File indexing completed on 2024-04-28 05:45:07

 /*
  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
  * SPDX-FileCopyrightText: 2011 Frank Reininghaus <frank78ac@googlemail.com>
  *
  * Based on the Itemviews NG project from Trolltech Labs
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #include "kitemlistselectionmanager.h"
 
 KItemListSelectionManager::KItemListSelectionManager(QObject *parent)
     : QObject(parent)
     , m_currentItem(-1)
     , m_anchorItem(-1)
     , m_selectedItems()
     , m_isAnchoredSelectionActive(false)
     , m_model(nullptr)
 {
 }
 
 KItemListSelectionManager::~KItemListSelectionManager()
 {
 }
 
 void KItemListSelectionManager::setCurrentItem(int current)
 {
     const int previous = m_currentItem;
     const KItemSet previousSelection = selectedItems();
 
     if (m_model && current >= 0 && current < m_model->count()) {
         m_currentItem = current;
     } else {
         m_currentItem = -1;
     }
 
     if (m_currentItem != previous) {
         Q_EMIT currentChanged(m_currentItem, previous);
 
         if (m_isAnchoredSelectionActive) {
             const KItemSet selection = selectedItems();
             if (selection != previousSelection) {
                 Q_EMIT selectionChanged(selection, previousSelection);
             }
         }
     }
 }
 
 int KItemListSelectionManager::currentItem() const
 {
     return m_currentItem;
 }
 
 void KItemListSelectionManager::setSelectedItems(const KItemSet &items)
 {
     if (m_selectedItems != items) {
         const KItemSet previous = m_selectedItems;
         m_selectedItems = items;
         Q_EMIT selectionChanged(m_selectedItems, previous);
     }
 }
 
 KItemSet KItemListSelectionManager::selectedItems() const
 {
     KItemSet selectedItems = m_selectedItems;
 
     if (m_isAnchoredSelectionActive && m_anchorItem != m_currentItem) {
         Q_ASSERT(m_anchorItem >= 0);
         Q_ASSERT(m_currentItem >= 0);
         const int from = qMin(m_anchorItem, m_currentItem);
         const int to = qMax(m_anchorItem, m_currentItem);
 
         for (int index = from; index <= to; ++index) {
             selectedItems.insert(index);
         }
     }
 
     return selectedItems;
 }
 
 bool KItemListSelectionManager::isSelected(int index) const
 {
     if (m_selectedItems.contains(index)) {
         return true;
     }
 
     if (m_isAnchoredSelectionActive && m_anchorItem != m_currentItem) {
         Q_ASSERT(m_anchorItem >= 0);
         Q_ASSERT(m_currentItem >= 0);
         const int from = qMin(m_anchorItem, m_currentItem);
         const int to = qMax(m_anchorItem, m_currentItem);
 
         if (from <= index && index <= to) {
             return true;
         }
     }
 
     return false;
 }
 
 bool KItemListSelectionManager::hasSelection() const
 {
     return !m_selectedItems.isEmpty() || (m_isAnchoredSelectionActive && m_anchorItem != m_currentItem);
 }
 
 void KItemListSelectionManager::setSelected(int index, int count, SelectionMode mode)
 {
     if (index < 0 || count < 1 || !m_model || index >= m_model->count()) {
         return;
     }
 
     endAnchoredSelection();
     const KItemSet previous = selectedItems();
 
     count = qMin(count, m_model->count() - index);
 
     const int endIndex = index + count - 1;
     switch (mode) {
     case Select:
         for (int i = index; i <= endIndex; ++i) {
             m_selectedItems.insert(i);
         }
         break;
 
     case Deselect:
         for (int i = index; i <= endIndex; ++i) {
             m_selectedItems.remove(i);
         }
         break;
 
     case Toggle:
         for (int i = index; i <= endIndex; ++i) {
             if (m_selectedItems.contains(i)) {
                 m_selectedItems.remove(i);
             } else {
                 m_selectedItems.insert(i);
             }
         }
         break;
 
     default:
         Q_ASSERT(false);
         break;
     }
 
     const KItemSet selection = selectedItems();
     if (selection != previous) {
         Q_EMIT selectionChanged(selection, previous);
     }
 }
 
