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ladybird/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
Sam Atkins 59501f1940 LibWeb: Implement and use FontStyleValue 
After working with the code for a while, it makes more sense to put all
the parsing in Parser, instead of some of it living in StyleResolver.
That means our current ValueListStyleValue needs to be replaced with
specific StyleValue types for the properties that are shorthands or
otherwise combine several values together.

Here we implement FontStyleProperty, which represents a `font` CSS
property.

Also adjusted the fonts.html test page so that font-weights are featured
in test cases without things we do not yet support.
2021-08-14 12:45:01 +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>
* Copyright (c) 2021, Tobias Christiansen <tobyase@serenityos.org>
*
* 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(int offset)
{
if (!has_next_token())
return m_eof;
return m_tokens.at(m_iterator_offset + 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_a_stylesheet(m_token_stream);
}
template<typename T>
NonnullRefPtr<CSSStyleSheet> Parser::parse_a_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);
if constexpr (CSS_PARSER_DEBUG) {
dump_sheet(stylesheet);
}
return stylesheet;
}
Optional<SelectorList> Parser::parse_as_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_as_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_a_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_a_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,
// FIXME: Case-sensitivity is defined by the document language.
// HTML is insensitive with attribute names, and our code generally assumes
// they are converted to lowercase, so we do that here too. If we want to be
// correct with XML later, we'll need to keep the original case and then do
// a case-insensitive compare later.
.name = attribute_part.token().ident().to_lowercase_string(),
}
};
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_a_rule(m_token_stream);
}
template<typename T>
RefPtr<CSSRule> Parser::parse_a_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_a_list_of_rules(m_token_stream);
}
template<typename T>
NonnullRefPtrVector<CSSRule> Parser::parse_a_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_a_declaration(m_token_stream);
}
template<typename T>
Optional<StyleProperty> Parser::parse_a_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_a_list_of_declarations(m_token_stream);
}
template<typename T>
RefPtr<CSSStyleDeclaration> Parser::parse_a_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_a_component_value(m_token_stream);
}
template<typename T>
Optional<StyleComponentValueRule> Parser::parse_a_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_a_list_of_component_values(m_token_stream);
}
template<typename T>
Vector<StyleComponentValueRule> Parser::parse_a_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_a_comma_separated_list_of_component_values(m_token_stream);
}
template<typename T>
Vector<Vector<StyleComponentValueRule>> Parser::parse_a_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
// FIXME: Handle data: urls (RFC2397)
auto is_data_url = [](StringView& url_string) -> bool {
return url_string.starts_with("data:", CaseSensitivity::CaseInsensitive);
};
if (component_value.is(Token::Type::Url)) {
auto url_string = component_value.token().url();
if (is_data_url(url_string))
return {};
return context.complete_url(url_string);
}
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)) {
auto url_string = value.token().string();
if (is_data_url(url_string))
return {};
return context.complete_url(url_string);
}
break;
}
}
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_a_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_builtin_or_dynamic_value(ParsingContext const& context, 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();
// FIXME: Implement `unset` keyword
}
if (component_value.is_function()) {
auto& function = component_value.function();
if (function.name().equals_ignoring_case("calc")) {
auto calc_expression = parse_calc_expression(context, function.values());
// FIXME: Either produce a string value of calc() here, or do so in CalculatedStyleValue::to_string().
if (calc_expression)
return CalculatedStyleValue::create("(FIXME:calc to string)", calc_expression.release_nonnull());
} else if (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 {};
}
Optional<Length> Parser::parse_length(ParsingContext const& context, StyleComponentValueRule const& component_value)
{
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);
} else if (component_value.is(Token::Type::Ident) && component_value.token().ident().equals_ignoring_case("auto")) {
return Length::make_auto();
}
if (!numeric_value.has_value())
return {};
return Length(numeric_value.value(), type);
}
RefPtr<StyleValue> Parser::parse_length_value(ParsingContext const& context, StyleComponentValueRule const& component_value)
{
// Numbers with no units can be lengths, in two situations:
// 1) We're in quirks mode, and it's an integer.
