1/*
2 * Copyright (C) 2012 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 *     * Neither the name of Google Inc. nor the names of its
11 * contributors may be used to endorse or promote products derived from
12 * this software without specific prior written permission.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
15 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
16 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
17 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
18 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
20 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "config.h"
28#include "core/dom/NodeRenderingTraversal.h"
29
30#include "core/HTMLNames.h"
31#include "core/dom/PseudoElement.h"
32#include "core/dom/shadow/ComposedTreeWalker.h"
33#include "core/rendering/RenderObject.h"
34
35namespace blink {
36
37namespace NodeRenderingTraversal {
38
39static bool isRendererReparented(const RenderObject* renderer)
40{
41    if (!renderer->node()->isElementNode())
42        return false;
43    if (toElement(renderer->node())->isInTopLayer())
44        return true;
45    return false;
46}
47
48void ParentDetails::didTraverseInsertionPoint(const InsertionPoint* insertionPoint)
49{
50    if (!m_insertionPoint) {
51        m_insertionPoint = insertionPoint;
52    }
53}
54
55ContainerNode* parent(const Node* node, ParentDetails* details)
56{
57    ASSERT(node);
58    ASSERT(!node->document().childNeedsDistributionRecalc());
59    if (isActiveInsertionPoint(*node))
60        return 0;
61    ComposedTreeWalker walker(node, ComposedTreeWalker::CanStartFromShadowBoundary);
62    return toContainerNode(walker.traverseParent(walker.get(), details));
63}
64
65bool contains(const ContainerNode* container, const Node* node)
66{
67    while (node) {
68        if (node == container)
69            return true;
70        node = NodeRenderingTraversal::parent(node);
71    }
72    return false;
73}
74
75Node* nextSibling(const Node* node)
76{
77    ComposedTreeWalker walker(node);
78    if (node->isBeforePseudoElement()) {
79        walker.parent();
80        walker.firstChild();
81    } else
82        walker.nextSibling();
83
84    if (walker.get() || node->isAfterPseudoElement())
85        return walker.get();
86
87    Node* parent = walker.traverseParent(node);
88    if (parent && parent->isElementNode())
89        return toElement(parent)->pseudoElement(AFTER);
90
91    return 0;
92}
93
94Node* previousSibling(const Node* node)
95{
96    ComposedTreeWalker walker(node);
97    if (node->isAfterPseudoElement()) {
98        walker.parent();
99        walker.lastChild();
100    } else
101        walker.previousSibling();
102
103    if (walker.get() || node->isBeforePseudoElement())
104        return walker.get();
105
106    Node* parent = walker.traverseParent(node);
107    if (parent && parent->isElementNode())
108        return toElement(parent)->pseudoElement(BEFORE);
109
110    return 0;
111}
112
113static Node* lastChild(const Node* node)
114{
115    ComposedTreeWalker walker(node);
116    walker.lastChild();
117    return walker.get();
118}
119
120static Node* pseudoAwarePreviousSibling(const Node* node)
121{
122    Node* previousNode = previousSibling(node);
123    Node* parentNode = parent(node);
124
125    if (parentNode && parentNode->isElementNode() && !previousNode) {
126        if (node->isAfterPseudoElement()) {
127            if (Node* child = lastChild(parentNode))
128                return child;
129        }
130        if (!node->isBeforePseudoElement())
131            return toElement(parentNode)->pseudoElement(BEFORE);
132    }
133    return previousNode;
134}
135
136static Node* pseudoAwareLastChild(const Node* node)
137{
138    if (node->isElementNode()) {
139        const Element* currentElement = toElement(node);
140        Node* last = currentElement->pseudoElement(AFTER);
141        if (last)
142            return last;
143
144        last = lastChild(currentElement);
145        if (!last)
146            last = currentElement->pseudoElement(BEFORE);
147        return last;
148    }
149
150    return lastChild(node);
151}
152
153Node* previous(const Node* node, const Node* stayWithin)
154{
155    if (node == stayWithin)
156        return 0;
157
158    if (Node* previousNode = pseudoAwarePreviousSibling(node)) {
159        while (Node* previousLastChild = pseudoAwareLastChild(previousNode))
160            previousNode = previousLastChild;
161        return previousNode;
162    }
163    return parent(node);
164}
165
166static Node* firstChild(const Node* node)
167{
168    ComposedTreeWalker walker(node);
169    walker.firstChild();
170    return walker.get();
171}
172
173static Node* pseudoAwareNextSibling(const Node* node)
174{
175    Node* parentNode = parent(node);
176    Node* nextNode = nextSibling(node);
177
178    if (parentNode && parentNode->isElementNode() && !nextNode) {
179        if (node->isBeforePseudoElement()) {
180            if (Node* child = firstChild(parentNode))
181                return child;
182        }
183        if (!node->isAfterPseudoElement())
184            return toElement(parentNode)->pseudoElement(AFTER);
185    }
186    return nextNode;
187}
188
189static Node* pseudoAwareFirstChild(const Node* node)
190{
191    if (node->isElementNode()) {
192        const Element* currentElement = toElement(node);
193        Node* first = currentElement->pseudoElement(BEFORE);
194        if (first)
195            return first;
196        first = firstChild(currentElement);
197        if (!first)
198            first = currentElement->pseudoElement(AFTER);
199        return first;
200    }
201
202    return firstChild(node);
203}
204
205Node* next(const Node* node, const Node* stayWithin)
206{
207    if (Node* child = pseudoAwareFirstChild(node))
208        return child;
209    if (node == stayWithin)
210        return 0;
211    if (Node* nextNode = pseudoAwareNextSibling(node))
212        return nextNode;
213    for (Node* parentNode = parent(node); parentNode; parentNode = parent(parentNode)) {
214        if (parentNode == stayWithin)
215            return 0;
216        if (Node* nextNode = pseudoAwareNextSibling(parentNode))
217            return nextNode;
218    }
219    return 0;
220}
221
222RenderObject* nextSiblingRenderer(const Node* node)
223{
224    for (Node* sibling = NodeRenderingTraversal::nextSibling(node); sibling; sibling = NodeRenderingTraversal::nextSibling(sibling)) {
225        RenderObject* renderer = sibling->renderer();
226        if (renderer && !isRendererReparented(renderer))
227            return renderer;
228    }
229    return 0;
230}
231
232RenderObject* previousSiblingRenderer(const Node* node)
233{
234    for (Node* sibling = NodeRenderingTraversal::previousSibling(node); sibling; sibling = NodeRenderingTraversal::previousSibling(sibling)) {
235        RenderObject* renderer = sibling->renderer();
236        if (renderer && !isRendererReparented(renderer))
237            return renderer;
238    }
239    return 0;
240}
241
242RenderObject* nextInTopLayer(const Element* element)
243{
244    if (!element->isInTopLayer())
245        return 0;
246    const WillBeHeapVector<RefPtrWillBeMember<Element> >& topLayerElements = element->document().topLayerElements();
247    size_t position = topLayerElements.find(element);
248    ASSERT(position != kNotFound);
249    for (size_t i = position + 1; i < topLayerElements.size(); ++i) {
250        if (RenderObject* renderer = topLayerElements[i]->renderer())
251            return renderer;
252    }
253    return 0;
254}
255
256}
257
258} // namespace
259