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ladybird/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
Aliaksandr Kalenik da2cd73bcf LibWeb: Add place-self css property support
2023-08-06 08:26:36 +02:00

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/*
* Copyright (c) 2018-2023, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2021, the SerenityOS developers.
* Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/BinarySearch.h>
#include <AK/Debug.h>
#include <AK/Error.h>
#include <AK/Find.h>
#include <AK/Function.h>
#include <AK/HashMap.h>
#include <AK/QuickSort.h>
#include <AK/TemporaryChange.h>
#include <LibGfx/Font/Font.h>
#include <LibGfx/Font/FontDatabase.h>
#include <LibGfx/Font/FontStyleMapping.h>
#include <LibGfx/Font/OpenType/Font.h>
#include <LibGfx/Font/ScaledFont.h>
#include <LibGfx/Font/VectorFont.h>
#include <LibGfx/Font/WOFF/Font.h>
#include <LibWeb/CSS/CSSFontFaceRule.h>
#include <LibWeb/CSS/CSSImportRule.h>
#include <LibWeb/CSS/CSSStyleRule.h>
#include <LibWeb/CSS/Parser/Parser.h>
#include <LibWeb/CSS/SelectorEngine.h>
#include <LibWeb/CSS/StyleComputer.h>
#include <LibWeb/CSS/StyleSheet.h>
#include <LibWeb/CSS/StyleValues/AngleStyleValue.h>
#include <LibWeb/CSS/StyleValues/BackgroundStyleValue.h>
#include <LibWeb/CSS/StyleValues/BorderRadiusShorthandStyleValue.h>
#include <LibWeb/CSS/StyleValues/BorderRadiusStyleValue.h>
#include <LibWeb/CSS/StyleValues/BorderStyleValue.h>
#include <LibWeb/CSS/StyleValues/ColorStyleValue.h>
#include <LibWeb/CSS/StyleValues/CompositeStyleValue.h>
#include <LibWeb/CSS/StyleValues/DisplayStyleValue.h>
#include <LibWeb/CSS/StyleValues/EasingStyleValue.h>
#include <LibWeb/CSS/StyleValues/FilterValueListStyleValue.h>
#include <LibWeb/CSS/StyleValues/FlexFlowStyleValue.h>
#include <LibWeb/CSS/StyleValues/FlexStyleValue.h>
#include <LibWeb/CSS/StyleValues/FontStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridAreaShorthandStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTrackPlacementShorthandStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTrackPlacementStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTrackSizeListShorthandStyleValue.h>
#include <LibWeb/CSS/StyleValues/GridTrackSizeListStyleValue.h>
#include <LibWeb/CSS/StyleValues/IdentifierStyleValue.h>
#include <LibWeb/CSS/StyleValues/IntegerStyleValue.h>
#include <LibWeb/CSS/StyleValues/LengthStyleValue.h>
#include <LibWeb/CSS/StyleValues/ListStyleStyleValue.h>
#include <LibWeb/CSS/StyleValues/NumberStyleValue.h>
#include <LibWeb/CSS/StyleValues/OverflowStyleValue.h>
#include <LibWeb/CSS/StyleValues/PercentageStyleValue.h>
#include <LibWeb/CSS/StyleValues/PlaceContentStyleValue.h>
#include <LibWeb/CSS/StyleValues/PlaceItemsStyleValue.h>
#include <LibWeb/CSS/StyleValues/PlaceSelfStyleValue.h>
#include <LibWeb/CSS/StyleValues/PositionStyleValue.h>
#include <LibWeb/CSS/StyleValues/RectStyleValue.h>
#include <LibWeb/CSS/StyleValues/StyleValueList.h>
#include <LibWeb/CSS/StyleValues/TextDecorationStyleValue.h>
#include <LibWeb/CSS/StyleValues/TimeStyleValue.h>
#include <LibWeb/CSS/StyleValues/TransformationStyleValue.h>
#include <LibWeb/CSS/StyleValues/UnresolvedStyleValue.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/Element.h>
#include <LibWeb/FontCache.h>
#include <LibWeb/HTML/HTMLHtmlElement.h>
#include <LibWeb/Layout/Node.h>
#include <LibWeb/Loader/ResourceLoader.h>
#include <LibWeb/Platform/FontPlugin.h>
#include <stdio.h>
namespace AK {
// traits for FontFaceKey
template<>
struct Traits<Web::CSS::FontFaceKey> : public GenericTraits<Web::CSS::FontFaceKey> {
static unsigned hash(Web::CSS::FontFaceKey const& key) { return pair_int_hash(key.family_name.hash(), pair_int_hash(key.weight, key.slope)); }
};
}
namespace Web::CSS {
static DOM::Element const* element_to_inherit_style_from(DOM::Element const*, Optional<CSS::Selector::PseudoElement>);
static NonnullRefPtr<StyleValue const> get_inherit_value(JS::Realm& initial_value_context_realm, CSS::PropertyID, DOM::Element const*, Optional<CSS::Selector::PseudoElement>);
StyleComputer::StyleComputer(DOM::Document& document)
: m_document(document)
, m_default_font_metrics(16, Gfx::FontDatabase::default_font().pixel_metrics(), 16)
, m_root_element_font_metrics(m_default_font_metrics)
{
}
StyleComputer::~StyleComputer() = default;
class StyleComputer::FontLoader : public ResourceClient {
public:
explicit FontLoader(StyleComputer& style_computer, FlyString family_name, Vector<AK::URL> urls)
: m_style_computer(style_computer)
, m_family_name(move(family_name))
, m_urls(move(urls))
{
start_loading_next_url();
}
virtual ~FontLoader() override { }
virtual void resource_did_load() override
{
auto result = try_load_font();
if (result.is_error())
return start_loading_next_url();
m_vector_font = result.release_value();
m_style_computer.did_load_font(m_family_name);
}
virtual void resource_did_fail() override
{
}
RefPtr<Gfx::Font> font_with_point_size(float point_size) const
{
if (!m_vector_font)
return nullptr;
if (auto it = m_cached_fonts.find(point_size); it != m_cached_fonts.end())
return it->value;
// FIXME: It might be nicer to have a global cap on the number of fonts we cache
// instead of doing it at the per-font level like this.
constexpr size_t max_cached_font_size_count = 64;
if (m_cached_fonts.size() > max_cached_font_size_count)
m_cached_fonts.remove(m_cached_fonts.begin());
auto font = adopt_ref(*new Gfx::ScaledFont(*m_vector_font, point_size, point_size));
m_cached_fonts.set(point_size, font);
return font;
}
private:
void start_loading_next_url()
{
if (m_urls.is_empty())
return;
LoadRequest request;
request.set_url(m_urls.take_first());
set_resource(ResourceLoader::the().load_resource(Resource::Type::Generic, request));
}
ErrorOr<NonnullRefPtr<Gfx::VectorFont>> try_load_font()
{
// FIXME: This could maybe use the format() provided in @font-face as well, since often the mime type is just application/octet-stream and we have to try every format
auto mime_type = resource()->mime_type();
if (mime_type == "font/ttf"sv || mime_type == "application/x-font-ttf"sv)
return TRY(OpenType::Font::try_load_from_externally_owned_memory(resource()->encoded_data()));
if (mime_type == "font/woff"sv || mime_type == "application/font-woff"sv)
return TRY(WOFF::Font::try_load_from_externally_owned_memory(resource()->encoded_data()));
auto ttf = OpenType::Font::try_load_from_externally_owned_memory(resource()->encoded_data());
if (!ttf.is_error())
return ttf.release_value();
auto woff = WOFF::Font::try_load_from_externally_owned_memory(resource()->encoded_data());
if (!woff.is_error())
return woff.release_value();
return ttf.release_error();
}
StyleComputer& m_style_computer;
FlyString m_family_name;
RefPtr<Gfx::VectorFont> m_vector_font;
Vector<AK::URL> m_urls;
HashMap<float, NonnullRefPtr<Gfx::ScaledFont>> mutable m_cached_fonts;
};
static CSSStyleSheet& default_stylesheet(DOM::Document const& document)
{
static JS::Handle<CSSStyleSheet> sheet;
if (!sheet.cell()) {
extern StringView default_stylesheet_source;
sheet = JS::make_handle(parse_css_stylesheet(CSS::Parser::ParsingContext(document), default_stylesheet_source));
}
return *sheet;
}
static CSSStyleSheet& quirks_mode_stylesheet(DOM::Document const& document)
{
static JS::Handle<CSSStyleSheet> sheet;
if (!sheet.cell()) {
extern StringView quirks_mode_stylesheet_source;
sheet = JS::make_handle(parse_css_stylesheet(CSS::Parser::ParsingContext(document), quirks_mode_stylesheet_source));
}
return *sheet;
}
template<typename Callback>
void StyleComputer::for_each_stylesheet(CascadeOrigin cascade_origin, Callback callback) const
{
if (cascade_origin == CascadeOrigin::UserAgent) {
callback(default_stylesheet(document()));
if (document().in_quirks_mode())
callback(quirks_mode_stylesheet(document()));
}
if (cascade_origin == CascadeOrigin::Author) {
for (auto const& sheet : document().style_sheets().sheets())
callback(*sheet);
}
}
StyleComputer::RuleCache const& StyleComputer::rule_cache_for_cascade_origin(CascadeOrigin cascade_origin) const
{
switch (cascade_origin) {
case CascadeOrigin::Author:
return *m_author_rule_cache;
case CascadeOrigin::UserAgent:
return *m_user_agent_rule_cache;
default:
TODO();
}
}
[[nodiscard]] static bool filter_namespace_rule(DOM::Element const& element, MatchingRule const& rule)
{
// FIXME: Filter out non-default namespace using prefixes
auto namespace_uri = rule.sheet->default_namespace();
if (namespace_uri.has_value() && namespace_uri.value() != element.namespace_uri()) {
return false;
}
return true;
}
Vector<MatchingRule> StyleComputer::collect_matching_rules(DOM::Element const& element, CascadeOrigin cascade_origin, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
auto const& rule_cache = rule_cache_for_cascade_origin(cascade_origin);
Vector<MatchingRule> rules_to_run;
auto add_rules_to_run = [&](Vector<MatchingRule> const& rules) {
rules_to_run.grow_capacity(rules_to_run.size() + rules.size());
if (pseudo_element.has_value()) {
for (auto const& rule : rules) {
if (rule.contains_pseudo_element && filter_namespace_rule(element, rule))
rules_to_run.append(rule);
}
} else {
for (auto const& rule : rules) {
if (filter_namespace_rule(element, rule))
rules_to_run.append(rule);
}
}
};
for (auto const& class_name : element.class_names()) {
if (auto it = rule_cache.rules_by_class.find(class_name); it != rule_cache.rules_by_class.end())
add_rules_to_run(it->value);
}
if (auto id = element.get_attribute(HTML::AttributeNames::id); !id.is_null()) {
if (auto it = rule_cache.rules_by_id.find(FlyString::from_deprecated_fly_string(id).release_value_but_fixme_should_propagate_errors()); it != rule_cache.rules_by_id.end())
add_rules_to_run(it->value);
}
if (auto it = rule_cache.rules_by_tag_name.find(FlyString::from_deprecated_fly_string(element.local_name()).release_value_but_fixme_should_propagate_errors()); it != rule_cache.rules_by_tag_name.end())
add_rules_to_run(it->value);
add_rules_to_run(rule_cache.other_rules);
Vector<MatchingRule> matching_rules;
matching_rules.ensure_capacity(rules_to_run.size());
for (auto const& rule_to_run : rules_to_run) {
auto const& selector = rule_to_run.rule->selectors()[rule_to_run.selector_index];
if (SelectorEngine::matches(selector, element, pseudo_element))
matching_rules.append(rule_to_run);
}
return matching_rules;
}
static void sort_matching_rules(Vector<MatchingRule>& matching_rules)
{
quick_sort(matching_rules, [&](MatchingRule& a, MatchingRule& b) {
auto const& a_selector = a.rule->selectors()[a.selector_index];
auto const& b_selector = b.rule->selectors()[b.selector_index];
auto a_specificity = a_selector->specificity();
auto b_specificity = b_selector->specificity();
if (a_selector->specificity() == b_selector->specificity()) {
if (a.style_sheet_index == b.style_sheet_index)
return a.rule_index < b.rule_index;
return a.style_sheet_index < b.style_sheet_index;
}
return a_specificity < b_specificity;
});
}
enum class Edge {
Top,
Right,
Bottom,
Left,
All,
};
static bool contains(Edge a, Edge b)
{
return a == b || b == Edge::All;
}
static void set_property_expanding_shorthands(StyleProperties& style, CSS::PropertyID property_id, StyleValue const& value, DOM::Document& document, CSS::CSSStyleDeclaration const* declaration, StyleProperties::PropertyValues const& properties_for_revert)
{
auto set_longhand_property = [&](CSS::PropertyID property_id, StyleValue const& value) {
if (value.is_revert()) {
auto& property_in_previous_cascade_origin = properties_for_revert[to_underlying(property_id)];
if (property_in_previous_cascade_origin.has_value())
style.set_property(property_id, property_in_previous_cascade_origin->style, property_in_previous_cascade_origin->declaration);
} else {
style.set_property(property_id, value, declaration);
}
};
auto map_logical_property_to_real_property = [](PropertyID property_id) -> Optional<PropertyID> {
// FIXME: Honor writing-mode, direction and text-orientation.
switch (property_id) {
case PropertyID::MarginBlockStart:
return PropertyID::MarginTop;
case PropertyID::MarginBlockEnd:
return PropertyID::MarginBottom;
case PropertyID::MarginInlineStart:
return PropertyID::MarginLeft;
case PropertyID::MarginInlineEnd:
return PropertyID::MarginRight;
case PropertyID::PaddingBlockStart:
return PropertyID::PaddingTop;
case PropertyID::PaddingBlockEnd:
return PropertyID::PaddingBottom;
case PropertyID::PaddingInlineStart:
return PropertyID::PaddingLeft;
case PropertyID::PaddingInlineEnd:
return PropertyID::PaddingRight;
case PropertyID::InsetBlockStart:
return PropertyID::Top;
case PropertyID::InsetBlockEnd:
return PropertyID::Bottom;
case PropertyID::InsetInlineStart:
return PropertyID::Left;
case PropertyID::InsetInlineEnd:
return PropertyID::Right;
default:
return {};
}
};
struct StartAndEndPropertyIDs {
PropertyID start;
PropertyID end;
};
auto map_logical_property_to_real_properties = [](PropertyID property_id) -> Optional<StartAndEndPropertyIDs> {
// FIXME: Honor writing-mode, direction and text-orientation.
