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99bce9a94d
CSSUnitValue is a typed-om type which we will implement separately in the future. However, it still seems useful to give our dimension values a base class. (Maybe they could be templated in the future?) So instead of deleting it entirely, rename it to DimensionStyleValue and make its API match our style better.
243 lines
12 KiB
C++
243 lines
12 KiB
C++
/*
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* Copyright (c) 2025, Sam Atkins <sam@ladybird.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <LibWeb/CSS/Parser/ErrorReporter.h>
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#include <LibWeb/CSS/Parser/Parser.h>
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#include <LibWeb/CSS/StyleValues/FontSourceStyleValue.h>
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#include <LibWeb/CSS/StyleValues/KeywordStyleValue.h>
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#include <LibWeb/CSS/StyleValues/LengthStyleValue.h>
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#include <LibWeb/CSS/StyleValues/PercentageStyleValue.h>
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#include <LibWeb/CSS/StyleValues/StringStyleValue.h>
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#include <LibWeb/CSS/StyleValues/StyleValueList.h>
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#include <LibWeb/CSS/StyleValues/UnicodeRangeStyleValue.h>
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#include <LibWeb/CSS/StyleValues/UnresolvedStyleValue.h>
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namespace Web::CSS::Parser {
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Parser::ParseErrorOr<NonnullRefPtr<StyleValue const>> Parser::parse_descriptor_value(AtRuleID at_rule_id, DescriptorID descriptor_id, TokenStream<ComponentValue>& unprocessed_tokens)
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{
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if (!at_rule_supports_descriptor(at_rule_id, descriptor_id)) {
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ErrorReporter::the().report(UnknownPropertyError {
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.rule_name = to_string(at_rule_id),
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.property_name = to_string(descriptor_id),
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});
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return ParseError::SyntaxError;
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}
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auto context_guard = push_temporary_value_parsing_context(DescriptorContext { at_rule_id, descriptor_id });
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Vector<ComponentValue> component_values;
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while (unprocessed_tokens.has_next_token()) {
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if (unprocessed_tokens.peek_token().is(Token::Type::Semicolon))
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break;
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auto const& token = unprocessed_tokens.consume_a_token();
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component_values.append(token);
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}
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TokenStream tokens { component_values };
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auto metadata = get_descriptor_metadata(at_rule_id, descriptor_id);
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for (auto const& option : metadata.syntax) {
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auto transaction = tokens.begin_transaction();
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auto parsed_style_value = option.visit(
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[&](Keyword keyword) {
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return parse_all_as_single_keyword_value(tokens, keyword);
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},
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[&](PropertyID property_id) -> RefPtr<StyleValue const> {
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auto value_or_error = parse_css_value(property_id, tokens);
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if (value_or_error.is_error())
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return nullptr;
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auto value_for_property = value_or_error.release_value();
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// Descriptors don't accept the following, which properties do:
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// - CSS-wide keywords
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// - Shorthands
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// - Arbitrary substitution functions (so, UnresolvedStyleValue)
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if (value_for_property->is_css_wide_keyword() || value_for_property->is_shorthand() || value_for_property->is_unresolved())
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return nullptr;
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return value_for_property;
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},
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[&](DescriptorMetadata::ValueType value_type) -> RefPtr<StyleValue const> {
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switch (value_type) {
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case DescriptorMetadata::ValueType::CropOrCross: {
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// crop || cross
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auto first = parse_keyword_value(tokens);
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tokens.discard_whitespace();
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auto second = parse_keyword_value(tokens);
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if (!first)
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return nullptr;
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RefPtr<StyleValue const> crop;
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RefPtr<StyleValue const> cross;
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if (first->to_keyword() == Keyword::Crop)
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crop = first;
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else if (first->to_keyword() == Keyword::Cross)
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cross = first;
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else
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return nullptr;
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if (!second)
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return first.release_nonnull();
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if (crop.is_null() && second->to_keyword() == Keyword::Crop)
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crop = second.release_nonnull();
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else if (cross.is_null() && second->to_keyword() == Keyword::Cross)
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cross = second.release_nonnull();
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else
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return nullptr;
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return StyleValueList::create(StyleValueVector { crop.release_nonnull(), cross.release_nonnull() }, StyleValueList::Separator::Space);
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}
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case DescriptorMetadata::ValueType::FamilyName:
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return parse_family_name_value(tokens);
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case DescriptorMetadata::ValueType::FontSrcList: {
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// "If a component value is parsed correctly and is of a font format or font tech that the UA
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// supports, add it to the list of supported sources. If parsing a component value results in a
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// parsing error or its format or tech are unsupported, do not add it to the list of supported
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// sources.
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// If there are no supported entries at the end of this process, the value for the src descriptor
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// is a parse error.
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// These parsing rules allow for graceful fallback of fonts for user agents which don’t support a
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// particular font tech or font format."
