673527d314
Currently we don't deal with them, so they shouldn't return a SimpleSelector - that'd be a false positive. Also don't produce a ComplexSelector if no SimpleSelector was parsed. This fixes a couple of rendering issues on awesomekling.github.io: link colours, footer size, content max-width (and possibly more!)
706 lines
21 KiB
C++
706 lines
21 KiB
C++
/*
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* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <AK/HashMap.h>
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#include <LibWeb/CSS/PropertyID.h>
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#include <LibWeb/CSS/StyleSheet.h>
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#include <LibWeb/Parser/CSSParser.h>
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#include <ctype.h>
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#include <stdio.h>
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#include <stdlib.h>
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#define PARSE_ASSERT(x) \
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if (!(x)) { \
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dbg() << "CSS PARSER ASSERTION FAILED: " << #x; \
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dbg() << "At character# " << index << " in CSS: _" << css << "_"; \
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ASSERT_NOT_REACHED(); \
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}
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namespace Web {
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static Optional<Color> parse_css_color(const StringView& view)
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{
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auto color = Color::from_string(view);
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if (color.has_value())
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return color;
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return {};
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}
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static Optional<float> try_parse_float(const StringView& string)
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{
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const char* str = string.characters_without_null_termination();
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size_t len = string.length();
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size_t weight = 1;
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int exp_val = 0;
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float value = 0.0f;
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float fraction = 0.0f;
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bool has_sign = false;
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bool is_negative = false;
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bool is_fractional = false;
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bool is_scientific = false;
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if (str[0] == '-') {
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is_negative = true;
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has_sign = true;
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}
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if (str[0] == '+') {
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has_sign = true;
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}
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for (size_t i = has_sign; i < len; i++) {
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// Looks like we're about to start working on the fractional part
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if (str[i] == '.') {
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is_fractional = true;
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continue;
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}
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if (str[i] == 'e' || str[i] == 'E') {
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if (str[i + 1] == '-' || str[i + 1] == '+')
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exp_val = atoi(str + i + 2);
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else
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exp_val = atoi(str + i + 1);
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is_scientific = true;
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continue;
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}
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if (str[i] < '0' || str[i] > '9' || exp_val != 0) {
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return {};
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continue;
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}
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if (is_fractional) {
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fraction *= 10;
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fraction += str[i] - '0';
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weight *= 10;
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} else {
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value = value * 10;
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value += str[i] - '0';
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}
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}
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fraction /= weight;
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value += fraction;
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if (is_scientific) {
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bool divide = exp_val < 0;
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if (divide)
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exp_val *= -1;
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for (int i = 0; i < exp_val; i++) {
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if (divide)
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value /= 10;
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else
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value *= 10;
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}
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}
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return is_negative ? -value : value;
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}
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static Optional<float> parse_number(const StringView& view)
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{
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if (view.length() >= 2 && view[view.length() - 2] == 'p' && view[view.length() - 1] == 'x')
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return parse_number(view.substring_view(0, view.length() - 2));
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return try_parse_float(view);
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}
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NonnullRefPtr<StyleValue> parse_css_value(const StringView& string)
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{
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auto number = parse_number(string);
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if (number.has_value())
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return LengthStyleValue::create(Length(number.value(), Length::Type::Absolute));
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if (string == "inherit")
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return InheritStyleValue::create();
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if (string == "initial")
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return InitialStyleValue::create();
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if (string == "auto")
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return LengthStyleValue::create(Length());
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auto color = parse_css_color(string);
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if (color.has_value())
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return ColorStyleValue::create(color.value());
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if (string == "-libhtml-link")
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return IdentifierStyleValue::create(CSS::ValueID::VendorSpecificLink);
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return StringStyleValue::create(string);
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}
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RefPtr<LengthStyleValue> parse_line_width(const StringView& part)
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{
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NonnullRefPtr<StyleValue> value = parse_css_value(part);
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if (value->is_length())
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return static_ptr_cast<LengthStyleValue>(value);
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return nullptr;
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}
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RefPtr<ColorStyleValue> parse_color(const StringView& part)
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{
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NonnullRefPtr<StyleValue> value = parse_css_value(part);
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if (value->is_color())
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return static_ptr_cast<ColorStyleValue>(value);
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return nullptr;
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}
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RefPtr<StringStyleValue> parse_line_style(const StringView& part)
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{
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NonnullRefPtr<StyleValue> parsed_value = parse_css_value(part);
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if (!parsed_value->is_string())
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return nullptr;
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auto value = static_ptr_cast<StringStyleValue>(parsed_value);
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if (value->to_string() == "dotted")
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return value;
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if (value->to_string() == "dashed")
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return value;
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if (value->to_string() == "solid")
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return value;
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if (value->to_string() == "double")
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return value;
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if (value->to_string() == "groove")
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return value;
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if (value->to_string() == "ridge")
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return value;
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return nullptr;
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}
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class CSSParser {
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public:
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CSSParser(const StringView& input)
