_int();
if (maybe_b.has_value()) {
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { -1, maybe_b.value() };
}
return syntax_error();
}
// -n
// -n <signed-integer>
// -n ['+' | '-'] <signless-integer>
if (is_dashn(first_value)) {
values.skip_whitespace();
// -n <signed-integer>
if (is_signed_integer(values.peek_token())) {
int b = values.next_token().token().to_integer();
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { -1, b };
}
// -n ['+' | '-'] <signless-integer>
{
auto child_transaction = transaction.create_child();
auto const& second_value = values.next_token();
values.skip_whitespace();
auto const& third_value = values.next_token();
if (is_sign(second_value) && is_signless_integer(third_value)) {
int b = third_value.token().to_integer() * (is_delim(second_value, '+') ? 1 : -1);
child_transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { -1, b };
}
}
// -n
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { -1, 0 };
}
// -n- <signless-integer>
if (is_dashndash(first_value)) {
values.skip_whitespace();
auto const& second_value = values.next_token();
if (is_signless_integer(second_value)) {
int b = -second_value.token().to_integer();
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { -1, b };
}
return syntax_error();
}
// All that's left now are these:
// '+'?† n
// '+'?† n <signed-integer>
// '+'?† n ['+' | '-'] <signless-integer>
// '+'?† n- <signless-integer>
// '+'?† <ndashdigit-ident>
// In all of these cases, the + is optional, and has no effect.
// So, we just skip the +, and carry on.
if (!is_delim(first_value, '+')) {
values.reconsume_current_input_token();
// We do *not* skip whitespace here.
}
auto const& first_after_plus = values.next_token();
// '+'?† n
// '+'?† n <signed-integer>
// '+'?† n ['+' | '-'] <signless-integer>
if (is_n(first_after_plus)) {
values.skip_whitespace();
// '+'?† n <signed-integer>
if (is_signed_integer(values.peek_token())) {
int b = values.next_token().token().to_integer();
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { 1, b };
}
// '+'?† n ['+' | '-'] <signless-integer>
{
auto child_transaction = transaction.create_child();
auto const& second_value = values.next_token();
values.skip_whitespace();
auto const& third_value = values.next_token();
if (is_sign(second_value) && is_signless_integer(third_value)) {
int b = third_value.token().to_integer() * (is_delim(second_value, '+') ? 1 : -1);
child_transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { 1, b };
}
}
// '+'?† n
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { 1, 0 };
}
// '+'?† n- <signless-integer>
if (is_ndash(first_after_plus)) {
values.skip_whitespace();
auto const& second_value = values.next_token();
if (is_signless_integer(second_value)) {
int b = -second_value.token().to_integer();
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { 1, b };
}
return syntax_error();
}
// '+'?† <ndashdigit-ident>
if (is_ndashdigit_ident(first_after_plus)) {
auto maybe_b = first_after_plus.token().ident().substring_view(1).to_int();
if (maybe_b.has_value()) {
transaction.commit();
return Selector::SimpleSelector::ANPlusBPattern { 1, maybe_b.value() };
}
return syntax_error();
}
return syntax_error();
}
class UnparsedCalculationNode final : public CalculationNode {
public:
static ErrorOr<NonnullOwnPtr<UnparsedCalculationNode>> create(ComponentValue component_value)
{
return adopt_nonnull_own_or_enomem(new (nothrow) UnparsedCalculationNode(move(component_value)));
}
virtual ~UnparsedCalculationNode() = default;
ComponentValue& component_value() { return m_component_value; }
virtual ErrorOr<String> to_string() const override { VERIFY_NOT_REACHED(); }
virtual Optional<CalculatedStyleValue::ResolvedType> resolved_type() const override { VERIFY_NOT_REACHED(); }
virtual bool contains_percentage() const override { VERIFY_NOT_REACHED(); }
virtual CalculatedStyleValue::CalculationResult resolve(Layout::Node const*, CalculatedStyleValue::PercentageBasis const&) const override { VERIFY_NOT_REACHED(); }
virtual ErrorOr<void> dump(StringBuilder& builder, int indent) const override
{
return builder.try_appendff("{: >{}}UNPARSED({})\n", "", indent, TRY(m_component_value.to_debug_string()));
}
private:
UnparsedCalculationNode(ComponentValue component_value)
: CalculationNode(Type::Unparsed)
, m_component_value(move(component_value))
{
}
ComponentValue m_component_value;
};
// https://www.w3.org/TR/css-values-4/#parse-a-calculation
ErrorOr<OwnPtr<CalculationNode>> Parser::parse_a_calculation(Vector<ComponentValue> const& original_values)
{
// 1. Discard any <whitespace-token>s from values.
