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/Document.h" 10 #include "core/dom/Element.h" 11 #include "core/dom/shadow/ShadowRoot.h" 12 13 namespace blink { 14 15 // Maintains the parent element stack (and bloom filter) inside recalcStyle. 16 class StyleResolverParentScope FINAL { 17 STACK_ALLOCATED(); 18 public: 19 explicit StyleResolverParentScope(Node& parent); 20 ~StyleResolverParentScope(); 21 22 static void ensureParentStackIsPushed(); 23 24 private: 25 void pushParentIfNeeded(); parent()26 Node& parent() const { return *m_parent; } 27 28 RawPtrWillBeMember<Node> m_parent; 29 bool m_pushed; 30 StyleResolverParentScope* m_previous; 31 StyleResolver& m_resolver; 32 33 static StyleResolverParentScope* s_currentScope; 34 }; 35 StyleResolverParentScope(Node & parent)36inline StyleResolverParentScope::StyleResolverParentScope(Node& parent) 37 : m_parent(parent) 38 , m_pushed(false) 39 , m_previous(s_currentScope) 40 , m_resolver(*parent.document().styleResolver()) 41 { 42 ASSERT(parent.document().inStyleRecalc()); 43 ASSERT(parent.isElementNode() || parent.isShadowRoot()); 44 s_currentScope = this; 45 m_resolver.increaseStyleSharingDepth(); 46 } 47 ~StyleResolverParentScope()48inline StyleResolverParentScope::~StyleResolverParentScope() 49 { 50 s_currentScope = m_previous; 51 m_resolver.decreaseStyleSharingDepth(); 52 if (!m_pushed) 53 return; 54 if (parent().isElementNode()) 55 m_resolver.popParentElement(toElement(parent())); 56 } 57 ensureParentStackIsPushed()58inline void StyleResolverParentScope::ensureParentStackIsPushed() 59 { 60 if (s_currentScope) 61 s_currentScope->pushParentIfNeeded(); 62 } 63 pushParentIfNeeded()64inline void StyleResolverParentScope::pushParentIfNeeded() 65 { 66 if (m_pushed) 67 return; 68 if (m_previous) 69 m_previous->pushParentIfNeeded(); 70 if (parent().isElementNode()) 71 m_resolver.pushParentElement(toElement(parent())); 72 m_pushed = true; 73 } 74 75 } // namespace blink 76 77 #endif // StyleResolverParentScope_h 78