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ladybird/Libraries/LibWeb/CSS/Parser/CSSParser.cpp
Luke 043b31ad9a LibWeb: Add pc CSS unit
2020-10-05 20:05:40 +02:00

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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/HashMap.h>
#include <LibWeb/CSS/Parser/CSSParser.h>
#include <LibWeb/CSS/PropertyID.h>
#include <LibWeb/CSS/StyleSheet.h>
#include <LibWeb/DOM/Document.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define PARSE_ASSERT(x) \
if (!(x)) { \
dbg() << "CSS PARSER ASSERTION FAILED: " << #x; \
dbg() << "At character# " << index << " in CSS: _" << css << "_"; \
ASSERT_NOT_REACHED(); \
}
#define PARSE_ERROR() \
do { \
dbg() << "CSS parse error"; \
} while (0)
namespace Web {
namespace CSS {
ParsingContext::ParsingContext()
{
}
ParsingContext::ParsingContext(const DOM::Document& document)
: m_document(&document)
{
}
ParsingContext::ParsingContext(const DOM::ParentNode& parent_node)
: m_document(&parent_node.document())
{
}
bool ParsingContext::in_quirks_mode() const
{
return m_document ? m_document->in_quirks_mode() : false;
}
}
static CSS::ValueID value_id_for_palette_string(const StringView& string)
{
if (string == "desktop-background")
return CSS::ValueID::VendorSpecificPaletteDesktopBackground;
else if (string == "active-window-border1")
return CSS::ValueID::VendorSpecificPaletteActiveWindowBorder1;
else if (string == "active-window-border2")
return CSS::ValueID::VendorSpecificPaletteActiveWindowBorder2;
else if (string == "active-window-title")
return CSS::ValueID::VendorSpecificPaletteActiveWindowTitle;
else if (string == "inactive-window-border1")
return CSS::ValueID::VendorSpecificPaletteInactiveWindowBorder1;
else if (string == "inactive-window-border2")
return CSS::ValueID::VendorSpecificPaletteInactiveWindowBorder2;
else if (string == "inactive-window-title")
return CSS::ValueID::VendorSpecificPaletteInactiveWindowTitle;
else if (string == "moving-window-border1")
return CSS::ValueID::VendorSpecificPaletteMovingWindowBorder1;
else if (string == "moving-window-border2")
return CSS::ValueID::VendorSpecificPaletteMovingWindowBorder2;
else if (string == "moving-window-title")
return CSS::ValueID::VendorSpecificPaletteMovingWindowTitle;
else if (string == "highlight-window-border1")
return CSS::ValueID::VendorSpecificPaletteHighlightWindowBorder1;
else if (string == "highlight-window-border2")
return CSS::ValueID::VendorSpecificPaletteHighlightWindowBorder2;
else if (string == "highlight-window-title")
return CSS::ValueID::VendorSpecificPaletteHighlightWindowTitle;
else if (string == "menu-stripe")
return CSS::ValueID::VendorSpecificPaletteMenuStripe;
else if (string == "menu-base")
return CSS::ValueID::VendorSpecificPaletteMenuBase;
else if (string == "menu-base-text")
return CSS::ValueID::VendorSpecificPaletteMenuBaseText;
else if (string == "menu-selection")
return CSS::ValueID::VendorSpecificPaletteMenuSelection;
else if (string == "menu-selection-text")
return CSS::ValueID::VendorSpecificPaletteMenuSelectionText;
else if (string == "window")
return CSS::ValueID::VendorSpecificPaletteWindow;
else if (string == "window-text")
return CSS::ValueID::VendorSpecificPaletteWindowText;
else if (string == "button")
return CSS::ValueID::VendorSpecificPaletteButton;
else if (string == "button-text")
return CSS::ValueID::VendorSpecificPaletteButtonText;
else if (string == "base")
return CSS::ValueID::VendorSpecificPaletteBase;
else if (string == "base-text")
return CSS::ValueID::VendorSpecificPaletteBaseText;
else if (string == "threed-highlight")
return CSS::ValueID::VendorSpecificPaletteThreedHighlight;
else if (string == "threed-shadow1")
return CSS::ValueID::VendorSpecificPaletteThreedShadow1;
else if (string == "threed-shadow2")