// 2. An item in values is an “operator” if it’s a <delim-token> with the value "+", "-", "*", or "/". Otherwise, it’s a “value”.
struct Operator {
char delim;
};
using Value = Variant<NonnullOwnPtr<CalculationNode>, Operator>;
Vector<Value> values;
for (auto& value : original_values) {
if (value.is(Token::Type::Whitespace))
continue;
if (value.is(Token::Type::Delim)) {
if (first_is_one_of(value.token().delim(), static_cast<u32>('+'), static_cast<u32>('-'), static_cast<u32>('*'), static_cast<u32>('/'))) {
// NOTE: Sequential operators are invalid syntax.
if (!values.is_empty() && values.last().has<Operator>())
return nullptr;
TRY(values.try_append(Operator { static_cast<char>(value.token().delim()) }));
continue;
}
}
if (value.is(Token::Type::Number)) {
TRY(values.try_append({ TRY(NumericCalculationNode::create(value.token().number())) }));
continue;
}
if (auto dimension = parse_dimension(value); dimension.has_value()) {
if (dimension->is_angle())
TRY(values.try_append({ TRY(NumericCalculationNode::create(dimension->angle())) }));
else if (dimension->is_frequency())
TRY(values.try_append({ TRY(NumericCalculationNode::create(dimension->frequency())) }));
else if (dimension->is_length())
TRY(values.try_append({ TRY(NumericCalculationNode::create(dimension->length())) }));
else if (dimension->is_percentage())
TRY(values.try_append({ TRY(NumericCalculationNode::create(dimension->percentage())) }));
// FIXME: Resolutions, once calc() supports them.
else if (dimension->is_time())
TRY(values.try_append({ TRY(NumericCalculationNode::create(dimension->time())) }));
else
VERIFY_NOT_REACHED();
continue;
}
TRY(values.try_append({ TRY(UnparsedCalculationNode::create(value)) }));
}
// If we have no values, the syntax is invalid.
if (values.is_empty())
return nullptr;
// NOTE: If the first or last value is an operator, the syntax is invalid.
if (values.first().has<Operator>() || values.last().has<Operator>())
return nullptr;
// 3. Collect children into Product and Invert nodes.
// For every consecutive run of value items in values separated by "*" or "/" operators:
while (true) {
Optional<size_t> first_product_operator = values.find_first_index_if([](auto const& item) {
return item.template has<Operator>()
&& first_is_one_of(item.template get<Operator>().delim, '*', '/');
});
if (!first_product_operator.has_value())
break;
auto start_of_run = first_product_operator.value() - 1;
auto end_of_run = first_product_operator.value() + 1;
for (auto i = start_of_run + 1; i < values.size(); i += 2) {
auto& item = values[i];
if (!item.has<Operator>()) {
end_of_run = i - 1;
break;
}
auto delim = item.get<Operator>().delim;
if (!first_is_one_of(delim, '*', '/')) {
end_of_run = i - 1;
break;
}
}
// 1. For each "/" operator in the run, replace its right-hand value item rhs with an Invert node containing rhs as its child.
Vector<NonnullOwnPtr<CalculationNode>> run_values;
TRY(run_values.try_append(move(values[start_of_run].get<NonnullOwnPtr<CalculationNode>>())));
for (auto i = start_of_run + 1; i <= end_of_run; i += 2) {
auto& operator_ = values[i].get<Operator>().delim;
auto& rhs = values[i + 1];
if (operator_ == '/') {
TRY(run_values.try_append(TRY(InvertCalculationNode::create(move(rhs.get<NonnullOwnPtr<CalculationNode>>())))));
continue;
}
VERIFY(operator_ == '*');
TRY(run_values.try_append(move(rhs.get<NonnullOwnPtr<CalculationNode>>())));
}
// 2. Replace the entire run with a Product node containing the value items of the run as its children.
auto product_node = TRY(ProductCalculationNode::create(move(run_values)));
values.remove(start_of_run, end_of_run - start_of_run + 1);
TRY(values.try_insert(start_of_run, { move(product_node) }));
}
// 4. Collect children into Sum and Negate nodes.