switch (property_id) {
case PropertyID::MarginBlock:
return StartAndEndPropertyIDs { PropertyID::MarginTop, PropertyID::MarginBottom };
case PropertyID::MarginInline:
return StartAndEndPropertyIDs { PropertyID::MarginLeft, PropertyID::MarginRight };
case PropertyID::PaddingBlock:
return StartAndEndPropertyIDs { PropertyID::PaddingTop, PropertyID::PaddingBottom };
case PropertyID::PaddingInline:
return StartAndEndPropertyIDs { PropertyID::PaddingLeft, PropertyID::PaddingRight };
case PropertyID::InsetBlock:
return StartAndEndPropertyIDs { PropertyID::Top, PropertyID::Bottom };
case PropertyID::InsetInline:
return StartAndEndPropertyIDs { PropertyID::Left, PropertyID::Right };
default:
return {};
}
};
if (auto real_property_id = map_logical_property_to_real_property(property_id); real_property_id.has_value())
return set_property_expanding_shorthands(style, real_property_id.value(), value, document, declaration, properties_for_revert);
if (auto real_property_ids = map_logical_property_to_real_properties(property_id); real_property_ids.has_value()) {
if (value.is_value_list() && value.as_value_list().size() == 2) {
auto const& start = value.as_value_list().values()[0];
auto const& end = value.as_value_list().values()[1];
set_property_expanding_shorthands(style, real_property_ids->start, start, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, real_property_ids->end, end, document, declaration, properties_for_revert);
return;
}
set_property_expanding_shorthands(style, real_property_ids->start, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, real_property_ids->end, value, document, declaration, properties_for_revert);
return;
}
if (value.is_composite()) {
auto& composite_value = value.as_composite();
auto& properties = composite_value.sub_properties();
auto& values = composite_value.values();
for (size_t i = 0; i < properties.size(); ++i)
set_property_expanding_shorthands(style, properties[i], values[i], document, declaration, properties_for_revert);
}
auto assign_edge_values = [&](PropertyID top_property, PropertyID right_property, PropertyID bottom_property, PropertyID left_property, auto const& values) {
if (values.size() == 4) {
set_longhand_property(top_property, values[0]);
set_longhand_property(right_property, values[1]);
set_longhand_property(bottom_property, values[2]);
set_longhand_property(left_property, values[3]);
} else if (values.size() == 3) {
set_longhand_property(top_property, values[0]);
set_longhand_property(right_property, values[1]);
set_longhand_property(bottom_property, values[2]);
set_longhand_property(left_property, values[1]);
} else if (values.size() == 2) {
set_longhand_property(top_property, values[0]);
set_longhand_property(right_property, values[1]);
set_longhand_property(bottom_property, values[0]);
set_longhand_property(left_property, values[1]);
} else if (values.size() == 1) {
set_longhand_property(top_property, values[0]);
set_longhand_property(right_property, values[0]);
set_longhand_property(bottom_property, values[0]);
set_longhand_property(left_property, values[0]);
}
};
if (property_id == CSS::PropertyID::TextDecoration) {
if (value.is_text_decoration()) {
auto const& text_decoration = value.as_text_decoration();
set_longhand_property(CSS::PropertyID::TextDecorationLine, text_decoration.line());
set_longhand_property(CSS::PropertyID::TextDecorationThickness, text_decoration.thickness());
set_longhand_property(CSS::PropertyID::TextDecorationStyle, text_decoration.style());
set_longhand_property(CSS::PropertyID::TextDecorationColor, text_decoration.color());
return;
}
set_longhand_property(CSS::PropertyID::TextDecorationLine, value);
set_longhand_property(CSS::PropertyID::TextDecorationThickness, value);
set_longhand_property(CSS::PropertyID::TextDecorationStyle, value);
set_longhand_property(CSS::PropertyID::TextDecorationColor, value);
return;
}
if (property_id == CSS::PropertyID::Overflow) {
if (value.is_overflow()) {
auto const& overflow = value.as_overflow();
set_longhand_property(CSS::PropertyID::OverflowX, overflow.overflow_x());
set_longhand_property(CSS::PropertyID::OverflowY, overflow.overflow_y());
return;
}
set_longhand_property(CSS::PropertyID::OverflowX, value);
set_longhand_property(CSS::PropertyID::OverflowY, value);
return;
}
if (property_id == CSS::PropertyID::PlaceContent) {
if (value.is_place_content()) {
auto const& place_content = value.as_place_content();
set_longhand_property(CSS::PropertyID::AlignContent, place_content.align_content());
set_longhand_property(CSS::PropertyID::JustifyContent, place_content.justify_content());
return;
}
style.set_property(CSS::PropertyID::AlignContent, value);
style.set_property(CSS::PropertyID::JustifyContent, value);
return;
}
if (property_id == CSS::PropertyID::PlaceItems) {
if (value.is_place_items()) {
auto const& place_items = value.as_place_items();
set_longhand_property(CSS::PropertyID::AlignItems, place_items.align_items());
set_longhand_property(CSS::PropertyID::JustifyItems, place_items.justify_items());
return;
}
set_longhand_property(CSS::PropertyID::AlignItems, value);
set_longhand_property(CSS::PropertyID::JustifyItems, value);
return;
}
if (property_id == CSS::PropertyID::PlaceSelf) {
if (value.is_place_self()) {
auto const& place_self = value.as_place_self();
set_longhand_property(CSS::PropertyID::AlignSelf, place_self.align_self());
set_longhand_property(CSS::PropertyID::JustifySelf, place_self.justify_self());
return;
}
set_longhand_property(CSS::PropertyID::AlignSelf, value);
set_longhand_property(CSS::PropertyID::JustifySelf, value);
return;
}
if (property_id == CSS::PropertyID::Border) {
set_property_expanding_shorthands(style, CSS::PropertyID::BorderTop, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BorderRight, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BorderBottom, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BorderLeft, value, document, declaration, properties_for_revert);
// FIXME: Also reset border-image, in line with the spec: https://www.w3.org/TR/css-backgrounds-3/#border-shorthands
return;
}
if (property_id == CSS::PropertyID::BorderRadius) {
if (value.is_border_radius_shorthand()) {
auto const& shorthand = value.as_border_radius_shorthand();
set_longhand_property(CSS::PropertyID::BorderTopLeftRadius, shorthand.top_left());
set_longhand_property(CSS::PropertyID::BorderTopRightRadius, shorthand.top_right());
set_longhand_property(CSS::PropertyID::BorderBottomRightRadius, shorthand.bottom_right());
set_longhand_property(CSS::PropertyID::BorderBottomLeftRadius, shorthand.bottom_left());
return;
}
set_longhand_property(CSS::PropertyID::BorderTopLeftRadius, value);
set_longhand_property(CSS::PropertyID::BorderTopRightRadius, value);
set_longhand_property(CSS::PropertyID::BorderBottomRightRadius, value);
set_longhand_property(CSS::PropertyID::BorderBottomLeftRadius, value);
return;
}
if (property_id == CSS::PropertyID::BorderTop
|| property_id == CSS::PropertyID::BorderRight
|| property_id == CSS::PropertyID::BorderBottom
|| property_id == CSS::PropertyID::BorderLeft) {
Edge edge = Edge::All;
switch (property_id) {
case CSS::PropertyID::BorderTop:
edge = Edge::Top;
break;
case CSS::PropertyID::BorderRight:
edge = Edge::Right;
break;
case CSS::PropertyID::BorderBottom:
edge = Edge::Bottom;
break;
case CSS::PropertyID::BorderLeft:
edge = Edge::Left;
break;
default:
break;
}
if (value.is_border()) {
auto const& border = value.as_border();
if (contains(Edge::Top, edge)) {
set_longhand_property(PropertyID::BorderTopWidth, border.border_width());
set_longhand_property(PropertyID::BorderTopStyle, border.border_style());
set_longhand_property(PropertyID::BorderTopColor, border.border_color());
}
if (contains(Edge::Right, edge)) {
set_longhand_property(PropertyID::BorderRightWidth, border.border_width());
set_longhand_property(PropertyID::BorderRightStyle, border.border_style());
set_longhand_property(PropertyID::BorderRightColor, border.border_color());
}
if (contains(Edge::Bottom, edge)) {
set_longhand_property(PropertyID::BorderBottomWidth, border.border_width());
set_longhand_property(PropertyID::BorderBottomStyle, border.border_style());
set_longhand_property(PropertyID::BorderBottomColor, border.border_color());
}
if (contains(Edge::Left, edge)) {
set_longhand_property(PropertyID::BorderLeftWidth, border.border_width());
set_longhand_property(PropertyID::BorderLeftStyle, border.border_style());
set_longhand_property(PropertyID::BorderLeftColor, border.border_color());
}
return;
}
return;
}
if (property_id == CSS::PropertyID::BorderStyle) {
if (value.is_value_list()) {
auto const& values_list = value.as_value_list();
assign_edge_values(PropertyID::BorderTopStyle, PropertyID::BorderRightStyle, PropertyID::BorderBottomStyle, PropertyID::BorderLeftStyle, values_list.values());
return;
}
set_longhand_property(CSS::PropertyID::BorderTopStyle, value);
set_longhand_property(CSS::PropertyID::BorderRightStyle, value);
set_longhand_property(CSS::PropertyID::BorderBottomStyle, value);
set_longhand_property(CSS::PropertyID::BorderLeftStyle, value);
return;
}
if (property_id == CSS::PropertyID::BorderWidth) {
if (value.is_value_list()) {
auto const& values_list = value.as_value_list();
assign_edge_values(PropertyID::BorderTopWidth, PropertyID::BorderRightWidth, PropertyID::BorderBottomWidth, PropertyID::BorderLeftWidth, values_list.values());
return;
}
set_longhand_property(CSS::PropertyID::BorderTopWidth, value);
set_longhand_property(CSS::PropertyID::BorderRightWidth, value);
set_longhand_property(CSS::PropertyID::BorderBottomWidth, value);
set_longhand_property(CSS::PropertyID::BorderLeftWidth, value);
return;
}
if (property_id == CSS::PropertyID::BorderColor) {
if (value.is_value_list()) {
auto const& values_list = value.as_value_list();
assign_edge_values(PropertyID::BorderTopColor, PropertyID::BorderRightColor, PropertyID::BorderBottomColor, PropertyID::BorderLeftColor, values_list.values());
return;
}
set_longhand_property(CSS::PropertyID::BorderTopColor, value);
set_longhand_property(CSS::PropertyID::BorderRightColor, value);
set_longhand_property(CSS::PropertyID::BorderBottomColor, value);
set_longhand_property(CSS::PropertyID::BorderLeftColor, value);
return;
}
if (property_id == CSS::PropertyID::Background) {
if (value.is_background()) {
auto const& background = value.as_background();
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundColor, background.color(), document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundImage, background.image(), document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundPosition, background.position(), document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundSize, background.size(), document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundRepeat, background.repeat(), document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundAttachment, background.attachment(), document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundOrigin, background.origin(), document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundClip, background.clip(), document, declaration, properties_for_revert);
return;
}
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundColor, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundImage, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundPosition, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundSize, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundRepeat, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundAttachment, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundOrigin, value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, CSS::PropertyID::BackgroundClip, value, document, declaration, properties_for_revert);
return;
}
if (property_id == CSS::PropertyID::BackgroundPosition) {
if (value.is_position()) {
auto const& position = value.as_position();
set_longhand_property(CSS::PropertyID::BackgroundPositionX, position.edge_x());
set_longhand_property(CSS::PropertyID::BackgroundPositionY, position.edge_y());
} else if (value.is_value_list()) {
// Expand background-position layer list into separate lists for x and y positions:
auto const& values_list = value.as_value_list();
StyleValueVector x_positions {};
StyleValueVector y_positions {};
x_positions.ensure_capacity(values_list.size());
y_positions.ensure_capacity(values_list.size());
for (auto& layer : values_list.values()) {
if (layer->is_position()) {
auto const& position = layer->as_position();
x_positions.unchecked_append(position.edge_x());
y_positions.unchecked_append(position.edge_y());
} else {
x_positions.unchecked_append(layer);
y_positions.unchecked_append(layer);
}
}
set_longhand_property(CSS::PropertyID::BackgroundPositionX, StyleValueList::create(move(x_positions), values_list.separator()).release_value_but_fixme_should_propagate_errors());
set_longhand_property(CSS::PropertyID::BackgroundPositionY, StyleValueList::create(move(y_positions), values_list.separator()).release_value_but_fixme_should_propagate_errors());
} else {
set_longhand_property(CSS::PropertyID::BackgroundPositionX, value);
set_longhand_property(CSS::PropertyID::BackgroundPositionY, value);
}
return;
}
if (property_id == CSS::PropertyID::Inset) {
if (value.is_value_list()) {
auto const& values_list = value.as_value_list();
assign_edge_values(PropertyID::Top, PropertyID::Right, PropertyID::Bottom, PropertyID::Left, values_list.values());
return;
}
set_longhand_property(CSS::PropertyID::Top, value);
set_longhand_property(CSS::PropertyID::Right, value);
set_longhand_property(CSS::PropertyID::Bottom, value);
set_longhand_property(CSS::PropertyID::Left, value);
return;
}
if (property_id == CSS::PropertyID::Margin) {
if (value.is_value_list()) {
auto const& values_list = value.as_value_list();
assign_edge_values(PropertyID::MarginTop, PropertyID::MarginRight, PropertyID::MarginBottom, PropertyID::MarginLeft, values_list.values());
return;
}
set_longhand_property(CSS::PropertyID::MarginTop, value);
set_longhand_property(CSS::PropertyID::MarginRight, value);
set_longhand_property(CSS::PropertyID::MarginBottom, value);
set_longhand_property(CSS::PropertyID::MarginLeft, value);
return;
}
if (property_id == CSS::PropertyID::Padding) {
if (value.is_value_list()) {
auto const& values_list = value.as_value_list();
