File indexing completed on 2024-04-28 05:45:10

 /*
  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
  *
  * Based on the Itemviews NG project from Trolltech Labs
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #ifndef KITEMMODELBASE_H
 #define KITEMMODELBASE_H
 
 #include "dolphin_export.h"
 #include "kitemviews/kitemrange.h"
 #include "kitemviews/kitemset.h"
 
 #include <QHash>
 #include <QObject>
 #include <QUrl>
 #include <QVariant>
 
 class QMimeData;
 
 /**
  * @brief Base class for model implementations used by KItemListView and KItemListController.
  *
  * An item-model consists of a variable number of items. The number of items
  * is given by KItemModelBase::count(). The data of an item is accessed by a unique index
  * with KItemModelBase::data(). The indexes are integer-values counting from 0 to the
  * KItemModelBase::count() - 1.
  *
  * One item consists of a variable number of role/value-pairs.
  *
  * A model can optionally provide sorting- and grouping-capabilities.
  *
  * Also optionally it is possible to provide a tree of items by implementing the methods
  * setExpanded(), isExpanded(), isExpandable() and expandedParentsCount().
  */
 class DOLPHIN_EXPORT KItemModelBase : public QObject
 {
     Q_OBJECT
 
 public:
     explicit KItemModelBase(QObject *parent = nullptr);
     explicit KItemModelBase(const QByteArray &sortRole, QObject *parent = nullptr);
     ~KItemModelBase() override;
 
     /** @return The number of items. */
     virtual int count() const = 0;
 
     virtual QHash<QByteArray, QVariant> data(int index) const = 0;
 
     /**
      * Sets the data for the item at \a index to the given \a values. Returns true
      * if the data was set on the item; returns false otherwise.
      *
      * The default implementation does not set the data, and will always return
      * false.
      */
     virtual bool setData(int index, const QHash<QByteArray, QVariant> &values);
 
     /**
      * Enables/disables the grouped sorting. The method KItemModelBase::onGroupedSortingChanged() will be
      * called so that model-implementations can react on the grouped-sorting change. Afterwards the
      * signal groupedSortingChanged() will be emitted. If the grouped sorting is enabled, the method
      * KItemModelBase::groups() must be implemented.
      */
     void setGroupedSorting(bool grouped);
     bool groupedSorting() const;
 
     /**
      * Sets the sort-role to \a role. The method KItemModelBase::onSortRoleChanged() will be
      * called so that model-implementations can react on the sort-role change. Afterwards the
      * signal sortRoleChanged() will be emitted.
      * The implementation should resort only if \a resortItems is true.
      */
     void setSortRole(const QByteArray &role, bool resortItems = true);
     QByteArray sortRole() const;
 
     /**
      * Sets the sort order to \a order. The method KItemModelBase::onSortOrderChanged() will be
      * called so that model-implementations can react on the sort order change. Afterwards the
      * signal sortOrderChanged() will be emitted.
      */
     void setSortOrder(Qt::SortOrder order);
     Qt::SortOrder sortOrder() const;
 
     /**
      * @return Translated description for the \p role. The description is e.g. used
      *         for the header in KItemListView.
      */
     virtual QString roleDescription(const QByteArray &role) const;
 
     /**
      * @return List of group headers. Each list-item consists of the index of the item
      *         that represents the first item of a group and a value represented
      *         as QVariant. The value is shown by an instance of KItemListGroupHeader.
      *         Per default an empty list is returned.
      */
     virtual QList<QPair<int, QVariant>> groups() const;
 
     /**
      * Expands the item with the index \a index if \a expanded is true.
      * If \a expanded is false the item will be collapsed.
      *
      * Per default no expanding of items is implemented. When implementing
      * this method it is mandatory to overwrite KItemModelBase::isExpandable()
      * and KItemListView::supportsExpandableItems() to return true.
      *
      * @return True if the operation has been successful.
      */
     virtual bool setExpanded(int index, bool expanded);
 
     /**
      * @return True if the item with the index \a index is expanded.
      *         Per default no expanding of items is implemented. When implementing
      *         this method it is mandatory to overwrite KItemModelBase::isExpandable()
      *         and KItemListView::supportsExpandableItems() to return true.
      */
     virtual bool isExpanded(int index) const;
 
     /**
      * @return True if expanding and collapsing of the item with the index \a index
      *         is supported. Per default false is returned.
      */
     virtual bool isExpandable(int index) const;
 
