src/third_party/WebKit/Source/core/dom/ChildListMutationScope.cpp

   1 /*
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   3  *
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   6  * met:
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   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
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  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "config.h"
  32 #include "core/dom/ChildListMutationScope.h"
  33
  34 #include "core/dom/MutationObserverInterestGroup.h"
  35 #include "core/dom/MutationRecord.h"
  36 #include "core/dom/StaticNodeList.h"
  37 #include "wtf/HashMap.h"
  38 #include "wtf/StdLibExtras.h"
  39
  40 namespace WebCore {
  41
  42 typedef HashMap<Node*, ChildListMutationAccumulator*> AccumulatorMap;
  43
  44 static AccumulatorMap& accumulatorMap()
  45 {
  46     DEFINE_STATIC_LOCAL(AccumulatorMap, map, ());
  47     return map;
  48 }
  49
  50 ChildListMutationAccumulator::ChildListMutationAccumulator(PassRefPtr<Node> target, PassOwnPtrWillBeRawPtr<MutationObserverInterestGroup> observers)
  51     : m_target(target)
  52     , m_lastAdded(0)
  53     , m_observers(observers)
  54 {
  55 }
  56
  57 ChildListMutationAccumulator::~ChildListMutationAccumulator()
  58 {
  59     if (!isEmpty())
  60         enqueueMutationRecord();
  61     accumulatorMap().remove(m_target.get());
  62 }
  63
  64 PassRefPtr<ChildListMutationAccumulator> ChildListMutationAccumulator::getOrCreate(Node& target)
  65 {
  66     AccumulatorMap::AddResult result = accumulatorMap().add(&target, 0);
  67     RefPtr<ChildListMutationAccumulator> accumulator;
  68     if (!result.isNewEntry)
  69         accumulator = result.storedValue->value;
  70     else {
  71         accumulator = adoptRef(new ChildListMutationAccumulator(PassRefPtr<Node>(target), MutationObserverInterestGroup::createForChildListMutation(target)));
  72         result.storedValue->value = accumulator.get();
  73     }
  74     return accumulator.release();
  75 }
  76
  77 inline bool ChildListMutationAccumulator::isAddedNodeInOrder(Node* child)
  78 {
  79     return isEmpty() || (m_lastAdded == child->previousSibling() && m_nextSibling == child->nextSibling());
  80 }
  81
  82 void ChildListMutationAccumulator::childAdded(PassRefPtr<Node> prpChild)
  83 {
  84     ASSERT(hasObservers());
  85
  86     RefPtr<Node> child = prpChild;
  87
  88     if (!isAddedNodeInOrder(child.get()))
  89         enqueueMutationRecord();
  90
  91     if (isEmpty()) {
  92         m_previousSibling = child->previousSibling();
  93         m_nextSibling = child->nextSibling();
  94     }
  95
  96     m_lastAdded = child.get();
  97     m_addedNodes.append(child.release());
  98 }
  99
 100 inline bool ChildListMutationAccumulator::isRemovedNodeInOrder(Node* child)
 101 {
 102     return isEmpty() || m_nextSibling == child;
 103 }
 104
 105 void ChildListMutationAccumulator::willRemoveChild(PassRefPtr<Node> prpChild)
 106 {
 107     ASSERT(hasObservers());
 108
 109     RefPtr<Node> child = prpChild;
 110
 111     if (!m_addedNodes.isEmpty() || !isRemovedNodeInOrder(child.get()))
 112         enqueueMutationRecord();
 113
 114     if (isEmpty()) {
 115         m_previousSibling = child->previousSibling();
 116         m_nextSibling = child->nextSibling();
 117         m_lastAdded = child->previousSibling();
 118     } else
 119         m_nextSibling = child->nextSibling();
 120
 121     m_removedNodes.append(child.release());
 122 }
 123
 124 void ChildListMutationAccumulator::enqueueMutationRecord()
 125 {
 126     ASSERT(hasObservers());
 127     ASSERT(!isEmpty());
 128
 129     RefPtr<NodeList> addedNodes = StaticNodeList::adopt(m_addedNodes);
 130     RefPtr<NodeList> removedNodes = StaticNodeList::adopt(m_removedNodes);
 131     RefPtrWillBeRawPtr<MutationRecord> record = MutationRecord::createChildList(m_target, addedNodes.release(), removedNodes.release(), m_previousSibling.release(), m_nextSibling.release());
 132     m_observers->enqueueMutationRecord(record.release());
 133     m_lastAdded = 0;
 134     ASSERT(isEmpty());
 135 }
 136
 137 bool ChildListMutationAccumulator::isEmpty()
 138 {
 139     bool result = m_removedNodes.isEmpty() && m_addedNodes.isEmpty();
 140 #ifndef NDEBUG
 141     if (result) {
 142         ASSERT(!m_previousSibling);
 143         ASSERT(!m_nextSibling);
 144         ASSERT(!m_lastAdded);
 145     }
 146 #endif
 147     return result;
 148 }
 149
 150 } // namespace WebCore