assign_edge_values(PropertyID::PaddingTop, PropertyID::PaddingRight, PropertyID::PaddingBottom, PropertyID::PaddingLeft, values_list.values());
return;
}
set_longhand_property(CSS::PropertyID::PaddingTop, value);
set_longhand_property(CSS::PropertyID::PaddingRight, value);
set_longhand_property(CSS::PropertyID::PaddingBottom, value);
set_longhand_property(CSS::PropertyID::PaddingLeft, value);
return;
}
if (property_id == CSS::PropertyID::ListStyle) {
if (value.is_list_style()) {
auto const& list_style = value.as_list_style();
set_longhand_property(CSS::PropertyID::ListStylePosition, list_style.position());
set_longhand_property(CSS::PropertyID::ListStyleImage, list_style.image());
set_longhand_property(CSS::PropertyID::ListStyleType, list_style.style_type());
return;
}
set_longhand_property(CSS::PropertyID::ListStylePosition, value);
set_longhand_property(CSS::PropertyID::ListStyleImage, value);
set_longhand_property(CSS::PropertyID::ListStyleType, value);
return;
}
if (property_id == CSS::PropertyID::Font) {
if (value.is_font()) {
auto const& font_shorthand = value.as_font();
set_longhand_property(CSS::PropertyID::FontSize, font_shorthand.font_size());
set_longhand_property(CSS::PropertyID::FontFamily, font_shorthand.font_families());
set_longhand_property(CSS::PropertyID::FontStretch, font_shorthand.font_stretch());
set_longhand_property(CSS::PropertyID::FontStyle, font_shorthand.font_style());
set_longhand_property(CSS::PropertyID::FontWeight, font_shorthand.font_weight());
set_longhand_property(CSS::PropertyID::LineHeight, font_shorthand.line_height());
// FIXME: Implement font-variant
return;
}
set_longhand_property(CSS::PropertyID::FontStretch, value);
set_longhand_property(CSS::PropertyID::FontSize, value);
set_longhand_property(CSS::PropertyID::FontFamily, value);
set_longhand_property(CSS::PropertyID::FontStyle, value);
set_longhand_property(CSS::PropertyID::FontWeight, value);
set_longhand_property(CSS::PropertyID::LineHeight, value);
// FIXME: Implement font-variant
return;
}
if (property_id == CSS::PropertyID::Flex) {
if (value.is_flex()) {
auto const& flex = value.as_flex();
set_longhand_property(CSS::PropertyID::FlexGrow, flex.grow());
set_longhand_property(CSS::PropertyID::FlexShrink, flex.shrink());
set_longhand_property(CSS::PropertyID::FlexBasis, flex.basis());
return;
}
set_longhand_property(CSS::PropertyID::FlexGrow, value);
set_longhand_property(CSS::PropertyID::FlexShrink, value);
set_longhand_property(CSS::PropertyID::FlexBasis, value);
return;
}
if (property_id == CSS::PropertyID::FlexFlow) {
if (value.is_flex_flow()) {
auto const& flex_flow = value.as_flex_flow();
set_longhand_property(CSS::PropertyID::FlexDirection, flex_flow.flex_direction());
set_longhand_property(CSS::PropertyID::FlexWrap, flex_flow.flex_wrap());
return;
}
set_longhand_property(CSS::PropertyID::FlexDirection, value);
set_longhand_property(CSS::PropertyID::FlexWrap, value);
return;
}
if (property_id == CSS::PropertyID::GridArea) {
if (value.is_grid_area_shorthand()) {
auto const& shorthand = value.as_grid_area_shorthand();
set_longhand_property(CSS::PropertyID::GridRowStart, shorthand.row_start());
set_longhand_property(CSS::PropertyID::GridColumnStart, shorthand.column_start());
set_longhand_property(CSS::PropertyID::GridRowEnd, shorthand.row_end());
set_longhand_property(CSS::PropertyID::GridColumnEnd, shorthand.column_end());
return;
}
set_longhand_property(CSS::PropertyID::GridRowStart, value);
set_longhand_property(CSS::PropertyID::GridColumnStart, value);
set_longhand_property(CSS::PropertyID::GridRowEnd, value);
set_longhand_property(CSS::PropertyID::GridColumnEnd, value);
return;
}
if (property_id == CSS::PropertyID::GridColumn) {
if (value.is_grid_track_placement_shorthand()) {
auto const& shorthand = value.as_grid_track_placement_shorthand();
set_longhand_property(CSS::PropertyID::GridColumnStart, shorthand.start());
set_longhand_property(CSS::PropertyID::GridColumnEnd, shorthand.end());
return;
}
set_longhand_property(CSS::PropertyID::GridColumnStart, value);
set_longhand_property(CSS::PropertyID::GridColumnEnd, value);
return;
}
if (property_id == CSS::PropertyID::GridRow) {
if (value.is_grid_track_placement_shorthand()) {
auto const& shorthand = value.as_grid_track_placement_shorthand();
set_longhand_property(CSS::PropertyID::GridRowStart, shorthand.start());
set_longhand_property(CSS::PropertyID::GridRowEnd, shorthand.end());
return;
}
set_longhand_property(CSS::PropertyID::GridRowStart, value);
set_longhand_property(CSS::PropertyID::GridRowEnd, value);
return;
}
if (property_id == CSS::PropertyID::GridTemplate || property_id == CSS::PropertyID::Grid) {
if (value.is_grid_track_size_list_shorthand()) {
auto const& shorthand = value.as_grid_track_size_list_shorthand();
set_longhand_property(CSS::PropertyID::GridTemplateAreas, shorthand.areas());
set_longhand_property(CSS::PropertyID::GridTemplateRows, shorthand.rows());
set_longhand_property(CSS::PropertyID::GridTemplateColumns, shorthand.columns());
return;
}
set_longhand_property(CSS::PropertyID::GridTemplateAreas, value);
set_longhand_property(CSS::PropertyID::GridTemplateRows, value);
set_longhand_property(CSS::PropertyID::GridTemplateColumns, value);
return;
}
if (property_id == CSS::PropertyID::Gap || property_id == CSS::PropertyID::GridGap) {
if (value.is_value_list()) {
auto const& values_list = value.as_value_list();
set_longhand_property(CSS::PropertyID::RowGap, values_list.values()[0]);
set_longhand_property(CSS::PropertyID::ColumnGap, values_list.values()[1]);
return;
}
set_longhand_property(CSS::PropertyID::RowGap, value);
set_longhand_property(CSS::PropertyID::ColumnGap, value);
return;
}
if (property_id == CSS::PropertyID::RowGap || property_id == CSS::PropertyID::GridRowGap) {
set_longhand_property(CSS::PropertyID::RowGap, value);
return;
}
if (property_id == CSS::PropertyID::ColumnGap || property_id == CSS::PropertyID::GridColumnGap) {
set_longhand_property(CSS::PropertyID::ColumnGap, value);
return;
}
if (property_id == CSS::PropertyID::MaxInlineSize || property_id == CSS::PropertyID::MinInlineSize) {
// FIXME: Use writing-mode to determine if we should set width or height.
bool is_horizontal = true;
if (is_horizontal) {
if (property_id == CSS::PropertyID::MaxInlineSize) {
set_longhand_property(CSS::PropertyID::MaxWidth, value);
} else {
set_longhand_property(CSS::PropertyID::MinWidth, value);
}
} else {
if (property_id == CSS::PropertyID::MaxInlineSize) {
set_longhand_property(CSS::PropertyID::MaxHeight, value);
} else {
set_longhand_property(CSS::PropertyID::MinHeight, value);
}
}
return;
}
set_longhand_property(property_id, value);
}
void StyleComputer::set_all_properties(DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element, StyleProperties& style, StyleValue const& value, DOM::Document& document, CSS::CSSStyleDeclaration const* declaration, StyleProperties::PropertyValues const& properties_for_revert) const
{
for (auto i = to_underlying(CSS::first_longhand_property_id); i <= to_underlying(CSS::last_longhand_property_id); ++i) {
auto property_id = (CSS::PropertyID)i;
if (value.is_revert()) {
style.m_property_values[to_underlying(property_id)] = properties_for_revert[to_underlying(property_id)];
continue;
}
if (value.is_unset()) {
if (is_inherited_property(property_id))
style.m_property_values[to_underlying(property_id)] = { { get_inherit_value(document.realm(), property_id, &element, pseudo_element), nullptr } };
else
style.m_property_values[to_underlying(property_id)] = { { property_initial_value(document.realm(), property_id).release_value_but_fixme_should_propagate_errors(), nullptr } };
continue;
}
NonnullRefPtr<StyleValue> property_value = value;
if (property_value->is_unresolved()) {
if (auto resolved = resolve_unresolved_style_value(element, pseudo_element, property_id, property_value->as_unresolved()))
property_value = resolved.release_nonnull();
}
if (!property_value->is_unresolved())
set_property_expanding_shorthands(style, property_id, property_value, document, declaration, properties_for_revert);
set_property_expanding_shorthands(style, property_id, value, document, declaration, properties_for_revert);
}
}
static RefPtr<StyleValue const> get_custom_property(DOM::Element const& element, Optional<CSS::Selector::PseudoElement> pseudo_element, FlyString const& custom_property_name)
{
if (pseudo_element.has_value()) {
if (auto it = element.custom_properties(pseudo_element).find(custom_property_name.to_string().to_deprecated_string()); it != element.custom_properties(pseudo_element).end())
return it->value.value;
}
for (auto const* current_element = &element; current_element; current_element = current_element->parent_element()) {
if (auto it = current_element->custom_properties({}).find(custom_property_name.to_string().to_deprecated_string()); it != current_element->custom_properties({}).end())
return it->value.value;
}
return nullptr;
}
bool StyleComputer::expand_variables(DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element, StringView property_name, HashMap<FlyString, NonnullRefPtr<PropertyDependencyNode>>& dependencies, Parser::TokenStream<Parser::ComponentValue>& source, Vector<Parser::ComponentValue>& dest) const
{
// Arbitrary large value chosen to avoid the billion-laughs attack.
// https://www.w3.org/TR/css-variables-1/#long-variables
size_t const MAX_VALUE_COUNT = 16384;
if (source.remaining_token_count() + dest.size() > MAX_VALUE_COUNT) {
dbgln("Stopped expanding CSS variables: maximum length reached.");
return false;
}
auto get_dependency_node = [&](FlyString name) -> NonnullRefPtr<PropertyDependencyNode> {
if (auto existing = dependencies.get(name); existing.has_value())
return *existing.value();
auto new_node = PropertyDependencyNode::create(name.to_string());
dependencies.set(name, new_node);
return new_node;
};
while (source.has_next_token()) {
auto const& value = source.next_token();
if (value.is_block()) {
auto const& source_block = value.block();
Vector<Parser::ComponentValue> block_values;
Parser::TokenStream source_block_contents { source_block.values() };
if (!expand_variables(element, pseudo_element, property_name, dependencies, source_block_contents, block_values))
return false;
NonnullRefPtr<Parser::Block> block = Parser::Block::create(source_block.token(), move(block_values));
dest.empend(block);
continue;
}
if (!value.is_function()) {
dest.empend(value);
continue;
}
if (!value.function().name().equals_ignoring_ascii_case("var"sv)) {
auto const& source_function = value.function();
Vector<Parser::ComponentValue> function_values;
Parser::TokenStream source_function_contents { source_function.values() };
if (!expand_variables(element, pseudo_element, property_name, dependencies, source_function_contents, function_values))
return false;
NonnullRefPtr<Parser::Function> function = Parser::Function::create(FlyString::from_utf8(source_function.name()).release_value_but_fixme_should_propagate_errors(), move(function_values));
dest.empend(function);
continue;
}
Parser::TokenStream var_contents { value.function().values() };
var_contents.skip_whitespace();
if (!var_contents.has_next_token())
return false;
auto const& custom_property_name_token = var_contents.next_token();
if (!custom_property_name_token.is(Parser::Token::Type::Ident))
return false;
auto custom_property_name = custom_property_name_token.token().ident();
if (!custom_property_name.starts_with("--"sv))
return false;
// Detect dependency cycles. https://www.w3.org/TR/css-variables-1/#cycles
// We do not do this by the spec, since we are not keeping a graph of var dependencies around,
// but rebuilding it every time.
if (custom_property_name == property_name)
return false;
auto parent = get_dependency_node(FlyString::from_utf8(property_name).release_value_but_fixme_should_propagate_errors());
auto child = get_dependency_node(FlyString::from_utf8(custom_property_name).release_value_but_fixme_should_propagate_errors());
parent->add_child(child);
if (parent->has_cycles())
return false;
if (auto custom_property_value = get_custom_property(element, pseudo_element, FlyString::from_utf8(custom_property_name).release_value_but_fixme_should_propagate_errors())) {
VERIFY(custom_property_value->is_unresolved());
Parser::TokenStream custom_property_tokens { custom_property_value->as_unresolved().values() };
if (!expand_variables(element, pseudo_element, custom_property_name, dependencies, custom_property_tokens, dest))
return false;
continue;
}
// Use the provided fallback value, if any.
var_contents.skip_whitespace();
if (var_contents.has_next_token()) {
auto const& comma_token = var_contents.next_token();
if (!comma_token.is(Parser::Token::Type::Comma))
return false;
var_contents.skip_whitespace();
if (!expand_variables(element, pseudo_element, property_name, dependencies, var_contents, dest))
return false;
}
}
return true;
}
bool StyleComputer::expand_unresolved_values(DOM::Element& element, StringView property_name, Parser::TokenStream<Parser::ComponentValue>& source, Vector<Parser::ComponentValue>& dest) const
{
// FIXME: Do this better!
// We build a copy of the tree of ComponentValues, with all var()s and attr()s replaced with their contents.
// This is a very naive solution, and we could do better if the CSS Parser could accept tokens one at a time.
while (source.has_next_token()) {
auto const& value = source.next_token();
if (value.is_function()) {
if (value.function().name().equals_ignoring_ascii_case("attr"sv)) {
// https://drafts.csswg.org/css-values-5/#attr-substitution
Parser::TokenStream attr_contents { value.function().values() };
attr_contents.skip_whitespace();
if (!attr_contents.has_next_token())
return false;
auto const& attr_name_token = attr_contents.next_token();
if (!attr_name_token.is(Parser::Token::Type::Ident))
return false;
auto attr_name = attr_name_token.token().ident();
auto attr_value = element.get_attribute(attr_name);
// 1. If the attr() function has a substitution value, replace the attr() function by the substitution value.
if (!attr_value.is_null()) {
// FIXME: attr() should also accept an optional type argument, not just strings.
dest.empend(Parser::Token::of_string(FlyString::from_deprecated_fly_string(attr_value).release_value_but_fixme_should_propagate_errors()));
continue;
}
// 2. Otherwise, if the attr() function has a fallback value as its last argument, replace the attr() function by the fallback value.
