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_anchoredSelectionMode(KItemListSelectionManager::Select),
  35     m_model(0)
  36 {
  37 }
  38
  39 KItemListSelectionManager::~KItemListSelectionManager()
  40 {
  41 }
  42
  43 void KItemListSelectionManager::setCurrentItem(int current)
  44 {
  45     const int previous = m_currentItem;
  46     if (m_model && current >= 0 && current < m_model->count()) {
  47         m_currentItem = current;
  48     } else {
  49         m_currentItem = -1;
  50     }
  51
  52     if (m_currentItem != previous) {
  53         emit currentChanged(m_currentItem, previous);
  54     }
  55 }
  56
  57 int KItemListSelectionManager::currentItem() const
  58 {
  59     return m_currentItem;
  60 }
  61
  62 void KItemListSelectionManager::setSelectedItems(const QSet<int>& items)
  63 {
  64     if (m_selectedItems != items) {
  65         const QSet<int> previous = m_selectedItems;
  66         m_selectedItems = items;
  67         emit selectionChanged(m_selectedItems, previous);
  68     }
  69 }
  70
  71 QSet<int> KItemListSelectionManager::selectedItems() const
  72 {
  73     QSet<int> selectedItems = m_selectedItems;
  74
  75     if (m_isAnchoredSelectionActive) {
  76         const int from = qMin(m_anchorItem, m_currentItem);
  77         const int to = qMax(m_anchorItem, m_currentItem);
  78
  79         for (int index = from; index <= to; index++) {
  80             switch (m_anchoredSelectionMode) {
  81             case Select:
  82                 selectedItems.insert(index);
  83                 break;
  84             case Deselect:
  85                 selectedItems.remove(index);
  86                 break;
  87             case Toggle:
  88                 if (selectedItems.contains(index)) {
  89                     selectedItems.remove(index);
  90                 } else {
  91                     selectedItems.insert(index);
  92                 }
  93                 break;
  94             }
  95         }
  96     }
  97
  98     return selectedItems;
  99 }
 100
 101 bool KItemListSelectionManager::hasSelection() const
 102 {
 103     return !m_selectedItems.isEmpty() || (m_isAnchoredSelectionActive && m_anchoredSelectionMode == KItemListSelectionManager::Select);
 104 }
 105
 106 void KItemListSelectionManager::setSelected(int index, int count, SelectionMode mode)
 107 {
 108     if (index < 0 || count < 1 || !m_model || index >= m_model->count()) {
 109         return;
 110     }
 111
 112     const QSet<int> previous = m_selectedItems;
 113
 114     count = qMin(count, m_model->count() - index);
 115
 116     const int endIndex = index + count -1;
 117     switch (mode) {
 118     case Select:
 119         for (int i = index; i <= endIndex; ++i) {
 120             m_selectedItems.insert(i);
 121         }
 122         break;
 123
 124     case Deselect:
 125         for (int i = index; i <= endIndex; ++i) {
 126             m_selectedItems.remove(i);
 127         }
 128         break;
 129
 130     case Toggle:
 131         for (int i = index; i <= endIndex; ++i) {
 132             if (m_selectedItems.contains(i)) {
 133                 m_selectedItems.remove(i);
 134             } else {
 135                 m_selectedItems.insert(i);
 136             }
 137         }
 138         break;
 139
 140     default:
 141         Q_ASSERT(false);
 142         break;
 143     }
 144
 145     if (m_selectedItems != previous) {
 146         emit selectionChanged(m_selectedItems, previous);
 147     }
 148 }
 149
 150 void KItemListSelectionManager::clearSelection()
 151 {
 152     if (!m_selectedItems.isEmpty()) {
 153         const QSet<int> previous = m_selectedItems;
 154         m_selectedItems.clear();
 155         m_isAnchoredSelectionActive = false;
 156         emit selectionChanged(m_selectedItems, previous);
 157     }
 158     else if (m_isAnchoredSelectionActive) {
 159         m_isAnchoredSelectionActive = false;
 160         // TODO: the 'previous' parameter of the signal has to be set correctly, but do we actually need it?
