src/kitemviews/kitemlistselectionmanager.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@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 "kitemlistselectionmanager.h"
  24
  25 #include "kitemmodelbase.h"
  26 #include <KDebug>
  27
  28 KItemListSelectionManager::KItemListSelectionManager(QObject* parent) :
  29     QObject(parent),
  30     m_currentItem(-1),
  31     m_anchorItem(-1),
  32     m_selectedItems(),
  33     m_model(0)
  34 {
  35 }
  36
  37 KItemListSelectionManager::~KItemListSelectionManager()
  38 {
  39 }
  40
  41 void KItemListSelectionManager::setCurrentItem(int current)
  42 {
  43     const int previous = m_currentItem;
  44     if (m_model && current >= 0 && current < m_model->count()) {
  45         m_currentItem = current;
  46     } else {
  47         m_currentItem = -1;
  48     }
  49
  50     if (m_currentItem != previous) {
  51         emit currentChanged(m_currentItem, previous);
  52     }
  53 }
  54
  55 int KItemListSelectionManager::currentItem() const
  56 {
  57     return m_currentItem;
  58 }
  59
  60 void KItemListSelectionManager::setSelectedItems(const QSet<int>& items)
  61 {
  62     if (m_selectedItems != items) {
  63         const QSet<int> previous = m_selectedItems;
  64         m_selectedItems = items;
  65         emit selectionChanged(m_selectedItems, previous);
  66     }
  67 }
  68
  69 QSet<int> KItemListSelectionManager::selectedItems() const
  70 {
  71     return m_selectedItems;
  72 }
  73
  74 bool KItemListSelectionManager::hasSelection() const
  75 {
  76     return !m_selectedItems.isEmpty();
  77 }
  78
  79 void KItemListSelectionManager::setSelected(int index, int count, SelectionMode mode)
  80 {
  81     if (index < 0 || count < 1 || !m_model || index >= m_model->count()) {
  82         return;
  83     }
  84
  85     const QSet<int> previous = m_selectedItems;
  86
  87     count = qMin(count, m_model->count() - index);
  88
  89     const int endIndex = index + count -1;
  90     switch (mode) {
  91     case Select:
  92         for (int i = index; i <= endIndex; ++i) {
  93             m_selectedItems.insert(i);
  94         }
  95         break;
  96
  97     case Deselect:
  98         for (int i = index; i <= endIndex; ++i) {
  99             m_selectedItems.remove(i);
 100         }
 101         break;
 102
 103     case Toggle:
 104         for (int i = index; i <= endIndex; ++i) {
 105             if (m_selectedItems.contains(i)) {
 106                 m_selectedItems.remove(i);
 107             } else {
 108                 m_selectedItems.insert(i);
 109             }
 110         }
 111         break;
 112
 113     default:
 114         Q_ASSERT(false);
 115         break;
 116     }
 117
 118     if (m_selectedItems != previous) {
 119         emit selectionChanged(m_selectedItems, previous);
 120     }
 121 }
 122
 123 void KItemListSelectionManager::clearSelection()
 124 {
 125     if (!m_selectedItems.isEmpty()) {
 126         const QSet<int> previous = m_selectedItems;
 127         m_selectedItems.clear();
 128         emit selectionChanged(m_selectedItems, previous);
 129     }
 130 }
 131
 132 void KItemListSelectionManager::beginAnchoredSelection(int anchor, SelectionMode mode)
 133 {
 134     Q_UNUSED(anchor);
 135     Q_UNUSED(mode);
 136 }
 137
 138 void KItemListSelectionManager::endAnchoredSelection()
 139 {
 140 }
 141
 142 void KItemListSelectionManager::setAnchorItem(int anchor)
 143 {
 144     const int previous = m_anchorItem;
 145     if (m_model && anchor < m_model->count()) {
 146         m_anchorItem = anchor;
 147     } else {
 148         m_anchorItem = -1;
 149     }
 150
 151     if (m_anchorItem != previous) {
 152         emit anchorChanged(m_anchorItem, previous);
 153     }
 154 }
 155
 156 int KItemListSelectionManager::anchorItem() const
 157 {
 158     return m_anchorItem;
 159 }
 160
 161 KItemModelBase* KItemListSelectionManager::model() const
 162 {
 163     return m_model;
 164 }
 165
 166 void KItemListSelectionManager::setModel(KItemModelBase* model)
 167 {
 168     m_model = model;
 169     if (model && model->count() > 0) {
 170         m_currentItem = 0;
 171     }
 172 }
 173
 174 void KItemListSelectionManager::itemsInserted(const KItemRangeList& itemRanges)
 175 {
 176     // Update the current item
