IntersectionObserver: second cut.

third_party/WebKit/Source/core/dom/ElementRareData.h

 /*
  * Copyright (C) 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith <catfish.man@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef ElementRareData_h
 #define ElementRareData_h
 
 #include "core/animation/ElementAnimations.h"
 #include "core/dom/Attr.h"
 #include "core/dom/DatasetDOMStringMap.h"
+#include "core/dom/IntersectionObservation.h"
+#include "core/dom/IntersectionObserver.h"
 #include "core/dom/NamedNodeMap.h"
 #include "core/dom/NodeRareData.h"
 #include "core/dom/PseudoElement.h"
 #include "core/dom/custom/CustomElementDefinition.h"
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/html/ClassList.h"
 #include "core/style/StyleInheritedData.h"
 #include "platform/heap/Handle.h"
+#include "wtf/HashSet.h"
 #include "wtf/OwnPtr.h"
+#include "wtf/WeakPtr.h"
 
 namespace blink {
 
 class HTMLElement;
 
 class ElementRareData : public NodeRareData {
 public:
     static ElementRareData* create(LayoutObject* layoutObject)
     {
         return new ElementRareData(layoutObject);
@@ skipping 53 matching lines @@
 
     IntSize savedLayerScrollOffset() const { return m_savedLayerScrollOffset; }
     void setSavedLayerScrollOffset(IntSize size) { m_savedLayerScrollOffset = size; }
 
     ElementAnimations* elementAnimations() { return m_elementAnimations.get(); }
     void setElementAnimations(ElementAnimations* elementAnimations)
     {
         m_elementAnimations = elementAnimations;
     }
 
+    bool hasIntersectionObservation() const
+    {
+        return m_intersectionObservations && m_intersectionObservations->size();
+    }
+
+    IntersectionObservation::HashSet& intersectionObservations()
+    {
+        if (!m_intersectionObservations)
+            m_intersectionObservations = adoptPtrWillBeNoop(new IntersectionObservation::HashSet());
+        return *m_intersectionObservations.get();
+    }
+
+    WeakPtr<Element> createWeakPtr(Element* element)
+    {
+        if (!m_weakPointerFactory)
+            m_weakPointerFactory = adoptPtrWillBeNoop(new WeakPtrFactory<Element>(element));
+        return m_weakPointerFactory->createWeakPtr();
+    }
+
     bool hasPseudoElements() const;
     void clearPseudoElements();
 
     uint32_t incrementProxyCount() { return ++m_proxyCount; }
     uint32_t decrementProxyCount()
     {
         ASSERT(m_proxyCount);
         return --m_proxyCount;
     }
     uint32_t proxyCount() const { return m_proxyCount; }
@@ skipping 17 matching lines @@
     IntSize m_savedLayerScrollOffset;
 
     OwnPtrWillBeMember<DatasetDOMStringMap> m_dataset;
     OwnPtrWillBeMember<ClassList> m_classList;
     OwnPtrWillBeMember<ElementShadow> m_shadow;
     OwnPtrWillBeMember<NamedNodeMap> m_attributeMap;
     OwnPtrWillBeMember<AttrNodeList> m_attrNodeList;
     PersistentWillBeMember<ElementAnimations> m_elementAnimations;
     OwnPtrWillBeMember<InlineCSSStyleDeclaration> m_cssomWrapper;
 
+    // Note that m_intersectionObservers will contain both observers for which this element is target,
+    // and observers for which this element is root.  To tell them apart, check (observer->root() == element).
+    OwnPtrWillBeMember<IntersectionObservation::HashSet> m_intersectionObservations;
+    OwnPtrWillBeMember<WeakPtrFactory<Element>> m_weakPointerFactory;
+
     RefPtr<ComputedStyle> m_computedStyle;
     RefPtrWillBeMember<CustomElementDefinition> m_customElementDefinition;
 
     RefPtrWillBeMember<PseudoElement> m_generatedBefore;
     RefPtrWillBeMember<PseudoElement> m_generatedAfter;
     RefPtrWillBeMember<PseudoElement> m_generatedFirstLetter;
     RefPtrWillBeMember<PseudoElement> m_backdrop;
 
     explicit ElementRareData(LayoutObject*);
 };
@@ skipping 78 matching lines @@
     case FIRST_LETTER:
         return m_generatedFirstLetter.get();
     default:
         return 0;
     }
 }
 
 } // namespace
 
 #endif // ElementRareData_h