// 2) It's a 0.
// We handle case 1 here. Case 2 is handled by NumericStyleValue pretending to be a LengthStyleValue if it is 0.
// FIXME: "auto" is also treated as a Length, and most of the time that is how it is used, but not always.
// Possibly it should always be an Identifier, and then quietly converted to a Length when needed, like 0 above.
// Right now, it instead is quietly converted to an Identifier when needed.
if (component_value.is(Token::Type::Dimension) || component_value.is(Token::Type::Percentage)
|| (component_value.is(Token::Type::Ident) && component_value.token().ident().equals_ignoring_case("auto"sv))
|| (context.in_quirks_mode() && component_value.is(Token::Type::Number) && component_value.token().m_value.string_view() != "0"sv)) {
auto length = parse_length(context, component_value);
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 {};
}
Optional<Color> Parser::parse_color(ParsingContext const&, StyleComponentValueRule const& component_value)
{
// https://www.w3.org/TR/css-color-3/
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 {};
}
RefPtr<StyleValue> Parser::parse_color_value(ParsingContext const& context, StyleComponentValueRule const& component_value)
{
auto color = parse_color(context, component_value);
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_box_shadow_value(ParsingContext const& context, Vector<StyleComponentValueRule> const& component_values)
{
// FIXME: Also support inset, spread-radius and multiple comma-seperated box-shadows
Length offset_x {};
Length offset_y {};
Length blur_radius {};
Color color {};
if (component_values.size() < 3 || component_values.size() > 4)
return nullptr;
auto maybe_x = parse_length(context, component_values[0]);
if (!maybe_x.has_value())
return nullptr;
offset_x = maybe_x.value();
auto maybe_y = parse_length(context, component_values[1]);
if (!maybe_y.has_value())
return nullptr;
offset_y = maybe_y.value();
if (component_values.size() == 3) {
auto parsed_color = parse_color(context, component_values[2]);
if (!parsed_color.has_value())
return nullptr;
color = parsed_color.value();
} else if (component_values.size() == 4) {
auto maybe_blur_radius = parse_length(context, component_values[2]);
if (!maybe_blur_radius.has_value())
return nullptr;
blur_radius = maybe_blur_radius.value();
auto parsed_color = parse_color(context, component_values[3]);
if (!parsed_color.has_value())
return nullptr;
color = parsed_color.value();
}
return BoxShadowStyleValue::create(offset_x, offset_y, blur_radius, color);
}
RefPtr<StyleValue> Parser::parse_font_value(ParsingContext const& context, Vector<StyleComponentValueRule> const& component_values)
{
auto is_font_size = [](StyleValue const& value) -> bool {
if (value.is_length())
return true;
switch (value.to_identifier()) {
case ValueID::XxSmall:
case ValueID::XSmall:
case ValueID::Small:
case ValueID::Medium:
case ValueID::Large:
case ValueID::XLarge:
case ValueID::XxLarge:
case ValueID::XxxLarge:
case ValueID::Smaller:
case ValueID::Larger:
return true;
default:
return false;
}
};
auto is_font_style = [](StyleValue const& value) -> bool {
// FIXME: Handle angle parameter to `oblique`: https://www.w3.org/TR/css-fonts-4/#font-style-prop
switch (value.to_identifier()) {
case ValueID::Normal:
case ValueID::Italic:
case ValueID::Oblique:
return true;
default:
return false;
}
};
auto is_font_weight = [](StyleValue const& value) -> bool {
if (value.is_numeric()) {
auto weight = static_cast<NumericStyleValue const&>(value).value();
return (weight >= 1 && weight <= 1000);
}
switch (value.to_identifier()) {
case ValueID::Normal:
case ValueID::Bold:
case ValueID::Bolder:
case ValueID::Lighter:
return true;
default:
return false;
}
};
auto is_line_height = [](StyleValue const& value) -> bool {
if (value.is_numeric())
return true;
if (value.is_length())
return true;
if (value.to_identifier() == ValueID::Normal)
return true;
return false;
};
auto is_font_family = [](StyleValue const& value) -> bool {
if (value.is_string())
return true;
switch (value.to_identifier()) {
case ValueID::Cursive:
case ValueID::Fantasy:
case ValueID::Monospace:
case ValueID::Serif:
case ValueID::SansSerif:
case ValueID::UiMonospace:
case ValueID::UiRounded:
case ValueID::UiSerif:
case ValueID::UiSansSerif:
return true;
default:
return false;
}
};
RefPtr<StyleValue> font_style;
RefPtr<StyleValue> font_weight;
RefPtr<StyleValue> font_size;
RefPtr<StyleValue> line_height;
NonnullRefPtrVector<StyleValue> font_families;
// FIXME: Implement font-stretch and font-variant.