 177     if (m_currentItem < 0) {
 178         setCurrentItem(0);
 179     } else {
 180         int inc = 0;
 181         foreach (const KItemRange& itemRange, itemRanges) {
 182             if (m_currentItem < itemRange.index) {
 183                 break;
 184             }
 185             inc += itemRange.count;
 186         }
 187         setCurrentItem(m_currentItem + inc);
 188     }
 189
 190     // Update the anchor item
 191     if (m_anchorItem < 0) {
 192         setAnchorItem(0);
 193     } else {
 194         int inc = 0;
 195         foreach (const KItemRange& itemRange, itemRanges) {
 196             if (m_anchorItem < itemRange.index) {
 197                 break;
 198             }
 199             inc += itemRange.count;
 200         }
 201         setAnchorItem(m_anchorItem + inc);
 202     }
 203
 204     // Update the selections
 205     if (!m_selectedItems.isEmpty()) {
 206         const QSet<int> previous = m_selectedItems;
 207
 208         QSet<int> current;
 209         current.reserve(m_selectedItems.count());
 210         QSetIterator<int> it(m_selectedItems);
 211         while (it.hasNext()) {
 212             const int index = it.next();
 213             int inc = 0;
 214             foreach (const KItemRange& itemRange, itemRanges) {
 215                 if (index < itemRange.index) {
 216                     break;
 217                 }
 218                 inc += itemRange.count;
 219             }
 220             current.insert(index + inc);
 221         }
 222
 223         if (current != previous) {
 224             m_selectedItems = current;
 225             emit selectionChanged(current, previous);
 226         }
 227     }
 228 }
 229
 230 void KItemListSelectionManager::itemsRemoved(const KItemRangeList& itemRanges)
 231 {
 232     // Update the current item
 233     if (m_currentItem >= 0) {
 234         int currentItem = m_currentItem;
 235         foreach (const KItemRange& itemRange, itemRanges) {
 236             if (currentItem < itemRange.index) {
 237                 break;
 238             }
 239             if (currentItem >= itemRange.index + itemRange.count) {
 240                 currentItem -= itemRange.count;
 241             } else if (currentItem >= m_model->count()) {
 242                 currentItem = m_model->count() - 1;
 243             }
 244         }
 245         setCurrentItem(currentItem);
 246     }
 247
 248     // Update the anchor item
 249     if (m_anchorItem >= 0) {
 250         int anchorItem = m_anchorItem;
 251         foreach (const KItemRange& itemRange, itemRanges) {
 252             if (anchorItem < itemRange.index) {
 253                 break;
 254             }
 255             if (anchorItem >= itemRange.index + itemRange.count) {
 256                 anchorItem -= itemRange.count;
 257             } else if (anchorItem >= m_model->count()) {
 258                 anchorItem = m_model->count() - 1;
 259             }
 260         }
 261         setAnchorItem(anchorItem);
 262     }
 263
 264     // Update the selections
 265     if (!m_selectedItems.isEmpty()) {
 266         const QSet<int> previous = m_selectedItems;
 267
 268         QSet<int> current;
 269         current.reserve(m_selectedItems.count());
 270         QSetIterator<int> it(m_selectedItems);
 271         while (it.hasNext()) {
 272             int index = it.next();
 273             int dec = 0;
 274             foreach (const KItemRange& itemRange, itemRanges) {
 275                 if (index < itemRange.index) {
 276                     break;
 277                 }
 278
 279                 if (index < itemRange.index + itemRange.count) {
 280                     // The selection is part of the removed range
 281                     // and will get deleted
 282                     index = -1;
 283                     break;
 284                 }
 285
 286                 dec += itemRange.count;
 287             }
 288             index -= dec;
 289             if (index >= 0)  {
 290                 current.insert(index);
 291             }
 292         }
 293
 294         if (current != previous) {
 295             m_selectedItems = current;
 296             emit selectionChanged(current, previous);
 297         }
 298     }
 299 }
 300
 301 #include "kitemlistselectionmanager.moc"