return CSS::ValueID::VendorSpecificPaletteThreedShadow2;
else if (string == "hover-highlight")
return CSS::ValueID::VendorSpecificPaletteHoverHighlight;
else if (string == "selection")
return CSS::ValueID::VendorSpecificPaletteSelection;
else if (string == "selection-text")
return CSS::ValueID::VendorSpecificPaletteSelectionText;
else if (string == "inactive-selection")
return CSS::ValueID::VendorSpecificPaletteInactiveSelection;
else if (string == "inactive-selection-text")
return CSS::ValueID::VendorSpecificPaletteInactiveSelectionText;
else if (string == "rubber-band-fill")
return CSS::ValueID::VendorSpecificPaletteRubberBandFill;
else if (string == "rubber-band-border")
return CSS::ValueID::VendorSpecificPaletteRubberBandBorder;
else if (string == "link")
return CSS::ValueID::VendorSpecificPaletteLink;
else if (string == "active-link")
return CSS::ValueID::VendorSpecificPaletteActiveLink;
else if (string == "visited-link")
return CSS::ValueID::VendorSpecificPaletteVisitedLink;
else if (string == "ruler")
return CSS::ValueID::VendorSpecificPaletteRuler;
else if (string == "ruler-border")
return CSS::ValueID::VendorSpecificPaletteRulerBorder;
else if (string == "ruler-active-text")
return CSS::ValueID::VendorSpecificPaletteRulerActiveText;
else if (string == "ruler-inactive-text")
return CSS::ValueID::VendorSpecificPaletteRulerInactiveText;
else if (string == "text-cursor")
return CSS::ValueID::VendorSpecificPaletteTextCursor;
else if (string == "focus-outline")
return CSS::ValueID::VendorSpecificPaletteFocusOutline;
else if (string == "syntax-comment")
return CSS::ValueID::VendorSpecificPaletteSyntaxComment;
else if (string == "syntax-number")
return CSS::ValueID::VendorSpecificPaletteSyntaxNumber;
else if (string == "syntax-string")
return CSS::ValueID::VendorSpecificPaletteSyntaxString;
else if (string == "syntax-type")
return CSS::ValueID::VendorSpecificPaletteSyntaxType;
else if (string == "syntax-punctuation")
return CSS::ValueID::VendorSpecificPaletteSyntaxPunctuation;
else if (string == "syntax-operator")
return CSS::ValueID::VendorSpecificPaletteSyntaxOperator;
else if (string == "syntax-keyword")
return CSS::ValueID::VendorSpecificPaletteSyntaxKeyword;
else if (string == "syntax-control-keyword")
return CSS::ValueID::VendorSpecificPaletteSyntaxControlKeyword;
else if (string == "syntax-identifier")
return CSS::ValueID::VendorSpecificPaletteSyntaxIdentifier;
else if (string == "syntax-preprocessor-statement")
return CSS::ValueID::VendorSpecificPaletteSyntaxPreprocessorStatement;
else if (string == "syntax-preprocessor-value")
return CSS::ValueID::VendorSpecificPaletteSyntaxPreprocessorValue;
else
return CSS::ValueID::Invalid;
}
static Optional<Color> parse_css_color(const CSS::ParsingContext&, const StringView& view)
{
if (view.equals_ignoring_case("transparent"))
return Color::from_rgba(0x00000000);
auto color = Color::from_string(view.to_string().to_lowercase());
if (color.has_value())
return color;
return {};
}
static Optional<float> try_parse_float(const StringView& string)
{
const char* str = string.characters_without_null_termination();
size_t len = string.length();
size_t weight = 1;
int exp_val = 0;
float value = 0.0f;
float fraction = 0.0f;
bool has_sign = false;
bool is_negative = false;
bool is_fractional = false;
bool is_scientific = false;
if (str[0] == '-') {
is_negative = true;
has_sign = true;
}
if (str[0] == '+') {
has_sign = true;
}
for (size_t i = has_sign; i < len; i++) {
// Looks like we're about to start working on the fractional part
if (str[i] == '.') {
is_fractional = true;
continue;
}
if (str[i] == 'e' || str[i] == 'E') {
if (str[i + 1] == '-' || str[i + 1] == '+')
exp_val = atoi(str + i + 2);
else
exp_val = atoi(str + i + 1);
is_scientific = true;
continue;
}
if (str[i] < '0' || str[i] > '9' || exp_val != 0) {
return {};
