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_isAnchoredSelectionActive(false),
  34     m_model(0)
  35 {
  36 }
  37
  38 KItemListSelectionManager::~KItemListSelectionManager()
  39 {
  40 }
  41
  42 void KItemListSelectionManager::setCurrentItem(int current)
  43 {
  44     const int previous = m_currentItem;
  45     if (m_model && current >= 0 && current < m_model->count()) {
  46         m_currentItem = current;
  47     } else {
  48         m_currentItem = -1;
  49     }
  50
  51     if (m_currentItem != previous) {
  52         emit currentChanged(m_currentItem, previous);
  53     }
  54 }
  55
  56 int KItemListSelectionManager::currentItem() const
  57 {
  58     return m_currentItem;
  59 }
  60
  61 void KItemListSelectionManager::setSelectedItems(const QSet<int>& items)
  62 {
  63     if (m_selectedItems != items) {
  64         const QSet<int> previous = m_selectedItems;
  65         m_selectedItems = items;
  66         emit selectionChanged(m_selectedItems, previous);
  67     }
  68 }
  69
  70 QSet<int> KItemListSelectionManager::selectedItems() const
  71 {
  72     QSet<int> selectedItems = m_selectedItems;
  73
  74     if (m_isAnchoredSelectionActive) {
  75         const int from = qMin(m_anchorItem, m_currentItem);
  76         const int to = qMax(m_anchorItem, m_currentItem);
  77
  78         for (int index = from; index <= to; index++) {
  79             selectedItems.insert(index);
  80         }
  81     }
  82
  83     return selectedItems;
  84 }
  85
  86 bool KItemListSelectionManager::hasSelection() const
  87 {
  88     return !m_selectedItems.isEmpty() || m_isAnchoredSelectionActive;
  89 }
  90
  91 void KItemListSelectionManager::setSelected(int index, int count, SelectionMode mode)
  92 {
  93     if (index < 0 || count < 1 || !m_model || index >= m_model->count()) {
  94         return;
  95     }
  96
  97     const QSet<int> previous = m_selectedItems;
  98
  99     count = qMin(count, m_model->count() - index);
 100
 101     const int endIndex = index + count -1;
 102     switch (mode) {
 103     case Select:
 104         for (int i = index; i <= endIndex; ++i) {
 105             m_selectedItems.insert(i);
 106         }
 107         break;
 108
 109     case Deselect:
 110         for (int i = index; i <= endIndex; ++i) {
 111             m_selectedItems.remove(i);
 112         }
 113         break;
 114
 115     case Toggle:
 116         for (int i = index; i <= endIndex; ++i) {
 117             if (m_selectedItems.contains(i)) {
 118                 m_selectedItems.remove(i);
 119             } else {
 120                 m_selectedItems.insert(i);
 121             }
 122         }
 123         break;
 124
 125     default:
 126         Q_ASSERT(false);
 127         break;
 128     }
 129
 130     if (m_selectedItems != previous) {
 131         emit selectionChanged(m_selectedItems, previous);
 132     }
 133 }
 134
 135 void KItemListSelectionManager::clearSelection()
 136 {
 137     if (!m_selectedItems.isEmpty()) {
 138         const QSet<int> previous = m_selectedItems;
 139         m_selectedItems.clear();
 140         m_isAnchoredSelectionActive = false;
 141         emit selectionChanged(m_selectedItems, previous);
 142     }
 143     else if (m_isAnchoredSelectionActive) {
 144         m_isAnchoredSelectionActive = false;
 145         // TODO: the 'previous' parameter of the signal has to be set correctly, but do we actually need it?