Optional<NonnullOwnPtr<CalculationNode>> single_value;
{
// 1. For each "-" operator item in values, replace its right-hand value item rhs with a Negate node containing rhs as its child.
for (auto i = 0u; i < values.size(); ++i) {
auto& maybe_minus_operator = values[i];
if (!maybe_minus_operator.has<Operator>() || maybe_minus_operator.get<Operator>().delim != '-')
continue;
auto rhs_index = ++i;
auto& rhs = values[rhs_index];
NonnullOwnPtr<CalculationNode> negate_node = TRY(NegateCalculationNode::create(move(rhs.get<NonnullOwnPtr<CalculationNode>>())));
values.remove(rhs_index);
values.insert(rhs_index, move(negate_node));
}
// 2. If values has only one item, and it is a Product node or a parenthesized simple block, replace values with that item.
if (values.size() == 1) {
TRY(values.first().visit(
[&](ComponentValue& component_value) -> ErrorOr<void> {
if (component_value.is_block() && component_value.block().is_paren())
single_value = TRY(UnparsedCalculationNode::create(component_value));
return {};
},
[&](NonnullOwnPtr<CalculationNode>& node) -> ErrorOr<void> {
if (node->type() == CalculationNode::Type::Product)
single_value = move(node);
return {};
},
[](auto&) -> ErrorOr<void> { return {}; }));
}
// Otherwise, replace values with a Sum node containing the value items of values as its children.
if (!single_value.has_value()) {
values.remove_all_matching([](Value& value) { return value.has<Operator>(); });
Vector<NonnullOwnPtr<CalculationNode>> value_items;
TRY(value_items.try_ensure_capacity(values.size()));
for (auto& value : values) {
if (value.has<Operator>())
continue;
value_items.unchecked_append(move(value.get<NonnullOwnPtr<CalculationNode>>()));
}
single_value = TRY(SumCalculationNode::create(move(value_items)));
}
}
// 5. At this point values is a tree of Sum, Product, Negate, and Invert nodes, with other types of values at the leaf nodes. Process the leaf nodes.
// For every leaf node leaf in values:
bool parsing_failed_for_child_node = false;
TRY(single_value.value()->for_each_child_node([&](NonnullOwnPtr<CalculationNode>& node) -> ErrorOr<void> {
if (node->type() != CalculationNode::Type::Unparsed)
return {};
auto& unparsed_node = static_cast<UnparsedCalculationNode&>(*node);
auto& component_value = unparsed_node.component_value();
// 1. If leaf is a parenthesized simple block, replace leaf with the result of parsing a calculation from leaf’s contents.
if (component_value.is_block() && component_value.block().is_paren()) {
auto leaf_calculation = TRY(parse_a_calculation(component_value.block().values()));
if (!leaf_calculation) {
parsing_failed_for_child_node = true;
return {};
}
node = leaf_calculation.release_nonnull();
return {};
}
// 2. If leaf is a math function, replace leaf with the internal representation of that math function.
// NOTE: All function tokens at this point should be math functions.
else if (component_value.is_function()) {
auto& function = component_value.function();
if (function.name().equals_ignoring_ascii_case("calc"sv)) {
auto leaf_calculation = TRY(parse_a_calculation(function.values()));
if (!leaf_calculation) {
parsing_failed_for_child_node = true;
return {};
}
node = leaf_calculation.release_nonnull();
return {};
} else {
// FIXME: Parse more math functions once we have them.
parsing_failed_for_child_node = true;
return {};
}
}
// NOTE: If we get here, then we have an UnparsedCalculationNode that didn't get replaced with something else.
// So, the calc() is invalid.
dbgln_if(CSS_PARSER_DEBUG, "Leftover UnparsedCalculationNode in calc tree! That probably means the syntax is invalid, but maybe we just didn't implement `{}` yet.", component_value.to_debug_string());
parsing_failed_for_child_node = true;
return {};
}));
if (parsing_failed_for_child_node)
return nullptr;
// FIXME: 6. Return the result of simplifying a calculation tree from values.