continue;
}
if (is_fractional) {
fraction *= 10;
fraction += str[i] - '0';
weight *= 10;
} else {
value = value * 10;
value += str[i] - '0';
}
}
fraction /= weight;
value += fraction;
if (is_scientific) {
bool divide = exp_val < 0;
if (divide)
exp_val *= -1;
for (int i = 0; i < exp_val; i++) {
if (divide)
value /= 10;
else
value *= 10;
}
}
return is_negative ? -value : value;
}
static CSS::Length parse_length(const CSS::ParsingContext& context, const StringView& view, bool& is_bad_length)
{
CSS::Length::Type type = CSS::Length::Type::Undefined;
Optional<float> value;
if (view.ends_with('%')) {
type = CSS::Length::Type::Percentage;
value = try_parse_float(view.substring_view(0, view.length() - 1));
} else if (view.ends_with("px", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Px;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("pt", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Pt;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("pc", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Pc;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("mm", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Mm;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("rem", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Rem;
value = try_parse_float(view.substring_view(0, view.length() - 3));
} else if (view.ends_with("em", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Em;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("ex", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Ex;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("vw", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Vw;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("vh", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Vh;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("vmax", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Vmax;
value = try_parse_float(view.substring_view(0, view.length() - 4));
} else if (view.ends_with("vmin", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Vmin;
value = try_parse_float(view.substring_view(0, view.length() - 4));
} else if (view.ends_with("cm", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Cm;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("in", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::In;
value = try_parse_float(view.substring_view(0, view.length() - 2));
} else if (view.ends_with("Q", CaseSensitivity::CaseInsensitive)) {
type = CSS::Length::Type::Q;
value = try_parse_float(view.substring_view(0, view.length() - 1));
} else if (view == "0") {
type = CSS::Length::Type::Px;
value = 0;
} else if (context.in_quirks_mode()) {
type = CSS::Length::Type::Px;
value = try_parse_float(view);
} else {
value = try_parse_float(view);
if (value.has_value())
is_bad_length = true;
}
if (!value.has_value())
return {};
return CSS::Length(value.value(), type);
}
RefPtr<CSS::StyleValue> parse_css_value(const CSS::ParsingContext& context, const StringView& string)
{
bool is_bad_length = false;
auto length = parse_length(context, string, is_bad_length);
if (is_bad_length)
return nullptr;
if (!length.is_undefined())
return CSS::LengthStyleValue::create(length);
if (string.equals_ignoring_case("inherit"))
return CSS::InheritStyleValue::create();
if (string.equals_ignoring_case("initial"))
return CSS::InitialStyleValue::create();
if (string.equals_ignoring_case("auto"))
return CSS::LengthStyleValue::create(CSS::Length::make_auto());
auto color = parse_css_color(context, string);
if (color.has_value())
return CSS::ColorStyleValue::create(color.value());
if (string == "-libweb-link")
return CSS::IdentifierStyleValue::create(CSS::ValueID::VendorSpecificLink);
else if (string.starts_with("-libweb-palette-")) {
auto value_id = value_id_for_palette_string(string.substring_view(16, string.length() - 16));
