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ladybird/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
Sam Atkins 6034fc0ee6 LibWeb: Make CSS 'An+B' parsing spec-compliant 
Parsing this pattern from CSS tokens turns out to be slightly crazy, but
thankfully well documented in the spec.

The spec lists the cases in order of simple -> complicated, but this
would cause problems in code, since `<n-dimension> <signed-.integer>`
would never by reached, as `<n-dimension>` comes before. Instead, I
have grouped them by their first token.

Also renamed the NthChildPattern class to ANPlusBPattern, to match spec
terminology.
2021-07-31 00:18:11 +02:00

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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2020-2021, the SerenityOS developers.
* Copyright (c) 2021, Sam Atkins <atkinssj@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/CharacterTypes.h>
#include <AK/Debug.h>
#include <AK/NonnullRefPtrVector.h>
#include <AK/SourceLocation.h>
#include <LibWeb/CSS/CSSStyleDeclaration.h>
#include <LibWeb/CSS/CSSStyleRule.h>
#include <LibWeb/CSS/CSSStyleSheet.h>
#include <LibWeb/CSS/Parser/DeclarationOrAtRule.h>
#include <LibWeb/CSS/Parser/Parser.h>
#include <LibWeb/CSS/Parser/StyleBlockRule.h>
#include <LibWeb/CSS/Parser/StyleComponentValueRule.h>
#include <LibWeb/CSS/Parser/StyleFunctionRule.h>
#include <LibWeb/CSS/Parser/StyleRule.h>
#include <LibWeb/CSS/Selector.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/Dump.h>
static void log_parse_error(const SourceLocation& location = SourceLocation::current())
{
dbgln_if(CSS_PARSER_DEBUG, "Parse error (CSS) {}", location);
}
namespace Web::CSS {
ParsingContext::ParsingContext()
{
}
ParsingContext::ParsingContext(DOM::Document& document)
: m_document(&document)
{
}
ParsingContext::ParsingContext(DOM::ParentNode& parent_node)
: m_document(&parent_node.document())
{
}
bool ParsingContext::in_quirks_mode() const
{
return m_document ? m_document->in_quirks_mode() : false;
}
URL ParsingContext::complete_url(String const& addr) const
{
return m_document ? m_document->url().complete_url(addr) : URL::create_with_url_or_path(addr);
}
template<typename T>
TokenStream<T>::TokenStream(Vector<T> const& tokens)
: m_tokens(tokens)
, m_eof(make_eof())
{
}
template<typename T>
TokenStream<T>::~TokenStream()
{
}
template<typename T>
bool TokenStream<T>::has_next_token()
{
return (size_t)(m_iterator_offset + 1) < m_tokens.size();
}
template<typename T>
T const& TokenStream<T>::peek_token()
{
if (!has_next_token())
return m_eof;
return m_tokens.at(m_iterator_offset + 1);
}
template<typename T>
T const& TokenStream<T>::next_token()
{
if (!has_next_token())
return m_eof;
++m_iterator_offset;
return m_tokens.at(m_iterator_offset);
}
template<typename T>
T const& TokenStream<T>::current_token()
{
if ((size_t)m_iterator_offset >= m_tokens.size())
return m_eof;
return m_tokens.at(m_iterator_offset);
}
template<typename T>
void TokenStream<T>::reconsume_current_input_token()
{
VERIFY(m_iterator_offset >= 0);
--m_iterator_offset;
}
template<typename T>
void TokenStream<T>::skip_whitespace()
{
while (peek_token().is(Token::Type::Whitespace))
next_token();
}
template<>
Token TokenStream<Token>::make_eof()
{
return Tokenizer::create_eof_token();
}
template<>
StyleComponentValueRule TokenStream<StyleComponentValueRule>::make_eof()
{
return StyleComponentValueRule(Tokenizer::create_eof_token());
}
template<typename T>
void TokenStream<T>::dump_all_tokens()
{
dbgln("Dumping all tokens:");
for (size_t i = 0; i < m_tokens.size(); ++i) {
auto& token = m_tokens[i];
if ((i - 1) == (size_t)m_iterator_offset)
dbgln("-> {}", token.to_debug_string());
else
dbgln(" {}", token.to_debug_string());
}
}
Parser::Parser(ParsingContext const& context, StringView const& input, String const& encoding)
: m_context(context)
, m_tokenizer(input, encoding)
, m_tokens(m_tokenizer.parse())
, m_token_stream(TokenStream(m_tokens))
{
}
Parser::~Parser()
{
}
NonnullRefPtr<CSSStyleSheet> Parser::parse_as_stylesheet()
{
return parse_as_stylesheet(m_token_stream);
}
template<typename T>
NonnullRefPtr<CSSStyleSheet> Parser::parse_as_stylesheet(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_as_stylesheet");
auto parser_rules = consume_a_list_of_rules(tokens, true);
NonnullRefPtrVector<CSSRule> rules;
for (auto& raw_rule : parser_rules) {
auto rule = convert_to_rule(raw_rule);
if (rule)
rules.append(*rule);
}
auto stylesheet = CSSStyleSheet::create(rules);
dump_sheet(stylesheet);
return stylesheet;
}
Optional<SelectorList> Parser::parse_a_selector()
{
return parse_a_selector(m_token_stream);
}
template<typename T>
Optional<SelectorList> Parser::parse_a_selector(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_a_selector");
auto selector_list = parse_a_selector_list(tokens);
if (selector_list.has_value())
return selector_list;
return {};
}
Optional<SelectorList> Parser::parse_a_relative_selector()
{
return parse_a_relative_selector(m_token_stream);
}
template<typename T>
Optional<SelectorList> Parser::parse_a_relative_selector(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_a_relative_selector");
auto selector_list = parse_a_relative_selector_list(tokens);
if (selector_list.has_value())
return selector_list;
return {};
}
template<typename T>
Optional<SelectorList> Parser::parse_a_selector_list(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_a_selector_list");
auto comma_separated_lists = parse_as_comma_separated_list_of_component_values(tokens);
NonnullRefPtrVector<Selector> selectors;
for (auto& selector_parts : comma_separated_lists) {
auto stream = TokenStream(selector_parts);
auto selector = parse_complex_selector(stream, false);
if (selector)
selectors.append(selector.release_nonnull());
else
return {};
}
if (selectors.is_empty())
return {};
return selectors;
}
template<typename T>
Optional<SelectorList> Parser::parse_a_relative_selector_list(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_a_relative_selector_list");
auto comma_separated_lists = parse_as_comma_separated_list_of_component_values(tokens);
NonnullRefPtrVector<Selector> selectors;
for (auto& selector_parts : comma_separated_lists) {
auto stream = TokenStream(selector_parts);
auto selector = parse_complex_selector(stream, true);
if (selector)
selectors.append(selector.release_nonnull());
else
return {};
}
if (selectors.is_empty())
return {};
return selectors;
}
RefPtr<Selector> Parser::parse_complex_selector(TokenStream<StyleComponentValueRule>& tokens, bool allow_starting_combinator)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_complex_selector");
Vector<Selector::CompoundSelector> compound_selectors;
auto first_selector = parse_compound_selector(tokens);
if (first_selector.is_error())
return {};
if (!allow_starting_combinator) {
if (first_selector.value().combinator != Selector::Combinator::Descendant)
return {};
first_selector.value().combinator = Selector::Combinator::None;
}
compound_selectors.append(first_selector.value());
while (tokens.has_next_token()) {
auto compound_selector = parse_compound_selector(tokens);
if (compound_selector.is_error()) {
if (compound_selector.error() == SelectorParsingResult::Done)