 146         emit selectionChanged(m_selectedItems, m_selectedItems);
 147     }
 148 }
 149
 150 void KItemListSelectionManager::beginAnchoredSelection(int anchor)
 151 {
 152     Q_UNUSED(anchor);
 153 }
 154
 155 void KItemListSelectionManager::endAnchoredSelection()
 156 {
 157 }
 158
 159 void KItemListSelectionManager::setAnchorItem(int anchor)
 160 {
 161     const int previous = m_anchorItem;
 162     if (m_model && anchor < m_model->count()) {
 163         m_anchorItem = anchor;
 164     } else {
 165         m_anchorItem = -1;
 166     }
 167
 168     if (m_anchorItem != previous) {
 169         emit anchorChanged(m_anchorItem, previous);
 170     }
 171 }
 172
 173 int KItemListSelectionManager::anchorItem() const
 174 {
 175     return m_anchorItem;
 176 }
 177
 178 bool KItemListSelectionManager::isAnchoredSelectionActive() const
 179 {
 180     return m_isAnchoredSelectionActive;
 181 }
 182
 183 void KItemListSelectionManager::setAnchoredSelectionActive(bool active)
 184 {
 185     m_isAnchoredSelectionActive = active;
 186 }
 187
 188 KItemModelBase* KItemListSelectionManager::model() const
 189 {
 190     return m_model;
 191 }
 192
 193 void KItemListSelectionManager::setModel(KItemModelBase* model)
 194 {
 195     m_model = model;
 196     if (model && model->count() > 0) {
 197         m_currentItem = 0;
 198     }
 199 }
 200
 201 void KItemListSelectionManager::itemsInserted(const KItemRangeList& itemRanges)
 202 {
 203     // Update the current item
 204     if (m_currentItem < 0) {
 205         setCurrentItem(0);
 206     } else {
 207         int inc = 0;
 208         foreach (const KItemRange& itemRange, itemRanges) {
 209             if (m_currentItem < itemRange.index) {
 210                 break;
 211             }
 212             inc += itemRange.count;
 213         }
 214         setCurrentItem(m_currentItem + inc);
 215     }
 216
 217     // Update the anchor item
 218     if (m_anchorItem < 0) {
 219         setAnchorItem(0);
 220     } else {
 221         int inc = 0;
 222         foreach (const KItemRange& itemRange, itemRanges) {
 223             if (m_anchorItem < itemRange.index) {
 224                 break;
 225             }
 226             inc += itemRange.count;
 227         }
 228         setAnchorItem(m_anchorItem + inc);
 229     }
 230
 231     // Update the selections
 232     if (!m_selectedItems.isEmpty()) {
 233         const QSet<int> previous = m_selectedItems;
 234
 235         QSet<int> current;
 236         current.reserve(m_selectedItems.count());
 237         QSetIterator<int> it(m_selectedItems);
 238         while (it.hasNext()) {
 239             const int index = it.next();
 240             int inc = 0;
 241             foreach (const KItemRange& itemRange, itemRanges) {
 242                 if (index < itemRange.index) {
 243                     break;
 244                 }
 245                 inc += itemRange.count;
 246             }
 247             current.insert(index + inc);
 248         }
 249
 250         if (current != previous) {
 251             m_selectedItems = current;
 252             emit selectionChanged(current, previous);
 253         }
 254     }
 255 }
 256
 257 void KItemListSelectionManager::itemsRemoved(const KItemRangeList& itemRanges)
 258 {
 259     // Update the current item
 260     if (m_currentItem >= 0) {
 261         int currentItem = m_currentItem;
 262         foreach (const KItemRange& itemRange, itemRanges) {
 263             if (currentItem < itemRange.index) {
 264                 break;
 265             }
 266             if (currentItem >= itemRange.index + itemRange.count) {
 267                 currentItem -= itemRange.count;
 268             } else if (currentItem >= m_model->count()) {
 269                 currentItem = m_model->count() - 1;
 270             }
 271         }
 272         setCurrentItem(currentItem);
 273     }
 274
 275     // Update the anchor item
 276     if (m_anchorItem >= 0) {
 277         int anchorItem = m_anchorItem;
 278         foreach (const KItemRange& itemRange, itemRanges) {
 279             if (anchorItem < itemRange.index) {
 280                 break;
 281             }
 282             if (anchorItem >= itemRange.index + itemRange.count) {
 283                 anchorItem -= itemRange.count;
 284             } else if (anchorItem >= m_model->count()) {
 285                 anchorItem = m_model->count() - 1;
 286             }
 287         }
 288         setAnchorItem(anchorItem);
 289     }
 290
 291     // Update the selections
 292     if (!m_selectedItems.isEmpty()) {
 293         const QSet<int> previous = m_selectedItems;
 294
 295         QSet<int> current;
 296         current.reserve(m_selectedItems.count());
 297         QSetIterator<int> it(m_selectedItems);
 298         while (it.hasNext()) {
 299             int index = it.next();
 300             int dec = 0;
 301             foreach (const KItemRange& itemRange, itemRanges) {
 302                 if (index < itemRange.index) {
 303                     break;
 304                 }
 305
 306                 if (index < itemRange.index + itemRange.count) {
 307                     // The selection is part of the removed range
 308                     // and will get deleted
 309                     index = -1;
 310                     break;
 311                 }
 312
 313                 dec += itemRange.count;
 314             }
 315             index -= dec;
 316             if (index >= 0)  {
 317                 current.insert(index);
 318             }
 319         }
 320
 321         if (current != previous) {
 322             m_selectedItems = current;
 323             emit selectionChanged(current, previous);
 324         }
 325     }
 326 }
 327
 328 #include "kitemlistselectionmanager.moc"