// FIXME: Handle system fonts. (caption, icon, menu, message-box, small-caption, status-bar)
// Several sub-properties can be "normal", and appear in any order: style, variant, weight, stretch
// So, we have to handle that separately.
int normal_count = 0;
for (size_t i = 0; i < component_values.size(); ++i) {
auto value = parse_css_value(context, PropertyID::Font, component_values[i]);
if (!value)
return nullptr;
if (value->to_identifier() == ValueID::Normal) {
normal_count++;
continue;
}
if (is_font_style(*value)) {
if (font_style)
return nullptr;
font_style = value.release_nonnull();
continue;
}
if (is_font_weight(*value)) {
if (font_weight)
return nullptr;
font_weight = value.release_nonnull();
continue;
}
if (is_font_size(*value)) {
if (font_size)
return nullptr;
font_size = value.release_nonnull();
// Consume `/ line-height` if present
if (i + 2 < component_values.size()) {
auto maybe_solidus = component_values[i + 1];
if (maybe_solidus.is(Token::Type::Delim) && maybe_solidus.token().delim() == "/"sv) {
auto maybe_line_height = parse_css_value(context, PropertyID::Font, component_values[i + 2]);
if (!(maybe_line_height && is_line_height(*maybe_line_height)))
return nullptr;
line_height = maybe_line_height.release_nonnull();
i += 2;
}
}
// Consume font-family
// FIXME: Handle multiple font-families separated by commas, for fallback purposes.
if (i + 1 < component_values.size()) {
auto& font_family_part = component_values[i + 1];
auto maybe_font_family = parse_css_value(context, PropertyID::Font, font_family_part);
if (!maybe_font_family) {
// Single-word font-families may not be quoted. We convert it to a String for convenience.
if (font_family_part.is(Token::Type::Ident))
maybe_font_family = StringStyleValue::create(font_family_part.token().ident());
else
return nullptr;
} else if (!is_font_family(*maybe_font_family)) {
dbgln("Unable to parse '{}' as a font-family.", font_family_part.to_debug_string());
return nullptr;
}
font_families.append(maybe_font_family.release_nonnull());
}
break;
}
return nullptr;
}
// Since normal is the default value for all the properties that can have it, we don't have to actually
// set anything to normal here. It'll be set when we create the FontStyleValue below.
// We just need to make sure we were not given more normals than will fit.
