src/kitemviews/kitemlistselectionmanager.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2011 by Peter Penz <peter.penz19@gmail.com>             *
   3  *   Copyright (C) 2011 by Frank Reininghaus <frank78ac@googlemail.com>    *
   4  *                                                                         *
   5  *   Based on the Itemviews NG project from Trolltech Labs:                *
   6  *   http://qt.gitorious.org/qt-labs/itemviews-ng                          *
   7  *                                                                         *
   8  *   This program is free software; you can redistribute it and/or modify  *
   9  *   it under the terms of the GNU General Public License as published by  *
  10  *   the Free Software Foundation; either version 2 of the License, or     *
  11  *   (at your option) any later version.                                   *
  12  *                                                                         *
  13  *   This program is distributed in the hope that it will be useful,       *
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  16  *   GNU General Public License for more details.                          *
  17  *                                                                         *
  18  *   You should have received a copy of the GNU General Public License     *
  19  *   along with this program; if not, write to the                         *
  20  *   Free Software Foundation, Inc.,                                       *
  21  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  22  ***************************************************************************/
  23
  24 #include "kitemlistselectionmanager.h"
  25
  26 #include "kitemmodelbase.h"
  27 #include <KDebug>
  28
  29 KItemListSelectionManager::KItemListSelectionManager(QObject* parent) :
  30     QObject(parent),
  31     m_currentItem(-1),
  32     m_anchorItem(-1),
  33     m_selectedItems(),
  34     m_isAnchoredSelectionActive(false),
  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             selectedItems.insert(index);
  81         }
  82     }
  83
  84     return selectedItems;
  85 }
  86
  87 bool KItemListSelectionManager::hasSelection() const
  88 {
  89     return !m_selectedItems.isEmpty() || m_isAnchoredSelectionActive;
  90 }
  91
  92 void KItemListSelectionManager::setSelected(int index, int count, SelectionMode mode)
  93 {
  94     if (index < 0 || count < 1 || !m_model || index >= m_model->count()) {
  95         return;
  96     }
  97
  98     const QSet<int> previous = m_selectedItems;
  99
 100     count = qMin(count, m_model->count() - index);
 101
 102     const int endIndex = index + count -1;
 103     switch (mode) {
 104     case Select:
 105         for (int i = index; i <= endIndex; ++i) {
 106             m_selectedItems.insert(i);
 107         }
 108         break;
 109
 110     case Deselect:
 111         for (int i = index; i <= endIndex; ++i) {
 112             m_selectedItems.remove(i);
 113         }
 114         break;
 115
 116     case Toggle:
 117         for (int i = index; i <= endIndex; ++i) {
 118             if (m_selectedItems.contains(i)) {
 119                 m_selectedItems.remove(i);
 120             } else {
 121                 m_selectedItems.insert(i);
 122             }
 123         }
 124         break;
 125
 126     default:
 127         Q_ASSERT(false);
 128         break;
 129     }
 130
 131     if (m_selectedItems != previous) {
 132         emit selectionChanged(m_selectedItems, previous);
 133     }
 134 }
 135
 136 void KItemListSelectionManager::clearSelection()
 137 {
 138     if (!m_selectedItems.isEmpty()) {
 139         const QSet<int> previous = m_selectedItems;
 140         m_selectedItems.clear();
 141         m_isAnchoredSelectionActive = false;
 142         emit selectionChanged(m_selectedItems, previous);
 143     }
 144     else if (m_isAnchoredSelectionActive) {
 145         m_isAnchoredSelectionActive = false;
 146         // TODO: the 'previous' parameter of the signal has to be set correctly, but do we actually need it?
