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 static AccumulatorMap& accumulatorMap()
  44 {
  45     DEFINE_STATIC_LOCAL(AccumulatorMap, map, ());
  46     return map;
  47 }
  48
  49 ChildListMutationAccumulator::ChildListMutationAccumulator(PassRefPtr<Node> target, PassOwnPtr<MutationObserverInterestGroup> observers)
  50     : m_target(target)
  51     , m_lastAdded(0)
  52     , m_observers(observers)
  53 {
  54 }
  55
  56 ChildListMutationAccumulator::~ChildListMutationAccumulator()
  57 {
  58     if (!isEmpty())
  59         enqueueMutationRecord();
  60     accumulatorMap().remove(m_target.get());
  61 }
  62
  63 PassRefPtr<ChildListMutationAccumulator> ChildListMutationAccumulator::getOrCreate(Node& target)
  64 {
  65     AccumulatorMap::AddResult result = accumulatorMap().add(&target, 0);
  66     RefPtr<ChildListMutationAccumulator> accumulator;
  67     if (!result.isNewEntry)
  68         accumulator = result.iterator->value;
  69     else {
  70         accumulator = adoptRef(new ChildListMutationAccumulator(PassRefPtr<Node>(target), MutationObserverInterestGroup::createForChildListMutation(target)));
  71         result.iterator->value = accumulator.get();
  72     }
  73     return accumulator.release();
  74 }
  75
  76 inline bool ChildListMutationAccumulator::isAddedNodeInOrder(Node* child)
  77 {
  78     return isEmpty() || (m_lastAdded == child->previousSibling() && m_nextSibling == child->nextSibling());
  79 }
  80
  81 void ChildListMutationAccumulator::childAdded(PassRefPtr<Node> prpChild)
  82 {
  83     ASSERT(hasObservers());
  84
  85     RefPtr<Node> child = prpChild;
  86
  87     if (!isAddedNodeInOrder(child.get()))
  88         enqueueMutationRecord();
  89
  90     if (isEmpty()) {
  91         m_previousSibling = child->previousSibling();
  92         m_nextSibling = child->nextSibling();
  93     }
  94
  95     m_lastAdded = child.get();
  96     m_addedNodes.append(child.release());
  97 }
  98
  99 inline bool ChildListMutationAccumulator::isRemovedNodeInOrder(Node* child)
 100 {
 101     return isEmpty() || m_nextSibling == child;
 102 }
 103
 104 void ChildListMutationAccumulator::willRemoveChild(PassRefPtr<Node> prpChild)
 105 {
 106     ASSERT(hasObservers());
 107
 108     RefPtr<Node> child = prpChild;
 109
 110     if (!m_addedNodes.isEmpty() || !isRemovedNodeInOrder(child.get()))
 111         enqueueMutationRecord();
 112
 113     if (isEmpty()) {
 114         m_previousSibling = child->previousSibling();
 115         m_nextSibling = child->nextSibling();
 116         m_lastAdded = child->previousSibling();
 117     } else
 118         m_nextSibling = child->nextSibling();
 119
 120     m_removedNodes.append(child.release());
 121 }
 122
 123 void ChildListMutationAccumulator::enqueueMutationRecord()
 124 {
 125     ASSERT(hasObservers());
 126     ASSERT(!isEmpty());
 127
 128     RefPtr<NodeList> addedNodes = StaticNodeList::adopt(m_addedNodes);
 129     RefPtr<NodeList> removedNodes = StaticNodeList::adopt(m_removedNodes);
 130     RefPtr<MutationRecord> record = MutationRecord::createChildList(m_target, addedNodes.release(), removedNodes.release(), m_previousSibling.release(), m_nextSibling.release());
 131     m_observers->enqueueMutationRecord(record.release());
 132     m_lastAdded = 0;
 133     ASSERT(isEmpty());
 134 }
 135
 136 bool ChildListMutationAccumulator::isEmpty()
 137 {
 138     bool result = m_removedNodes.isEmpty() && m_addedNodes.isEmpty();
 139 #ifndef NDEBUG
 140     if (result) {
 141         ASSERT(!m_previousSibling);
 142         ASSERT(!m_nextSibling);
 143         ASSERT(!m_lastAdded);
 144     }
 145 #endif
 146     return result;
 147 }
 148
 149 } // namespace WebCore