// If there are any var() or attr() references in the fallback, substitute them as well.
attr_contents.skip_whitespace();
if (attr_contents.has_next_token()) {
auto const& comma_token = attr_contents.next_token();
if (!comma_token.is(Parser::Token::Type::Comma))
return false;
attr_contents.skip_whitespace();
if (!expand_unresolved_values(element, property_name, attr_contents, dest))
return false;
continue;
}
// 3. Otherwise, the property containing the attr() function is invalid at computed-value time.
return false;
}
// FIXME: Handle all math functions.
if (value.function().name().equals_ignoring_ascii_case("calc"sv)) {
auto const& calc_function = value.function();
if (auto calc_value = Parser::Parser::parse_calculated_value({}, Parser::ParsingContext { document() }, calc_function.values()).release_value_but_fixme_should_propagate_errors()) {
if (calc_value->resolves_to_number()) {
auto resolved_value = calc_value->resolve_number();
dest.empend(Parser::Token::create_number(resolved_value.value()));
continue;
} else if (calc_value->resolves_to_percentage()) {
auto resolved_value = calc_value->resolve_percentage();
dest.empend(Parser::Token::create_percentage(resolved_value.value().value()));
continue;
} else {
dbgln_if(LIBWEB_CSS_DEBUG, "FIXME: Unimplemented calc() expansion: {}", calc_value->to_string());
}
}
}
auto const& source_function = value.function();
Vector<Parser::ComponentValue> function_values;
Parser::TokenStream source_function_contents { source_function.values() };
if (!expand_unresolved_values(element, property_name, source_function_contents, function_values))
return false;
// FIXME: This would be much nicer if we could access the source_function's FlyString value directly.
NonnullRefPtr<Parser::Function> function = Parser::Function::create(FlyString::from_utf8(source_function.name()).release_value_but_fixme_should_propagate_errors(), move(function_values));
dest.empend(function);
continue;
}
if (value.is_block()) {
auto const& source_block = value.block();
Parser::TokenStream source_block_values { source_block.values() };
Vector<Parser::ComponentValue> block_values;
if (!expand_unresolved_values(element, property_name, source_block_values, block_values))
return false;
NonnullRefPtr<Parser::Block> block = Parser::Block::create(source_block.token(), move(block_values));
dest.empend(move(block));
continue;
}
dest.empend(value.token());
}
return true;
}
RefPtr<StyleValue> StyleComputer::resolve_unresolved_style_value(DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element, PropertyID property_id, UnresolvedStyleValue const& unresolved) const
{
// Unresolved always contains a var() or attr(), unless it is a custom property's value, in which case we shouldn't be trying
// to produce a different StyleValue from it.
VERIFY(unresolved.contains_var_or_attr());
Parser::TokenStream unresolved_values_without_variables_expanded { unresolved.values() };
Vector<Parser::ComponentValue> values_with_variables_expanded;
HashMap<FlyString, NonnullRefPtr<PropertyDependencyNode>> dependencies;
if (!expand_variables(element, pseudo_element, string_from_property_id(property_id), dependencies, unresolved_values_without_variables_expanded, values_with_variables_expanded))
return {};
Parser::TokenStream unresolved_values_with_variables_expanded { values_with_variables_expanded };
Vector<Parser::ComponentValue> expanded_values;
if (!expand_unresolved_values(element, string_from_property_id(property_id), unresolved_values_with_variables_expanded, expanded_values))
return {};
if (auto parsed_value = Parser::Parser::parse_css_value({}, Parser::ParsingContext { document() }, property_id, expanded_values).release_value_but_fixme_should_propagate_errors())
return parsed_value.release_nonnull();
return {};
}
void StyleComputer::cascade_declarations(StyleProperties& style, DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element, Vector<MatchingRule> const& matching_rules, CascadeOrigin cascade_origin, Important important) const
{
auto properties_for_revert = style.properties();
for (auto const& match : matching_rules) {
for (auto const& property : verify_cast<PropertyOwningCSSStyleDeclaration>(match.rule->declaration()).properties()) {
if (important != property.important)
continue;
if (property.property_id == CSS::PropertyID::All) {
set_all_properties(element, pseudo_element, style, property.value, m_document, &match.rule->declaration(), properties_for_revert);
continue;
}
auto property_value = property.value;
if (property.value->is_unresolved()) {
if (auto resolved = resolve_unresolved_style_value(element, pseudo_element, property.property_id, property.value->as_unresolved()))
property_value = resolved.release_nonnull();
}
if (!property_value->is_unresolved())
set_property_expanding_shorthands(style, property.property_id, property_value, m_document, &match.rule->declaration(), properties_for_revert);
}
}
if (cascade_origin == CascadeOrigin::Author && !pseudo_element.has_value()) {
if (auto const* inline_style = verify_cast<ElementInlineCSSStyleDeclaration>(element.inline_style())) {
for (auto const& property : inline_style->properties()) {
if (important != property.important)
continue;
if (property.property_id == CSS::PropertyID::All) {
set_all_properties(element, pseudo_element, style, property.value, m_document, inline_style, properties_for_revert);
continue;
}
auto property_value = property.value;
if (property.value->is_unresolved()) {
if (auto resolved = resolve_unresolved_style_value(element, pseudo_element, property.property_id, property.value->as_unresolved()))
property_value = resolved.release_nonnull();
}
if (!property_value->is_unresolved())
set_property_expanding_shorthands(style, property.property_id, property_value, m_document, inline_style, properties_for_revert);
}
}
}
}
static ErrorOr<void> cascade_custom_properties(DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element, Vector<MatchingRule> const& matching_rules)
{
size_t needed_capacity = 0;
for (auto const& matching_rule : matching_rules)
needed_capacity += verify_cast<PropertyOwningCSSStyleDeclaration>(matching_rule.rule->declaration()).custom_properties().size();
if (!pseudo_element.has_value()) {
if (auto const* inline_style = verify_cast<PropertyOwningCSSStyleDeclaration>(element.inline_style()))
needed_capacity += inline_style->custom_properties().size();
}
HashMap<DeprecatedFlyString, StyleProperty> custom_properties;
TRY(custom_properties.try_ensure_capacity(needed_capacity));
for (auto const& matching_rule : matching_rules) {
for (auto const& it : verify_cast<PropertyOwningCSSStyleDeclaration>(matching_rule.rule->declaration()).custom_properties())
custom_properties.set(it.key, it.value);
}
if (!pseudo_element.has_value()) {
if (auto const* inline_style = verify_cast<PropertyOwningCSSStyleDeclaration>(element.inline_style())) {
for (auto const& it : inline_style->custom_properties())
custom_properties.set(it.key, it.value);
}
}
element.set_custom_properties(pseudo_element, move(custom_properties));
return {};
}
StyleComputer::AnimationStepTransition StyleComputer::Animation::step(CSS::Time const& time_step)
{
auto delay_ms = remaining_delay.to_milliseconds();
auto time_step_ms = time_step.to_milliseconds();
if (delay_ms > time_step_ms) {
remaining_delay = CSS::Time { static_cast<float>(delay_ms - time_step_ms), CSS::Time::Type::Ms };
return AnimationStepTransition::NoTransition;
}
remaining_delay = CSS::Time { 0, CSS::Time::Type::Ms };
time_step_ms -= delay_ms;
// "auto": For time-driven animations, equivalent to 0s.
// https://www.w3.org/TR/2023/WD-css-animations-2-20230602/#valdef-animation-duration-auto
auto used_duration = duration.value_or(CSS::Time { 0, CSS::Time::Type::S });
auto added_progress = time_step_ms / used_duration.to_milliseconds();
auto new_progress = progress.as_fraction() + added_progress;
auto changed_iteration = false;
if (new_progress >= 1) {
if (iteration_count.has_value()) {
if (iteration_count.value() <= 1) {
progress = CSS::Percentage(100);
return AnimationStepTransition::ActiveToAfter;
}
--iteration_count.value();
changed_iteration = true;
}
++current_iteration;
new_progress = 0;
}
progress = CSS::Percentage(new_progress * 100);
if (changed_iteration)
return AnimationStepTransition::ActiveToActiveChangingTheIteration;
return AnimationStepTransition::AfterToActive;
}
static ErrorOr<NonnullRefPtr<StyleValue>> interpolate_property(StyleValue const& from, StyleValue const& to, float delta)
{
if (from.type() != to.type()) {
if (delta > 0.999f)
return to;
return from;
}
auto interpolate_raw = [delta = static_cast<double>(delta)](auto from, auto to) {
return static_cast<RemoveCVReference<decltype(from)>>(static_cast<double>(from) + static_cast<double>(to - from) * delta);
};
switch (from.type()) {
case StyleValue::Type::Angle:
return AngleStyleValue::create(Angle::make_degrees(interpolate_raw(from.as_angle().angle().to_degrees(), to.as_angle().angle().to_degrees())));
case StyleValue::Type::Color: {
auto from_color = from.as_color().color();
auto to_color = to.as_color().color();
auto from_hsv = from_color.to_hsv();
auto to_hsv = to_color.to_hsv();
auto color = Color::from_hsv(
interpolate_raw(from_hsv.hue, to_hsv.hue),
interpolate_raw(from_hsv.saturation, to_hsv.saturation),
interpolate_raw(from_hsv.value, to_hsv.value));
color.set_alpha(interpolate_raw(from_color.alpha(), to_color.alpha()));
return ColorStyleValue::create(color);
}
case StyleValue::Type::Integer:
return IntegerStyleValue::create(interpolate_raw(from.as_integer().integer(), to.as_integer().integer()));
case StyleValue::Type::Length: {
auto& from_length = from.as_length().length();
auto& to_length = to.as_length().length();
return LengthStyleValue::create(Length(interpolate_raw(from_length.raw_value(), to_length.raw_value()), from_length.type()));
}
case StyleValue::Type::Number:
return NumberStyleValue::create(interpolate_raw(from.as_number().number(), to.as_number().number()));
case StyleValue::Type::Percentage:
return PercentageStyleValue::create(Percentage(interpolate_raw(from.as_percentage().percentage().value(), to.as_percentage().percentage().value())));
case StyleValue::Type::Position: {
auto& from_position = from.as_position();
auto& to_position = to.as_position();
return PositionStyleValue::create(
TRY(interpolate_property(from_position.edge_x(), to_position.edge_x(), delta)),
TRY(interpolate_property(from_position.edge_y(), to_position.edge_y(), delta)));
}
case StyleValue::Type::Rect: {
auto from_rect = from.as_rect().rect();
auto to_rect = to.as_rect().rect();
return RectStyleValue::create({
Length(interpolate_raw(from_rect.top_edge.raw_value(), to_rect.top_edge.raw_value()), from_rect.top_edge.type()),
Length(interpolate_raw(from_rect.right_edge.raw_value(), to_rect.right_edge.raw_value()), from_rect.right_edge.type()),
Length(interpolate_raw(from_rect.bottom_edge.raw_value(), to_rect.bottom_edge.raw_value()), from_rect.bottom_edge.type()),
Length(interpolate_raw(from_rect.left_edge.raw_value(), to_rect.left_edge.raw_value()), from_rect.left_edge.type()),
});
}
case StyleValue::Type::Transformation: {
auto& from_transform = from.as_transformation();
auto& to_transform = to.as_transformation();
if (from_transform.transform_function() != to_transform.transform_function())
return from;
auto from_input_values = from_transform.values();
auto to_input_values = to_transform.values();
if (from_input_values.size() != to_input_values.size())
return from;
StyleValueVector interpolated_values;
interpolated_values.ensure_capacity(from_input_values.size());
for (size_t i = 0; i < from_input_values.size(); ++i)
interpolated_values.append(TRY(interpolate_property(*from_input_values[i], *to_input_values[i], delta)));
return TransformationStyleValue::create(from_transform.transform_function(), move(interpolated_values));
}
case StyleValue::Type::ValueList: {
auto& from_list = from.as_value_list();
auto& to_list = to.as_value_list();
if (from_list.size() != to_list.size())
return from;
StyleValueVector interpolated_values;
interpolated_values.ensure_capacity(from_list.size());
for (size_t i = 0; i < from_list.size(); ++i)
interpolated_values.append(TRY(interpolate_property(from_list.values()[i], to_list.values()[i], delta)));
return StyleValueList::create(move(interpolated_values), from_list.separator());
}
default:
return from;
}
}
bool StyleComputer::Animation::is_animating_backwards() const
{
return (direction == CSS::AnimationDirection::AlternateReverse && current_iteration % 2 == 1)
|| (direction == CSS::AnimationDirection::Alternate && current_iteration % 2 == 0)
|| direction == CSS::AnimationDirection::Reverse;
}
ErrorOr<void> StyleComputer::Animation::collect_into(StyleProperties& style_properties, RuleCache const& rule_cache) const
{
if (remaining_delay.to_milliseconds() != 0) {
// If the fill mode is backwards or both, we'll pretend that the animation is started, but stuck at progress 0
if (fill_mode != CSS::AnimationFillMode::Backwards && fill_mode != CSS::AnimationFillMode::Both)
return {};
}
auto matching_keyframes = rule_cache.rules_by_animation_keyframes.get(name);
if (!matching_keyframes.has_value())
return {};
auto& keyframes = matching_keyframes.value()->keyframes_by_key;
auto output_progress = compute_output_progress(progress.as_fraction()) * 100.f;
auto is_backwards = is_animating_backwards();
auto key = static_cast<u64>(output_progress * AnimationKeyFrameKeyScaleFactor);
auto matching_keyframe_it = is_backwards ? keyframes.find_smallest_not_below_iterator(key) : keyframes.find_largest_not_above_iterator(key);
if (matching_keyframe_it.is_end()) {
if constexpr (LIBWEB_CSS_ANIMATION_DEBUG) {
dbgln(" Did not find any start keyframe for the current state ({}) :(", key);
dbgln(" (have {} keyframes)", keyframes.size());