 void KItemListSelectionManager::clearSelection()
 {
     const KItemSet previous = selectedItems();
     if (!previous.isEmpty()) {
         m_selectedItems.clear();
         m_isAnchoredSelectionActive = false;
         Q_EMIT selectionChanged(KItemSet(), previous);
     }
 }
 
 void KItemListSelectionManager::replaceSelection(int index, int count)
 {
     const KItemSet previous = selectedItems();
     if (!previous.isEmpty()) {
         m_selectedItems.clear();
         m_isAnchoredSelectionActive = false;
     }
     setSelected(index, count);
 }
 
 void KItemListSelectionManager::beginAnchoredSelection(int anchor)
 {
     if (anchor >= 0 && m_model && anchor < m_model->count()) {
         m_isAnchoredSelectionActive = true;
         m_anchorItem = anchor;
     }
 }
 
 void KItemListSelectionManager::endAnchoredSelection()
 {
     if (m_isAnchoredSelectionActive && (m_anchorItem != m_currentItem)) {
         Q_ASSERT(m_anchorItem >= 0);
         Q_ASSERT(m_currentItem >= 0);
         const int from = qMin(m_anchorItem, m_currentItem);
         const int to = qMax(m_anchorItem, m_currentItem);
 
         for (int index = from; index <= to; ++index) {
             m_selectedItems.insert(index);
         }
     }
 
     m_isAnchoredSelectionActive = false;
 }
 
 bool KItemListSelectionManager::isAnchoredSelectionActive() const
 {
     return m_isAnchoredSelectionActive;
 }
 
 KItemModelBase *KItemListSelectionManager::model() const
 {
     return m_model;
 }
 
 void KItemListSelectionManager::setModel(KItemModelBase *model)
 {
     m_model = model;
     if (model && model->count() > 0) {
         m_currentItem = 0;
     }
 }
 
 void KItemListSelectionManager::itemsInserted(const KItemRangeList &itemRanges)
 {
     // Store the current selection (needed in the selectionChanged() signal)
     const KItemSet previousSelection = selectedItems();
 
     // Update the current item
     if (m_currentItem < 0) {
         setCurrentItem(0);
     } else {
         const int previousCurrent = m_currentItem;
         int inc = 0;
         for (const KItemRange &itemRange : itemRanges) {
             if (m_currentItem < itemRange.index) {
                 break;
             }
             inc += itemRange.count;
         }
         // Calling setCurrentItem would trigger the selectionChanged signal, but we want to
         // emit it only once in this function -> change the current item manually and emit currentChanged
         m_currentItem += inc;
         if (m_currentItem >= m_model->count()) {
             m_currentItem = -1;
         }
         Q_EMIT currentChanged(m_currentItem, previousCurrent);
     }
 
     // Update the anchor item
     if (m_anchorItem < 0) {
         m_anchorItem = 0;
     } else {
         int inc = 0;
         for (const KItemRange &itemRange : itemRanges) {
             if (m_anchorItem < itemRange.index) {
                 break;
             }
             inc += itemRange.count;
         }
         m_anchorItem += inc;
     }
 
     // Update the selections
     if (!m_selectedItems.isEmpty()) {
         const KItemSet previous = m_selectedItems;
         m_selectedItems.clear();
 
         for (int index : previous) {
             int inc = 0;
             for (const KItemRange &itemRange : itemRanges) {
                 if (index < itemRange.index) {
                     break;
                 }
                 inc += itemRange.count;
             }
             m_selectedItems.insert(index + inc);
         }
     }
 
     const KItemSet selection = selectedItems();
     if (selection != previousSelection) {
         Q_EMIT selectionChanged(selection, previousSelection);
     }
 }
 
 void KItemListSelectionManager::itemsRemoved(const KItemRangeList &itemRanges)
 {
     // Store the current selection (needed in the selectionChanged() signal)
     const KItemSet previousSelection = selectedItems();
     const int previousCurrent = m_currentItem;
 