 147         emit selectionChanged(m_selectedItems, m_selectedItems);
 148     }
 149 }
 150
 151 void KItemListSelectionManager::beginAnchoredSelection(int anchor)
 152 {
 153     m_isAnchoredSelectionActive = true;
 154     setAnchorItem(anchor);
 155 }
 156
 157 void KItemListSelectionManager::endAnchoredSelection()
 158 {
 159     if (m_isAnchoredSelectionActive) {
 160         const int from = qMin(m_anchorItem, m_currentItem);
 161         const int to = qMax(m_anchorItem, m_currentItem);
 162
 163         for (int index = from; index <= to; index++) {
 164             m_selectedItems.insert(index);
 165         }
 166
 167         m_isAnchoredSelectionActive = false;
 168     }
 169 }
 170
 171 void KItemListSelectionManager::setAnchorItem(int anchor)
 172 {
 173     const int previous = m_anchorItem;
 174     if (m_model && anchor < m_model->count()) {
 175         m_anchorItem = anchor;
 176     } else {
 177         m_anchorItem = -1;
 178     }
 179
 180     if (m_anchorItem != previous) {
 181         emit anchorChanged(m_anchorItem, previous);
 182     }
 183 }
 184
 185 int KItemListSelectionManager::anchorItem() const
 186 {
 187     return m_anchorItem;
 188 }
 189
 190 bool KItemListSelectionManager::isAnchoredSelectionActive() const
 191 {
 192     return m_isAnchoredSelectionActive;
 193 }
 194
 195 void KItemListSelectionManager::setAnchoredSelectionActive(bool active)
 196 {
 197     m_isAnchoredSelectionActive = active;
 198 }
 199
 200 KItemModelBase* KItemListSelectionManager::model() const
 201 {
 202     return m_model;
 203 }
 204
 205 void KItemListSelectionManager::setModel(KItemModelBase* model)
 206 {
 207     m_model = model;
 208     if (model && model->count() > 0) {
 209         m_currentItem = 0;
 210     }
 211 }
 212
 213 void KItemListSelectionManager::itemsInserted(const KItemRangeList& itemRanges)
 214 {
 215     // Update the current item
 216     if (m_currentItem < 0) {
 217         setCurrentItem(0);
 218     } else {
 219         int inc = 0;
 220         foreach (const KItemRange& itemRange, itemRanges) {
 221             if (m_currentItem < itemRange.index) {
 222                 break;
 223             }
 224             inc += itemRange.count;
 225         }
 226         setCurrentItem(m_currentItem + inc);
 227     }
 228
 229     // Update the anchor item
 230     if (m_anchorItem < 0) {
 231         setAnchorItem(0);
 232     } else {
 233         int inc = 0;
 234         foreach (const KItemRange& itemRange, itemRanges) {
 235             if (m_anchorItem < itemRange.index) {
 236                 break;
 237             }
 238             inc += itemRange.count;
 239         }
 240         setAnchorItem(m_anchorItem + inc);
 241     }
 242
 243     // Update the selections
 244     if (!m_selectedItems.isEmpty()) {
 245         const QSet<int> previous = m_selectedItems;
 246
 247         QSet<int> current;
 248         current.reserve(m_selectedItems.count());
 249         QSetIterator<int> it(m_selectedItems);
 250         while (it.hasNext()) {
 251             const int index = it.next();
 252             int inc = 0;
 253             foreach (const KItemRange& itemRange, itemRanges) {
 254                 if (index < itemRange.index) {
 255                     break;
 256                 }
 257                 inc += itemRange.count;
 258             }
 259             current.insert(index + inc);
 260         }
 261
 262         if (current != previous) {
 263             m_selectedItems = current;
 264             emit selectionChanged(current, previous);
 265         }
 266     }
 267 }
 268
 269 void KItemListSelectionManager::itemsRemoved(const KItemRangeList& itemRanges)
 270 {
 271     // Update the current item
 272     if (m_currentItem >= 0) {
 273         int currentItem = m_currentItem;
 274         foreach (const KItemRange& itemRange, itemRanges) {
 275             if (currentItem < itemRange.index) {
 276                 break;
 277             }
 278             if (currentItem >= itemRange.index + itemRange.count) {
 279                 currentItem -= itemRange.count;
 280             } else if (currentItem >= m_model->count()) {
 281                 currentItem = m_model->count() - 1;
 282             }
 283         }
 284         setCurrentItem(currentItem);
 285     }
 286
 287     // Update the anchor item
 288     if (m_anchorItem >= 0) {
 289         int anchorItem = m_anchorItem;
 290         foreach (const KItemRange& itemRange, itemRanges) {
 291             if (anchorItem < itemRange.index) {
 292                 break;
 293             }
 294             if (anchorItem >= itemRange.index + itemRange.count) {
 295                 anchorItem -= itemRange.count;
 296             } else if (anchorItem >= m_model->count()) {
 297                 anchorItem = m_model->count() - 1;
 298             }
 299         }
 300         setAnchorItem(anchorItem);
 301     }
 302
 303     // Update the selections
 304     if (!m_selectedItems.isEmpty()) {
 305         const QSet<int> previous = m_selectedItems;
 306
 307         QSet<int> current;
 308         current.reserve(m_selectedItems.count());
 309         QSetIterator<int> it(m_selectedItems);
 310         while (it.hasNext()) {
 311             int index = it.next();
 312             int dec = 0;
 313             foreach (const KItemRange& itemRange, itemRanges) {
 314                 if (index < itemRange.index) {
 315                     break;
 316                 }
 317
 318                 if (index < itemRange.index + itemRange.count) {
 319                     // The selection is part of the removed range
 320                     // and will get deleted
 321                     index = -1;
 322                     break;
 323                 }
 324
 325                 dec += itemRange.count;
 326             }
 327             index -= dec;
 328             if (index >= 0)  {
 329                 current.insert(index);
 330             }
 331         }
 332
 333         if (current != previous) {
 334             m_selectedItems = current;
 335             emit selectionChanged(current, previous);
 336         }
 337     }
 338 }
 339
 340 #include "kitemlistselectionmanager.moc"