 161         emit selectionChanged(m_selectedItems, m_selectedItems);
 162     }
 163 }
 164
 165 void KItemListSelectionManager::beginAnchoredSelection(int anchor, SelectionMode mode)
 166 {
 167     Q_UNUSED(anchor);
 168     Q_UNUSED(mode);
 169 }
 170
 171 void KItemListSelectionManager::endAnchoredSelection()
 172 {
 173 }
 174
 175 void KItemListSelectionManager::setAnchorItem(int anchor)
 176 {
 177     const int previous = m_anchorItem;
 178     if (m_model && anchor < m_model->count()) {
 179         m_anchorItem = anchor;
 180     } else {
 181         m_anchorItem = -1;
 182     }
 183
 184     if (m_anchorItem != previous) {
 185         emit anchorChanged(m_anchorItem, previous);
 186     }
 187 }
 188
 189 int KItemListSelectionManager::anchorItem() const
 190 {
 191     return m_anchorItem;
 192 }
 193
 194 bool KItemListSelectionManager::isAnchoredSelectionActive() const
 195 {
 196     return m_isAnchoredSelectionActive;
 197 }
 198
 199 void KItemListSelectionManager::setAnchoredSelectionActive(bool active)
 200 {
 201     m_isAnchoredSelectionActive = active;
 202 }
 203
 204 KItemListSelectionManager::SelectionMode KItemListSelectionManager::anchoredSelectionMode() const
 205 {
 206     return m_anchoredSelectionMode;
 207 }
 208
 209 void KItemListSelectionManager::setAnchoredSelectionMode(KItemListSelectionManager::SelectionMode mode)
 210 {
 211     m_anchoredSelectionMode = mode;
 212 }
 213
 214 KItemModelBase* KItemListSelectionManager::model() const
 215 {
 216     return m_model;
 217 }
 218
 219 void KItemListSelectionManager::setModel(KItemModelBase* model)
 220 {
 221     m_model = model;
 222     if (model && model->count() > 0) {
 223         m_currentItem = 0;
 224     }
 225 }
 226
 227 void KItemListSelectionManager::itemsInserted(const KItemRangeList& itemRanges)
 228 {
 229     // Update the current item
 230     if (m_currentItem < 0) {
 231         setCurrentItem(0);
 232     } else {
 233         int inc = 0;
 234         foreach (const KItemRange& itemRange, itemRanges) {
 235             if (m_currentItem < itemRange.index) {
 236                 break;
 237             }
 238             inc += itemRange.count;
 239         }
 240         setCurrentItem(m_currentItem + inc);
 241     }
 242
 243     // Update the anchor item
 244     if (m_anchorItem < 0) {
 245         setAnchorItem(0);
 246     } else {
 247         int inc = 0;
 248         foreach (const KItemRange& itemRange, itemRanges) {
 249             if (m_anchorItem < itemRange.index) {
 250                 break;
 251             }
 252             inc += itemRange.count;
 253         }
 254         setAnchorItem(m_anchorItem + inc);
 255     }
 256
 257     // Update the selections
 258     if (!m_selectedItems.isEmpty()) {
 259         const QSet<int> previous = m_selectedItems;
 260
 261         QSet<int> current;
 262         current.reserve(m_selectedItems.count());
 263         QSetIterator<int> it(m_selectedItems);
 264         while (it.hasNext()) {
 265             const int index = it.next();
 266             int inc = 0;
 267             foreach (const KItemRange& itemRange, itemRanges) {
 268                 if (index < itemRange.index) {
 269                     break;
 270                 }
 271                 inc += itemRange.count;
 272             }
 273             current.insert(index + inc);
 274         }
 275
 276         if (current != previous) {
 277             m_selectedItems = current;
 278             emit selectionChanged(current, previous);
 279         }
 280     }
 281 }
 282
 283 void KItemListSelectionManager::itemsRemoved(const KItemRangeList& itemRanges)
 284 {
 285     // Update the current item
 286     if (m_currentItem >= 0) {
 287         int currentItem = m_currentItem;
 288         foreach (const KItemRange& itemRange, itemRanges) {
 289             if (currentItem < itemRange.index) {
 290                 break;
 291             }
 292             if (currentItem >= itemRange.index + itemRange.count) {
 293                 currentItem -= itemRange.count;
 294             } else if (currentItem >= m_model->count()) {
 295                 currentItem = m_model->count() - 1;
 296             }
 297         }
 298         setCurrentItem(currentItem);
 299     }
 300
 301     // Update the anchor item
 302     if (m_anchorItem >= 0) {
 303         int anchorItem = m_anchorItem;
 304         foreach (const KItemRange& itemRange, itemRanges) {
 305             if (anchorItem < itemRange.index) {
 306                 break;
 307             }
 308             if (anchorItem >= itemRange.index + itemRange.count) {
 309                 anchorItem -= itemRange.count;
 310             } else if (anchorItem >= m_model->count()) {
 311                 anchorItem = m_model->count() - 1;
 312             }
 313         }
 314         setAnchorItem(anchorItem);
 315     }
 316
 317     // Update the selections
 318     if (!m_selectedItems.isEmpty()) {
 319         const QSet<int> previous = m_selectedItems;
 320
 321         QSet<int> current;
 322         current.reserve(m_selectedItems.count());
 323         QSetIterator<int> it(m_selectedItems);
 324         while (it.hasNext()) {
 325             int index = it.next();
 326             int dec = 0;
 327             foreach (const KItemRange& itemRange, itemRanges) {
 328                 if (index < itemRange.index) {
 329                     break;
 330                 }
 331
 332                 if (index < itemRange.index + itemRange.count) {
 333                     // The selection is part of the removed range
 334                     // and will get deleted
 335                     index = -1;
 336                     break;
 337                 }
 338
 339                 dec += itemRange.count;
 340             }
 341             index -= dec;
 342             if (index >= 0)  {
 343                 current.insert(index);
 344             }
 345         }
 346
 347         if (current != previous) {
 348             m_selectedItems = current;
 349             emit selectionChanged(current, previous);
 350         }
 351     }
 352 }
 353
 354 #include "kitemlistselectionmanager.moc"