break;
else
return {};
}
compound_selectors.append(compound_selector.value());
}
if (compound_selectors.is_empty())
return {};
return Selector::create(move(compound_selectors));
}
Result<Selector::CompoundSelector, Parser::SelectorParsingResult> Parser::parse_compound_selector(TokenStream<StyleComponentValueRule>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_compound_selector");
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 = parse_simple_selector(tokens);
if (component.is_error()) {
if (component.error() == SelectorParsingResult::Done)
break;
else
return component.error();
}
simple_selectors.append(component.value());
}
if (simple_selectors.is_empty())
return SelectorParsingResult::Done;
return Selector::CompoundSelector { combinator, move(simple_selectors) };
}
Optional<Selector::Combinator> Parser::parse_selector_combinator(TokenStream<StyleComponentValueRule>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_selector_combinator");
auto& current_value = tokens.next_token();
if (current_value.is(Token::Type::Delim)) {
auto delim = current_value.token().delim();
if (delim == ">"sv) {
return Selector::Combinator::ImmediateChild;
} else if (delim == "+"sv) {
return Selector::Combinator::NextSibling;
} else if (delim == "~"sv) {
return Selector::Combinator::SubsequentSibling;
} else if (delim == "|"sv) {
auto& next = tokens.peek_token();
if (next.is(Token::Type::EndOfFile))
return {};
if (next.is(Token::Type::Delim) && next.token().delim() == "|"sv) {
tokens.next_token();
return Selector::Combinator::Column;
}
}
}
tokens.reconsume_current_input_token();
return {};
}
Result<Selector::SimpleSelector, Parser::SelectorParsingResult> Parser::parse_simple_selector(TokenStream<StyleComponentValueRule>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_simple_selector");
auto peek_token_ends_selector = [&]() -> bool {
auto& 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 SelectorParsingResult::Done;
auto& first_value = tokens.next_token();
if (first_value.is(Token::Type::Delim) && first_value.token().delim() == "*"sv) {
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::Universal
};
} else 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 SelectorParsingResult::SyntaxError;
}
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::Id,
.value = first_value.token().hash_value()
};
} else if (first_value.is(Token::Type::Delim) && first_value.token().delim() == "."sv) {
if (peek_token_ends_selector())
return SelectorParsingResult::SyntaxError;
auto& 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 SelectorParsingResult::SyntaxError;
}
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::Class,
.value = class_name_value.token().ident()
};
} else if (first_value.is(Token::Type::Ident)) {
return Selector::SimpleSelector {
.type = Selector::SimpleSelector::Type::TagName,
.value = first_value.token().ident()
};
} else if (first_value.is_block() && first_value.block().is_square()) {
auto& attribute_parts = first_value.block().values();
if (attribute_parts.is_empty()) {
dbgln_if(CSS_PARSER_DEBUG, "CSS attribute selector is empty!");
return SelectorParsingResult::SyntaxError;
}
// FIXME: Handle namespace prefix for attribute name.
auto& attribute_part = attribute_parts.first();
if (!attribute_part.is(Token::Type::Ident)) {
dbgln_if(CSS_PARSER_DEBUG, "Expected ident for attribute name, got: '{}'", attribute_part.to_debug_string());
return SelectorParsingResult::SyntaxError;
}
Selector::SimpleSelector simple_selector {
.type = Selector::SimpleSelector::Type::Attribute,
.attribute = {
.match_type = Selector::SimpleSelector::Attribute::MatchType::HasAttribute,
.name = attribute_part.token().ident(),
}
};
if (attribute_parts.size() == 1)
return simple_selector;
size_t attribute_index = 1;
auto& delim_part = attribute_parts.at(attribute_index);
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 SelectorParsingResult::SyntaxError;
}
if (delim_part.token().delim() == "="sv) {
simple_selector.attribute.match_type = Selector::SimpleSelector::Attribute::MatchType::ExactValueMatch;
attribute_index++;
} else {
attribute_index++;
if (attribute_index >= attribute_parts.size()) {
dbgln_if(CSS_PARSER_DEBUG, "Attribute selector ended part way through a match type.");
return SelectorParsingResult::SyntaxError;
}
auto& delim_second_part = attribute_parts.at(attribute_index);
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 SelectorParsingResult::SyntaxError;
}
if (delim_part.token().delim() == "~"sv) {
simple_selector.attribute.match_type = Selector::SimpleSelector::Attribute::MatchType::ContainsWord;
attribute_index++;
} else if (delim_part.token().delim() == "*"sv) {
simple_selector.attribute.match_type = Selector::SimpleSelector::Attribute::MatchType::ContainsString;
attribute_index++;
} else if (delim_part.token().delim() == "|"sv) {
simple_selector.attribute.match_type = Selector::SimpleSelector::Attribute::MatchType::StartsWithSegment;
attribute_index++;
} else if (delim_part.token().delim() == "^"sv) {
simple_selector.attribute.match_type = Selector::SimpleSelector::Attribute::MatchType::StartsWithString;
attribute_index++;
} else if (delim_part.token().delim() == "$"sv) {
simple_selector.attribute.match_type = Selector::SimpleSelector::Attribute::MatchType::EndsWithString;
attribute_index++;
}
}
if (attribute_index >= attribute_parts.size()) {
dbgln_if(CSS_PARSER_DEBUG, "Attribute selector ended without a value to match.");
return SelectorParsingResult::SyntaxError;
}
auto& value_part = attribute_parts.at(attribute_index);
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 SelectorParsingResult::SyntaxError;
}
simple_selector.attribute.value = value_part.token().is(Token::Type::Ident) ? value_part.token().ident() : value_part.token().string();
// FIXME: Handle case-sensitivity suffixes. https://www.w3.org/TR/selectors-4/#attribute-case
return simple_selector;
} else if (first_value.is(Token::Type::Colon)) {
if (peek_token_ends_selector())
return SelectorParsingResult::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 SelectorParsingResult::SyntaxError;
}
if (is_pseudo) {
Selector::SimpleSelector simple_selector {
.type = Selector::SimpleSelector::Type::PseudoElement
};
auto& 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 SelectorParsingResult::SyntaxError;
}
auto pseudo_name = name_token.token().ident();
if (pseudo_name.equals_ignoring_case("after")) {
simple_selector.pseudo_element = Selector::SimpleSelector::PseudoElement::After;
} else if (pseudo_name.equals_ignoring_case("before")) {
simple_selector.pseudo_element = Selector::SimpleSelector::PseudoElement::Before;
} else if (pseudo_name.equals_ignoring_case("first-letter")) {
simple_selector.pseudo_element = Selector::SimpleSelector::PseudoElement::FirstLetter;
} else if (pseudo_name.equals_ignoring_case("first-line")) {
simple_selector.pseudo_element = Selector::SimpleSelector::PseudoElement::FirstLine;
} else {
dbgln_if(CSS_PARSER_DEBUG, "Unrecognized pseudo-element: '{}'", pseudo_name);
return SelectorParsingResult::SyntaxError;
}
return simple_selector;
}
if (peek_token_ends_selector())
return SelectorParsingResult::SyntaxError;