for (auto it = keyframes.begin(); it != keyframes.end(); ++it)
dbgln(" - {}", it.key());
}
return {};
}
auto keyframe_start = matching_keyframe_it.key();
auto keyframe_values = *matching_keyframe_it;
auto initial_keyframe_it = matching_keyframe_it;
auto keyframe_end_it = is_backwards ? --matching_keyframe_it : ++matching_keyframe_it;
if (keyframe_end_it.is_end())
keyframe_end_it = initial_keyframe_it;
auto keyframe_end = keyframe_end_it.key();
auto keyframe_end_values = *keyframe_end_it;
auto progress_in_keyframe = [&] {
if (keyframe_start == keyframe_end)
return is_backwards ? 1.f : 0.f;
return is_backwards
? static_cast<float>(keyframe_start - key) / static_cast<float>(keyframe_start - keyframe_end)
: static_cast<float>(key - keyframe_start) / static_cast<float>(keyframe_end - keyframe_start);
}();
auto valid_properties = 0;
for (auto const& property : keyframe_values.resolved_properties) {
if (property.has<Empty>())
continue;
valid_properties++;
}
dbgln_if(LIBWEB_CSS_ANIMATION_DEBUG, "Animation {} contains {} properties to interpolate, progress = {}%", name, valid_properties, progress_in_keyframe * 100);
if (fill_mode == CSS::AnimationFillMode::Forwards || fill_mode == CSS::AnimationFillMode::Both) {
if (!active_state_if_fill_forward)
active_state_if_fill_forward = make<AnimationStateSnapshot>();
}
UnderlyingType<PropertyID> property_id_value = 0;
for (auto const& property : keyframe_values.resolved_properties) {
auto property_id = static_cast<PropertyID>(property_id_value++);
if (property.has<Empty>())
continue;
auto resolve_property = [&](auto& property) {
return property.visit(
[](Empty) -> RefPtr<StyleValue const> { VERIFY_NOT_REACHED(); },
[&](AnimationKeyFrameSet::ResolvedKeyFrame::UseInitial) {
if (auto value = initial_state.state[to_underlying(property_id)])
return value;
auto value = style_properties.maybe_null_property(property_id);
initial_state.state[to_underlying(property_id)] = value;
return value;
},
[&](RefPtr<StyleValue const> value) { return value; });
};
auto resolved_start_property = resolve_property(property);
auto const& end_property = keyframe_end_values.resolved_properties[to_underlying(property_id)];
if (end_property.has<Empty>()) {
if (resolved_start_property) {
style_properties.set_property(property_id, resolved_start_property.release_nonnull());
dbgln_if(LIBWEB_CSS_ANIMATION_DEBUG, "No end property for property {}, using {}", string_from_property_id(property_id), resolved_start_property->to_string());
}
continue;
}
auto resolved_end_property = resolve_property(end_property);
if (!resolved_start_property || !resolved_end_property)
continue;
auto start = resolved_start_property.release_nonnull();
auto end = resolved_end_property.release_nonnull();
auto next_value = TRY(interpolate_property(*start, *end, progress_in_keyframe));
dbgln_if(LIBWEB_CSS_ANIMATION_DEBUG, "Interpolated value for property {} at {}: {} -> {} = {}", string_from_property_id(property_id), progress_in_keyframe, start->to_string(), end->to_string(), next_value->to_string());
style_properties.set_property(property_id, next_value);
if (active_state_if_fill_forward)
active_state_if_fill_forward->state[to_underlying(property_id)] = next_value;
}
return {};
}
bool StyleComputer::Animation::is_done() const
{
return progress.as_fraction() >= 0.9999 && iteration_count.has_value() && iteration_count.value() == 0;
}
// NOTE: Magic values from <https://www.w3.org/TR/css-easing-1/#valdef-cubic-bezier-easing-function-ease>
static auto ease_timing_function = StyleComputer::AnimationTiming::CubicBezier { 0.25, 0.1, 0.25, 1.0 };
static auto ease_in_timing_function = StyleComputer::AnimationTiming::CubicBezier { 0.42, 0.0, 1.0, 1.0 };
static auto ease_out_timing_function = StyleComputer::AnimationTiming::CubicBezier { 0.0, 0.0, 0.58, 1.0 };
static auto ease_in_out_timing_function = StyleComputer::AnimationTiming::CubicBezier { 0.42, 0.0, 0.58, 1.0 };
float StyleComputer::Animation::compute_output_progress(float input_progress) const
{
auto output_progress = input_progress;
auto going_forwards = true;
switch (direction) {
case AnimationDirection::Alternate:
if (current_iteration % 2 == 0) {
output_progress = 1.0f - output_progress;
going_forwards = false;
}
break;
case AnimationDirection::AlternateReverse:
if (current_iteration % 2 == 1) {
output_progress = 1.0f - output_progress;
going_forwards = false;
}
break;
case AnimationDirection::Normal:
break;
case AnimationDirection::Reverse:
output_progress = 1.0f - output_progress;
going_forwards = false;
break;
}
if (remaining_delay.to_milliseconds() != 0)
return output_progress;
return timing_function.timing_function.visit(
[&](AnimationTiming::Linear) { return output_progress; },
[&](AnimationTiming::Steps const& steps) {
auto before_flag = (current_state == AnimationState::Before && going_forwards) || (current_state == AnimationState::After && !going_forwards);
auto progress_step = output_progress * static_cast<float>(steps.number_of_steps);
auto current_step = floorf(progress_step);
if (steps.jump_at_start)
current_step += 1;
if (before_flag && truncf(progress_step) == progress_step)
current_step -= 1;
if (output_progress >= 0 && current_step < 0)
current_step = 0;
size_t jumps;
if (steps.jump_at_start ^ steps.jump_at_end)
jumps = steps.number_of_steps;
else if (steps.jump_at_start && steps.jump_at_end)
jumps = steps.number_of_steps + 1;
else
jumps = steps.number_of_steps - 1;
if (output_progress <= 1 && current_step > static_cast<float>(jumps))
current_step = static_cast<float>(jumps);
return current_step / static_cast<float>(steps.number_of_steps);
},
[&](AnimationTiming::CubicBezier const& bezier) {
// Special cases first:
if (bezier == AnimationTiming::CubicBezier { 0.0, 0.0, 1.0, 1.0 })
return output_progress;
// FIXME: This is quite inefficient on memory and CPU, find a better way to do this.
auto sample = bezier.sample_around(static_cast<double>(output_progress));
return static_cast<float>(sample.y);
});
}
static double cubic_bezier_at(double x1, double x2, double t)
{
auto a = 1.0 - 3.0 * x2 + 3.0 * x1;
auto b = 3.0 * x2 - 6.0 * x1;
auto c = 3.0 * x1;
auto t2 = t * t;
auto t3 = t2 * t;
return (a * t3) + (b * t2) + (c * t);
}
StyleComputer::AnimationTiming::CubicBezier::CachedSample StyleComputer::AnimationTiming::CubicBezier::sample_around(double x) const
{
x = clamp(x, 0, 1);
auto solve = [&](auto t) {
auto x = cubic_bezier_at(x1, x2, t);
auto y = cubic_bezier_at(y1, y2, t);
return CachedSample { x, y, t };
};
if (m_cached_x_samples.is_empty())
m_cached_x_samples.append(solve(0.));
size_t nearby_index = 0;
if (auto found = binary_search(m_cached_x_samples, x, &nearby_index, [](auto x, auto& sample) {
if (x > sample.x)
return 1;
if (x < sample.x)
return -1;
return 0;
}))
return *found;
if (nearby_index == m_cached_x_samples.size() || nearby_index + 1 == m_cached_x_samples.size()) {
// Produce more samples until we have enough.
auto last_t = m_cached_x_samples.is_empty() ? 0 : m_cached_x_samples.last().t;
auto last_x = m_cached_x_samples.is_empty() ? 0 : m_cached_x_samples.last().x;
while (last_x <= x) {
last_t += 1. / 60.;
auto solution = solve(last_t);
m_cached_x_samples.append(solution);
last_x = solution.x;
}
if (auto found = binary_search(m_cached_x_samples, x, &nearby_index, [](auto x, auto& sample) {
if (x > sample.x)
return 1;
if (x < sample.x)
return -1;
return 0;
}))
return *found;
}
// We have two samples on either side of the x value we want, so we can linearly interpolate between them.
auto& sample1 = m_cached_x_samples[nearby_index];
auto& sample2 = m_cached_x_samples[nearby_index + 1];
auto factor = (x - sample1.x) / (sample2.x - sample1.x);
return CachedSample {
x,
clamp(sample1.y + factor * (sample2.y - sample1.y), 0, 1),
sample1.t + factor * (sample2.t - sample1.t),
};
}
void StyleComputer::ensure_animation_timer() const
{
constexpr static auto timer_delay_ms = 1000 / 60;
if (!m_animation_driver_timer) {
m_animation_driver_timer = Platform::Timer::create_repeating(timer_delay_ms, [this] {
// If we run out of animations, stop the timer - it'll turn back on the next time we have an active animation.
if (m_active_animations.is_empty()) {
m_animation_driver_timer->stop();
return;
}
HashTable<AnimationKey> animations_to_remove;
HashTable<DOM::Element*> owning_elements_to_invalidate;
for (auto& it : m_active_animations) {
if (!it.value->owning_element) {
// The element disappeared since we last ran, just discard the animation.
animations_to_remove.set(it.key);
continue;
}
auto transition = it.value->step(CSS::Time { timer_delay_ms, CSS::Time::Type::Ms });
owning_elements_to_invalidate.set(it.value->owning_element);
switch (transition) {
case AnimationStepTransition::NoTransition:
break;
case AnimationStepTransition::IdleOrBeforeToActive:
// FIXME: Dispatch `animationstart`.
break;
case AnimationStepTransition::IdleOrBeforeToAfter:
// FIXME: Dispatch `animationstart` then `animationend`.
m_finished_animations.set(it.key, move(it.value->active_state_if_fill_forward));
break;
case AnimationStepTransition::ActiveToBefore:
// FIXME: Dispatch `animationend`.
m_finished_animations.set(it.key, move(it.value->active_state_if_fill_forward));
break;
case AnimationStepTransition::ActiveToActiveChangingTheIteration:
// FIXME: Dispatch `animationiteration`.
break;
case AnimationStepTransition::ActiveToAfter:
// FIXME: Dispatch `animationend`.
m_finished_animations.set(it.key, move(it.value->active_state_if_fill_forward));
break;
case AnimationStepTransition::AfterToActive:
// FIXME: Dispatch `animationstart`.
break;
case AnimationStepTransition::AfterToBefore:
// FIXME: Dispatch `animationstart` then `animationend`.
m_finished_animations.set(it.key, move(it.value->active_state_if_fill_forward));
break;
case AnimationStepTransition::Cancelled:
// FIXME: Dispatch `animationcancel`.
m_finished_animations.set(it.key, nullptr);
break;
}
if (it.value->is_done())
animations_to_remove.set(it.key);
}
for (auto key : animations_to_remove)
m_active_animations.remove(key);
for (auto* element : owning_elements_to_invalidate)
element->set_needs_style_update(true);
});
}
m_animation_driver_timer->start();
}
// https://www.w3.org/TR/css-cascade/#cascading
ErrorOr<void> StyleComputer::compute_cascaded_values(StyleProperties& style, DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element, bool& did_match_any_pseudo_element_rules, ComputeStyleMode mode) const
{
// First, we collect all the CSS rules whose selectors match `element`:
MatchingRuleSet matching_rule_set;
matching_rule_set.user_agent_rules = collect_matching_rules(element, CascadeOrigin::UserAgent, pseudo_element);
sort_matching_rules(matching_rule_set.user_agent_rules);
matching_rule_set.author_rules = collect_matching_rules(element, CascadeOrigin::Author, pseudo_element);
sort_matching_rules(matching_rule_set.author_rules);
if (mode == ComputeStyleMode::CreatePseudoElementStyleIfNeeded) {
VERIFY(pseudo_element.has_value());
if (matching_rule_set.author_rules.is_empty() && matching_rule_set.user_agent_rules.is_empty()) {
did_match_any_pseudo_element_rules = false;
return {};
}
did_match_any_pseudo_element_rules = true;
}
// Then we resolve all the CSS custom properties ("variables") for this element:
TRY(cascade_custom_properties(element, pseudo_element, matching_rule_set.author_rules));
// Then we apply the declarations from the matched rules in cascade order:
// Normal user agent declarations
cascade_declarations(style, element, pseudo_element, matching_rule_set.user_agent_rules, CascadeOrigin::UserAgent, Important::No);
// FIXME: Normal user declarations
// Author presentational hints (NOTE: The spec doesn't say exactly how to prioritize these.)
if (!pseudo_element.has_value()) {
element.apply_presentational_hints(style);
// SVG presentation attributes are parsed as CSS values, so we need to handle potential custom properties here.
if (element.is_svg_element()) {
// FIXME: This is not very efficient, we should only resolve the custom properties that are actually used.
for (auto i = to_underlying(CSS::first_property_id); i <= to_underlying(CSS::last_property_id); ++i) {
auto property_id = (CSS::PropertyID)i;
auto& property = style.m_property_values[i];
if (property.has_value() && property->style->is_unresolved()) {
if (auto resolved = resolve_unresolved_style_value(element, pseudo_element, property_id, property->style->as_unresolved()))
property->style = resolved.release_nonnull();
}
}
}
}
// Normal author declarations
cascade_declarations(style, element, pseudo_element, matching_rule_set.author_rules, CascadeOrigin::Author, Important::No);
// Animation declarations [css-animations-2]
if (auto animation_name = style.maybe_null_property(PropertyID::AnimationName)) {
if (auto source_declaration = style.property_source_declaration(PropertyID::AnimationName)) {
AnimationKey animation_key {
.source_declaration = source_declaration,
.element = &element,
};
if (auto finished_state = m_finished_animations.get(animation_key); finished_state.has_value()) {
// We've already finished going through this animation, so drop it from the active animations.
m_active_animations.remove(animation_key);
// If the animation's fill mode was set to forwards/both, we need to collect and use the final frame's styles.
if (*finished_state) {
auto& state = (*finished_state)->state;
for (size_t property_id_value = 0; property_id_value < state.size(); ++property_id_value) {
if (auto& property_value = state[property_id_value])
style.set_property(static_cast<PropertyID>(property_id_value), *property_value);
}
}
} else if (auto name = TRY(animation_name->to_string()); !name.is_empty()) {
auto active_animation = m_active_animations.get(animation_key);
if (!active_animation.has_value()) {
// New animation!
