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      1 /*
      2  * Copyright (C) 2011 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      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
     15  * contributors may be used to endorse or promote products derived from
     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
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     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/rendering/OrderIterator.h"
     33 
     34 #include "core/rendering/RenderBox.h"
     35 
     36 namespace WebCore {
     37 
     38 OrderIterator::OrderIterator(const RenderBox* containerBox)
     39     : m_containerBox(containerBox)
     40     , m_currentChild(0)
     41     , m_orderValuesIterator(0)
     42 {
     43 }
     44 
     45 RenderBox* OrderIterator::first()
     46 {
     47     reset();
     48     return next();
     49 }
     50 
     51 RenderBox* OrderIterator::next()
     52 {
     53     do {
     54         if (!m_currentChild) {
     55             if (m_orderValuesIterator == m_orderValues.end())
     56                 return 0;
     57             if (m_orderValuesIterator) {
     58                 ++m_orderValuesIterator;
     59                 if (m_orderValuesIterator == m_orderValues.end())
     60                     return 0;
     61             } else {
     62                 m_orderValuesIterator = m_orderValues.begin();
     63             }
     64 
     65             m_currentChild = m_containerBox->firstChildBox();
     66         } else {
     67             m_currentChild = m_currentChild->nextSiblingBox();
     68         }
     69     } while (!m_currentChild || m_currentChild->style()->order() != *m_orderValuesIterator);
     70 
     71     return m_currentChild;
     72 }
     73 
     74 void OrderIterator::reset()
     75 {
     76     m_currentChild = 0;
     77     m_orderValuesIterator = 0;
     78 }
     79 
     80 OrderIteratorPopulator::~OrderIteratorPopulator()
     81 {
     82     m_iterator.reset();
     83 
     84     if (m_anyChildHasDefaultOrderValue)
     85         m_iterator.m_orderValues.append(0);
     86 
     87     if (m_iterator.m_orderValues.size() > 1)
     88         removeDuplicatedOrderValues();
     89 
     90     // Ensure that we release any extra memory we hold onto.
     91     m_iterator.m_orderValues.shrinkToFit();
     92 }
     93 
     94 void OrderIteratorPopulator::removeDuplicatedOrderValues()
     95 {
     96     OrderIterator::OrderValues& orderValues = m_iterator.m_orderValues;
     97 
     98     std::sort(orderValues.begin(), orderValues.end());
     99 
    100     int previous = orderValues[0];
    101     size_t uniqueItemIndex = 0;
    102     for (size_t i = 1; i < orderValues.size(); ++i) {
    103         int current = orderValues[i];
    104         if (current == previous)
    105             continue;
    106         ++uniqueItemIndex;
    107         std::swap(orderValues[i], orderValues[uniqueItemIndex]);
    108         previous = current;
    109     }
    110     orderValues.shrink(uniqueItemIndex + 1);
    111 }
    112 
    113 void OrderIteratorPopulator::collectChild(const RenderBox* child)
    114 {
    115     // Avoid growing the vector for the common-case default value of 0.
    116     if (int order = child->style()->order())
    117         m_iterator.m_orderValues.append(order);
    118     else
    119         m_anyChildHasDefaultOrderValue = true;
    120 }
    121 
    122 } // namespace WebCore
    123