auto& pseudo_class_token = tokens.next_token();
Selector::SimpleSelector simple_selector {
.type = Selector::SimpleSelector::Type::PseudoClass
};
if (pseudo_class_token.is(Token::Type::Ident)) {
auto pseudo_name = pseudo_class_token.token().ident();
if (pseudo_name.equals_ignoring_case("active")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Active;
} else if (pseudo_name.equals_ignoring_case("checked")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Checked;
} else if (pseudo_name.equals_ignoring_case("disabled")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Disabled;
} else if (pseudo_name.equals_ignoring_case("empty")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Empty;
} else if (pseudo_name.equals_ignoring_case("enabled")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Enabled;
} else if (pseudo_name.equals_ignoring_case("first-child")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::FirstChild;
} else if (pseudo_name.equals_ignoring_case("first-of-type")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::FirstOfType;
} else if (pseudo_name.equals_ignoring_case("focus")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Focus;
} else if (pseudo_name.equals_ignoring_case("hover")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Hover;
} else if (pseudo_name.equals_ignoring_case("last-child")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::LastChild;
} else if (pseudo_name.equals_ignoring_case("last-of-type")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::LastOfType;
} else if (pseudo_name.equals_ignoring_case("link")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Link;
} else if (pseudo_name.equals_ignoring_case("only-child")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::OnlyChild;
} else if (pseudo_name.equals_ignoring_case("root")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Root;
} else if (pseudo_name.equals_ignoring_case("visited")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Visited;
} else if (pseudo_name.equals_ignoring_case("after")) {
// Single-colon syntax allowed for compatibility. https://www.w3.org/TR/selectors/#pseudo-element-syntax
simple_selector.type = Selector::SimpleSelector::Type::PseudoElement;
simple_selector.pseudo_element = Selector::SimpleSelector::PseudoElement::After;
} else if (pseudo_name.equals_ignoring_case("before")) {
// See :after
simple_selector.type = Selector::SimpleSelector::Type::PseudoElement;
simple_selector.pseudo_element = Selector::SimpleSelector::PseudoElement::Before;
} else if (pseudo_name.equals_ignoring_case("first-letter")) {
// See :after
simple_selector.type = Selector::SimpleSelector::Type::PseudoElement;
simple_selector.pseudo_element = Selector::SimpleSelector::PseudoElement::FirstLetter;
} else if (pseudo_name.equals_ignoring_case("first-line")) {
// See :after
simple_selector.type = Selector::SimpleSelector::Type::PseudoElement;
simple_selector.pseudo_element = Selector::SimpleSelector::PseudoElement::FirstLine;
} else {
dbgln_if(CSS_PARSER_DEBUG, "Unknown pseudo class: '{}'", pseudo_name);
return SelectorParsingResult::SyntaxError;
}
return simple_selector;
} else if (pseudo_class_token.is_function()) {
auto& pseudo_function = pseudo_class_token.function();
if (pseudo_function.name().equals_ignoring_case("not")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::Not;
auto function_token_stream = TokenStream(pseudo_function.values());
auto not_selector = parse_a_selector(function_token_stream);
if (!not_selector.has_value()) {
dbgln_if(CSS_PARSER_DEBUG, "Invalid selector in :not() clause");
return SelectorParsingResult::SyntaxError;
}
simple_selector.pseudo_class.not_selector = not_selector.value();
} else if (pseudo_function.name().equals_ignoring_case("nth-child")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::NthChild;
auto function_values = TokenStream<StyleComponentValueRule>(pseudo_function.values());
auto nth_child_pattern = parse_a_n_plus_b_pattern(function_values);
if (nth_child_pattern.has_value()) {
simple_selector.pseudo_class.nth_child_pattern = nth_child_pattern.value();
} else {
dbgln_if(CSS_PARSER_DEBUG, "!!! Invalid nth-child format");
return SelectorParsingResult::SyntaxError;
}
} else if (pseudo_function.name().equals_ignoring_case("nth-last-child")) {
simple_selector.pseudo_class.type = Selector::SimpleSelector::PseudoClass::Type::NthLastChild;
auto function_values = TokenStream<StyleComponentValueRule>(pseudo_function.values());
auto nth_child_pattern = parse_a_n_plus_b_pattern(function_values);
if (nth_child_pattern.has_value()) {
simple_selector.pseudo_class.nth_child_pattern = nth_child_pattern.value();
} else {
dbgln_if(CSS_PARSER_DEBUG, "!!! Invalid nth-child format");
return SelectorParsingResult::SyntaxError;
}
} else {
dbgln_if(CSS_PARSER_DEBUG, "Unknown pseudo class: '{}'()", pseudo_function.name());
return SelectorParsingResult::SyntaxError;
}
return simple_selector;
} else {
dbgln_if(CSS_PARSER_DEBUG, "Unexpected Block in pseudo-class name, expected a function or identifier. '{}'", pseudo_class_token.to_debug_string());
return SelectorParsingResult::SyntaxError;
}
}
dbgln_if(CSS_PARSER_DEBUG, "!!! Invalid simple selector!");
return SelectorParsingResult::SyntaxError;
}
NonnullRefPtrVector<StyleRule> Parser::consume_a_list_of_rules(bool top_level)
{
return consume_a_list_of_rules(m_token_stream, top_level);
}
template<typename T>
NonnullRefPtrVector<StyleRule> Parser::consume_a_list_of_rules(TokenStream<T>& tokens, bool top_level)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_a_list_of_rules");
NonnullRefPtrVector<StyleRule> rules;
for (;;) {
auto& token = tokens.next_token();
if (token.is(Token::Type::Whitespace)) {
continue;
}
if (token.is(Token::Type::EndOfFile)) {
break;
}
if (token.is(Token::Type::CDO) || token.is(Token::Type::CDC)) {
if (top_level) {
continue;
}
tokens.reconsume_current_input_token();
auto maybe_qualified = consume_a_qualified_rule(tokens);
if (maybe_qualified) {
rules.append(maybe_qualified.release_nonnull());
}
continue;
}
if (token.is(Token::Type::AtKeyword)) {
tokens.reconsume_current_input_token();
rules.append(consume_an_at_rule(tokens));
continue;
}
tokens.reconsume_current_input_token();
auto maybe_qualified = consume_a_qualified_rule(tokens);
if (maybe_qualified) {
rules.append(maybe_qualified.release_nonnull());
}
}
return rules;
}
NonnullRefPtr<StyleRule> Parser::consume_an_at_rule()
{
return consume_an_at_rule(m_token_stream);
}
template<typename T>
NonnullRefPtr<StyleRule> Parser::consume_an_at_rule(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_an_at_rule");
auto& name_ident = tokens.next_token();
VERIFY(name_ident.is(Token::Type::AtKeyword));
NonnullRefPtr<StyleRule> rule = create<StyleRule>(StyleRule::Type::At);
rule->m_name = ((Token)name_ident).at_keyword();
for (;;) {
auto& token = tokens.next_token();
if (token.is(Token::Type::Semicolon)) {
return rule;
}
if (token.is(Token::Type::EndOfFile)) {
log_parse_error();
return rule;
}
if (token.is(Token::Type::OpenCurly)) {
rule->m_block = consume_a_simple_block(tokens);
return rule;
}
// how is "simple block with an associated token of <{-token>" a valid token?