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: css(input)
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{
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}
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bool next_is(const char* str) const
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{
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size_t len = strlen(str);
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for (size_t i = 0; i < len; ++i) {
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if (peek(i) != str[i])
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return false;
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}
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return true;
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}
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char peek(size_t offset = 0) const
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{
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if ((index + offset) < css.length())
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return css[index + offset];
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return 0;
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}
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char consume_specific(char ch)
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{
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if (peek() != ch) {
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dbg() << "peek() != '" << ch << "'";
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}
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PARSE_ASSERT(peek() == ch);
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PARSE_ASSERT(index < css.length());
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++index;
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return ch;
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}
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char consume_one()
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{
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PARSE_ASSERT(index < css.length());
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return css[index++];
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};
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bool consume_whitespace_or_comments()
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{
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size_t original_index = index;
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bool in_comment = false;
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for (; index < css.length(); ++index) {
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char ch = peek();
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if (isspace(ch))
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continue;
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if (!in_comment && ch == '/' && peek(1) == '*') {
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in_comment = true;
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++index;
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continue;
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}
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if (in_comment && ch == '*' && peek(1) == '/') {
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in_comment = false;
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++index;
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continue;
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}
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if (in_comment)
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continue;
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break;
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}
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return original_index != index;
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}
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bool is_valid_selector_char(char ch) const
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{
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return isalnum(ch) || ch == '-' || ch == '_' || ch == '(' || ch == ')' || ch == '@';
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}
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bool is_combinator(char ch) const
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{
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return ch == '~' || ch == '>' || ch == '+';
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}
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Optional<Selector::SimpleSelector> parse_simple_selector()
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{
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auto index_at_start = index;
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if (consume_whitespace_or_comments())
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return {};
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if (!peek() || peek() == '{' || peek() == ',' || is_combinator(peek()))
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return {};
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Selector::SimpleSelector::Type type;
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if (peek() == '*') {
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type = Selector::SimpleSelector::Type::Universal;
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consume_one();
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return Selector::SimpleSelector {
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type,
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Selector::SimpleSelector::PseudoClass::None,
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String(),
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Selector::SimpleSelector::AttributeMatchType::None,
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String(),
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String()
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};
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}
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if (peek() == '.') {
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type = Selector::SimpleSelector::Type::Class;
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consume_one();
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} else if (peek() == '#') {
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type = Selector::SimpleSelector::Type::Id;
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consume_one();
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} else if (isalpha(peek())) {
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type = Selector::SimpleSelector::Type::TagName;
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} else {
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type = Selector::SimpleSelector::Type::Universal;
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}
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if (type != Selector::SimpleSelector::Type::Universal) {
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while (is_valid_selector_char(peek()))
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buffer.append(consume_one());
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PARSE_ASSERT(!buffer.is_null());
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}
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Selector::SimpleSelector simple_selector {
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type,
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Selector::SimpleSelector::PseudoClass::None,
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String::copy(buffer),
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Selector::SimpleSelector::AttributeMatchType::None,
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String(),
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String()
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};
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buffer.clear();
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if (peek() == '[') {
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Selector::SimpleSelector::AttributeMatchType attribute_match_type = Selector::SimpleSelector::AttributeMatchType::HasAttribute;
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String attribute_name;
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String attribute_value;
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bool in_value = false;
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consume_specific('[');
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char expected_end_of_attribute_selector = ']';
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while (peek() != expected_end_of_attribute_selector) {
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char ch = consume_one();
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if (ch == '=') {
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attribute_match_type = Selector::SimpleSelector::AttributeMatchType::ExactValueMatch;
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attribute_name = String::copy(buffer);
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buffer.clear();
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in_value = true;
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consume_whitespace_or_comments();
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if (peek() == '\'') {
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expected_end_of_attribute_selector = '\'';
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consume_one();
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} else if (peek() == '"') {
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expected_end_of_attribute_selector = '"';
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consume_one();
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}
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continue;
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}
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buffer.append(ch);
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}
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if (in_value)
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attribute_value = String::copy(buffer);
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else
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attribute_name = String::copy(buffer);
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buffer.clear();
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simple_selector.attribute_match_type = attribute_match_type;
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simple_selector.attribute_name = attribute_name;
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simple_selector.attribute_value = attribute_value;
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if (expected_end_of_attribute_selector != ']')
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consume_specific(expected_end_of_attribute_selector);
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consume_whitespace_or_comments();
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consume_specific(']');
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}
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if (peek() == ':') {
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// FIXME: Implement pseudo elements.