     // Update the current item
     m_currentItem = indexAfterRangesRemoving(m_currentItem, itemRanges, DiscardRemovedIndex);
     if (m_currentItem != previousCurrent) {
         Q_EMIT currentChanged(m_currentItem, previousCurrent);
         if (m_currentItem < 0) {
             // Calling setCurrentItem() would trigger the selectionChanged signal, but we want to
             // emit it only once in this function -> change the current item manually and emit currentChanged
             m_currentItem = indexAfterRangesRemoving(previousCurrent, itemRanges, AdjustRemovedIndex);
             Q_EMIT currentChanged(m_currentItem, -1);
         }
     }
 
     // Update the anchor item
     if (m_anchorItem >= 0) {
         m_anchorItem = indexAfterRangesRemoving(m_anchorItem, itemRanges, DiscardRemovedIndex);
         if (m_anchorItem < 0) {
             m_isAnchoredSelectionActive = false;
         }
     }
 
     // Update the selections and the anchor item
     if (!m_selectedItems.isEmpty()) {
         const KItemSet previous = m_selectedItems;
         m_selectedItems.clear();
 
         for (int oldIndex : previous) {
             const int index = indexAfterRangesRemoving(oldIndex, itemRanges, DiscardRemovedIndex);
             if (index >= 0) {
                 m_selectedItems.insert(index);
             }
         }
     }
 
     const KItemSet selection = selectedItems();
     if (selection != previousSelection) {
         Q_EMIT selectionChanged(selection, previousSelection);
     }
 
     Q_ASSERT(m_currentItem < m_model->count());
     Q_ASSERT(m_anchorItem < m_model->count());
 }
 
 void KItemListSelectionManager::itemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes)
 {
     // Store the current selection (needed in the selectionChanged() signal)
     const KItemSet previousSelection = selectedItems();
 
     // Store whether we were doing an anchored selection
     const bool wasInAnchoredSelection = isAnchoredSelectionActive();
 
     // endAnchoredSelection() adds all items between m_currentItem and
     // m_anchorItem to m_selectedItems. They can then be moved
     // individually later in this function.
     endAnchoredSelection();
 
     // Update the current item
     if (m_currentItem >= itemRange.index && m_currentItem < itemRange.index + itemRange.count) {
         const int previousCurrentItem = m_currentItem;
         const int newCurrentItem = movedToIndexes.at(previousCurrentItem - itemRange.index);
 
         // Calling setCurrentItem would trigger the selectionChanged signal, but we want to
         // emit it only once in this function -> change the current item manually and emit currentChanged
         m_currentItem = newCurrentItem;
         Q_EMIT currentChanged(newCurrentItem, previousCurrentItem);
     }
 
     // Start a new anchored selection.
     if (wasInAnchoredSelection) {
         beginAnchoredSelection(m_currentItem);
     }
 
     // Update the selections
     if (!m_selectedItems.isEmpty()) {
         const KItemSet previous = m_selectedItems;
         m_selectedItems.clear();
 
         for (int index : previous) {
             if (index >= itemRange.index && index < itemRange.index + itemRange.count) {
                 m_selectedItems.insert(movedToIndexes.at(index - itemRange.index));
             } else {
                 m_selectedItems.insert(index);
             }
         }
     }
 
     const KItemSet selection = selectedItems();
     if (selection != previousSelection) {
         Q_EMIT selectionChanged(selection, previousSelection);
     }
 }
 
 int KItemListSelectionManager::indexAfterRangesRemoving(int index, const KItemRangeList &itemRanges, const RangesRemovingBehaviour behaviour) const
 {
     int dec = 0;
     for (const KItemRange &itemRange : itemRanges) {
         if (index < itemRange.index) {
             break;
         }
 
         dec += itemRange.count;
 
         const int firstIndexAfterRange = itemRange.index + itemRange.count;
         if (index < firstIndexAfterRange) {
             // The index is part of the removed range
             if (behaviour == DiscardRemovedIndex) {
                 return -1;
             } else {
                 // Use the first item after the range as new index
                 index = firstIndexAfterRange;
                 break;
             }
         }
     }
     return qBound(-1, index - dec, m_model->count() - 1);
 }
 
 #include "moc_kitemlistselectionmanager.cpp"