1 /*
2 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
3 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
4 * (C) 1999 Antti Koivisto (koivisto@kde.org)
5 * (C) 2001 Dirk Mueller (mueller@kde.org)
6 * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
7 * (C) 2006 Alexey Proskuryakov (ap@nypop.com)
8 * Copyright (C) 2010 Google Inc. All rights reserved.
9 * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
10 *
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Library General Public
13 * License as published by the Free Software Foundation; either
14 * version 2 of the License, or (at your option) any later version.
15 *
16 * This library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Library General Public License for more details.
20 *
21 * You should have received a copy of the GNU Library General Public License
22 * along with this library; see the file COPYING.LIB. If not, write to
23 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24 * Boston, MA 02110-1301, USA.
25 *
26 */
27
28 #include "config.h"
29 #include "core/html/forms/TypeAhead.h"
30
31 #include "core/events/KeyboardEvent.h"
32 #include "wtf/unicode/CharacterNames.h"
33
34 using namespace WTF::Unicode;
35
36 namespace WebCore {
37
TypeAhead(TypeAheadDataSource * dataSource)38 TypeAhead::TypeAhead(TypeAheadDataSource* dataSource)
39 : m_dataSource(dataSource)
40 , m_lastTypeTime(0)
41 , m_repeatingChar(0)
42 {
43 }
44
45 static const DOMTimeStamp typeAheadTimeout = 1000;
46
stripLeadingWhiteSpace(const String & string)47 static String stripLeadingWhiteSpace(const String& string)
48 {
49 unsigned length = string.length();
50
51 unsigned i;
52 for (i = 0; i < length; ++i) {
53 if (string[i] != noBreakSpace && !isSpaceOrNewline(string[i]))
54 break;
55 }
56
57 return string.substring(i, length - i);
58 }
59
handleEvent(KeyboardEvent * event,MatchModeFlags matchMode)60 int TypeAhead::handleEvent(KeyboardEvent* event, MatchModeFlags matchMode)
61 {
62 if (event->timeStamp() < m_lastTypeTime)
63 return -1;
64
65 int optionCount = m_dataSource->optionCount();
66 DOMTimeStamp delta = event->timeStamp() - m_lastTypeTime;
67 m_lastTypeTime = event->timeStamp();
68
69 UChar c = event->charCode();
70
71 if (delta > typeAheadTimeout)
72 m_buffer.clear();
73 m_buffer.append(c);
74
75 if (optionCount < 1)
76 return -1;
77
78 int searchStartOffset = 1;
79 String prefix;
80 if (matchMode & CycleFirstChar && c == m_repeatingChar) {
81 // The user is likely trying to cycle through all the items starting
82 // with this character, so just search on the character.
83 prefix = String(&c, 1);
84 m_repeatingChar = c;
85 } else if (matchMode & MatchPrefix) {
86 prefix = m_buffer.toString();
87 if (m_buffer.length() > 1) {
88 m_repeatingChar = 0;
89 searchStartOffset = 0;
90 } else {
91 m_repeatingChar = c;
92 }
93 }
94
95 if (!prefix.isEmpty()) {
96 int selected = m_dataSource->indexOfSelectedOption();
97 int index = (selected < 0 ? 0 : selected) + searchStartOffset;
98 index %= optionCount;
99
100 // Compute a case-folded copy of the prefix string before beginning the search for
101 // a matching element. This code uses foldCase to work around the fact that
102 // String::startWith does not fold non-ASCII characters. This code can be changed
103 // to use startWith once that is fixed.
104 String prefixWithCaseFolded(prefix.foldCase());
105 for (int i = 0; i < optionCount; ++i, index = (index + 1) % optionCount) {
106 // Fold the option string and check if its prefix is equal to the folded prefix.
107 String text = m_dataSource->optionAtIndex(index);
108 if (stripLeadingWhiteSpace(text).foldCase().startsWith(prefixWithCaseFolded))
109 return index;
110 }
111 }
112
113 if (matchMode & MatchIndex) {
114 bool ok = false;
115 int index = m_buffer.toString().toInt(&ok);
116 if (index > 0 && index <= optionCount)
117 return index - 1;
118 }
119 return -1;
120 }
121
122 } // namespace WebCore
123