jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>
4 *
5 * SPDX-License-Identifier: BSD-2-Clause
6 */
7
8#pragma once
9
10#include <AK/HashMap.h>
11#include <AK/Optional.h>
12#include <AK/OwnPtr.h>
13#include <LibWeb/CSS/CSSFontFaceRule.h>
14#include <LibWeb/CSS/CSSStyleDeclaration.h>
15#include <LibWeb/CSS/Parser/ComponentValue.h>
16#include <LibWeb/CSS/Parser/TokenStream.h>
17#include <LibWeb/CSS/Selector.h>
18#include <LibWeb/CSS/StyleProperties.h>
19#include <LibWeb/Forward.h>
20
21namespace Web::CSS {
22
23struct MatchingRule {
24 CSSStyleRule const* rule { nullptr };
25 size_t style_sheet_index { 0 };
26 size_t rule_index { 0 };
27 size_t selector_index { 0 };
28 u32 specificity { 0 };
29 bool contains_pseudo_element { false };
30};
31
32class PropertyDependencyNode : public RefCounted<PropertyDependencyNode> {
33public:
34 static NonnullRefPtr<PropertyDependencyNode> create(String name)
35 {
36 return adopt_ref(*new PropertyDependencyNode(move(name)));
37 }
38
39 void add_child(NonnullRefPtr<PropertyDependencyNode>);
40 bool has_cycles();
41
42private:
43 explicit PropertyDependencyNode(String name);
44
45 String m_name;
46 Vector<NonnullRefPtr<PropertyDependencyNode>> m_children;
47 bool m_marked { false };
48};
49
50class StyleComputer {
51public:
52 explicit StyleComputer(DOM::Document&);
53 ~StyleComputer();
54
55 DOM::Document& document() { return m_document; }
56 DOM::Document const& document() const { return m_document; }
57
58 NonnullRefPtr<StyleProperties> create_document_style() const;
59 ErrorOr<NonnullRefPtr<StyleProperties>> compute_style(DOM::Element&, Optional<CSS::Selector::PseudoElement> = {}) const;
60
61 // https://www.w3.org/TR/css-cascade/#origin
62 enum class CascadeOrigin {
63 Author,
64 User,
65 UserAgent,
66 Animation,
67 Transition,
68 };
69
70 Vector<MatchingRule> collect_matching_rules(DOM::Element const&, CascadeOrigin, Optional<CSS::Selector::PseudoElement>) const;
71
72 void invalidate_rule_cache();
73
74 Gfx::Font const& initial_font() const;
75
76 void did_load_font(FlyString const& family_name);
77
78 void load_fonts_from_sheet(CSSStyleSheet const&);
79
80private:
81 ErrorOr<void> compute_cascaded_values(StyleProperties&, DOM::Element&, Optional<CSS::Selector::PseudoElement>) const;
82 void compute_font(StyleProperties&, DOM::Element const*, Optional<CSS::Selector::PseudoElement>) const;
83 void compute_defaulted_values(StyleProperties&, DOM::Element const*, Optional<CSS::Selector::PseudoElement>) const;
84 void absolutize_values(StyleProperties&, DOM::Element const*, Optional<CSS::Selector::PseudoElement>) const;
85 void transform_box_type_if_needed(StyleProperties&, DOM::Element const&, Optional<CSS::Selector::PseudoElement>) const;
86
87 void compute_defaulted_property_value(StyleProperties&, DOM::Element const*, CSS::PropertyID, Optional<CSS::Selector::PseudoElement>) const;
88
89 RefPtr<StyleValue> resolve_unresolved_style_value(DOM::Element&, PropertyID, UnresolvedStyleValue const&) const;
90 bool expand_variables(DOM::Element&, StringView property_name, HashMap<FlyString, NonnullRefPtr<PropertyDependencyNode>>& dependencies, Parser::TokenStream<Parser::ComponentValue>& source, Vector<Parser::ComponentValue>& dest) const;
91 bool expand_unresolved_values(DOM::Element&, StringView property_name, Parser::TokenStream<Parser::ComponentValue>& source, Vector<Parser::ComponentValue>& dest) const;
92
93 template<typename Callback>
94 void for_each_stylesheet(CascadeOrigin, Callback) const;
95
96 CSSPixelRect viewport_rect() const;
97 CSSPixels root_element_font_size() const;
98
99 struct MatchingRuleSet {
100 Vector<MatchingRule> user_agent_rules;
101 Vector<MatchingRule> author_rules;
102 };
103
104 void cascade_declarations(StyleProperties&, DOM::Element&, Vector<MatchingRule> const&, CascadeOrigin, Important important) const;
105
106 void build_rule_cache();
107 void build_rule_cache_if_needed() const;
108
109 DOM::Document& m_document;
110
111 struct RuleCache {
112 HashMap<FlyString, Vector<MatchingRule>> rules_by_id;
113 HashMap<FlyString, Vector<MatchingRule>> rules_by_class;
114 HashMap<FlyString, Vector<MatchingRule>> rules_by_tag_name;
115 Vector<MatchingRule> other_rules;
116 };
117
118 NonnullOwnPtr<RuleCache> make_rule_cache_for_cascade_origin(CascadeOrigin);
119
120 RuleCache const& rule_cache_for_cascade_origin(CascadeOrigin) const;
121
122 OwnPtr<RuleCache> m_author_rule_cache;
123 OwnPtr<RuleCache> m_user_agent_rule_cache;
124
125 class FontLoader;
126 HashMap<String, NonnullOwnPtr<FontLoader>> m_loaded_fonts;
127};
128
129}