return CSS::IdentifierStyleValue::create(value_id);
}
return CSS::StringStyleValue::create(string);
}
RefPtr<CSS::LengthStyleValue> parse_line_width(const CSS::ParsingContext& context, const StringView& part)
{
auto value = parse_css_value(context, part);
if (value && value->is_length())
return static_ptr_cast<CSS::LengthStyleValue>(value);
return nullptr;
}
RefPtr<CSS::ColorStyleValue> parse_color(const CSS::ParsingContext& context, const StringView& part)
{
auto value = parse_css_value(context, part);
if (value && value->is_color())
return static_ptr_cast<CSS::ColorStyleValue>(value);
return nullptr;
}
RefPtr<CSS::StringStyleValue> parse_line_style(const CSS::ParsingContext& context, const StringView& part)
{
auto parsed_value = parse_css_value(context, part);
if (!parsed_value || !parsed_value->is_string())
return nullptr;
auto value = static_ptr_cast<CSS::StringStyleValue>(parsed_value);
if (value->to_string() == "dotted")
return value;
if (value->to_string() == "dashed")
return value;
if (value->to_string() == "solid")
return value;
if (value->to_string() == "double")
return value;
if (value->to_string() == "groove")
return value;
if (value->to_string() == "ridge")
return value;
return nullptr;
}
class CSSParser {
public:
CSSParser(const CSS::ParsingContext& context, const StringView& input)
: m_context(context)
, css(input)
{
}
bool next_is(const char* str) const
{
size_t len = strlen(str);
for (size_t i = 0; i < len; ++i) {
if (peek(i) != str[i])
return false;
}
return true;
}
char peek(size_t offset = 0) const
{
if ((index + offset) < css.length())
return css[index + offset];
return 0;
}
char consume_specific(char ch)
{
if (peek() != ch) {
dbg() << "peek() != '" << ch << "'";
}
if (peek() != ch) {
PARSE_ERROR();
}
PARSE_ASSERT(index < css.length());
++index;
return ch;
}
char consume_one()
{
PARSE_ASSERT(index < css.length());
return css[index++];
};
bool consume_whitespace_or_comments()
{
size_t original_index = index;
bool in_comment = false;
for (; index < css.length(); ++index) {
char ch = peek();
if (isspace(ch))
continue;
if (!in_comment && ch == '/' && peek(1) == '*') {
in_comment = true;
++index;
continue;
}
if (in_comment && ch == '*' && peek(1) == '/') {
in_comment = false;
++index;
continue;
}
if (in_comment)
continue;
break;
}
return original_index != index;
}
bool is_valid_selector_char(char ch) const
{
return isalnum(ch) || ch == '-' || ch == '_' || ch == '(' || ch == ')' || ch == '@';
}
bool is_combinator(char ch) const
{
return ch == '~' || ch == '>' || ch == '+';
}
Optional<CSS::Selector::SimpleSelector> parse_simple_selector()
{
auto index_at_start = index;
if (consume_whitespace_or_comments())
return {};
if (!peek() || peek() == '{' || peek() == ',' || is_combinator(peek()))
return {};
CSS::Selector::SimpleSelector::Type type;
if (peek() == '*') {
type = CSS::Selector::SimpleSelector::Type::Universal;
consume_one();
return CSS::Selector::SimpleSelector {
type,
CSS::Selector::SimpleSelector::PseudoClass::None,
String(),
CSS::Selector::SimpleSelector::AttributeMatchType::None,
String(),
String()
};
}
if (peek() == '.') {
type = CSS::Selector::SimpleSelector::Type::Class;
consume_one();
} else if (peek() == '#') {
type = CSS::Selector::SimpleSelector::Type::Id;
consume_one();
} else if (isalpha(peek())) {
type = CSS::Selector::SimpleSelector::Type::TagName;
} else {
type = CSS::Selector::SimpleSelector::Type::Universal;
}
if (type != CSS::Selector::SimpleSelector::Type::Universal) {
while (is_valid_selector_char(peek()))
buffer.append(consume_one());
PARSE_ASSERT(!buffer.is_null());
}
auto value = String::copy(buffer);
if (type == CSS::Selector::SimpleSelector::Type::TagName) {
// Some stylesheets use uppercase tag names, so here's a hack to just lowercase them internally.
