chromium/third_party/blink/renderer/core/css/style_scope_frame.h

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_CSS_STYLE_SCOPE_FRAME_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_STYLE_SCOPE_FRAME_H_

#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/css/resolver/match_flags.h"
#include "third_party/blink/renderer/platform/heap/collection_support/heap_hash_map.h"
#include "third_party/blink/renderer/platform/heap/collection_support/heap_hash_set.h"
#include "third_party/blink/renderer/platform/heap/collection_support/heap_vector.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/heap/member.h"
#include "third_party/blink/renderer/platform/heap/visitor.h"

namespace blink {

class ContainerNode;
class Element;
class StyleScope;
class SelectorChecker;

// The *activations* for a given StyleScope/node, is a list of active
// scopes found in the ancestor chain, their roots (ContainerNode*), and the
// proximities to those roots.
//
// The idea is that, if we're matching a selector ':scope' within some
// StyleScope, we look up the activations for that StyleScope, and
// and check if the current element (`SelectorCheckingContext.element`)
// matches any of the activation roots.
struct CORE_EXPORT StyleScopeActivation { … };

struct CORE_EXPORT StyleScopeActivations
    : public GarbageCollected<StyleScopeActivations> { … };

// Stores the current @scope activations for a given subject element.
//
// See `StyleScopeActivation` for more information about activations.
//
// StyleScopeFrames are placed on the stack in `Element::RecalcStyle`, and
// serve as a cache of all @scope activations until that point in the tree.
// The actual contents of a StyleScopeFrame is populated lazily during
// `SelectorChecker::CheckPseudoScope`.
//
// StyleScopeFrames may contain a pointer to a parent frame, in which case
// `SelectorChecker::CheckPseudoScope` will store data applicable to the parent
// element in that frame.
class CORE_EXPORT StyleScopeFrame { … };

}  // namespace blink

WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(…)

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_CSS_STYLE_SCOPE_FRAME_H_