chromium/third_party/blink/renderer/core/css/resolver/selector_filter_parent_scope.h

// Copyright 2014 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_RESOLVER_SELECTOR_FILTER_PARENT_SCOPE_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_CSS_RESOLVER_SELECTOR_FILTER_PARENT_SCOPE_H_

#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/css/resolver/style_resolver.h"
#include "third_party/blink/renderer/core/css/selector_filter.h"
#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/dom/element.h"

namespace blink {

// Maintains the parent element stack (and bloom filter) inside RecalcStyle.
// SelectorFilterParentScope for the parent element is added to the stack before
// recalculating style for its children. The bloom filter is populated lazily by
// PushParentIfNeeded().
class CORE_EXPORT SelectorFilterParentScope { … };

// When starting the style recalc, we push an object of this class onto the
// stack to establish a root scope for the SelectorFilter for a document to
// make the style recalc re-entrant. If we do a style recalc for a document
// inside a style recalc for another document (which can happen when
// synchronously loading an svg generated content image), the previous_ pointer
// for the root scope of the inner recalc will point to the current scope of the
// outer one, but the root scope will isolate the inner from trying to push any
// parent stacks in the outer document.
class CORE_EXPORT SelectorFilterRootScope final
    : private SelectorFilterParentScope { … };

inline SelectorFilterParentScope::SelectorFilterParentScope(
    Element* parent,
    ScopeType scope_type)
    : … { … }

inline SelectorFilterParentScope::~SelectorFilterParentScope() { … }

inline void SelectorFilterParentScope::EnsureParentStackIsPushed() { … }

inline void SelectorFilterParentScope::PushParentIfNeeded() { … }

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_CSS_RESOLVER_SELECTOR_FILTER_PARENT_SCOPE_H_