1/*
2 * Copyright (C) 2013 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/RenderLayerStackingNodeIterator.h"
33
34#include "core/rendering/RenderLayer.h"
35#include "core/rendering/RenderLayerStackingNode.h"
36
37namespace blink {
38
39RenderLayerStackingNode* RenderLayerStackingNodeIterator::next()
40{
41    if (m_remainingChildren & NegativeZOrderChildren) {
42        Vector<RenderLayerStackingNode*>* negZOrderList = m_root.negZOrderList();
43        if (negZOrderList && m_index < negZOrderList->size())
44            return negZOrderList->at(m_index++);
45
46        m_index = 0;
47        m_remainingChildren &= ~NegativeZOrderChildren;
48    }
49
50    if (m_remainingChildren & NormalFlowChildren) {
51        Vector<RenderLayerStackingNode*>* normalFlowList = m_root.normalFlowList();
52        if (normalFlowList && m_index < normalFlowList->size())
53            return normalFlowList->at(m_index++);
54
55        m_index = 0;
56        m_remainingChildren &= ~NormalFlowChildren;
57    }
58
59    if (m_remainingChildren & PositiveZOrderChildren) {
60        Vector<RenderLayerStackingNode*>* posZOrderList = m_root.posZOrderList();
61        if (posZOrderList && m_index < posZOrderList->size())
62            return posZOrderList->at(m_index++);
63
64        m_index = 0;
65        m_remainingChildren &= ~PositiveZOrderChildren;
66    }
67
68    return 0;
69}
70
71RenderLayerStackingNode* RenderLayerStackingNodeReverseIterator::next()
72{
73    if (m_remainingChildren & NegativeZOrderChildren) {
74        Vector<RenderLayerStackingNode*>* negZOrderList = m_root.negZOrderList();
75        if (negZOrderList && m_index >= 0)
76            return negZOrderList->at(m_index--);
77
78        m_remainingChildren &= ~NegativeZOrderChildren;
79        setIndexToLastItem();
80    }
81
82    if (m_remainingChildren & NormalFlowChildren) {
83        Vector<RenderLayerStackingNode*>* normalFlowList = m_root.normalFlowList();
84        if (normalFlowList && m_index >= 0)
85            return normalFlowList->at(m_index--);
86
87        m_remainingChildren &= ~NormalFlowChildren;
88        setIndexToLastItem();
89    }
90
91    if (m_remainingChildren & PositiveZOrderChildren) {
92        Vector<RenderLayerStackingNode*>* posZOrderList = m_root.posZOrderList();
93        if (posZOrderList && m_index >= 0)
94            return posZOrderList->at(m_index--);
95
96        m_remainingChildren &= ~PositiveZOrderChildren;
97        setIndexToLastItem();
98    }
99
100    return 0;
101}
102
103void RenderLayerStackingNodeReverseIterator::setIndexToLastItem()
104{
105    if (m_remainingChildren & NegativeZOrderChildren) {
106        Vector<RenderLayerStackingNode*>* negZOrderList = m_root.negZOrderList();
107        if (negZOrderList) {
108            m_index  = negZOrderList->size() - 1;
109            return;
110        }
111
112        m_remainingChildren &= ~NegativeZOrderChildren;
113    }
114
115    if (m_remainingChildren & NormalFlowChildren) {
116        Vector<RenderLayerStackingNode*>* normalFlowList = m_root.normalFlowList();
117        if (normalFlowList) {
118            m_index = normalFlowList->size() - 1;
119            return;
120        }
121
122        m_remainingChildren &= ~NormalFlowChildren;
123    }
124
125    if (m_remainingChildren & PositiveZOrderChildren) {
126        Vector<RenderLayerStackingNode*>* posZOrderList = m_root.posZOrderList();
127        if (posZOrderList) {
128            m_index = posZOrderList->size() - 1;
129            return;
130        }
131
132        m_remainingChildren &= ~PositiveZOrderChildren;
133    }
134
135    // No more list to visit.
136    ASSERT(!m_remainingChildren);
137    m_index = -1;
138}
139
140} // namespace blink
141