return single_value.release_value();
}
bool Parser::has_ignored_vendor_prefix(StringView string)
{
if (!string.starts_with('-'))
return false;
if (string.starts_with("--"sv))
return false;
if (string.starts_with("-libweb-"sv))
return false;
return true;
}
bool Parser::is_builtin(StringView name)
{
return name.equals_ignoring_ascii_case("inherit"sv)
|| name.equals_ignoring_ascii_case("initial"sv)
|| name.equals_ignoring_ascii_case("unset"sv);
}
ErrorOr<RefPtr<CalculatedStyleValue>> Parser::parse_calculated_value(Badge<StyleComputer>, ParsingContext const& context, Vector<ComponentValue> const& tokens)
{
if (tokens.is_empty())
return nullptr;
auto parser = TRY(Parser::create(context, ""sv));
return parser.parse_calculated_value(tokens);
}
ErrorOr<RefPtr<StyleValue>> Parser::parse_css_value(Badge<StyleComputer>, ParsingContext const& context, PropertyID property_id, Vector<ComponentValue> const& tokens)
{
if (tokens.is_empty() || property_id == CSS::PropertyID::Invalid || property_id == CSS::PropertyID::Custom)
return nullptr;
auto parser = TRY(Parser::create(context, ""sv));
TokenStream<ComponentValue> token_stream { tokens };
auto result = parser.parse_css_value(property_id, token_stream);
if (result.is_error())
return nullptr;
return result.release_value();
}
bool Parser::Dimension::is_angle() const
{
return m_value.has<Angle>();
}
Angle Parser::Dimension::angle() const
{
return m_value.get<Angle>();
}
bool Parser::Dimension::is_angle_percentage() const
{
return is_angle() || is_percentage();
}
AnglePercentage Parser::Dimension::angle_percentage() const
{
if (is_angle())
return angle();
if (is_percentage())
return percentage();
VERIFY_NOT_REACHED();
}
bool Parser::Dimension::is_frequency() const
{
return m_value.has<Frequency>();
}
Frequency Parser::Dimension::frequency() const
{
return m_value.get<Frequency>();
}
bool Parser::Dimension::is_frequency_percentage() const
{
return is_frequency() || is_percentage();
}
FrequencyPercentage Parser::Dimension::frequency_percentage() const
{
if (is_frequency())
return frequency();
if (is_percentage())
return percentage();
VERIFY_NOT_REACHED();
}
bool Parser::Dimension::is_length() const
{
return m_value.has<Length>();
}
Length Parser::Dimension::length() const
{
return m_value.get<Length>();
}
bool Parser::Dimension::is_length_percentage() const
{
return is_length() || is_percentage();
}
LengthPercentage Parser::Dimension::length_percentage() const
{
if (is_length())
return length();
if (is_percentage())
return percentage();
VERIFY_NOT_REACHED();
}
bool Parser::Dimension::is_percentage() const
{
return m_value.has<Percentage>();
}
Percentage Parser::Dimension::percentage() const
{
return m_value.get<Percentage>();
}
bool Parser::Dimension::is_resolution() const
{
return m_value.has<Resolution>();
}
Resolution Parser::Dimension::resolution() const
{
return m_value.get<Resolution>();
}
bool Parser::Dimension::is_time() const
{
return m_value.has<Time>();
}
Time Parser::Dimension::time() const
{
return m_value.get<Time>();
}
bool Parser::Dimension::is_time_percentage() const
{
return is_time() || is_percentage();
}
TimePercentage Parser::Dimension::time_percentage() const
{
if (is_time())
return time();
if (is_percentage())
return percentage();
VERIFY_NOT_REACHED();
}
}
namespace Web {
CSS::CSSStyleSheet* parse_css_stylesheet(CSS::Parser::ParsingContext const& context, StringView css, Optional<AK::URL> location)
{
if (css.is_empty()) {
auto rule_list = CSS::CSSRuleList::create_empty(context.realm()).release_value_but_fixme_should_propagate_errors();
auto media_list = CSS::MediaList::create(context.realm(), {}).release_value_but_fixme_should_propagate_errors();
return CSS::CSSStyleSheet::create(context.realm(), rule_list, media_list, location).release_value_but_fixme_should_propagate_errors();
}
auto parser = CSS::Parser::Parser::create(context, css).release_value_but_fixme_should_propagate_errors();
return parser.parse_as_css_stylesheet(location);
}
CSS::ElementInlineCSSStyleDeclaration* parse_css_style_attribute(CSS::Parser::ParsingContext const& context, StringView css, DOM::Element& element)
{
if (css.is_empty())
return CSS::ElementInlineCSSStyleDeclaration::create(element, {}, {}).release_value_but_fixme_should_propagate_errors();