tokens.reconsume_current_input_token();
auto value = consume_a_component_value(tokens);
rule->m_prelude.append(value);
}
}
RefPtr<StyleRule> Parser::consume_a_qualified_rule()
{
return consume_a_qualified_rule(m_token_stream);
}
template<typename T>
RefPtr<StyleRule> Parser::consume_a_qualified_rule(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_a_qualified_rule");
NonnullRefPtr<StyleRule> rule = create<StyleRule>(StyleRule::Type::Qualified);
for (;;) {
auto& token = tokens.next_token();
if (token.is(Token::Type::EndOfFile)) {
log_parse_error();
return {};
}
if (token.is(Token::Type::OpenCurly)) {
rule->m_block = consume_a_simple_block(tokens);
return rule;
}
// how is "simple block with an associated token of <{-token>" a valid token?
tokens.reconsume_current_input_token();
auto value = consume_a_component_value(tokens);
rule->m_prelude.append(value);
}
return rule;
}
template<>
StyleComponentValueRule Parser::consume_a_component_value(TokenStream<StyleComponentValueRule>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_a_component_value - shortcut: '{}'", tokens.peek_token().to_debug_string());
return tokens.next_token();
}
template<typename T>
StyleComponentValueRule Parser::consume_a_component_value(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_a_component_value");
auto& token = tokens.next_token();
if (token.is(Token::Type::OpenCurly) || token.is(Token::Type::OpenSquare) || token.is(Token::Type::OpenParen))
return StyleComponentValueRule(consume_a_simple_block(tokens));
if (token.is(Token::Type::Function))
return StyleComponentValueRule(consume_a_function(tokens));
return StyleComponentValueRule(token);
}
StyleComponentValueRule Parser::consume_a_component_value()
{
return consume_a_component_value(m_token_stream);
}
NonnullRefPtr<StyleBlockRule> Parser::consume_a_simple_block()
{
return consume_a_simple_block(m_token_stream);
}
template<typename T>
NonnullRefPtr<StyleBlockRule> Parser::consume_a_simple_block(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_a_simple_block");
auto ending_token = ((Token)tokens.current_token()).mirror_variant();
NonnullRefPtr<StyleBlockRule> block = create<StyleBlockRule>();
block->m_token = tokens.current_token();
for (;;) {
auto& token = tokens.next_token();
if (token.is(ending_token)) {
return block;
}
if (token.is(Token::Type::EndOfFile)) {
log_parse_error();
return block;
}
tokens.reconsume_current_input_token();
auto value = consume_a_component_value(tokens);
block->m_values.append(value);
}
}
NonnullRefPtr<StyleFunctionRule> Parser::consume_a_function()
{
return consume_a_function(m_token_stream);
}
template<typename T>
NonnullRefPtr<StyleFunctionRule> Parser::consume_a_function(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_a_function");
auto name_ident = tokens.current_token();
VERIFY(name_ident.is(Token::Type::Function));
NonnullRefPtr<StyleFunctionRule> function = create<StyleFunctionRule>(((Token)name_ident).m_value.to_string());
for (;;) {
auto& token = tokens.next_token();
if (token.is(Token::Type::CloseParen)) {
return function;
}
if (token.is(Token::Type::EndOfFile)) {
log_parse_error();
return function;
}
tokens.reconsume_current_input_token();
auto value = consume_a_component_value(tokens);
function->m_values.append(value);
}
return function;
}
Optional<StyleDeclarationRule> Parser::consume_a_declaration()
{
return consume_a_declaration(m_token_stream);
}
template<typename T>
Optional<StyleDeclarationRule> Parser::consume_a_declaration(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_a_declaration");
auto& token = tokens.next_token();
StyleDeclarationRule declaration;
VERIFY(token.is(Token::Type::Ident));
declaration.m_name = ((Token)token).ident();
tokens.skip_whitespace();
auto& maybe_colon = tokens.next_token();
if (!maybe_colon.is(Token::Type::Colon)) {
log_parse_error();
return {};
}
tokens.skip_whitespace();
for (;;) {
if (tokens.peek_token().is(Token::Type::EndOfFile)) {
break;
}
declaration.m_values.append(consume_a_component_value(tokens));
}
if (declaration.m_values.size() >= 2) {
auto second_last = declaration.m_values.at(declaration.m_values.size() - 2);
auto last = declaration.m_values.at(declaration.m_values.size() - 1);
if (second_last.m_type == StyleComponentValueRule::ComponentType::Token && last.m_type == StyleComponentValueRule::ComponentType::Token) {
auto last_token = last.m_token;
auto second_last_token = second_last.m_token;
if (second_last_token.is(Token::Type::Delim) && second_last_token.m_value.to_string().equals_ignoring_case("!")) {
if (last_token.is(Token::Type::Ident) && last_token.m_value.to_string().equals_ignoring_case("important")) {
declaration.m_values.remove(declaration.m_values.size() - 2);
declaration.m_values.remove(declaration.m_values.size() - 1);
declaration.m_important = true;
}
}
}
}
while (!declaration.m_values.is_empty()) {
auto maybe_whitespace = declaration.m_values.last();
if (!(maybe_whitespace.is(Token::Type::Whitespace))) {
break;
}
declaration.m_values.take_last();
}
return declaration;
}
Vector<DeclarationOrAtRule> Parser::consume_a_list_of_declarations()
{
return consume_a_list_of_declarations(m_token_stream);
}
template<typename T>
Vector<DeclarationOrAtRule> Parser::consume_a_list_of_declarations(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::consume_a_list_of_declarations");
Vector<DeclarationOrAtRule> list;
for (;;) {
auto& token = tokens.next_token();
if (token.is(Token::Type::Whitespace) || token.is(Token::Type::Semicolon)) {
continue;
}
if (token.is(Token::Type::EndOfFile)) {
return list;
}
if (token.is(Token::Type::AtKeyword)) {
tokens.reconsume_current_input_token();
list.append(DeclarationOrAtRule(consume_an_at_rule(tokens)));
continue;
}
if (token.is(Token::Type::Ident)) {
Vector<StyleComponentValueRule> temp;
temp.append(token);
for (;;) {
auto& peek = tokens.peek_token();
if (peek.is(Token::Type::Semicolon) || peek.is(Token::Type::EndOfFile)) {
break;
}
temp.append(consume_a_component_value(tokens));
}
auto token_stream = TokenStream(temp);
auto maybe_declaration = consume_a_declaration(token_stream);
if (maybe_declaration.has_value()) {
list.append(DeclarationOrAtRule(maybe_declaration.value()));
}
continue;
}
log_parse_error();
tokens.reconsume_current_input_token();
for (;;) {
auto& peek = tokens.peek_token();
if (peek.is(Token::Type::Semicolon) || peek.is(Token::Type::EndOfFile))
break;
dbgln("Discarding token: '{}'", peek.to_debug_string());
(void)consume_a_component_value(tokens);
}
}
return list;
}
RefPtr<CSSRule> Parser::parse_as_rule()
{
return parse_as_rule(m_token_stream);
}
template<typename T>
RefPtr<CSSRule> Parser::parse_as_rule(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_as_rule");
RefPtr<CSSRule> rule;
tokens.skip_whitespace();
auto& token = tokens.peek_token();
if (token.is(Token::Type::EndOfFile)) {
return {};
} else if (token.is(Token::Type::AtKeyword)) {
auto at_rule = consume_an_at_rule();
rule = convert_to_rule(at_rule);
} else {
auto qualified_rule = consume_a_qualified_rule(tokens);
if (!qualified_rule)
return {};
rule = convert_to_rule(*qualified_rule);
}
tokens.skip_whitespace();
auto& maybe_eof = tokens.peek_token();
if (maybe_eof.is(Token::Type::EndOfFile)) {
return rule;
}
return {};
}
NonnullRefPtrVector<CSSRule> Parser::parse_as_list_of_rules()