int unset_value_count = (font_style ? 1 : 0) + (font_weight ? 1 : 0);
if (unset_value_count < normal_count)
return nullptr;
if (!font_size || font_families.is_empty())
return nullptr;
if (!font_style)
font_style = IdentifierStyleValue::create(ValueID::Normal);
if (!font_weight)
font_weight = IdentifierStyleValue::create(ValueID::Normal);
if (!line_height)
line_height = IdentifierStyleValue::create(ValueID::Normal);
return FontStyleValue::create(font_style.release_nonnull(), font_weight.release_nonnull(), font_size.release_nonnull(), line_height.release_nonnull(), move(font_families));
}
RefPtr<StyleValue> Parser::parse_as_css_value(PropertyID property_id)
{
auto component_values = parse_as_list_of_component_values();
auto tokens = TokenStream(component_values);
return parse_css_value(property_id, tokens);
}
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 {};
// Special-case property handling
switch (property_id) {
case PropertyID::BoxShadow:
if (auto parsed_box_shadow = parse_box_shadow_value(m_context, component_values))
return parsed_box_shadow;
break;
case PropertyID::Font:
if (auto parsed_value = parse_font_value(m_context, component_values))
return parsed_value;
break;
default:
break;
}
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 builtin_or_dynamic = parse_builtin_or_dynamic_value(context, component_value))
return builtin_or_dynamic;
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();
}
OwnPtr<CalculatedStyleValue::CalcSum> Parser::parse_calc_expression(ParsingContext const& context, Vector<StyleComponentValueRule> const& values)
{
auto tokens = TokenStream(values);
return parse_calc_sum(context, tokens);
}
Optional<CalculatedStyleValue::CalcValue> Parser::parse_calc_value(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
auto current_token = tokens.next_token();
if (current_token.is_block() && current_token.block().is_paren()) {
auto block_values = TokenStream(current_token.block().values());
auto parsed_calc_sum = parse_calc_sum(context, block_values);
if (!parsed_calc_sum)
return {};
return (CalculatedStyleValue::CalcValue) { parsed_calc_sum.release_nonnull() };
}
if (current_token.is(Token::Type::Number)) {
auto try_the_number = try_parse_float(current_token.token().number_string_value());
if (try_the_number.has_value())
return (CalculatedStyleValue::CalcValue) { try_the_number.value() };
return {};
}
if (current_token.is(Token::Type::Dimension) || current_token.is(Token::Type::Percentage)) {
auto maybe_length = parse_length(context, current_token);
if (maybe_length.has_value() && !maybe_length.value().is_undefined())
return (CalculatedStyleValue::CalcValue) { maybe_length.value() };
return {};
}
return {};
}
OwnPtr<CalculatedStyleValue::CalcProductPartWithOperator> Parser::parse_calc_product_part_with_operator(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
// Note: The default value is not used or passed around.
auto product_with_operator = make<CalculatedStyleValue::CalcProductPartWithOperator>(
CalculatedStyleValue::CalcProductPartWithOperator::Multiply,
CalculatedStyleValue::CalcNumberValue(0));
tokens.skip_whitespace();
auto& op_token = tokens.peek_token();
if (!op_token.is(Token::Type::Delim))
return nullptr;
auto op = op_token.token().delim();
if (op == "*"sv) {
tokens.next_token();
tokens.skip_whitespace();
product_with_operator->op = CalculatedStyleValue::CalcProductPartWithOperator::Multiply;
auto parsed_calc_value = parse_calc_value(context, tokens);
if (!parsed_calc_value.has_value())
return nullptr;
product_with_operator->value = { parsed_calc_value.release_value() };
} else if (op == "/"sv) {
tokens.next_token();
tokens.skip_whitespace();
product_with_operator->op = CalculatedStyleValue::CalcProductPartWithOperator::Divide;
auto parsed_calc_number_value = parse_calc_number_value(context, tokens);
if (!parsed_calc_number_value.has_value())
return nullptr;
product_with_operator->value = { parsed_calc_number_value.release_value() };
} else {
return nullptr;
}
return product_with_operator;
}
OwnPtr<CalculatedStyleValue::CalcNumberProductPartWithOperator> Parser::parse_calc_number_product_part_with_operator(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
// Note: The default value is not used or passed around.
