1/*
2 * Copyright (C) 2012 Apple 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
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "SimplifyMarkupCommand.h"
28
29#include "NodeRenderStyle.h"
30#include "NodeTraversal.h"
31#include "RenderInline.h"
32#include "RenderObject.h"
33#include "RenderStyle.h"
34
35namespace WebCore {
36
37SimplifyMarkupCommand::SimplifyMarkupCommand(Document& document, Node* firstNode, Node* nodeAfterLast)
38 : CompositeEditCommand(document)
39 , m_firstNode(firstNode)
40 , m_nodeAfterLast(nodeAfterLast)
41{
42}
43
44void SimplifyMarkupCommand::doApply()
45{
46 Node* rootNode = m_firstNode->parentNode();
47 Vector<Ref<Node>> nodesToRemove;
48
49 document().updateLayoutIgnorePendingStylesheets();
50
51 // Walk through the inserted nodes, to see if there are elements that could be removed
52 // without affecting the style. The goal is to produce leaner markup even when starting
53 // from a verbose fragment.
54 // We look at inline elements as well as non top level divs that don't have attributes.
55 for (Node* node = m_firstNode.get(); node && node != m_nodeAfterLast; node = NodeTraversal::next(*node)) {
56 if (node->firstChild() || (node->isTextNode() && node->nextSibling()))
57 continue;
58
59 Node* startingNode = node->parentNode();
60 auto* startingStyle = startingNode->renderStyle();
61 if (!startingStyle)
62 continue;
63 Node* currentNode = startingNode;
64 Node* topNodeWithStartingStyle = nullptr;
65 while (currentNode != rootNode) {
66 if (currentNode->parentNode() != rootNode && isRemovableBlock(currentNode))
67 nodesToRemove.append(*currentNode);
68
69 currentNode = currentNode->parentNode();
70 if (!currentNode)
71 break;
72
73 auto* renderer = currentNode->renderer();
74 if (!is<RenderInline>(renderer) || downcast<RenderInline>(*renderer).alwaysCreateLineBoxes())
75 continue;
76
77 if (currentNode->firstChild() != currentNode->lastChild()) {
78 topNodeWithStartingStyle = nullptr;
79 break;
80 }
81
82 OptionSet<StyleDifferenceContextSensitiveProperty> contextSensitiveProperties;
83 if (currentNode->renderStyle()->diff(*startingStyle, contextSensitiveProperties) == StyleDifference::Equal)
84 topNodeWithStartingStyle = currentNode;
85
86 }
87 if (topNodeWithStartingStyle) {
88 for (Node* node = startingNode; node && node != topNodeWithStartingStyle; node = node->parentNode())
89 nodesToRemove.append(*node);
90 }
91 }
92
93 // we perform all the DOM mutations at once.
94 for (size_t i = 0; i < nodesToRemove.size(); ++i) {
95 // FIXME: We can do better by directly moving children from nodesToRemove[i].
96 int numPrunedAncestors = pruneSubsequentAncestorsToRemove(nodesToRemove, i);
97 if (numPrunedAncestors < 0)
98 continue;
99 removeNodePreservingChildren(nodesToRemove[i], AssumeContentIsAlwaysEditable);
100 i += numPrunedAncestors;
101 }
102}
103
104int SimplifyMarkupCommand::pruneSubsequentAncestorsToRemove(Vector<Ref<Node>>& nodesToRemove, size_t startNodeIndex)
105{
106 size_t pastLastNodeToRemove = startNodeIndex + 1;
107 for (; pastLastNodeToRemove < nodesToRemove.size(); ++pastLastNodeToRemove) {
108 if (nodesToRemove[pastLastNodeToRemove - 1]->parentNode() != nodesToRemove[pastLastNodeToRemove].ptr())
109 break;
110 if (nodesToRemove[pastLastNodeToRemove]->firstChild() != nodesToRemove[pastLastNodeToRemove]->lastChild())
111 break;
112 }
113
114 Node* highestAncestorToRemove = nodesToRemove[pastLastNodeToRemove - 1].ptr();
115 RefPtr<ContainerNode> parent = highestAncestorToRemove->parentNode();
116 if (!parent) // Parent has already been removed.
117 return -1;
118
119 if (pastLastNodeToRemove == startNodeIndex + 1)
120 return 0;
121
122 removeNode(nodesToRemove[startNodeIndex], AssumeContentIsAlwaysEditable);
123 insertNodeBefore(nodesToRemove[startNodeIndex].copyRef(), *highestAncestorToRemove, AssumeContentIsAlwaysEditable);
124 removeNode(*highestAncestorToRemove, AssumeContentIsAlwaysEditable);
125
126 return pastLastNodeToRemove - startNodeIndex - 1;
127}
128
129} // namespace WebCore
130