{
return parse_as_list_of_rules(m_token_stream);
}
template<typename T>
NonnullRefPtrVector<CSSRule> Parser::parse_as_list_of_rules(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_as_list_of_rules");
auto parsed_rules = consume_a_list_of_rules(tokens, false);
NonnullRefPtrVector<CSSRule> rules;
for (auto& rule : parsed_rules) {
auto converted_rule = convert_to_rule(rule);
if (converted_rule)
rules.append(*converted_rule);
}
return rules;
}
Optional<StyleProperty> Parser::parse_as_declaration()
{
return parse_as_declaration(m_token_stream);
}
template<typename T>
Optional<StyleProperty> Parser::parse_as_declaration(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_as_declaration");
tokens.skip_whitespace();
auto& token = tokens.peek_token();
if (!token.is(Token::Type::Ident)) {
return {};
}
auto declaration = consume_a_declaration(tokens);
if (declaration.has_value())
return convert_to_style_property(declaration.value());
return {};
}
RefPtr<CSSStyleDeclaration> Parser::parse_as_list_of_declarations()
{
return parse_as_list_of_declarations(m_token_stream);
}
template<typename T>
RefPtr<CSSStyleDeclaration> Parser::parse_as_list_of_declarations(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_as_list_of_declarations");
auto declarations_and_at_rules = consume_a_list_of_declarations(tokens);
Vector<StyleProperty> properties;
HashMap<String, StyleProperty> custom_properties;
for (auto& declaration_or_at_rule : declarations_and_at_rules) {
if (declaration_or_at_rule.is_at_rule()) {
dbgln("Parser::parse_as_list_of_declarations(): At-rule is not allowed here!");
continue;
}
auto& declaration = declaration_or_at_rule.m_declaration;
auto maybe_property = convert_to_style_property(declaration);
if (maybe_property.has_value()) {
auto property = maybe_property.value();
if (property.property_id == PropertyID::Custom) {
custom_properties.set(property.custom_name, property);
} else {
properties.append(property);
}
}
}
return CSSStyleDeclaration::create(move(properties), move(custom_properties));
}
Optional<StyleComponentValueRule> Parser::parse_as_component_value()
{
return parse_as_component_value(m_token_stream);
}
template<typename T>
Optional<StyleComponentValueRule> Parser::parse_as_component_value(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_as_component_value");
tokens.skip_whitespace();
auto& token = tokens.peek_token();
if (token.is(Token::Type::EndOfFile)) {
return {};
}
auto value = consume_a_component_value(tokens);
tokens.skip_whitespace();
auto& maybe_eof = tokens.peek_token();
if (maybe_eof.is(Token::Type::EndOfFile)) {
return value;
}
return {};
}
Vector<StyleComponentValueRule> Parser::parse_as_list_of_component_values()
{
return parse_as_list_of_component_values(m_token_stream);
}
template<typename T>
Vector<StyleComponentValueRule> Parser::parse_as_list_of_component_values(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_as_list_of_component_values");
Vector<StyleComponentValueRule> rules;
for (;;) {
if (tokens.peek_token().is(Token::Type::EndOfFile)) {
break;
}
rules.append(consume_a_component_value(tokens));
}
return rules;
}
Vector<Vector<StyleComponentValueRule>> Parser::parse_as_comma_separated_list_of_component_values()
{
return parse_as_comma_separated_list_of_component_values(m_token_stream);
}
template<typename T>
Vector<Vector<StyleComponentValueRule>> Parser::parse_as_comma_separated_list_of_component_values(TokenStream<T>& tokens)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_as_comma_separated_list_of_component_values");
Vector<Vector<StyleComponentValueRule>> lists;
lists.append({});
for (;;) {
auto& next = tokens.next_token();
if (next.is(Token::Type::Comma)) {
lists.append({});
continue;
} else if (next.is(Token::Type::EndOfFile)) {
break;
}
tokens.reconsume_current_input_token();
auto component_value = consume_a_component_value(tokens);
lists.last().append(component_value);
}
return lists;
}
Optional<URL> Parser::parse_url_function(ParsingContext const& context, StyleComponentValueRule const& component_value)
{
// FIXME: Handle list of media queries. https://www.w3.org/TR/css-cascade-3/#conditional-import
if (component_value.is(Token::Type::Url))
return context.complete_url(component_value.token().url());
if (component_value.is_function() && component_value.function().name().equals_ignoring_case("url")) {
auto& 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& value = function_values[i];
if (value.is(Token::Type::Whitespace))
continue;
if (value.is(Token::Type::String)) {
// FIXME: RFC2397
if (value.token().string().starts_with("data:"))
break;
return context.complete_url(value.token().string());
}
}
}
return {};
}
RefPtr<CSSRule> Parser::convert_to_rule(NonnullRefPtr<StyleRule> rule)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::convert_to_rule");
if (rule->m_type == StyleRule::Type::At) {
if (rule->m_name.equals_ignoring_case("import"sv) && !rule->prelude().is_empty()) {
Optional<URL> url;
for (auto& 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(m_context, 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());
else
dbgln("Unable to parse url from @import rule");
} else {
dbgln("Unrecognized CSS at-rule: {}", rule->m_name);
}
// FIXME: More at rules!
} else {
auto prelude_stream = TokenStream(rule->m_prelude);
auto selectors = parse_a_selector(prelude_stream);
if (!selectors.has_value() || selectors.value().is_empty()) {
dbgln("CSSParser: style rule selectors invalid; discarding.");
prelude_stream.dump_all_tokens();
return {};
}
auto declaration = convert_to_declaration(*rule->m_block);
if (!declaration) {
dbgln("CSSParser: style rule declaration invalid; discarding.");
return {};
}
return CSSStyleRule::create(move(selectors.value()), move(*declaration));
}
return {};
}
RefPtr<CSSStyleDeclaration> Parser::convert_to_declaration(NonnullRefPtr<StyleBlockRule> block)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::convert_to_declaration");
if (!block->is_curly())
return {};
auto stream = TokenStream(block->m_values);
return parse_as_list_of_declarations(stream);
}
Optional<StyleProperty> Parser::convert_to_style_property(StyleDeclarationRule& declaration)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::convert_to_style_property");
auto& property_name = declaration.m_name;
auto property_id = property_id_from_string(property_name);
if (property_id == PropertyID::Invalid && property_name.starts_with("--"))
property_id = PropertyID::Custom;
if (property_id == PropertyID::Invalid && !property_name.starts_with("-")) {
dbgln("Parser::convert_to_style_property(): Unrecognized property '{}'", property_name);
return {};
}
auto value_token_stream = TokenStream(declaration.m_values);
auto value = parse_css_value(property_id, value_token_stream);
if (!value) {
dbgln("Parser::convert_to_style_property(): Property '{}' has no value.", property_name);
return {};
}
if (property_id == PropertyID::Custom) {
return StyleProperty { property_id, value.release_nonnull(), declaration.m_name, declaration.m_important };
} else {
return StyleProperty { property_id, value.release_nonnull(), {}, declaration.m_important };
}
}
Optional<float> Parser::try_parse_float(StringView string)
{
// FIXME: This is copied from DeprecatedCSSParser, so may not be to spec.
