Home | History | Annotate | Download | only in forms 
      1 /*
      2  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
      3  * Copyright (C) 1999 Lars Knoll (knoll (at) kde.org)
      4  *           (C) 1999 Antti Koivisto (koivisto (at) kde.org)
      5  *           (C) 2001 Dirk Mueller (mueller (at) kde.org)
      6  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
      7  *           (C) 2006 Alexey Proskuryakov (ap (at) 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 
     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 
     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 
     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