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// https://drafts.csswg.org/css-fonts-4/#font-face-src-parsing
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auto source_lists = parse_a_comma_separated_list_of_component_values(tokens);
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StyleValueVector valid_sources;
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for (auto const& source_list : source_lists) {
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TokenStream source_tokens { source_list };
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if (auto font_source = parse_font_source_value(source_tokens); font_source && !source_tokens.has_next_token())
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valid_sources.append(font_source.release_nonnull());
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}
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if (valid_sources.is_empty())
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return nullptr;
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return StyleValueList::create(move(valid_sources), StyleValueList::Separator::Comma);
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}
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case DescriptorMetadata::ValueType::Length:
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return parse_length_value(tokens);
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case DescriptorMetadata::ValueType::OptionalDeclarationValue: {
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// `component_values` already has what we want. Just skip through its tokens so code below knows we consumed them.
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while (tokens.has_next_token())
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tokens.discard_a_token();
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return UnresolvedStyleValue::create(move(component_values));
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}
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case DescriptorMetadata::ValueType::PageSize: {
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// https://drafts.csswg.org/css-page-3/#page-size-prop
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// <length [0,∞]>{1,2} | auto | [ <page-size> || [ portrait | landscape ] ]
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// auto
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if (auto value = parse_all_as_single_keyword_value(tokens, Keyword::Auto))
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return value.release_nonnull();
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// <length [0,∞]>{1,2}
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if (auto first_length = parse_length_value(tokens)) {
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if (first_length->is_length() && first_length->as_length().raw_value() < 0)
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return nullptr;
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tokens.discard_whitespace();
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if (auto second_length = parse_length_value(tokens)) {
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if (second_length->is_length() && second_length->as_length().raw_value() < 0)
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return nullptr;
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return StyleValueList::create(StyleValueVector { first_length.release_nonnull(), second_length.release_nonnull() }, StyleValueList::Separator::Space);
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}
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return first_length.release_nonnull();
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}
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// [ <page-size> || [ portrait | landscape ] ]
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RefPtr<StyleValue const> page_size;
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RefPtr<StyleValue const> orientation;
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if (auto first_keyword = parse_keyword_value(tokens)) {
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if (first_is_one_of(first_keyword->to_keyword(), Keyword::Landscape, Keyword::Portrait)) {
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orientation = first_keyword.release_nonnull();
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} else if (keyword_to_page_size(first_keyword->to_keyword()).has_value()) {
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page_size = first_keyword.release_nonnull();
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} else {
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return nullptr;
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}
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} else {
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return nullptr;
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}
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tokens.discard_whitespace();
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if (auto second_keyword = parse_keyword_value(tokens)) {
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if (orientation.is_null() && first_is_one_of(second_keyword->to_keyword(), Keyword::Landscape, Keyword::Portrait)) {
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orientation = second_keyword.release_nonnull();
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} else if (page_size.is_null() && keyword_to_page_size(second_keyword->to_keyword()).has_value()) {
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page_size = second_keyword.release_nonnull();
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} else {
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return nullptr;
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}
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// Portrait is considered the default orientation, so don't include it.
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if (orientation->to_keyword() == Keyword::Portrait)
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return page_size.release_nonnull();
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return StyleValueList::create(StyleValueVector { page_size.release_nonnull(), orientation.release_nonnull() }, StyleValueList::Separator::Space);
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}
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return page_size ? page_size.release_nonnull() : orientation.release_nonnull();
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}
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case DescriptorMetadata::ValueType::PositivePercentage: {
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if (auto percentage_value = parse_percentage_value(tokens)) {
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if (percentage_value->is_percentage()) {
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if (percentage_value->as_percentage().raw_value() < 0)
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return nullptr;
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return percentage_value.release_nonnull();
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}
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// All calculations in descriptors must be resolvable at parse-time.
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if (percentage_value->is_calculated()) {
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auto percentage = percentage_value->as_calculated().resolve_percentage_deprecated({});
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if (percentage.has_value() && percentage->value() >= 0)
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return PercentageStyleValue::create(percentage.release_value());
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return nullptr;
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}
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}
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return nullptr;
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}
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case DescriptorMetadata::ValueType::String:
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return parse_string_value(tokens);
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case DescriptorMetadata::ValueType::UnicodeRangeTokens: {
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return parse_comma_separated_value_list(tokens, [this](auto& tokens) -> RefPtr<StyleValue const> {
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return parse_unicode_range_value(tokens);
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});
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}
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}
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return nullptr;
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});
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if (!parsed_style_value || tokens.has_next_token())
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continue;
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transaction.commit();
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return parsed_style_value.release_nonnull();
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}
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ErrorReporter::the().report(InvalidPropertyError {
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.rule_name = to_string(at_rule_id),
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.property_name = to_string(descriptor_id),
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.value_string = tokens.dump_string(),
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.description = "Failed to parse."_string,
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});
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return ParseError::SyntaxError;
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}
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Optional<Descriptor> Parser::convert_to_descriptor(AtRuleID at_rule_id, Declaration const& declaration)
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{
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auto descriptor_id = descriptor_id_from_string(at_rule_id, declaration.name);
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if (!descriptor_id.has_value())
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return {};
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auto value_token_stream = TokenStream(declaration.value);
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auto value = parse_descriptor_value(at_rule_id, descriptor_id.value(), value_token_stream);
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if (value.is_error())
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return {};
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return Descriptor { *descriptor_id, value.release_value() };
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}
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}
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