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;
}
RefPtr<StyleValue> Parser::parse_keyword_or_custom_value(ParsingContext const&, StyleComponentValueRule const& component_value)
{
if (component_value.is(Token::Type::Ident)) {
auto ident = component_value.token().ident();
if (ident.equals_ignoring_case("inherit"))
return InheritStyleValue::create();
if (ident.equals_ignoring_case("initial"))
return InitialStyleValue::create();
if (ident.equals_ignoring_case("auto"))
return LengthStyleValue::create(Length::make_auto());
// FIXME: Implement `unset` keyword
}
if (component_value.is_function() && component_value.function().name().equals_ignoring_case("var")) {
// FIXME: Handle fallback value as second parameter
// https://www.w3.org/TR/css-variables-1/#using-variables
if (!component_value.function().values().is_empty()) {
auto& property_name_token = component_value.function().values().first();
if (property_name_token.is(Token::Type::Ident))
return CustomStyleValue::create(property_name_token.token().ident());
else
dbgln("First argument to var() function was not an ident: '{}'", property_name_token.to_debug_string());
}
}
return {};
}
RefPtr<StyleValue> Parser::parse_length_value(ParsingContext const& context, StyleComponentValueRule const& component_value)
{
auto parse_length = [&]() -> Optional<Length> {
Length::Type type = Length::Type::Undefined;
Optional<float> numeric_value;
if (component_value.is(Token::Type::Dimension)) {
auto length_string = component_value.token().m_value.string_view();
auto unit_string = component_value.token().m_unit.string_view();
if (unit_string.equals_ignoring_case("%")) {
type = Length::Type::Percentage;
} else if (unit_string.equals_ignoring_case("px")) {
type = Length::Type::Px;
} else if (unit_string.equals_ignoring_case("pt")) {
type = Length::Type::Pt;
} else if (unit_string.equals_ignoring_case("pc")) {
type = Length::Type::Pc;
} else if (unit_string.equals_ignoring_case("mm")) {
type = Length::Type::Mm;
} else if (unit_string.equals_ignoring_case("rem")) {
type = Length::Type::Rem;
} else if (unit_string.equals_ignoring_case("em")) {
type = Length::Type::Em;
} else if (unit_string.equals_ignoring_case("ex")) {
type = Length::Type::Ex;
} else if (unit_string.equals_ignoring_case("vw")) {
type = Length::Type::Vw;
} else if (unit_string.equals_ignoring_case("vh")) {
type = Length::Type::Vh;
} else if (unit_string.equals_ignoring_case("vmax")) {
type = Length::Type::Vmax;
} else if (unit_string.equals_ignoring_case("vmin")) {
type = Length::Type::Vmin;
} else if (unit_string.equals_ignoring_case("cm")) {
type = Length::Type::Cm;
} else if (unit_string.equals_ignoring_case("in")) {
type = Length::Type::In;
} else if (unit_string.equals_ignoring_case("Q")) {
type = Length::Type::Q;
} else if (context.in_quirks_mode()) {
type = Length::Type::Px;
}
numeric_value = try_parse_float(length_string);
} else if (component_value.is(Token::Type::Number)) {
auto value_string = component_value.token().m_value.string_view();
if (value_string == "0") {
type = Length::Type::Px;
numeric_value = 0;
} else if (context.in_quirks_mode()) {
type = Length::Type::Px;
numeric_value = try_parse_float(value_string);
}
} else if (component_value.is(Token::Type::Percentage)) {
type = Length::Type::Percentage;
auto value_string = component_value.token().m_value.string_view();
numeric_value = try_parse_float(value_string);
}
if (!numeric_value.has_value())
return {};
return Length(numeric_value.value(), type);
};
if (component_value.is(Token::Type::Dimension) || component_value.is(Token::Type::Number) || component_value.is(Token::Type::Percentage)) {
auto length = parse_length();
if (length.has_value())
return LengthStyleValue::create(length.value());
}
return {};
}
RefPtr<StyleValue> Parser::parse_numeric_value(ParsingContext const&, StyleComponentValueRule const& component_value)
{
if (component_value.is(Token::Type::Number)) {
auto number = component_value.token();
if (number.m_number_type == Token::NumberType::Integer) {
return NumericStyleValue::create(number.to_integer());
} else {
auto float_value = try_parse_float(number.m_value.string_view());
if (float_value.has_value())
return NumericStyleValue::create(float_value.value());
}
}
return {};
}
RefPtr<StyleValue> Parser::parse_identifier_value(ParsingContext const&, StyleComponentValueRule const& component_value)
{
if (component_value.is(Token::Type::Ident)) {
auto value_id = value_id_from_string(component_value.token().ident());
if (value_id != ValueID::Invalid)
return IdentifierStyleValue::create(value_id);
}
return {};
}
RefPtr<StyleValue> Parser::parse_color_value(ParsingContext const&, StyleComponentValueRule const& component_value)
{
// https://www.w3.org/TR/css-color-3/
auto parse_css_color = [&]() -> Optional<Color> {
if (component_value.is(Token::Type::Ident)) {
auto ident = component_value.token().ident();
if (ident.equals_ignoring_case("transparent"))
return Color::from_rgba(0x00000000);
auto color = Color::from_string(ident.to_string().to_lowercase());
if (color.has_value())
return color;
} else if (component_value.is(Token::Type::Hash)) {
// FIXME: Read it directly
auto color = Color::from_string(String::formatted("#{}", component_value.token().m_value.to_string().to_lowercase()));
if (color.has_value())
return color;
} else if (component_value.is_function()) {
auto& function = component_value.function();
auto& values = function.values();
Vector<Token> params;
for (size_t i = 0; i < values.size(); ++i) {
auto& value = values.at(i);
if (value.is(Token::Type::Whitespace))
continue;
if (value.is(Token::Type::Percentage) || value.is(Token::Type::Number)) {
params.append(value.token());
// Eat following comma and whitespace
while ((i + 1) < values.size()) {
auto& next = values.at(i + 1);
if (next.is(Token::Type::Whitespace))
i++;
else if (next.is(Token::Type::Comma))
break;
return {};
}
}
}
if (function.name().equals_ignoring_case("rgb")) {
if (params.size() != 3)
return {};
auto r_val = params[0];
auto g_val = params[1];
auto b_val = params[2];
if (r_val.is(Token::NumberType::Integer)
&& g_val.is(Token::NumberType::Integer)
&& b_val.is(Token::NumberType::Integer)) {
auto maybe_r = r_val.m_value.string_view().to_uint<u8>();
auto maybe_g = g_val.m_value.string_view().to_uint<u8>();
auto maybe_b = b_val.m_value.string_view().to_uint<u8>();
if (maybe_r.has_value() && maybe_g.has_value() && maybe_b.has_value())
return Color(maybe_r.value(), maybe_g.value(), maybe_b.value());
} else if (r_val.is(Token::Type::Percentage)
&& g_val.is(Token::Type::Percentage)
&& b_val.is(Token::Type::Percentage)) {
auto maybe_r = try_parse_float(r_val.m_value.string_view());