auto number_product_with_operator = make<CalculatedStyleValue::CalcNumberProductPartWithOperator>(
CalculatedStyleValue::CalcNumberProductPartWithOperator::Multiply,
CalculatedStyleValue::CalcNumberValue(0));
tokens.skip_whitespace();
auto& op_token = tokens.peek_token();
if (!op_token.is(Token::Type::Delim))
return nullptr;
auto op = op_token.token().delim();
if (op == "*"sv) {
tokens.next_token();
tokens.skip_whitespace();
number_product_with_operator->op = CalculatedStyleValue::CalcNumberProductPartWithOperator::Multiply;
} else if (op == "/"sv) {
tokens.next_token();
tokens.skip_whitespace();
number_product_with_operator->op = CalculatedStyleValue::CalcNumberProductPartWithOperator::Divide;
} else {
return nullptr;
}
auto parsed_calc_value = parse_calc_number_value(context, tokens);
if (!parsed_calc_value.has_value())
return nullptr;
number_product_with_operator->value = parsed_calc_value.release_value();
return number_product_with_operator;
}
OwnPtr<CalculatedStyleValue::CalcNumberProduct> Parser::parse_calc_number_product(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
auto calc_number_product = make<CalculatedStyleValue::CalcNumberProduct>(
CalculatedStyleValue::CalcNumberValue(0),
NonnullOwnPtrVector<CalculatedStyleValue::CalcNumberProductPartWithOperator> {});
auto first_calc_number_value_or_error = parse_calc_number_value(context, tokens);
if (!first_calc_number_value_or_error.has_value())
return nullptr;
calc_number_product->first_calc_number_value = first_calc_number_value_or_error.release_value();
while (tokens.has_next_token()) {
auto number_product_with_operator = parse_calc_number_product_part_with_operator(context, tokens);
if (!number_product_with_operator)
break;
calc_number_product->zero_or_more_additional_calc_number_values.append(number_product_with_operator.release_nonnull());
}
return calc_number_product;
}
OwnPtr<CalculatedStyleValue::CalcNumberSumPartWithOperator> Parser::parse_calc_number_sum_part_with_operator(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
if (!(tokens.peek_token().is(Token::Type::Delim)
&& tokens.peek_token().token().delim().is_one_of("+"sv, "-"sv)
&& tokens.peek_token(1).is(Token::Type::Whitespace)))
return nullptr;
auto& token = tokens.next_token();
tokens.skip_whitespace();
CalculatedStyleValue::CalcNumberSumPartWithOperator::Operation op;
auto delim = token.token().delim();
if (delim == "+"sv)
op = CalculatedStyleValue::CalcNumberSumPartWithOperator::Operation::Add;
else if (delim == "-"sv)
op = CalculatedStyleValue::CalcNumberSumPartWithOperator::Operation::Subtract;
else
return nullptr;
auto calc_number_product = parse_calc_number_product(context, tokens);
if (!calc_number_product)
return nullptr;
return make<CalculatedStyleValue::CalcNumberSumPartWithOperator>(op, calc_number_product.release_nonnull());
}
OwnPtr<CalculatedStyleValue::CalcNumberSum> Parser::parse_calc_number_sum(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
auto first_calc_number_product_or_error = parse_calc_number_product(context, tokens);
if (!first_calc_number_product_or_error)
return nullptr;
NonnullOwnPtrVector<CalculatedStyleValue::CalcNumberSumPartWithOperator> additional {};
while (tokens.has_next_token()) {
auto calc_sum_part = parse_calc_number_sum_part_with_operator(context, tokens);
if (!calc_sum_part)
return nullptr;
additional.append(calc_sum_part.release_nonnull());
}
tokens.skip_whitespace();
auto calc_number_sum = make<CalculatedStyleValue::CalcNumberSum>(first_calc_number_product_or_error.release_nonnull(), move(additional));
return calc_number_sum;
}
Optional<CalculatedStyleValue::CalcNumberValue> Parser::parse_calc_number_value(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
auto& first = tokens.peek_token();
if (first.is_block() && first.block().is_paren()) {
tokens.next_token();
auto block_values = TokenStream(first.block().values());
auto calc_number_sum = parse_calc_number_sum(context, block_values);
if (calc_number_sum)
return { calc_number_sum.release_nonnull() };
}
if (!first.is(Token::Type::Number))
return {};
tokens.next_token();
auto try_the_number = try_parse_float(first.token().number_string_value());
if (!try_the_number.has_value())
return {};
return try_the_number.value();
}
OwnPtr<CalculatedStyleValue::CalcProduct> Parser::parse_calc_product(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
auto calc_product = make<CalculatedStyleValue::CalcProduct>(
CalculatedStyleValue::CalcValue(0),
NonnullOwnPtrVector<CalculatedStyleValue::CalcProductPartWithOperator> {});
auto first_calc_value_or_error = parse_calc_value(context, tokens);
if (!first_calc_value_or_error.has_value())
return nullptr;
calc_product->first_calc_value = first_calc_value_or_error.release_value();
while (tokens.has_next_token()) {
auto product_with_operator = parse_calc_product_part_with_operator(context, tokens);
if (!product_with_operator)
break;
calc_product->zero_or_more_additional_calc_values.append(product_with_operator.release_nonnull());
}
return calc_product;
}
OwnPtr<CalculatedStyleValue::CalcSumPartWithOperator> Parser::parse_calc_sum_part_with_operator(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
// The following has to have the shape of <Whitespace><+ or -><Whitespace>
// But the first whitespace gets eaten in parse_calc_product_part_with_operator().