auto parser = CSS::Parser::Parser::create(context, css).release_value_but_fixme_should_propagate_errors();
return parser.parse_as_style_attribute(element);
}
ErrorOr<RefPtr<CSS::StyleValue>> parse_css_value(CSS::Parser::ParsingContext const& context, StringView string, CSS::PropertyID property_id)
{
if (string.is_empty())
return nullptr;
auto parser = TRY(CSS::Parser::Parser::create(context, string));
return parser.parse_as_css_value(property_id);
}
CSS::CSSRule* parse_css_rule(CSS::Parser::ParsingContext const& context, StringView css_text)
{
auto parser = CSS::Parser::Parser::create(context, css_text).release_value_but_fixme_should_propagate_errors();
return parser.parse_as_css_rule();
}
Optional<CSS::SelectorList> parse_selector(CSS::Parser::ParsingContext const& context, StringView selector_text)
{
auto parser = CSS::Parser::Parser::create(context, selector_text).release_value_but_fixme_should_propagate_errors();
return parser.parse_as_selector();
}
RefPtr<CSS::MediaQuery> parse_media_query(CSS::Parser::ParsingContext const& context, StringView string)
{
auto parser = CSS::Parser::Parser::create(context, string).release_value_but_fixme_should_propagate_errors();
return parser.parse_as_media_query();
}
Vector<NonnullRefPtr<CSS::MediaQuery>> parse_media_query_list(CSS::Parser::ParsingContext const& context, StringView string)
{
auto parser = CSS::Parser::Parser::create(context, string).release_value_but_fixme_should_propagate_errors();
return parser.parse_as_media_query_list();
}
RefPtr<CSS::Supports> parse_css_supports(CSS::Parser::ParsingContext const& context, StringView string)
{
if (string.is_empty())
return {};
auto parser = CSS::Parser::Parser::create(context, string).release_value_but_fixme_should_propagate_errors();
return parser.parse_as_supports();
}
Optional<CSS::StyleProperty> parse_css_supports_condition(CSS::Parser::ParsingContext const& context, StringView string)
{
if (string.is_empty())
return {};
auto parser = CSS::Parser::Parser::create(context, string).release_value_but_fixme_should_propagate_errors();
return parser.parse_as_supports_condition();
}
// https://html.spec.whatwg.org/multipage/images.html#parse-a-srcset-attribute
CSS::Length CSS::Parser::Parser::parse_as_sizes_attribute()
{
Optional<CSS::Length> size;
// When asked to parse a sizes attribute from an element,
// parse a comma-separated list of component values from the value of the element's sizes attribute
// (or the empty string, if the attribute is absent), and let unparsed sizes list be the result.
auto unparsed_sizes_list = parse_a_comma_separated_list_of_component_values(m_token_stream);
// For each unparsed size in unparsed sizes list:
for (auto& unparsed_size : unparsed_sizes_list) {
// 1. Remove all consecutive <whitespace-token>s from the end of unparsed size.
// If unparsed size is now empty, that is a parse error; continue.
while (!unparsed_size.is_empty() && unparsed_size.last().is_token() && unparsed_size.last().token().is(Token::Type::Whitespace))
unparsed_size.take_last();
if (unparsed_size.is_empty())
continue;
// 2. If the last component value in unparsed size is a valid non-negative <source-size-value>,
// let size be its value and remove the component value from unparsed size.
// FIXME: Any CSS function other than the math functions is invalid.
// Otherwise, there is a parse error; continue.
auto length = parse_length(unparsed_size.last());
if (length.has_value() && length.value().raw_value() >= 0) {
size = length.value();
unparsed_size.take_last();
} else {
continue;
}
// 3. Remove all consecutive <whitespace-token>s from the end of unparsed size.
// If unparsed size is now empty, return size and exit this algorithm.
// If this was not the last item in unparsed sizes list, that is a parse error.
while (!unparsed_size.is_empty() && unparsed_size.last().is_token() && unparsed_size.last().token().is(Token::Type::Whitespace))
unparsed_size.take_last();
if (unparsed_size.is_empty())
return size.value();
// FIXME: 4. Parse the remaining component values in unparsed size as a <media-condition>.
// If it does not parse correctly, or it does parse correctly but the <media-condition> evaluates to false, continue. [MQ]
dbgln("FIXME: Implement parsing of media conditions in sizes attribute");
}
return CSS::Length(100, CSS::Length::Type::Vw);
}
}