auto maybe_g = try_parse_float(g_val.m_value.string_view());
auto maybe_b = try_parse_float(b_val.m_value.string_view());
if (maybe_r.has_value() && maybe_g.has_value() && maybe_b.has_value()) {
u8 r = clamp(lroundf(maybe_r.value() * 2.55f), 0, 255);
u8 g = clamp(lroundf(maybe_g.value() * 2.55f), 0, 255);
u8 b = clamp(lroundf(maybe_b.value() * 2.55f), 0, 255);
return Color(r, g, b);
}
}
} else if (function.name().equals_ignoring_case("rgba")) {
if (params.size() != 4)
return {};
auto r_val = params[0];
auto g_val = params[1];
auto b_val = params[2];
auto a_val = params[3];
if (r_val.is(Token::NumberType::Integer)
&& g_val.is(Token::NumberType::Integer)
&& b_val.is(Token::NumberType::Integer)
&& a_val.is(Token::Type::Number)) {
auto maybe_r = r_val.m_value.string_view().to_uint<u8>();
auto maybe_g = g_val.m_value.string_view().to_uint<u8>();
auto maybe_b = b_val.m_value.string_view().to_uint<u8>();
auto maybe_a = try_parse_float(a_val.m_value.string_view());
if (maybe_r.has_value() && maybe_g.has_value() && maybe_b.has_value() && maybe_a.has_value()) {
u8 a = clamp(lroundf(maybe_a.value() * 255.0f), 0, 255);
return Color(maybe_r.value(), maybe_g.value(), maybe_b.value(), a);
}
} else if (r_val.is(Token::Type::Percentage)
&& g_val.is(Token::Type::Percentage)
&& b_val.is(Token::Type::Percentage)
&& a_val.is(Token::Type::Number)) {
auto maybe_r = try_parse_float(r_val.m_value.string_view());
auto maybe_g = try_parse_float(g_val.m_value.string_view());
auto maybe_b = try_parse_float(b_val.m_value.string_view());
auto maybe_a = try_parse_float(a_val.m_value.string_view());
if (maybe_r.has_value() && maybe_g.has_value() && maybe_b.has_value() && maybe_a.has_value()) {
u8 r = clamp(lroundf(maybe_r.value() * 2.55f), 0, 255);
u8 g = clamp(lroundf(maybe_g.value() * 2.55f), 0, 255);
u8 b = clamp(lroundf(maybe_b.value() * 2.55f), 0, 255);
u8 a = clamp(lroundf(maybe_a.value() * 255.0f), 0, 255);
return Color(r, g, b, a);
}
}
} else if (function.name().equals_ignoring_case("hsl")) {
if (params.size() != 3)
return {};
auto h_val = params[0];
auto s_val = params[1];
auto l_val = params[2];
if (h_val.is(Token::Type::Number)
&& s_val.is(Token::Type::Percentage)
&& l_val.is(Token::Type::Percentage)) {
auto maybe_h = try_parse_float(h_val.m_value.string_view());
auto maybe_s = try_parse_float(s_val.m_value.string_view());
auto maybe_l = try_parse_float(l_val.m_value.string_view());
if (maybe_h.has_value() && maybe_s.has_value() && maybe_l.has_value()) {
float h = maybe_h.value();
float s = maybe_s.value() / 100.0f;
float l = maybe_l.value() / 100.0f;
return Color::from_hsl(h, s, l);
}
}
} else if (function.name().equals_ignoring_case("hsla")) {
if (params.size() != 4)
return {};
auto h_val = params[0];
auto s_val = params[1];
auto l_val = params[2];
auto a_val = params[3];
if (h_val.is(Token::Type::Number)
&& s_val.is(Token::Type::Percentage)
&& l_val.is(Token::Type::Percentage)
&& a_val.is(Token::Type::Number)) {
auto maybe_h = try_parse_float(h_val.m_value.string_view());
auto maybe_s = try_parse_float(s_val.m_value.string_view());
auto maybe_l = try_parse_float(l_val.m_value.string_view());
auto maybe_a = try_parse_float(a_val.m_value.string_view());
if (maybe_h.has_value() && maybe_s.has_value() && maybe_l.has_value() && maybe_a.has_value()) {
float h = maybe_h.value();
float s = maybe_s.value() / 100.0f;
float l = maybe_l.value() / 100.0f;
float a = maybe_a.value();
return Color::from_hsla(h, s, l, a);
}
}
}
return {};
}
return {};
};
auto color = parse_css_color();
if (color.has_value())
return ColorStyleValue::create(color.value());
return {};
}
RefPtr<StyleValue> Parser::parse_string_value(ParsingContext const&, StyleComponentValueRule const& component_value)
{
if (component_value.is(Token::Type::String))
return StringStyleValue::create(component_value.token().string());
return {};
}
RefPtr<StyleValue> Parser::parse_image_value(ParsingContext const& context, StyleComponentValueRule const& component_value)
{
auto url = parse_url_function(context, component_value);
if (url.has_value())
return ImageStyleValue::create(url.value(), *context.document());
// FIXME: Handle gradients.
return {};
}
RefPtr<StyleValue> Parser::parse_css_value(PropertyID property_id, TokenStream<StyleComponentValueRule>& tokens)
{
Vector<StyleComponentValueRule> component_values;
while (tokens.has_next_token()) {
auto& token = tokens.next_token();
if (token.is(Token::Type::Semicolon)) {
tokens.reconsume_current_input_token();
break;
}
if (token.is(Token::Type::Whitespace))
continue;
component_values.append(token);
}
if (component_values.is_empty())
return {};
if (component_values.size() == 1)
return parse_css_value(m_context, property_id, component_values.first());
return ValueListStyleValue::create(move(component_values));
}
RefPtr<StyleValue> Parser::parse_css_value(ParsingContext const& context, PropertyID property_id, StyleComponentValueRule const& component_value)
{
// FIXME: Figure out if we still need takes_integer_value, and if so, move this information
// into Properties.json.
auto takes_integer_value = [](PropertyID property_id) -> bool {
return property_id == PropertyID::ZIndex
|| property_id == PropertyID::FontWeight
|| property_id == PropertyID::Custom;
};
if (takes_integer_value(property_id) && component_value.is(Token::Type::Number)) {
auto number = component_value.token();
if (number.m_number_type == Token::NumberType::Integer) {
return LengthStyleValue::create(Length::make_px(number.to_integer()));
}
}
if (auto keyword_or_custom = parse_keyword_or_custom_value(context, component_value))
return keyword_or_custom;
if (auto length = parse_length_value(context, component_value))
return length;
if (auto numeric = parse_numeric_value(context, component_value))
return numeric;
if (auto identifier = parse_identifier_value(context, component_value))
return identifier;
if (auto color = parse_color_value(context, component_value))
return color;
if (auto string = parse_string_value(context, component_value))
return string;
if (auto image = parse_image_value(context, component_value))
return image;
return {};
}
Optional<Selector::SimpleSelector::ANPlusBPattern> Parser::parse_a_n_plus_b_pattern(TokenStream<StyleComponentValueRule>& values)
{
dbgln_if(CSS_PARSER_DEBUG, "Parser::parse_a_n_plus_b_pattern");
int a = 0;
int b = 0;
auto syntax_error = [&]() -> Optional<Selector::SimpleSelector::ANPlusBPattern> {
if constexpr (CSS_PARSER_DEBUG) {
dbgln("Invalid An+B value:");
values.dump_all_tokens();
}
return {};
};
auto make_return_value = [&]() -> Optional<Selector::SimpleSelector::ANPlusBPattern> {
// When we think we are done, but there are more non-whitespace tokens, then it's a parse error.