Optional<CSS::Time> duration;
if (auto duration_value = style.maybe_null_property(PropertyID::AnimationDuration); duration_value) {
if (duration_value->is_time()) {
duration = duration_value->as_time().time();
} else if (duration_value->is_identifier() && duration_value->as_identifier().id() == ValueID::Auto) {
// We use empty optional to represent "auto".
duration = {};
}
}
CSS::Time delay { 0, CSS::Time::Type::S };
if (auto delay_value = style.maybe_null_property(PropertyID::AnimationDelay); delay_value && delay_value->is_time())
delay = delay_value->as_time().time();
Optional<size_t> iteration_count = 1;
if (auto iteration_count_value = style.maybe_null_property(PropertyID::AnimationIterationCount); iteration_count_value) {
if (iteration_count_value->is_identifier() && iteration_count_value->to_identifier() == ValueID::Infinite)
iteration_count = {};
else if (iteration_count_value->is_number())
iteration_count = static_cast<size_t>(iteration_count_value->as_number().number());
}
CSS::AnimationFillMode fill_mode { CSS::AnimationFillMode::None };
if (auto fill_mode_property = style.maybe_null_property(PropertyID::AnimationFillMode); fill_mode_property && fill_mode_property->is_identifier()) {
if (auto fill_mode_value = value_id_to_animation_fill_mode(fill_mode_property->to_identifier()); fill_mode_value.has_value())
fill_mode = *fill_mode_value;
}
CSS::AnimationDirection direction { CSS::AnimationDirection::Normal };
if (auto direction_property = style.maybe_null_property(PropertyID::AnimationDirection); direction_property && direction_property->is_identifier()) {
if (auto direction_value = value_id_to_animation_direction(direction_property->to_identifier()); direction_value.has_value())
direction = *direction_value;
}
AnimationTiming timing_function { ease_timing_function };
if (auto timing_property = style.maybe_null_property(PropertyID::AnimationTimingFunction); timing_property && timing_property->is_easing()) {
auto& easing_value = timing_property->as_easing();
switch (easing_value.easing_function()) {
case EasingFunction::Linear:
timing_function = AnimationTiming { AnimationTiming::Linear {} };
break;
case EasingFunction::Ease:
timing_function = AnimationTiming { ease_timing_function };
break;
case EasingFunction::EaseIn:
timing_function = AnimationTiming { ease_in_timing_function };
break;
case EasingFunction::EaseOut:
timing_function = AnimationTiming { ease_out_timing_function };
break;
case EasingFunction::EaseInOut:
timing_function = AnimationTiming { ease_in_out_timing_function };
break;
case EasingFunction::CubicBezier: {
auto values = easing_value.values();
timing_function = AnimationTiming {
AnimationTiming::CubicBezier {
values[0]->as_number().number(),
values[1]->as_number().number(),
values[2]->as_number().number(),
values[3]->as_number().number(),
},
};
break;
}
case EasingFunction::Steps: {
auto values = easing_value.values();
auto jump_at_start = false;
auto jump_at_end = true;
if (values.size() > 1) {
auto identifier = values[1]->to_identifier();
switch (identifier) {
case ValueID::JumpStart:
case ValueID::Start:
jump_at_start = true;
jump_at_end = false;
break;
case ValueID::JumpEnd:
case ValueID::End:
jump_at_start = false;
jump_at_end = true;
break;
case ValueID::JumpNone:
jump_at_start = false;
jump_at_end = false;
break;
default:
break;
}
}
timing_function = AnimationTiming { AnimationTiming::Steps {
.number_of_steps = static_cast<size_t>(max(values[0]->as_integer().integer(), !(jump_at_end && jump_at_start) ? 1 : 0)),
.jump_at_start = jump_at_start,
.jump_at_end = jump_at_end,
} };
break;
}
case EasingFunction::StepEnd:
timing_function = AnimationTiming { AnimationTiming::Steps {
.number_of_steps = 1,
.jump_at_start = false,
.jump_at_end = true,
} };
break;
case EasingFunction::StepStart:
timing_function = AnimationTiming { AnimationTiming::Steps {
.number_of_steps = 1,
.jump_at_start = true,
.jump_at_end = false,
} };
break;
}
}
auto animation = make<Animation>(Animation {
.name = move(name),
.duration = duration,
.delay = delay,
.iteration_count = iteration_count,
.timing_function = timing_function,
.direction = direction,
.fill_mode = fill_mode,
.owning_element = TRY(element.try_make_weak_ptr<DOM::Element>()),
.progress = CSS::Percentage(0),
.remaining_delay = delay,
});
active_animation = animation;
m_active_animations.set(animation_key, move(animation));
}
TRY((*active_animation)->collect_into(style, rule_cache_for_cascade_origin(CascadeOrigin::Author)));
} else {
m_active_animations.remove(animation_key);
}
}
if (!m_active_animations.is_empty())
ensure_animation_timer();
}
// Important author declarations
cascade_declarations(style, element, pseudo_element, matching_rule_set.author_rules, CascadeOrigin::Author, Important::Yes);
// FIXME: Important user declarations
// Important user agent declarations
cascade_declarations(style, element, pseudo_element, matching_rule_set.user_agent_rules, CascadeOrigin::UserAgent, Important::Yes);
// FIXME: Transition declarations [css-transitions-1]
return {};
}
DOM::Element const* element_to_inherit_style_from(DOM::Element const* element, Optional<CSS::Selector::PseudoElement> pseudo_element)
{
// Pseudo-elements treat their originating element as their parent.
DOM::Element const* parent_element = nullptr;
if (pseudo_element.has_value()) {
parent_element = element;
} else if (element) {
parent_element = element->parent_or_shadow_host_element();
}
return parent_element;
}
NonnullRefPtr<StyleValue const> get_inherit_value(JS::Realm& initial_value_context_realm, CSS::PropertyID property_id, DOM::Element const* element, Optional<CSS::Selector::PseudoElement> pseudo_element)
{
auto* parent_element = element_to_inherit_style_from(element, pseudo_element);
if (!parent_element || !parent_element->computed_css_values())
return property_initial_value(initial_value_context_realm, property_id).release_value_but_fixme_should_propagate_errors();
return parent_element->computed_css_values()->property(property_id);
}
void StyleComputer::compute_defaulted_property_value(StyleProperties& style, DOM::Element const* element, CSS::PropertyID property_id, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
// FIXME: If we don't know the correct initial value for a property, we fall back to InitialStyleValue.
auto& value_slot = style.m_property_values[to_underlying(property_id)];
if (!value_slot.has_value()) {
if (is_inherited_property(property_id))
style.m_property_values[to_underlying(property_id)] = { { get_inherit_value(document().realm(), property_id, element, pseudo_element), nullptr } };
else
style.m_property_values[to_underlying(property_id)] = { { property_initial_value(document().realm(), property_id).release_value_but_fixme_should_propagate_errors(), nullptr } };
return;
}
if (value_slot->style->is_initial()) {
value_slot->style = property_initial_value(document().realm(), property_id).release_value_but_fixme_should_propagate_errors();
return;
}
if (value_slot->style->is_inherit()) {
value_slot->style = get_inherit_value(document().realm(), property_id, element, pseudo_element);
return;
}
// https://www.w3.org/TR/css-cascade-4/#inherit-initial
// If the cascaded value of a property is the unset keyword,
if (value_slot->style->is_unset()) {
if (is_inherited_property(property_id)) {
// then if it is an inherited property, this is treated as inherit,
value_slot->style = get_inherit_value(document().realm(), property_id, element, pseudo_element);
} else {
// and if it is not, this is treated as initial.
value_slot->style = property_initial_value(document().realm(), property_id).release_value_but_fixme_should_propagate_errors();
}
}
}
// https://www.w3.org/TR/css-cascade/#defaulting
void StyleComputer::compute_defaulted_values(StyleProperties& style, DOM::Element const* element, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
// Walk the list of all known CSS properties and:
// - Add them to `style` if they are missing.
// - Resolve `inherit` and `initial` as needed.
for (auto i = to_underlying(CSS::first_longhand_property_id); i <= to_underlying(CSS::last_longhand_property_id); ++i) {
auto property_id = (CSS::PropertyID)i;
compute_defaulted_property_value(style, element, property_id, pseudo_element);
}
// https://www.w3.org/TR/css-color-4/#resolving-other-colors
// In the color property, the used value of currentcolor is the inherited value.
auto color = style.property(CSS::PropertyID::Color);
if (color->to_identifier() == CSS::ValueID::Currentcolor) {
color = get_inherit_value(document().realm(), CSS::PropertyID::Color, element, pseudo_element);
style.set_property(CSS::PropertyID::Color, color);
}
}
Length::FontMetrics StyleComputer::calculate_root_element_font_metrics(StyleProperties const& style) const
{
auto root_value = style.property(CSS::PropertyID::FontSize);
auto font_pixel_metrics = style.computed_font().pixel_metrics();
Length::FontMetrics font_metrics { m_default_font_metrics.font_size, font_pixel_metrics, font_pixel_metrics.line_spacing() };
font_metrics.font_size = root_value->as_length().length().to_px(viewport_rect(), font_metrics, font_metrics);
font_metrics.line_height = style.line_height(viewport_rect(), font_metrics, font_metrics);
return font_metrics;
}
RefPtr<Gfx::Font const> StyleComputer::find_matching_font_weight_ascending(Vector<MatchingFontCandidate> const& candidates, int target_weight, float font_size_in_pt, bool inclusive)
{
using Fn = AK::Function<bool(MatchingFontCandidate const&)>;
auto pred = inclusive ? Fn([&](auto const& matching_font_candidate) { return matching_font_candidate.key.weight >= target_weight; })
: Fn([&](auto const& matching_font_candidate) { return matching_font_candidate.key.weight > target_weight; });
auto it = find_if(candidates.begin(), candidates.end(), pred);
for (; it != candidates.end(); ++it)
if (auto found_font = it->loader->font_with_point_size(font_size_in_pt))
return found_font;
return {};
}
RefPtr<Gfx::Font const> StyleComputer::find_matching_font_weight_descending(Vector<MatchingFontCandidate> const& candidates, int target_weight, float font_size_in_pt, bool inclusive)
{
using Fn = AK::Function<bool(MatchingFontCandidate const&)>;
auto pred = inclusive ? Fn([&](auto const& matching_font_candidate) { return matching_font_candidate.key.weight <= target_weight; })
: Fn([&](auto const& matching_font_candidate) { return matching_font_candidate.key.weight < target_weight; });
auto it = find_if(candidates.rbegin(), candidates.rend(), pred);
for (; it != candidates.rend(); ++it)
if (auto found_font = it->loader->font_with_point_size(font_size_in_pt))
return found_font;
return {};
}
// Partial implementation of the font-matching algorithm: https://www.w3.org/TR/css-fonts-4/#font-matching-algorithm
// FIXME: This should be replaced by the full CSS font selection algorithm.
RefPtr<Gfx::Font const> StyleComputer::font_matching_algorithm(FontFaceKey const& key, float font_size_in_pt) const
{
// If a font family match occurs, the user agent assembles the set of font faces in that family and then
// narrows the set to a single face using other font properties in the order given below.
Vector<MatchingFontCandidate> matching_family_fonts;
for (auto const& font_key_and_loader : m_loaded_fonts) {
if (font_key_and_loader.key.family_name.equals_ignoring_ascii_case(key.family_name))
matching_family_fonts.empend(font_key_and_loader.key, font_key_and_loader.value.ptr());
}
// FIXME: 1. font-stretch is tried first.
// FIXME: 2. font-style is tried next.
// We don't have complete support of italic and oblique fonts, so matching on font-style can be simplified to:
// If a matching slope is found, all faces which don't have that matching slope are excluded from the matching set.
auto style_it = find_if(matching_family_fonts.begin(), matching_family_fonts.end(),
[&](auto const& matching_font_candidate) { return matching_font_candidate.key.slope == key.slope; });
if (style_it != matching_family_fonts.end()) {
matching_family_fonts.remove_all_matching([&](auto const& matching_font_candidate) {
return matching_font_candidate.key.slope != key.slope;
});
}
// 3. font-weight is matched next.
// If the desired weight is inclusively between 400 and 500, weights greater than or equal to the target weight
// are checked in ascending order until 500 is hit and checked, followed by weights less than the target weight
// in descending order, followed by weights greater than 500, until a match is found.
if (key.weight >= 400 && key.weight <= 500) {
auto it = find_if(matching_family_fonts.begin(), matching_family_fonts.end(),
[&](auto const& matching_font_candidate) { return matching_font_candidate.key.weight >= key.weight; });
for (; it != matching_family_fonts.end() && it->key.weight <= 500; ++it) {
if (auto found_font = it->loader->font_with_point_size(font_size_in_pt))
return found_font;
}
if (auto found_font = find_matching_font_weight_descending(matching_family_fonts, key.weight, font_size_in_pt, false))
return found_font;
for (; it != matching_family_fonts.end(); ++it) {
if (auto found_font = it->loader->font_with_point_size(font_size_in_pt))
return found_font;
}
}
// If the desired weight is less than 400, weights less than or equal to the desired weight are checked in descending order
// followed by weights above the desired weight in ascending order until a match is found.
if (key.weight < 400) {
if (auto found_font = find_matching_font_weight_descending(matching_family_fonts, key.weight, font_size_in_pt, true))
return found_font;
if (auto found_font = find_matching_font_weight_ascending(matching_family_fonts, key.weight, font_size_in_pt, false))
return found_font;
}
// If the desired weight is greater than 500, weights greater than or equal to the desired weight are checked in ascending order
// followed by weights below the desired weight in descending order until a match is found.
if (key.weight > 500) {
if (auto found_font = find_matching_font_weight_ascending(matching_family_fonts, key.weight, font_size_in_pt, true))
return found_font;
if (auto found_font = find_matching_font_weight_descending(matching_family_fonts, key.weight, font_size_in_pt, false))
return found_font;
}
return {};
}
void StyleComputer::compute_font(StyleProperties& style, DOM::Element const* element, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
// To compute the font, first ensure that we've defaulted the relevant CSS font properties.
