src/third_party/WebKit/Source/core/css/resolver/StyleResolverParentScope.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef StyleResolverParentScope_h
   6 #define StyleResolverParentScope_h
   7
   8 #include "core/css/resolver/StyleResolver.h"
   9 #include "core/dom/Element.h"
  10 #include "core/dom/shadow/ShadowRoot.h"
  11
  12 namespace WebCore {
  13
  14 // Maintains the parent element stack (and bloom filter) inside recalcStyle.
  15 class StyleResolverParentScope FINAL {
  16 public:
  17     explicit StyleResolverParentScope(Node& parent);
  18     ~StyleResolverParentScope();
  19
  20     static void ensureParentStackIsPushed();
  21
  22 private:
  23     void pushParentIfNeeded();
  24
  25     Node& m_parent;
  26     bool m_pushed;
  27     StyleResolverParentScope* m_previous;
  28     StyleResolver& m_resolver;
  29
  30     static StyleResolverParentScope* s_currentScope;
  31 };
  32
  33 inline StyleResolverParentScope::StyleResolverParentScope(Node& parent)
  34     : m_parent(parent)
  35     , m_pushed(false)
  36     , m_previous(s_currentScope)
  37     , m_resolver(*m_parent.document().styleResolver())
  38 {
  39     ASSERT(m_parent.document().inStyleRecalc());
  40     ASSERT(parent.isElementNode() || parent.isShadowRoot());
  41     s_currentScope = this;
  42     m_resolver.increaseStyleSharingDepth();
  43 }
  44
  45 inline StyleResolverParentScope::~StyleResolverParentScope()
  46 {
  47     s_currentScope = m_previous;
  48     m_resolver.decreaseStyleSharingDepth();
  49     if (!m_pushed)
  50         return;
  51     if (m_parent.isElementNode())
  52         m_resolver.popParentElement(toElement(m_parent));
  53     else
  54         m_resolver.popParentShadowRoot(toShadowRoot(m_parent));
  55 }
  56
  57 inline void StyleResolverParentScope::ensureParentStackIsPushed()
  58 {
  59     if (s_currentScope)
  60         s_currentScope->pushParentIfNeeded();
  61 }
  62
  63 inline void StyleResolverParentScope::pushParentIfNeeded()
  64 {
  65     if (m_pushed)
  66         return;
  67     if (m_previous)
  68         m_previous->pushParentIfNeeded();
  69     if (m_parent.isElementNode())
  70         m_resolver.pushParentElement(toElement(m_parent));
  71     else
  72         m_resolver.pushParentShadowRoot(toShadowRoot(m_parent));
  73     m_pushed = true;
  74 }
  75
  76 } // namespace WebCore
  77
  78 #endif // StyleResolverParentScope_h