src/kitemviews/private/kitemlistkeyboardsearchmanager.cpp

   1 /***************************************************************************
   2  * Copyright (C) 2011 by Tirtha Chatterjee <tirtha.p.chatterjee@gmail.com> *
   3  *                                                                         *
   4  *   Based on the Itemviews NG project from Trolltech Labs:                *
   5  *   http://qt.gitorious.org/qt-labs/itemviews-ng                          *
   6  *                                                                         *
   7  *   This program is free software; you can redistribute it and/or modify  *
   8  *   it under the terms of the GNU General Public License as published by  *
   9  *   the Free Software Foundation; either version 2 of the License, or     *
  10  *   (at your option) any later version.                                   *
  11  *                                                                         *
  12  *   This program is distributed in the hope that it will be useful,       *
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  15  *   GNU General Public License for more details.                          *
  16  *                                                                         *
  17  *   You should have received a copy of the GNU General Public License     *
  18  *   along with this program; if not, write to the                         *
  19  *   Free Software Foundation, Inc.,                                       *
  20  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  21  ***************************************************************************/
  22
  23 #include "kitemlistkeyboardsearchmanager.h"
  24
  25 KItemListKeyboardSearchManager::KItemListKeyboardSearchManager(QObject* parent) :
  26     QObject(parent),
  27     m_isSearchRestarted(false),
  28     m_timeout(1000)
  29 {
  30     m_keyboardInputTime.invalidate();
  31 }
  32
  33 KItemListKeyboardSearchManager::~KItemListKeyboardSearchManager()
  34 {
  35 }
  36
  37 bool KItemListKeyboardSearchManager::shouldClearSearchIfInputTimeReached()
  38 {
  39     const bool keyboardTimeWasValid = m_keyboardInputTime.isValid();
  40     const qint64 keyboardInputTimeElapsed = m_keyboardInputTime.restart();
  41     return (keyboardInputTimeElapsed > m_timeout) || !keyboardTimeWasValid;
  42 }
  43
  44 void KItemListKeyboardSearchManager::addKeys(const QString& keys)
  45 {
  46     if (shouldClearSearchIfInputTimeReached()) {
  47         m_searchedString.clear();
  48     }
  49
  50     const bool newSearch = m_searchedString.isEmpty();
  51
  52     // Do not start a new search if the user pressed Space. Only add
  53     // it to the search string if a search is in progress already.
  54     if (newSearch && keys == QLatin1Char(' ')) {
  55         return;
  56     }
  57
  58     if (!keys.isEmpty()) {
  59         m_searchedString.append(keys);
  60
  61         // Special case:
  62         // If the same key is pressed repeatedly, the next item matching that key should be highlighted
  63         const QChar firstKey = m_searchedString.length() > 0 ? m_searchedString.at(0) : QChar();
  64         const bool sameKey = m_searchedString.length() > 1 && m_searchedString.count(firstKey) == m_searchedString.length();
  65
  66         // Searching for a matching item should start from the next item if either
  67         // 1. a new search is started and a search has not been restarted or
  68         // 2. a 'repeated key' search is done.
  69         const bool searchFromNextItem = (!m_isSearchRestarted && newSearch) || sameKey;
  70
  71         // to remember not to searchFromNextItem if selection was deselected
  72         // loosing keyboard search context basically
  73         m_isSearchRestarted = false;
  74
  75         emit changeCurrentItem(sameKey ? firstKey : m_searchedString, searchFromNextItem);
  76     }
  77     m_keyboardInputTime.start();
  78 }
  79
  80 void KItemListKeyboardSearchManager::setTimeout(qint64 milliseconds)
  81 {
  82     m_timeout = milliseconds;
  83 }
  84
  85 qint64 KItemListKeyboardSearchManager::timeout() const
  86 {
  87     return m_timeout;
  88 }
  89
  90 void KItemListKeyboardSearchManager::cancelSearch()
  91 {
  92     m_isSearchRestarted = true;
  93     m_searchedString.clear();
  94 }
  95
  96 void KItemListKeyboardSearchManager::slotCurrentChanged(int current, int previous)
  97 {
  98     Q_UNUSED(previous);
  99
 100     if (current < 0) {
 101         // The current item has been removed. We should cancel the search.
 102         cancelSearch();
 103     }
 104 }
 105
 106 void KItemListKeyboardSearchManager::slotSelectionChanged(const KItemSet& current, const KItemSet& previous)
 107 {
 108     if (!previous.isEmpty() && current.isEmpty() && previous.count() > 0 && current.count() == 0) {
 109         // The selection has been emptied. We should cancel the search.
 110         cancelSearch();
 111     }
 112 }