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[[maybe_unused]] bool is_pseudo_element = false;
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consume_one();
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if (peek() == ':') {
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is_pseudo_element = true;
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consume_one();
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}
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if (next_is("not")) {
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buffer.append(consume_one());
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buffer.append(consume_one());
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buffer.append(consume_one());
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buffer.append(consume_specific('('));
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while (peek() != ')')
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buffer.append(consume_one());
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buffer.append(consume_specific(')'));
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} else {
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while (is_valid_selector_char(peek()))
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buffer.append(consume_one());
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}
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auto pseudo_name = String::copy(buffer);
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buffer.clear();
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// Ignore for now, otherwise we produce a "false positive" selector
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// and apply styles to the element itself, not its pseudo element
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if (is_pseudo_element)
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return {};
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if (pseudo_name == "link")
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simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::Link;
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else if (pseudo_name == "hover")
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simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::Hover;
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else if (pseudo_name == "focus")
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simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::Focus;
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else if (pseudo_name == "first-child")
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simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::FirstChild;
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else if (pseudo_name == "last-child")
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simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::LastChild;
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else if (pseudo_name == "only-child")
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simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::OnlyChild;
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else if (pseudo_name == "empty")
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simple_selector.pseudo_class = Selector::SimpleSelector::PseudoClass::Empty;
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}
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if (index == index_at_start) {
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// We consumed nothing.
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return {};
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}
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return simple_selector;
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}
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Optional<Selector::ComplexSelector> parse_complex_selector()
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{
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auto relation = Selector::ComplexSelector::Relation::Descendant;
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if (peek() == '{' || peek() == ',')
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return {};
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if (is_combinator(peek())) {
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switch (peek()) {
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case '>':
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relation = Selector::ComplexSelector::Relation::ImmediateChild;
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break;
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case '+':
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relation = Selector::ComplexSelector::Relation::AdjacentSibling;
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break;
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case '~':
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relation = Selector::ComplexSelector::Relation::GeneralSibling;
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break;
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}
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consume_one();
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consume_whitespace_or_comments();
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}
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consume_whitespace_or_comments();
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Vector<Selector::SimpleSelector> simple_selectors;
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for (;;) {
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auto component = parse_simple_selector();
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if (!component.has_value())
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break;
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simple_selectors.append(component.value());
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// If this assert triggers, we're most likely up to no good.
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PARSE_ASSERT(simple_selectors.size() < 100);
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}
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if (simple_selectors.is_empty())
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return {};
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return Selector::ComplexSelector { relation, move(simple_selectors) };
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}
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void parse_selector()
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{
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Vector<Selector::ComplexSelector> complex_selectors;
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for (;;) {
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auto complex_selector = parse_complex_selector();
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if (complex_selector.has_value())
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complex_selectors.append(complex_selector.value());
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consume_whitespace_or_comments();
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if (!peek() || peek() == ',' || peek() == '{')
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break;
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}
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if (complex_selectors.is_empty())
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return;
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complex_selectors.first().relation = Selector::ComplexSelector::Relation::None;
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current_rule.selectors.append(Selector(move(complex_selectors)));
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}
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Optional<Selector> parse_individual_selector()
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{
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parse_selector();
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if (current_rule.selectors.is_empty())
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return {};
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return current_rule.selectors.last();
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}
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void parse_selector_list()
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{
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for (;;) {
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parse_selector();
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consume_whitespace_or_comments();
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if (peek() == ',') {
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consume_one();
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continue;
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}
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if (peek() == '{')
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break;
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}
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}
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bool is_valid_property_name_char(char ch) const
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{
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return ch && !isspace(ch) && ch != ':';
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}
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bool is_valid_property_value_char(char ch) const
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{
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return ch && ch != '!' && ch != ';' && ch != '}';
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}
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struct ValueAndImportant {
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String value;
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bool important { false };
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};
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ValueAndImportant consume_css_value()
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{
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buffer.clear();
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int paren_nesting_level = 0;
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bool important = false;
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for (;;) {
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char ch = peek();
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if (ch == '(') {
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++paren_nesting_level;
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buffer.append(consume_one());
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continue;
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}
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if (ch == ')') {
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PARSE_ASSERT(paren_nesting_level > 0);
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--paren_nesting_level;
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buffer.append(consume_one());
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continue;
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}
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if (paren_nesting_level > 0) {
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buffer.append(consume_one());
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continue;
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}
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if (next_is("!important")) {
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consume_specific('!');
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consume_specific('i');
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consume_specific('m');
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consume_specific('p');
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consume_specific('o');
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consume_specific('r');
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consume_specific('t');
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consume_specific('a');
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consume_specific('n');
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consume_specific('t');
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important = true;
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continue;
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}
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|
if (next_is("/*")) {
|
|
consume_whitespace_or_comments();
|
|
continue;
|
|
}
|
|
if (!ch)
|
|
break;
|
|
if (ch == '}')
|
|
break;
|
|
if (ch == ';')
|
|
break;
|
|
buffer.append(consume_one());
|
|
}
|
|
|
|
// Remove trailing whitespace.
