Source/WebCore/style/StyleLocalPropertyRegistry.h

/*
 * Copyright (C) 2026 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
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#pragma once

#include "CSSRegisteredCustomProperty.h"
#include <wtf/HashMap.h>
#include <wtf/text/AtomStringHash.h>

namespace WebCore {
namespace Style {

// Lightweight property registration for custom function evaluation.
// Unlike CustomPropertyRegistry, this has no association with a Style::Scope
// and no invalidation or prototype style management.
class LocalPropertyRegistry {
public:
    explicit LocalPropertyRegistry(const LocalPropertyRegistry* enclosing = nullptr)
        : m_enclosing(enclosing)
    { }

    // The registration for a name, from this function or an enclosing one.
    const CSSRegisteredCustomProperty* get(const AtomString&) const;
    // Whether this function declares the name itself. A name declared by an enclosing function has its
    // value inherited from the calling context rather than resolving to a registered value here.
    bool declares(const AtomString&) const;
    bool isInherited(const AtomString&) const;

    void add(CSSRegisteredCustomProperty&&);

private:
    // The registry of the function this one was invoked from, so a typed parameter keeps its type across
    // frames. https://github.com/w3c/csswg-drafts/issues/12315
    const LocalPropertyRegistry* m_enclosing { nullptr };
    UncheckedKeyHashMap<AtomString, UniqueRef<CSSRegisteredCustomProperty>> m_properties;
};

} // namespace Style
} // namespace WebCore