values.skip_whitespace();
if (values.has_next_token()) {
if constexpr (CSS_PARSER_DEBUG) {
dbgln("Extra tokens at end of An+B value:");
values.dump_all_tokens();
}
return syntax_error();
} else {
return Selector::SimpleSelector::ANPlusBPattern { a, b };
}
};
auto is_n = [](StyleComponentValueRule const& value) -> bool {
return value.is(Token::Type::Ident) && value.token().ident().equals_ignoring_case("n"sv);
};
auto is_ndash = [](StyleComponentValueRule const& value) -> bool {
return value.is(Token::Type::Ident) && value.token().ident().equals_ignoring_case("n-"sv);
};
auto is_dashn = [](StyleComponentValueRule const& value) -> bool {
return value.is(Token::Type::Ident) && value.token().ident().equals_ignoring_case("-n"sv);
};
auto is_dashndash = [](StyleComponentValueRule const& value) -> bool {
return value.is(Token::Type::Ident) && value.token().ident().equals_ignoring_case("-n-"sv);
};
auto is_delim = [](StyleComponentValueRule const& value, StringView const& delim) -> bool {
return value.is(Token::Type::Delim) && value.token().delim().equals_ignoring_case(delim);
};
auto is_n_dimension = [](StyleComponentValueRule const& value) -> bool {
if (!value.is(Token::Type::Dimension))
return false;
if (value.token().number_type() != Token::NumberType::Integer)
return false;
if (!value.token().dimension_unit().equals_ignoring_case("n"sv))
return false;
return true;
};
auto is_ndash_dimension = [](StyleComponentValueRule const& value) -> bool {
if (!value.is(Token::Type::Dimension))
return false;
if (value.token().number_type() != Token::NumberType::Integer)
return false;
if (!value.token().dimension_unit().equals_ignoring_case("n-"sv))
return false;
return true;
};
auto is_ndashdigit_dimension = [](StyleComponentValueRule const& value) -> bool {
if (!value.is(Token::Type::Dimension))
return false;
if (value.token().number_type() != Token::NumberType::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 = [](StyleComponentValueRule 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 = [](StyleComponentValueRule 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 = 3; i < ident.length(); ++i) {
if (!is_ascii_digit(ident[i]))
return false;
}
return true;
};
auto is_integer = [](StyleComponentValueRule const& value) -> bool {
return value.is(Token::Type::Number) && value.token().is(Token::NumberType::Integer);
};
auto is_signed_integer = [is_integer](StyleComponentValueRule const& value) -> bool {
return is_integer(value) && value.token().is_integer_value_signed();
};
auto is_signless_integer = [is_integer](StyleComponentValueRule const& value) -> bool {
return is_integer(value) && !value.token().is_integer_value_signed();
};
// 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& first_value = values.next_token();
// odd | even
if (first_value.is(Token::Type::Ident)) {
auto ident = first_value.token().ident();
if (ident.equals_ignoring_case("odd")) {
a = 2;
b = 1;
return make_return_value();
} else if (ident.equals_ignoring_case("even")) {
a = 2;
return make_return_value();
}
}
// <integer>
if (is_integer(first_value)) {
b = first_value.token().to_integer();
return make_return_value();
}
// <n-dimension>
// <n-dimension> <signed-integer>
// <n-dimension> ['+' | '-'] <signless-integer>
if (is_n_dimension(first_value)) {
a = first_value.token().dimension_value_int();
values.skip_whitespace();
auto& second_value = values.next_token();
if (second_value.is(Token::Type::EndOfFile)) {
// <n-dimension>
return make_return_value();
} else if (is_signed_integer(second_value)) {
// <n-dimension> <signed-integer>
b = second_value.token().to_integer();
return make_return_value();
}
values.skip_whitespace();
auto& third_value = values.next_token();
if ((is_delim(second_value, "+"sv) || is_delim(second_value, "-"sv)) && is_signless_integer(third_value)) {
// <n-dimension> ['+' | '-'] <signless-integer>
b = third_value.token().to_integer() * (is_delim(second_value, "+"sv) ? 1 : -1);
return make_return_value();
}
return syntax_error();
}
// <ndash-dimension> <signless-integer>
if (is_ndash_dimension(first_value)) {
values.skip_whitespace();
auto& second_value = values.next_token();
if (is_signless_integer(second_value)) {
a = first_value.token().dimension_value_int();
b = -second_value.token().to_integer();
return make_return_value();
}
return syntax_error();
}
// <ndashdigit-dimension>
if (is_ndashdigit_dimension(first_value)) {
auto& dimension = first_value.token();
a = dimension.dimension_value_int();
auto maybe_b = dimension.dimension_unit().substring_view(1).to_int();
if (maybe_b.has_value()) {
b = maybe_b.value();
return make_return_value();
}
return syntax_error();
}
// <dashndashdigit-ident>
if (is_dashndashdigit_ident(first_value)) {
a = -1;
auto maybe_b = first_value.token().ident().substring_view(2).to_int();
if (maybe_b.has_value()) {
b = maybe_b.value();
return make_return_value();
}
return syntax_error();
}
// -n
// -n <signed-integer>
// -n ['+' | '-'] <signless-integer>
if (is_dashn(first_value)) {
a = -1;
values.skip_whitespace();
auto& second_value = values.next_token();
if (second_value.is(Token::Type::EndOfFile)) {
// -n
return make_return_value();
} else if (is_signed_integer(second_value)) {
// -n <signed-integer>
b = second_value.token().to_integer();
return make_return_value();
}
values.skip_whitespace();
auto& third_value = values.next_token();
if ((is_delim(second_value, "+"sv) || is_delim(second_value, "-"sv)) && is_signless_integer(third_value)) {
// -n ['+' | '-'] <signless-integer>
b = third_value.token().to_integer() * (is_delim(second_value, "+"sv) ? 1 : -1);
return make_return_value();
}
return syntax_error();
}
// -n- <signless-integer>
if (is_dashndash(first_value)) {
values.skip_whitespace();
auto& second_value = values.next_token();
if (is_signless_integer(second_value)) {
a = -1;
b = -second_value.token().to_integer();
return make_return_value();
}
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, "+"sv)) {
values.reconsume_current_input_token();
// We do *not* skip whitespace here.
}
auto& first_after_plus = values.next_token();
// '+'?† n
// '+'?† n <signed-integer>
// '+'?† n ['+' | '-'] <signless-integer>
if (is_n(first_after_plus)) {
a = 1;
values.skip_whitespace();
auto& second_value = values.next_token();
if (second_value.is(Token::Type::EndOfFile)) {
// '+'?† n
return make_return_value();
} else if (is_signed_integer(second_value)) {
// '+'?† n <signed-integer>
b = second_value.token().to_integer();
return make_return_value();
}
values.skip_whitespace();
auto& third_value = values.next_token();
if ((is_delim(second_value, "+"sv) || is_delim(second_value, "-"sv)) && is_signless_integer(third_value)) {
// '+'?† n ['+' | '-'] <signless-integer>
b = third_value.token().to_integer() * (is_delim(second_value, "+"sv) ? 1 : -1);
return make_return_value();
}
return syntax_error();
}
// '+'?† n- <signless-integer>
if (is_ndash(first_after_plus)) {
values.skip_whitespace();
auto& second_value = values.next_token();
if (is_signless_integer(second_value)) {
a = 1;
b = -second_value.token().to_integer();
return make_return_value();
}
return syntax_error();
}
// '+'?† <ndashdigit-ident>
if (is_ndashdigit_ident(first_after_plus)) {
a = 1;
auto maybe_b = first_after_plus.token().ident().substring_view(1).to_int();
if (maybe_b.has_value()) {
b = maybe_b.value();
return make_return_value();
}
return syntax_error();
}
return syntax_error();
}
}
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