|
|
while (!buffer.is_empty() && isspace(buffer.last()))
|
|
buffer.take_last();
|
|
|
|
auto string = String::copy(buffer);
|
|
buffer.clear();
|
|
|
|
return { string, important };
|
|
}
|
|
|
|
Optional<StyleProperty> parse_property()
|
|
{
|
|
consume_whitespace_or_comments();
|
|
if (peek() == ';') {
|
|
consume_one();
|
|
return {};
|
|
}
|
|
if (peek() == '}')
|
|
return {};
|
|
buffer.clear();
|
|
while (is_valid_property_name_char(peek()))
|
|
buffer.append(consume_one());
|
|
auto property_name = String::copy(buffer);
|
|
buffer.clear();
|
|
consume_whitespace_or_comments();
|
|
consume_specific(':');
|
|
consume_whitespace_or_comments();
|
|
|
|
auto [property_value, important] = consume_css_value();
|
|
|
|
consume_whitespace_or_comments();
|
|
|
|
if (peek() && peek() != '}')
|
|
consume_specific(';');
|
|
|
|
auto property_id = CSS::property_id_from_string(property_name);
|
|
return StyleProperty { property_id, parse_css_value(property_value), important };
|
|
}
|
|
|
|
void parse_declaration()
|
|
{
|
|
for (;;) {
|
|
auto property = parse_property();
|
|
if (property.has_value())
|
|
current_rule.properties.append(property.value());
|
|
consume_whitespace_or_comments();
|
|
if (peek() == '}')
|
|
break;
|
|
}
|
|
}
|
|
|
|
void parse_rule()
|
|
{
|
|
consume_whitespace_or_comments();
|
|
if (index >= css.length())
|
|
return;
|
|
|
|
// FIXME: We ignore @-rules for now.
|
|
if (peek() == '@') {
|
|
while (peek() != '{')
|
|
consume_one();
|
|
int level = 0;
|
|
for (;;) {
|
|
auto ch = consume_one();
|
|
if (ch == '{') {
|
|
++level;
|
|
} else if (ch == '}') {
|
|
--level;
|
|
if (level == 0)
|
|
break;
|
|
}
|
|
}
|
|
consume_whitespace_or_comments();
|
|
return;
|
|
}
|
|
|
|
parse_selector_list();
|
|
consume_specific('{');
|
|
parse_declaration();
|
|
consume_specific('}');
|
|
rules.append(StyleRule::create(move(current_rule.selectors), StyleDeclaration::create(move(current_rule.properties))));
|
|
consume_whitespace_or_comments();
|
|
}
|
|
|
|
RefPtr<StyleSheet> parse_sheet()
|
|
{
|
|
while (index < css.length()) {
|
|
parse_rule();
|
|
}
|
|
|
|
return StyleSheet::create(move(rules));
|
|
}
|
|
|
|
RefPtr<StyleDeclaration> parse_standalone_declaration()
|
|
{
|
|
consume_whitespace_or_comments();
|
|
for (;;) {
|
|
auto property = parse_property();
|
|
if (property.has_value())
|
|
current_rule.properties.append(property.value());
|
|
consume_whitespace_or_comments();
|
|
if (!peek())
|
|
break;
|
|
}
|
|
return StyleDeclaration::create(move(current_rule.properties));
|
|
}
|
|
|
|
private:
|
|
NonnullRefPtrVector<StyleRule> rules;
|
|
|
|
struct CurrentRule {
|
|
Vector<Selector> selectors;
|
|
Vector<StyleProperty> properties;
|
|
};
|
|
|
|
CurrentRule current_rule;
|
|
Vector<char> buffer;
|
|
|
|
size_t index = 0;
|
|
|
|
StringView css;
|
|
};
|
|
|
|
Optional<Selector> parse_selector(const StringView& selector_text)
|
|
{
|
|
CSSParser parser(selector_text);
|
|
return parser.parse_individual_selector();
|
|
}
|
|
|
|
RefPtr<StyleSheet> parse_css(const StringView& css)
|
|
{
|
|
CSSParser parser(css);
|
|
return parser.parse_sheet();
|
|
}
|
|
|
|
RefPtr<StyleDeclaration> parse_css_declaration(const StringView& css)
|
|
{
|
|
CSSParser parser(css);
|
|
return parser.parse_standalone_declaration();
|
|
}
|
|
|
|
}
|