// FIXME: This should be more sophisticated.
compute_defaulted_property_value(style, element, CSS::PropertyID::FontFamily, pseudo_element);
compute_defaulted_property_value(style, element, CSS::PropertyID::FontSize, pseudo_element);
compute_defaulted_property_value(style, element, CSS::PropertyID::FontStretch, pseudo_element);
compute_defaulted_property_value(style, element, CSS::PropertyID::FontStyle, pseudo_element);
compute_defaulted_property_value(style, element, CSS::PropertyID::FontWeight, pseudo_element);
compute_defaulted_property_value(style, element, CSS::PropertyID::LineHeight, pseudo_element);
auto* parent_element = element_to_inherit_style_from(element, pseudo_element);
auto font_size = style.property(CSS::PropertyID::FontSize);
auto font_style = style.property(CSS::PropertyID::FontStyle);
auto font_weight = style.property(CSS::PropertyID::FontWeight);
auto font_stretch = style.property(CSS::PropertyID::FontStretch);
int width = Gfx::FontWidth::Normal;
if (font_stretch->is_identifier()) {
switch (static_cast<IdentifierStyleValue const&>(*font_stretch).id()) {
case CSS::ValueID::UltraCondensed:
width = Gfx::FontWidth::UltraCondensed;
break;
case CSS::ValueID::ExtraCondensed:
width = Gfx::FontWidth::ExtraCondensed;
break;
case CSS::ValueID::Condensed:
width = Gfx::FontWidth::Condensed;
break;
case CSS::ValueID::SemiCondensed:
width = Gfx::FontWidth::SemiCondensed;
break;
case CSS::ValueID::Normal:
width = Gfx::FontWidth::Normal;
break;
case CSS::ValueID::SemiExpanded:
width = Gfx::FontWidth::SemiExpanded;
break;
case CSS::ValueID::Expanded:
width = Gfx::FontWidth::Expanded;
break;
case CSS::ValueID::ExtraExpanded:
width = Gfx::FontWidth::ExtraExpanded;
break;
case CSS::ValueID::UltraExpanded:
width = Gfx::FontWidth::UltraExpanded;
break;
default:
break;
}
} else if (font_stretch->is_percentage()) {
float percentage = font_stretch->as_percentage().percentage().value();
if (percentage <= 50) {
width = Gfx::FontWidth::UltraCondensed;
} else if (percentage <= 62.5f) {
width = Gfx::FontWidth::ExtraCondensed;
} else if (percentage <= 75.0f) {
width = Gfx::FontWidth::Condensed;
} else if (percentage <= 87.5f) {
width = Gfx::FontWidth::SemiCondensed;
} else if (percentage <= 100.0f) {
width = Gfx::FontWidth::Normal;
} else if (percentage <= 112.5f) {
width = Gfx::FontWidth::SemiExpanded;
} else if (percentage <= 125.0f) {
width = Gfx::FontWidth::Expanded;
} else if (percentage <= 150.0f) {
width = Gfx::FontWidth::ExtraExpanded;
} else {
width = Gfx::FontWidth::UltraExpanded;
}
}
auto weight = font_weight->to_font_weight();
bool bold = weight > Gfx::FontWeight::Regular;
// FIXME: Should be based on "user's default font size"
float font_size_in_px = 16;
auto parent_line_height = parent_or_root_element_line_height(element, pseudo_element);
Gfx::FontPixelMetrics font_pixel_metrics;
if (parent_element && parent_element->computed_css_values())
font_pixel_metrics = parent_element->computed_css_values()->computed_font().pixel_metrics();
else
font_pixel_metrics = Platform::FontPlugin::the().default_font().pixel_metrics();
auto parent_font_size = [&]() -> CSSPixels {
if (!parent_element || !parent_element->computed_css_values())
return font_size_in_px;
auto value = parent_element->computed_css_values()->property(CSS::PropertyID::FontSize);
if (value->is_length()) {
auto length = value->as_length().length();
auto parent_line_height = parent_or_root_element_line_height(parent_element, {});
if (length.is_absolute() || length.is_relative()) {
Length::FontMetrics font_metrics { font_size_in_px, font_pixel_metrics, parent_line_height };
return length.to_px(viewport_rect(), font_metrics, m_root_element_font_metrics);
}
}
return font_size_in_px;
};
Length::FontMetrics font_metrics { parent_font_size(), font_pixel_metrics, parent_line_height };
if (font_size->is_identifier()) {
// https://w3c.github.io/csswg-drafts/css-fonts/#absolute-size-mapping
AK::HashMap<Web::CSS::ValueID, float> absolute_size_mapping = {
{ CSS::ValueID::XxSmall, 0.6 },
{ CSS::ValueID::XSmall, 0.75 },
{ CSS::ValueID::Small, 8.0 / 9.0 },
{ CSS::ValueID::Medium, 1.0 },
{ CSS::ValueID::Large, 1.2 },
{ CSS::ValueID::XLarge, 1.5 },
{ CSS::ValueID::XxLarge, 2.0 },
{ CSS::ValueID::XxxLarge, 3.0 },
{ CSS::ValueID::Smaller, 0.8 },
{ CSS::ValueID::Larger, 1.25 },
};
auto const identifier = static_cast<IdentifierStyleValue const&>(*font_size).id();
// https://w3c.github.io/csswg-drafts/css-fonts/#valdef-font-size-relative-size
// TODO: If the parent element has a keyword font size in the absolute size keyword mapping table,
// larger may compute the font size to the next entry in the table,
// and smaller may compute the font size to the previous entry in the table.
if (identifier == CSS::ValueID::Smaller || identifier == CSS::ValueID::Larger) {
if (parent_element && parent_element->computed_css_values()) {
font_size_in_px = parent_element->computed_css_values()->computed_font().pixel_metrics().size;
}
}
auto const multiplier = absolute_size_mapping.get(identifier).value_or(1.0);
font_size_in_px *= multiplier;
} else {
Length::ResolutionContext const length_resolution_context {
.viewport_rect = viewport_rect(),
.font_metrics = font_metrics,
.root_font_metrics = m_root_element_font_metrics,
};
Optional<Length> maybe_length;
if (font_size->is_percentage()) {
// Percentages refer to parent element's font size
maybe_length = Length::make_px(font_size->as_percentage().percentage().as_fraction() * parent_font_size().to_double());
} else if (font_size->is_length()) {
maybe_length = font_size->as_length().length();
} else if (font_size->is_calculated()) {
maybe_length = font_size->as_calculated().resolve_length(length_resolution_context);
}
if (maybe_length.has_value()) {
auto px = maybe_length.value().to_px(length_resolution_context).to_int();
if (px != 0)
font_size_in_px = px;
}
}
auto slope = font_style->to_font_slope();
// FIXME: Implement the full font-matching algorithm: https://www.w3.org/TR/css-fonts-4/#font-matching-algorithm
// Note: This is modified by the find_font() lambda
FontSelector font_selector;
bool monospace = false;
float const font_size_in_pt = font_size_in_px * 0.75f;
auto find_font = [&](String const& family) -> RefPtr<Gfx::Font const> {
font_selector = { family, font_size_in_pt, weight, width, slope };
FontFaceKey key {
.family_name = family,
.weight = weight,
.slope = slope,
};
if (auto it = m_loaded_fonts.find(key); it != m_loaded_fonts.end()) {
auto& loader = *it->value;
if (auto found_font = loader.font_with_point_size(font_size_in_pt))
return found_font;
}
if (auto found_font = font_matching_algorithm(key, font_size_in_pt))
return found_font;
if (auto found_font = FontCache::the().get(font_selector))
return found_font;
if (auto found_font = Gfx::FontDatabase::the().get(family.to_deprecated_string(), font_size_in_pt, weight, width, slope, Gfx::Font::AllowInexactSizeMatch::Yes))
return found_font;
return {};
};
auto find_generic_font = [&](ValueID font_id) -> RefPtr<Gfx::Font const> {
Platform::GenericFont generic_font {};
switch (font_id) {
case ValueID::Monospace:
case ValueID::UiMonospace:
generic_font = Platform::GenericFont::Monospace;
monospace = true;
break;
case ValueID::Serif:
generic_font = Platform::GenericFont::Serif;
break;
case ValueID::Fantasy:
generic_font = Platform::GenericFont::Fantasy;
break;
case ValueID::SansSerif:
generic_font = Platform::GenericFont::SansSerif;
break;
case ValueID::Cursive:
generic_font = Platform::GenericFont::Cursive;
break;
case ValueID::UiSerif:
generic_font = Platform::GenericFont::UiSerif;
break;
case ValueID::UiSansSerif:
generic_font = Platform::GenericFont::UiSansSerif;
break;
case ValueID::UiRounded:
generic_font = Platform::GenericFont::UiRounded;
break;
default:
return {};
}
return find_font(String::from_deprecated_string(Platform::FontPlugin::the().generic_font_name(generic_font)).release_value_but_fixme_should_propagate_errors());
};
RefPtr<Gfx::Font const> found_font;
auto family_value = style.property(PropertyID::FontFamily);
if (family_value->is_value_list()) {
auto const& family_list = static_cast<StyleValueList const&>(*family_value).values();
for (auto const& family : family_list) {
if (family->is_identifier()) {
found_font = find_generic_font(family->to_identifier());
} else if (family->is_string()) {
found_font = find_font(family->to_string().release_value_but_fixme_should_propagate_errors());
}
if (found_font)
break;
}
} else if (family_value->is_identifier()) {
found_font = find_generic_font(family_value->to_identifier());
} else if (family_value->is_string()) {
found_font = find_font(family_value->to_string().release_value_but_fixme_should_propagate_errors());
}
if (!found_font) {
found_font = StyleProperties::font_fallback(monospace, bold);
if (found_font) {
if (auto scaled_fallback_font = found_font->with_size(font_size_in_pt))
found_font = scaled_fallback_font;
}
}
FontCache::the().set(font_selector, *found_font);
style.set_property(CSS::PropertyID::FontSize, LengthStyleValue::create(CSS::Length::make_px(font_size_in_px)).release_value_but_fixme_should_propagate_errors(), nullptr);
style.set_property(CSS::PropertyID::FontWeight, NumberStyleValue::create(weight).release_value_but_fixme_should_propagate_errors(), nullptr);
style.set_computed_font(found_font.release_nonnull());
if (element && is<HTML::HTMLHtmlElement>(*element)) {
const_cast<StyleComputer&>(*this).m_root_element_font_metrics = calculate_root_element_font_metrics(style);
}
}
Gfx::Font const& StyleComputer::initial_font() const
{
// FIXME: This is not correct.
return StyleProperties::font_fallback(false, false);
}
CSSPixels StyleComputer::parent_or_root_element_line_height(DOM::Element const* element, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
auto* parent_element = element_to_inherit_style_from(element, pseudo_element);
if (!parent_element)
return m_root_element_font_metrics.line_height;
auto const* computed_values = parent_element->computed_css_values();
auto parent_font_pixel_metrics = computed_values->computed_font().pixel_metrics();
auto parent_font_size = computed_values->property(CSS::PropertyID::FontSize)->as_length().length();
// FIXME: Can the parent font size be non-absolute here?
auto parent_font_size_value = parent_font_size.is_absolute() ? parent_font_size.absolute_length_to_px() : m_root_element_font_metrics.font_size;
auto parent_parent_line_height = parent_or_root_element_line_height(parent_element, {});
Length::FontMetrics parent_font_metrics { parent_font_size_value, parent_font_pixel_metrics, parent_parent_line_height };
return computed_values->line_height(viewport_rect(), parent_font_metrics, m_root_element_font_metrics);
}
ErrorOr<void> StyleComputer::absolutize_values(StyleProperties& style, DOM::Element const* element, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
auto parent_or_root_line_height = parent_or_root_element_line_height(element, pseudo_element);
auto font_pixel_metrics = style.computed_font().pixel_metrics();
Length::FontMetrics font_metrics { m_root_element_font_metrics.font_size, font_pixel_metrics, parent_or_root_line_height };
auto font_size = style.property(CSS::PropertyID::FontSize)->as_length().length().to_px(viewport_rect(), font_metrics, m_root_element_font_metrics);
font_metrics.font_size = font_size;
// NOTE: Percentage line-height values are relative to the font-size of the element.
// We have to resolve them right away, so that the *computed* line-height is ready for inheritance.
// We can't simply absolutize *all* percentage values against the font size,
// because most percentages are relative to containing block metrics.
auto line_height_value_slot = style.m_property_values[to_underlying(CSS::PropertyID::LineHeight)].map([](auto& x) -> auto& { return x.style; });
if (line_height_value_slot.has_value() && (*line_height_value_slot)->is_percentage()) {
*line_height_value_slot = TRY(LengthStyleValue::create(
Length::make_px(font_size * static_cast<double>((*line_height_value_slot)->as_percentage().percentage().as_fraction()))));
}
auto line_height = style.line_height(viewport_rect(), font_metrics, m_root_element_font_metrics);
font_metrics.line_height = line_height;
// NOTE: line-height might be using lh which should be resolved against the parent line height (like we did here already)
if (line_height_value_slot.has_value() && (*line_height_value_slot)->is_length())
(*line_height_value_slot) = TRY(LengthStyleValue::create(Length::make_px(line_height)));
for (size_t i = 0; i < style.m_property_values.size(); ++i) {
auto& value_slot = style.m_property_values[i];
if (!value_slot.has_value())
continue;
value_slot->style = TRY(value_slot->style->absolutized(viewport_rect(), font_metrics, m_root_element_font_metrics));
}
return {};
}
enum class BoxTypeTransformation {
None,
Blockify,
Inlinify,
};
static BoxTypeTransformation required_box_type_transformation(StyleProperties const& style, DOM::Element const& element, Optional<CSS::Selector::PseudoElement> const& pseudo_element)
{
// Absolute positioning or floating an element blockifies the box’s display type. [CSS2]
if (style.position() == CSS::Position::Absolute || style.position() == CSS::Position::Fixed || style.float_() != CSS::Float::None)
return BoxTypeTransformation::Blockify;
// FIXME: Containment in a ruby container inlinifies the box’s display type, as described in [CSS-RUBY-1].
