ladybird/Userland/Libraries/LibWeb/CSS/CSS.cpp
2023-08-22 17:51:48 +01:00

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/*
* Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>
* Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibJS/Runtime/VM.h>
#include <LibWeb/CSS/CSS.h>
#include <LibWeb/CSS/Parser/Parser.h>
#include <LibWeb/CSS/PropertyID.h>
#include <LibWeb/CSS/Serialize.h>
namespace Web::CSS {
// https://www.w3.org/TR/cssom-1/#dom-css-escape
WebIDL::ExceptionOr<String> escape(JS::VM&, StringView identifier)
{
// The escape(ident) operation must return the result of invoking serialize an identifier of ident.
return serialize_an_identifier(identifier);
}
// https://www.w3.org/TR/css-conditional-3/#dom-css-supports
bool supports(JS::VM& vm, StringView property, StringView value)
{
auto& realm = *vm.current_realm();
// 1. If property is an ASCII case-insensitive match for any defined CSS property that the UA supports,
// and value successfully parses according to that propertys grammar, return true.
if (auto property_id = property_id_from_string(property); property_id.has_value()) {
if (parse_css_value(Parser::ParsingContext { realm }, value, property_id.value()))
return true;
}
// 2. Otherwise, if property is a custom property name string, return true.
// FIXME: This check is not enough to make sure this is a valid custom property name, but it's close enough.
else if (property.starts_with("--"sv) && property.length() >= 3) {
return true;
}
// 3. Otherwise, return false.
return false;
}
// https://www.w3.org/TR/css-conditional-3/#dom-css-supports
WebIDL::ExceptionOr<bool> supports(JS::VM& vm, StringView condition_text)
{
auto& realm = *vm.current_realm();
// 1. If conditionText, parsed and evaluated as a <supports-condition>, would return true, return true.
if (auto supports = parse_css_supports(Parser::ParsingContext { realm }, condition_text); supports && supports->matches())
return true;
// 2. Otherwise, If conditionText, wrapped in parentheses and then parsed and evaluated as a <supports-condition>, would return true, return true.
auto wrapped_condition_text = TRY_OR_THROW_OOM(vm, String::formatted("({})", condition_text));
if (auto supports = parse_css_supports(Parser::ParsingContext { realm }, wrapped_condition_text); supports && supports->matches())
return true;
// 3. Otherwise, return false.
return false;
}
}