c3437bccb3
We now detect situations like this, where variables infinitely recur,
without crashing:
```css
div {
--a: var(--b);
--b: var(--a);
background: var(--a);
}
p {
--foo: var(--foo);
background: var(--foo);
}
```
100 lines
3.3 KiB
C++
100 lines
3.3 KiB
C++
/*
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* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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* Copyright (c) 2021, Sam Atkins <atkinssj@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/HashMap.h>
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#include <AK/NonnullRefPtrVector.h>
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#include <AK/OwnPtr.h>
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#include <LibWeb/CSS/CSSStyleDeclaration.h>
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#include <LibWeb/CSS/Parser/StyleComponentValueRule.h>
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#include <LibWeb/CSS/StyleProperties.h>
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#include <LibWeb/Forward.h>
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namespace Web::CSS {
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struct MatchingRule {
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RefPtr<CSSStyleRule> rule;
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size_t style_sheet_index { 0 };
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size_t rule_index { 0 };
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size_t selector_index { 0 };
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u32 specificity { 0 };
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};
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class PropertyDependencyNode : public RefCounted<PropertyDependencyNode> {
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public:
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static NonnullRefPtr<PropertyDependencyNode> create(String name)
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{
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return adopt_ref(*new PropertyDependencyNode(move(name)));
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}
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void add_child(NonnullRefPtr<PropertyDependencyNode>);
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bool has_cycles();
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private:
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explicit PropertyDependencyNode(String name);
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String m_name;
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NonnullRefPtrVector<PropertyDependencyNode> m_children;
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bool m_marked { false };
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};
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class StyleComputer {
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public:
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explicit StyleComputer(DOM::Document&);
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~StyleComputer();
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DOM::Document& document() { return m_document; }
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DOM::Document const& document() const { return m_document; }
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NonnullRefPtr<StyleProperties> create_document_style() const;
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NonnullRefPtr<StyleProperties> compute_style(DOM::Element&) const;
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// https://www.w3.org/TR/css-cascade/#origin
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enum class CascadeOrigin {
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Any, // FIXME: This is not part of the spec. Get rid of it.
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Author,
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User,
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UserAgent,
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Animation,
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Transition,
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};
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Vector<MatchingRule> collect_matching_rules(DOM::Element const&, CascadeOrigin = CascadeOrigin::Any) const;
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void sort_matching_rules(Vector<MatchingRule>&) const;
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struct CustomPropertyResolutionTuple {
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Optional<StyleProperty> style {};
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u32 specificity { 0 };
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};
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CustomPropertyResolutionTuple resolve_custom_property_with_specificity(DOM::Element&, String const&) const;
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Optional<StyleProperty> resolve_custom_property(DOM::Element&, String const&) const;
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private:
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void compute_cascaded_values(StyleProperties&, DOM::Element&) const;
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void compute_font(StyleProperties&, DOM::Element const*) const;
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void compute_defaulted_values(StyleProperties&, DOM::Element const*) const;
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void absolutize_values(StyleProperties&, DOM::Element const*) const;
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void compute_defaulted_property_value(StyleProperties&, DOM::Element const*, CSS::PropertyID) const;
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RefPtr<StyleValue> resolve_unresolved_style_value(DOM::Element&, PropertyID, UnresolvedStyleValue const&) const;
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bool expand_unresolved_values(DOM::Element&, StringView property_name, HashMap<String, NonnullRefPtr<PropertyDependencyNode>>& dependencies, Vector<StyleComponentValueRule> const& source, Vector<StyleComponentValueRule>& dest, size_t source_start_index = 0) const;
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template<typename Callback>
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void for_each_stylesheet(CascadeOrigin, Callback) const;
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struct MatchingRuleSet {
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Vector<MatchingRule> user_agent_rules;
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Vector<MatchingRule> author_rules;
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};
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void cascade_declarations(StyleProperties&, DOM::Element&, Vector<MatchingRule> const&, CascadeOrigin, bool important) const;
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DOM::Document& m_document;
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};
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}
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