value = value.to_lowercase();
}
CSS::Selector::SimpleSelector simple_selector {
type,
CSS::Selector::SimpleSelector::PseudoClass::None,
value,
CSS::Selector::SimpleSelector::AttributeMatchType::None,
String(),
String()
};
buffer.clear();
if (peek() == '[') {
CSS::Selector::SimpleSelector::AttributeMatchType attribute_match_type = CSS::Selector::SimpleSelector::AttributeMatchType::HasAttribute;
String attribute_name;
String attribute_value;
bool in_value = false;
consume_specific('[');
char expected_end_of_attribute_selector = ']';
while (peek() != expected_end_of_attribute_selector) {
char ch = consume_one();
if (ch == '=' || (ch == '~' && peek() == '=')) {
if (ch == '=') {
attribute_match_type = CSS::Selector::SimpleSelector::AttributeMatchType::ExactValueMatch;
} else if (ch == '~') {
consume_one();
attribute_match_type = CSS::Selector::SimpleSelector::AttributeMatchType::Contains;
}
attribute_name = String::copy(buffer);
buffer.clear();
in_value = true;
consume_whitespace_or_comments();
if (peek() == '\'') {
expected_end_of_attribute_selector = '\'';
consume_one();
} else if (peek() == '"') {
expected_end_of_attribute_selector = '"';
consume_one();
}
continue;
}
// FIXME: This is a hack that will go away when we replace this with a big boy CSS parser.
if (ch == '\\')
ch = consume_one();
buffer.append(ch);
}
if (in_value)
attribute_value = String::copy(buffer);
else
attribute_name = String::copy(buffer);
buffer.clear();
simple_selector.attribute_match_type = attribute_match_type;
simple_selector.attribute_name = attribute_name;
simple_selector.attribute_value = attribute_value;
if (expected_end_of_attribute_selector != ']')
consume_specific(expected_end_of_attribute_selector);
consume_whitespace_or_comments();
consume_specific(']');
}
if (peek() == ':') {
// FIXME: Implement pseudo elements.
[[maybe_unused]] bool is_pseudo_element = false;
consume_one();
if (peek() == ':') {
is_pseudo_element = true;
consume_one();
}
if (next_is("not")) {
buffer.append(consume_one());
buffer.append(consume_one());
buffer.append(consume_one());
buffer.append(consume_specific('('));
while (peek() != ')')
buffer.append(consume_one());
buffer.append(consume_specific(')'));
} else {
while (is_valid_selector_char(peek()))
buffer.append(consume_one());
}
auto pseudo_name = String::copy(buffer);
buffer.clear();
// Ignore for now, otherwise we produce a "false positive" selector
// and apply styles to the element itself, not its pseudo element
if (is_pseudo_element)
return {};
if (pseudo_name.equals_ignoring_case("link"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::Link;
else if (pseudo_name.equals_ignoring_case("visited"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::Visited;
else if (pseudo_name.equals_ignoring_case("hover"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::Hover;
else if (pseudo_name.equals_ignoring_case("focus"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::Focus;
else if (pseudo_name.equals_ignoring_case("first-child"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::FirstChild;
else if (pseudo_name.equals_ignoring_case("last-child"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::LastChild;
else if (pseudo_name.equals_ignoring_case("only-child"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::OnlyChild;
else if (pseudo_name.equals_ignoring_case("empty"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::Empty;
else if (pseudo_name.equals_ignoring_case("root"))
simple_selector.pseudo_class = CSS::Selector::SimpleSelector::PseudoClass::Root;
}
if (index == index_at_start) {
// We consumed nothing.