// NOTE: If we're computing style for a pseudo-element, the effective parent will be the originating element itself, not its parent.
auto const* parent = pseudo_element.has_value() ? &element : element.parent_element();
// A parent with a grid or flex display value blockifies the box’s display type. [CSS-GRID-1] [CSS-FLEXBOX-1]
if (parent && parent->computed_css_values()) {
auto const& parent_display = parent->computed_css_values()->display();
if (parent_display.is_grid_inside() || parent_display.is_flex_inside())
return BoxTypeTransformation::Blockify;
}
return BoxTypeTransformation::None;
}
// https://drafts.csswg.org/css-display/#transformations
void StyleComputer::transform_box_type_if_needed(StyleProperties& style, DOM::Element const& element, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
// 2.7. Automatic Box Type Transformations
// Some layout effects require blockification or inlinification of the box type,
// which sets the box’s computed outer display type to block or inline (respectively).
// (This has no effect on display types that generate no box at all, such as none or contents.)
auto display = style.display();
if (display.is_none() || display.is_contents())
return;
auto new_display = display;
switch (required_box_type_transformation(style, element, pseudo_element)) {
case BoxTypeTransformation::None:
break;
case BoxTypeTransformation::Blockify:
if (display.is_block_outside())
return;
// If a layout-internal box is blockified, its inner display type converts to flow so that it becomes a block container.
if (display.is_internal()) {
new_display = CSS::Display::from_short(CSS::Display::Short::Block);
} else {
VERIFY(display.is_outside_and_inside());
// For legacy reasons, if an inline block box (inline flow-root) is blockified, it becomes a block box (losing its flow-root nature).
// For consistency, a run-in flow-root box also blockifies to a block box.
if (display.is_inline_block()) {
new_display = CSS::Display { CSS::Display::Outside::Block, CSS::Display::Inside::Flow, display.list_item() };
} else {
new_display = CSS::Display { CSS::Display::Outside::Block, display.inside(), display.list_item() };
}
}
break;
case BoxTypeTransformation::Inlinify:
if (display.is_inline_outside()) {
// FIXME: If an inline box (inline flow) is inlinified, it recursively inlinifies all of its in-flow children,
// so that no block-level descendants break up the inline formatting context in which it participates.
if (display.is_flow_inside()) {
dbgln("FIXME: Inlinify inline box children recursively");
}
break;
}
if (display.is_internal()) {
// Inlinification has no effect on layout-internal boxes. (However, placement in such an inline context will typically cause them
// to be wrapped in an appropriately-typed anonymous inline-level box.)
} else {
VERIFY(display.is_outside_and_inside());
// If a block box (block flow) is inlinified, its inner display type is set to flow-root so that it remains a block container.
if (display.is_block_outside() && display.is_flow_inside()) {
new_display = CSS::Display { CSS::Display::Outside::Inline, CSS::Display::Inside::FlowRoot, display.list_item() };
}
new_display = CSS::Display { CSS::Display::Outside::Inline, display.inside(), display.list_item() };
}
break;
}
if (new_display != display)
style.set_property(CSS::PropertyID::Display, DisplayStyleValue::create(new_display).release_value_but_fixme_should_propagate_errors(), style.property_source_declaration(CSS::PropertyID::Display));
}
NonnullRefPtr<StyleProperties> StyleComputer::create_document_style() const
{
auto style = StyleProperties::create();
compute_font(style, nullptr, {});
compute_defaulted_values(style, nullptr, {});
absolutize_values(style, nullptr, {}).release_value_but_fixme_should_propagate_errors();
style->set_property(CSS::PropertyID::Width, CSS::LengthStyleValue::create(CSS::Length::make_px(viewport_rect().width())).release_value_but_fixme_should_propagate_errors(), nullptr);
style->set_property(CSS::PropertyID::Height, CSS::LengthStyleValue::create(CSS::Length::make_px(viewport_rect().height())).release_value_but_fixme_should_propagate_errors(), nullptr);
style->set_property(CSS::PropertyID::Display, CSS::DisplayStyleValue::create(CSS::Display::from_short(CSS::Display::Short::Block)).release_value_but_fixme_should_propagate_errors(), nullptr);
return style;
}
ErrorOr<NonnullRefPtr<StyleProperties>> StyleComputer::compute_style(DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
auto style = TRY(compute_style_impl(element, move(pseudo_element), ComputeStyleMode::Normal));
return style.release_nonnull();
}
ErrorOr<RefPtr<StyleProperties>> StyleComputer::compute_pseudo_element_style_if_needed(DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element) const
{
return compute_style_impl(element, move(pseudo_element), ComputeStyleMode::CreatePseudoElementStyleIfNeeded);
}
ErrorOr<RefPtr<StyleProperties>> StyleComputer::compute_style_impl(DOM::Element& element, Optional<CSS::Selector::PseudoElement> pseudo_element, ComputeStyleMode mode) const
{
build_rule_cache_if_needed();
auto style = StyleProperties::create();
// 1. Perform the cascade. This produces the "specified style"
bool did_match_any_pseudo_element_rules = false;
TRY(compute_cascaded_values(style, element, pseudo_element, did_match_any_pseudo_element_rules, mode));
if (mode == ComputeStyleMode::CreatePseudoElementStyleIfNeeded && !did_match_any_pseudo_element_rules)
return nullptr;
// 2. Compute the font, since that may be needed for font-relative CSS units
compute_font(style, &element, pseudo_element);
// 3. Absolutize values, turning font/viewport relative lengths into absolute lengths
TRY(absolutize_values(style, &element, pseudo_element));
// 4. Default the values, applying inheritance and 'initial' as needed
compute_defaulted_values(style, &element, pseudo_element);
// 5. Run automatic box type transformations
transform_box_type_if_needed(style, element, pseudo_element);
return style;
}
PropertyDependencyNode::PropertyDependencyNode(String name)
: m_name(move(name))
{
}
void PropertyDependencyNode::add_child(NonnullRefPtr<PropertyDependencyNode> new_child)
{
for (auto const& child : m_children) {
if (child->m_name == new_child->m_name)
return;
}
// We detect self-reference already.
VERIFY(new_child->m_name != m_name);
m_children.append(move(new_child));
}
bool PropertyDependencyNode::has_cycles()
{
if (m_marked)
return true;
TemporaryChange change { m_marked, true };
for (auto& child : m_children) {
if (child->has_cycles())
return true;
}
return false;
}
void StyleComputer::build_rule_cache_if_needed() const
{
if (m_author_rule_cache && m_user_agent_rule_cache)
return;
const_cast<StyleComputer&>(*this).build_rule_cache();
}
NonnullOwnPtr<StyleComputer::RuleCache> StyleComputer::make_rule_cache_for_cascade_origin(CascadeOrigin cascade_origin)
{
auto rule_cache = make<RuleCache>();
size_t num_class_rules = 0;
size_t num_id_rules = 0;
size_t num_tag_name_rules = 0;
size_t num_pseudo_element_rules = 0;
Vector<MatchingRule> matching_rules;
size_t style_sheet_index = 0;
for_each_stylesheet(cascade_origin, [&](auto& sheet) {
size_t rule_index = 0;
sheet.for_each_effective_style_rule([&](auto const& rule) {
size_t selector_index = 0;
for (CSS::Selector const& selector : rule.selectors()) {
MatchingRule matching_rule {
&rule,
sheet,
style_sheet_index,
rule_index,
selector_index,
selector.specificity()
};
for (auto const& simple_selector : selector.compound_selectors().last().simple_selectors) {
if (simple_selector.type == CSS::Selector::SimpleSelector::Type::PseudoElement) {
matching_rule.contains_pseudo_element = true;
++num_pseudo_element_rules;
break;
}
}
bool added_to_bucket = false;
for (auto const& simple_selector : selector.compound_selectors().last().simple_selectors) {
if (simple_selector.type == CSS::Selector::SimpleSelector::Type::Id) {
rule_cache->rules_by_id.ensure(simple_selector.name()).append(move(matching_rule));
++num_id_rules;
added_to_bucket = true;
break;
}
if (simple_selector.type == CSS::Selector::SimpleSelector::Type::Class) {
rule_cache->rules_by_class.ensure(simple_selector.name()).append(move(matching_rule));
++num_class_rules;
added_to_bucket = true;
break;
}
if (simple_selector.type == CSS::Selector::SimpleSelector::Type::TagName) {
rule_cache->rules_by_tag_name.ensure(simple_selector.name()).append(move(matching_rule));
++num_tag_name_rules;
added_to_bucket = true;
break;
}
}
if (!added_to_bucket)
rule_cache->other_rules.append(move(matching_rule));
++selector_index;
}
++rule_index;
});
sheet.for_each_effective_keyframes_at_rule([&](CSSKeyframesRule const& rule) {
auto keyframe_set = make<AnimationKeyFrameSet>();
AnimationKeyFrameSet::ResolvedKeyFrame resolved_keyframe;
// Forwards pass, resolve all the user-specified keyframe properties.
for (auto const& keyframe : rule.keyframes()) {
auto key = static_cast<u64>(keyframe->key().value() * AnimationKeyFrameKeyScaleFactor);
auto keyframe_rule = keyframe->style();
if (!is<PropertyOwningCSSStyleDeclaration>(*keyframe_rule))
continue;
auto current_keyframe = resolved_keyframe;
auto& keyframe_style = static_cast<PropertyOwningCSSStyleDeclaration const&>(*keyframe_rule);
for (auto& property : keyframe_style.properties())
current_keyframe.resolved_properties[to_underlying(property.property_id)] = property.value;
resolved_keyframe = move(current_keyframe);
keyframe_set->keyframes_by_key.insert(key, resolved_keyframe);
}
// If there is no 'from' keyframe, make a synthetic one.
auto made_a_synthetic_from_keyframe = false;
if (!keyframe_set->keyframes_by_key.find(0)) {
keyframe_set->keyframes_by_key.insert(0, AnimationKeyFrameSet::ResolvedKeyFrame());
made_a_synthetic_from_keyframe = true;
}
// Backwards pass, resolve all the implied properties, go read <https://drafts.csswg.org/css-animations-2/#keyframe-processing> to see why.
auto first = true;
for (auto const& keyframe : rule.keyframes().in_reverse()) {
auto key = static_cast<u64>(keyframe->key().value() * AnimationKeyFrameKeyScaleFactor);
auto keyframe_rule = keyframe->style();
if (!is<PropertyOwningCSSStyleDeclaration>(*keyframe_rule))
continue;
// The last keyframe is already fully resolved.
if (first) {
first = false;
continue;
}
auto next_keyframe = resolved_keyframe;
auto& current_keyframes = *keyframe_set->keyframes_by_key.find(key);
for (auto it = next_keyframe.resolved_properties.begin(); !it.is_end(); ++it) {
auto& current_property = current_keyframes.resolved_properties[it.index()];
if (!current_property.has<Empty>() || it->has<Empty>())
continue;
if (key == 0)
current_property = AnimationKeyFrameSet::ResolvedKeyFrame::UseInitial();
else
current_property = *it;
}
resolved_keyframe = current_keyframes;
}
if (made_a_synthetic_from_keyframe && !first) {
auto next_keyframe = resolved_keyframe;
auto& current_keyframes = *keyframe_set->keyframes_by_key.find(0);
for (auto it = next_keyframe.resolved_properties.begin(); !it.is_end(); ++it) {
auto& current_property = current_keyframes.resolved_properties[it.index()];
if (!current_property.has<Empty>() || it->has<Empty>())
continue;
current_property = AnimationKeyFrameSet::ResolvedKeyFrame::UseInitial();
}
resolved_keyframe = current_keyframes;
}
if constexpr (LIBWEB_CSS_DEBUG) {
dbgln("Resolved keyframe set '{}' into {} keyframes:", rule.name(), keyframe_set->keyframes_by_key.size());
for (auto it = keyframe_set->keyframes_by_key.begin(); it != keyframe_set->keyframes_by_key.end(); ++it) {
size_t props = 0;
for (auto& entry : it->resolved_properties)
props += !entry.has<Empty>();
dbgln(" - keyframe {}: {} properties", it.key(), props);
}
}
rule_cache->rules_by_animation_keyframes.set(rule.name(), move(keyframe_set));
});
++style_sheet_index;
});
if constexpr (LIBWEB_CSS_DEBUG) {
dbgln("Built rule cache!");
dbgln(" ID: {}", num_id_rules);
dbgln(" Class: {}", num_class_rules);
dbgln(" TagName: {}", num_tag_name_rules);
dbgln("PseudoElement: {}", num_pseudo_element_rules);
dbgln(" Other: {}", rule_cache->other_rules.size());
dbgln(" Total: {}", num_class_rules + num_id_rules + num_tag_name_rules + rule_cache->other_rules.size());
}
return rule_cache;
}
void StyleComputer::build_rule_cache()
{
m_author_rule_cache = make_rule_cache_for_cascade_origin(CascadeOrigin::Author);
m_user_agent_rule_cache = make_rule_cache_for_cascade_origin(CascadeOrigin::UserAgent);
}
void StyleComputer::invalidate_rule_cache()
{
m_author_rule_cache = nullptr;
// NOTE: It might not be necessary to throw away the UA rule cache.
// If we are sure that it's safe, we could keep it as an optimization.
m_user_agent_rule_cache = nullptr;
}
CSSPixelRect StyleComputer::viewport_rect() const
{
if (auto const* browsing_context = document().browsing_context())
return browsing_context->viewport_rect();
return {};
}
void StyleComputer::did_load_font([[maybe_unused]] FlyString const& family_name)
{
document().invalidate_style();
}
void StyleComputer::load_fonts_from_sheet(CSSStyleSheet const& sheet)
{
for (auto const& rule : static_cast<CSSStyleSheet const&>(sheet).rules()) {
if (!is<CSSFontFaceRule>(*rule))
continue;
auto const& font_face = static_cast<CSSFontFaceRule const&>(*rule).font_face();
if (font_face.sources().is_empty())
continue;
FontFaceKey key {
.family_name = font_face.font_family(),
.weight = font_face.weight().value_or(0),
.slope = font_face.slope().value_or(0),
};
if (m_loaded_fonts.contains(key))
continue;
Vector<AK::URL> urls;
for (auto& source : font_face.sources()) {
// FIXME: These should be loaded relative to the stylesheet URL instead of the document URL.
urls.append(m_document->parse_url(source.url.to_deprecated_string()));
}
if (urls.is_empty())
continue;
auto loader = make<FontLoader>(const_cast<StyleComputer&>(*this), font_face.font_family(), move(urls));
const_cast<StyleComputer&>(*this).m_loaded_fonts.set(key, move(loader));
}
}
}
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