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
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. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25 #include "config.h"
26 #include "DOMTextContentWalker.h"
27
28 #if OS(ANDROID)
29
30 #include "Range.h"
31 #include "TextIterator.h"
32 #include "VisiblePosition.h"
33 #include "VisibleSelection.h"
34 #include "visible_units.h"
35
36 namespace WebCore {
37
getRange(const Position & start,const Position & end)38 static PassRefPtr<Range> getRange(const Position& start, const Position& end)
39 {
40 return VisibleSelection(start.parentAnchoredEquivalent(), end.parentAnchoredEquivalent(), DOWNSTREAM).firstRange();
41 }
42
DOMTextContentWalker(const VisiblePosition & position,unsigned maxLength)43 DOMTextContentWalker::DOMTextContentWalker(const VisiblePosition& position, unsigned maxLength)
44 : m_hitOffsetInContent(0)
45 {
46 const unsigned halfMaxLength = maxLength / 2;
47 RefPtr<Range> forwardRange = makeRange(position, endOfDocument(position));
48 if (!forwardRange)
49 return;
50 CharacterIterator forwardChar(forwardRange.get(), TextIteratorStopsOnFormControls);
51 forwardChar.advance(maxLength - halfMaxLength);
52
53 // No forward contents, started inside form control.
54 if (getRange(position.deepEquivalent(), forwardChar.range()->startPosition())->text().length() == 0)
55 return;
56
57 RefPtr<Range> backwardsRange = makeRange(startOfDocument(position), position);
58 if (!backwardsRange)
59 return;
60 BackwardsCharacterIterator backwardsChar(backwardsRange.get(), TextIteratorStopsOnFormControls);
61 backwardsChar.advance(halfMaxLength);
62
63 m_hitOffsetInContent = getRange(backwardsChar.range()->endPosition(), position.deepEquivalent())->text().length();
64 m_contentRange = getRange(backwardsChar.range()->endPosition(), forwardChar.range()->startPosition());
65 }
66
contentOffsetsToRange(unsigned startInContent,unsigned endInContent)67 PassRefPtr<Range> DOMTextContentWalker::contentOffsetsToRange(unsigned startInContent, unsigned endInContent)
68 {
69 if (startInContent >= endInContent || endInContent > content().length())
70 return 0;
71
72 CharacterIterator iterator(m_contentRange.get());
73 iterator.advance(startInContent);
74
75 Position start = iterator.range()->startPosition();
76 iterator.advance(endInContent - startInContent);
77 Position end = iterator.range()->startPosition();
78 return getRange(start, end);
79 }
80
content() const81 String DOMTextContentWalker::content() const
82 {
83 if (m_contentRange)
84 return m_contentRange->text();
85 return String();
86 }
87
hitOffsetInContent() const88 unsigned DOMTextContentWalker::hitOffsetInContent() const
89 {
90 return m_hitOffsetInContent;
91 }
92
93 } // namespace WebCore
94
95 #endif // OS(ANDROID)
96