return {};
}
return simple_selector;
}
Optional<CSS::Selector::ComplexSelector> parse_complex_selector()
{
auto relation = CSS::Selector::ComplexSelector::Relation::Descendant;
if (peek() == '{' || peek() == ',')
return {};
if (is_combinator(peek())) {
switch (peek()) {
case '>':
relation = CSS::Selector::ComplexSelector::Relation::ImmediateChild;
break;
case '+':
relation = CSS::Selector::ComplexSelector::Relation::AdjacentSibling;
break;
case '~':
relation = CSS::Selector::ComplexSelector::Relation::GeneralSibling;
break;
}
consume_one();
consume_whitespace_or_comments();
}
consume_whitespace_or_comments();
Vector<CSS::Selector::SimpleSelector> simple_selectors;
for (;;) {
auto component = parse_simple_selector();
if (!component.has_value())
break;
simple_selectors.append(component.value());
// If this assert triggers, we're most likely up to no good.
PARSE_ASSERT(simple_selectors.size() < 100);
}
if (simple_selectors.is_empty())
return {};
return CSS::Selector::ComplexSelector { relation, move(simple_selectors) };
}
void parse_selector()
{
Vector<CSS::Selector::ComplexSelector> complex_selectors;
for (;;) {
auto index_before = index;
auto complex_selector = parse_complex_selector();
if (complex_selector.has_value())
complex_selectors.append(complex_selector.value());
consume_whitespace_or_comments();
if (!peek() || peek() == ',' || peek() == '{')
break;
// HACK: If we didn't move forward, just let go.
if (index == index_before)
break;
}
if (complex_selectors.is_empty())
return;
complex_selectors.first().relation = CSS::Selector::ComplexSelector::Relation::None;
current_rule.selectors.append(CSS::Selector(move(complex_selectors)));
}
Optional<CSS::Selector> parse_individual_selector()
{
parse_selector();
if (current_rule.selectors.is_empty())
return {};
return current_rule.selectors.last();
}
void parse_selector_list()
{
for (;;) {
auto index_before = index;
parse_selector();
consume_whitespace_or_comments();
if (peek() == ',') {
consume_one();
continue;
}
if (peek() == '{')
break;
// HACK: If we didn't move forward, just let go.
if (index_before == index)
break;
}
}
bool is_valid_property_name_char(char ch) const
{
return ch && !isspace(ch) && ch != ':';
}
bool is_valid_property_value_char(char ch) const
{
return ch && ch != '!' && ch != ';' && ch != '}';
}
struct ValueAndImportant {
String value;
bool important { false };
};
ValueAndImportant consume_css_value()
{
buffer.clear();
int paren_nesting_level = 0;
bool important = false;
for (;;) {
char ch = peek();
if (ch == '(') {
++paren_nesting_level;
buffer.append(consume_one());
continue;
}
if (ch == ')') {
PARSE_ASSERT(paren_nesting_level > 0);
--paren_nesting_level;
buffer.append(consume_one());
continue;
}
if (paren_nesting_level > 0) {
buffer.append(consume_one());
continue;
}
if (next_is("!important")) {
consume_specific('!');
consume_specific('i');
consume_specific('m');
consume_specific('p');
consume_specific('o');
consume_specific('r');
consume_specific('t');
consume_specific('a');
consume_specific('n');
consume_specific('t');
important = true;
continue;
}
if (next_is("/*")) {
consume_whitespace_or_comments();
continue;
}
if (!ch)
break;
if (ch == '\\') {
consume_one();
buffer.append(consume_one());
continue;
}
if (ch == '}')
break;
if (ch == ';')
break;
buffer.append(consume_one());
}
// Remove trailing whitespace.