if (!(tokens.peek_token().is(Token::Type::Delim)
&& tokens.peek_token().token().delim().is_one_of("+"sv, "-"sv)
&& tokens.peek_token(1).is(Token::Type::Whitespace)))
return nullptr;
auto& token = tokens.next_token();
tokens.skip_whitespace();
CalculatedStyleValue::CalcSumPartWithOperator::Operation op;
auto delim = token.token().delim();
if (delim == "+"sv)
op = CalculatedStyleValue::CalcSumPartWithOperator::Operation::Add;
else if (delim == "-"sv)
op = CalculatedStyleValue::CalcSumPartWithOperator::Operation::Subtract;
else
return nullptr;
auto calc_product = parse_calc_product(context, tokens);
if (!calc_product)
return nullptr;
return make<CalculatedStyleValue::CalcSumPartWithOperator>(op, calc_product.release_nonnull());
};
OwnPtr<CalculatedStyleValue::CalcSum> Parser::parse_calc_sum(ParsingContext const& context, TokenStream<StyleComponentValueRule>& tokens)
{
auto parsed_calc_product = parse_calc_product(context, tokens);
if (!parsed_calc_product)
return nullptr;
NonnullOwnPtrVector<CalculatedStyleValue::CalcSumPartWithOperator> additional {};
while (tokens.has_next_token()) {
auto calc_sum_part = parse_calc_sum_part_with_operator(context, tokens);
if (!calc_sum_part)
return nullptr;
additional.append(calc_sum_part.release_nonnull());
}
tokens.skip_whitespace();
return make<CalculatedStyleValue::CalcSum>(parsed_calc_product.release_nonnull(), move(additional));
}
}
namespace Web {
RefPtr<CSS::CSSStyleSheet> parse_css(CSS::ParsingContext const& context, StringView const& css)
{
if (css.is_empty())
return CSS::CSSStyleSheet::create({});
CSS::Parser parser(context, css);
return parser.parse_as_stylesheet();
}
RefPtr<CSS::CSSStyleDeclaration> parse_css_declaration(CSS::ParsingContext const& context, StringView const& css)
{
if (css.is_empty())
return CSS::CSSStyleDeclaration::create({}, {});
CSS::Parser parser(context, css);
return parser.parse_as_list_of_declarations();
}
RefPtr<CSS::StyleValue> parse_css_value(CSS::ParsingContext const& context, StringView const& string, CSS::PropertyID property_id)
{
if (string.is_empty())
return {};
CSS::Parser parser(context, string);
return parser.parse_as_css_value(property_id);
}
Optional<CSS::SelectorList> parse_selector(CSS::ParsingContext const& context, StringView const& selector_text)
{
CSS::Parser parser(context, selector_text);
return parser.parse_as_selector();
}
RefPtr<CSS::StyleValue> parse_html_length(DOM::Document const& document, StringView const& string)
{
auto integer = string.to_int();
if (integer.has_value())
return CSS::LengthStyleValue::create(CSS::Length::make_px(integer.value()));
// FIXME: The const_cast is a hack.
return parse_css_value(CSS::ParsingContext(const_cast<DOM::Document&>(document)), string);
}
}
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