while (!buffer.is_empty() && isspace(buffer.last()))
buffer.take_last();
auto string = String::copy(buffer);
buffer.clear();
return { string, important };
}
Optional<CSS::StyleProperty> parse_property()
{
consume_whitespace_or_comments();
if (peek() == ';') {
consume_one();
return {};
}
if (peek() == '}')
return {};
buffer.clear();
while (is_valid_property_name_char(peek()))
buffer.append(consume_one());
auto property_name = String::copy(buffer);
buffer.clear();
consume_whitespace_or_comments();
consume_specific(':');
consume_whitespace_or_comments();
auto [property_value, important] = consume_css_value();
consume_whitespace_or_comments();
if (peek() && peek() != '}')
consume_specific(';');
auto property_id = CSS::property_id_from_string(property_name);
if (property_id == CSS::PropertyID::Invalid) {
dbg() << "CSSParser: Unrecognized property '" << property_name << "'";
}
auto value = parse_css_value(m_context, property_value);
if (!value)
return {};
return CSS::StyleProperty { property_id, value.release_nonnull(), important };
}
void parse_declaration()
{
for (;;) {
auto property = parse_property();
if (property.has_value())
current_rule.properties.append(property.value());
consume_whitespace_or_comments();
if (peek() == '}')
break;
}
}
void parse_rule()
{
consume_whitespace_or_comments();
if (index >= css.length())
return;
// FIXME: We ignore @-rules for now.
if (peek() == '@') {
while (peek() != '{')
consume_one();
int level = 0;
for (;;) {
auto ch = consume_one();
if (ch == '{') {
++level;
} else if (ch == '}') {
--level;
if (level == 0)
break;
}
}
consume_whitespace_or_comments();
return;
}
parse_selector_list();
consume_specific('{');
parse_declaration();
consume_specific('}');
rules.append(CSS::StyleRule::create(move(current_rule.selectors), CSS::StyleDeclaration::create(move(current_rule.properties))));
consume_whitespace_or_comments();
}
RefPtr<CSS::StyleSheet> parse_sheet()
{
while (index < css.length()) {
parse_rule();
}
return CSS::StyleSheet::create(move(rules));
}
RefPtr<CSS::StyleDeclaration> parse_standalone_declaration()
{
consume_whitespace_or_comments();
for (;;) {
auto property = parse_property();
if (property.has_value())
current_rule.properties.append(property.value());
consume_whitespace_or_comments();
if (!peek())
break;
}
return CSS::StyleDeclaration::create(move(current_rule.properties));
}
private:
CSS::ParsingContext m_context;
NonnullRefPtrVector<CSS::StyleRule> rules;
struct CurrentRule {
Vector<CSS::Selector> selectors;
Vector<CSS::StyleProperty> properties;
};
CurrentRule current_rule;
Vector<char> buffer;
size_t index = 0;
StringView css;
};
Optional<CSS::Selector> parse_selector(const CSS::ParsingContext& context, const StringView& selector_text)
{
CSSParser parser(context, selector_text);
return parser.parse_individual_selector();
}
RefPtr<CSS::StyleSheet> parse_css(const CSS::ParsingContext& context, const StringView& css)
{
if (css.is_empty())
return CSS::StyleSheet::create({});
CSSParser parser(context, css);
return parser.parse_sheet();
}
RefPtr<CSS::StyleDeclaration> parse_css_declaration(const CSS::ParsingContext& context, const StringView& css)
{
if (css.is_empty())
return CSS::StyleDeclaration::create({});
CSSParser parser(context, css);
return parser.parse_standalone_declaration();
}
RefPtr<CSS::StyleValue> parse_html_length(const DOM::Document& document, const StringView& string)
{
auto integer = string.to_int();
if (integer.has_value())
return CSS::LengthStyleValue::create(CSS::Length::make_px(integer.value()));
return parse_css_value(CSS::ParsingContext(document), string);
}
}
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