     /**
      * @return Number of expanded parent items for the item with the given index.
      *         Per default 0 is returned.
      */
     virtual int expandedParentsCount(int index) const;
 
     /**
      * @return MIME-data for the items given by \a indexes. The default implementation
      *         returns 0. The ownership of the returned instance is in the hand of the
      *         caller of this method. The method must be implemented if dragging of
      *         items should be possible.
      */
     virtual QMimeData *createMimeData(const KItemSet &indexes) const;
 
     /**
      * @return Reimplement this to return the index for the first item
      * beginning with string typed in through the keyboard, -1 if not found.
      * @param text              the text which has been typed in through the keyboard
      * @param startFromIndex    the index from which to start searching from
      */
     virtual int indexForKeyboardSearch(const QString &text, int startFromIndex = 0) const;
 
     /**
      * @return True, if the item with the index \a index basically supports dropping.
      *         Per default false is returned.
      *
      *         The information is used only to give a visual feedback during a drag operation
      *         and not to decide whether a drop event gets emitted. It is it is still up to
      *         the receiver of KItemListController::itemDropEvent() to decide how to handle
      *         the drop event.
      */
     // TODO: Should the MIME-data be passed too so that the model can do a more specific
     // decision whether it accepts the drop?
     virtual bool supportsDropping(int index) const;
 
     /**
      * @return An internal mimetype to signal that an itemDropEvent() should be rejected by
      *         the receiving model.
      *
      *         This mimeType can be used in createMimeData() to notify that the
      *         drop-onto-items events should be ignored, while the drop-between-items
      *         ones should be still accepted.
      */
     QString blacklistItemDropEventMimeType() const;
 
     /**
      * @return URL of the item at the specified index
      */
     virtual QUrl url(int index) const;
 
     /**
      * @return True, if item at specified index is a directory
      */
     virtual bool isDir(int index) const;
 
     /**
      * @return Parent directory of the items that are shown
      */
     virtual QUrl directory() const;
 Q_SIGNALS:
     /**
      * Is emitted if one or more items have been inserted. Each item-range consists
      * of:
      * - an index where items have been inserted
      * - the number of inserted items.
      * The index of each item-range represents the index of the model
      * before the items have been inserted.
      *
      * For the item-ranges it is assured that:
      * - They don't overlap
      * - The index of item-range n is smaller than the index of item-range n + 1.
      */
     void itemsInserted(const KItemRangeList &itemRanges);
 
     /**
      * Is emitted if one or more items have been removed. Each item-range consists
      * of:
      * - an index where items have been inserted
      * - the number of inserted items.
      * The index of each item-range represents the index of the model
      * before the items have been removed.
      *
      * For the item-ranges it is assured that:
      * - They don't overlap
      * - The index of item-range n is smaller than the index of item-range n + 1.
      */
     void itemsRemoved(const KItemRangeList &itemRanges);
 
     /**
      * Is emitted if one ore more items get moved.
      * @param itemRange      Item-range that gets moved to a new position.
      * @param movedToIndexes New positions for each element of the item-range.
      *
      * For example if the model has 10 items and the items 0 and 1 get exchanged
      * with the items 5 and 6 then the parameters look like this:
      * - itemRange: has the index 0 and a count of 7.
      * - movedToIndexes: Contains the seven values 5, 6, 2, 3, 4, 0, 1
      *
      * This signal implies that the groups might have changed. Therefore,
      * gropusChanged() is not emitted if this signal is emitted.
      */
     void itemsMoved(const KItemRange &itemRange, const QList<int> &movedToIndexes);
 
     void itemsChanged(const KItemRangeList &itemRanges, const QSet<QByteArray> &roles);
 
     /**
      * Is emitted if the groups have changed, even though the order of the
      * items has not been modified.
      */
     void groupsChanged();
 
     void groupedSortingChanged(bool current);
     void sortRoleChanged(const QByteArray &current, const QByteArray &previous);
     void sortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 
 protected:
     /**
      * Is invoked if the grouped sorting has been changed by KItemModelBase::setGroupedSorting(). Allows
      * to react on the changed grouped sorting  before the signal groupedSortingChanged() will be emitted.
      */
     virtual void onGroupedSortingChanged(bool current);
 
     /**
      * Is invoked if the sort role has been changed by KItemModelBase::setSortRole(). Allows
      * to react on the changed sort role before the signal sortRoleChanged() will be emitted.
      * The implementation must assure that the items are sorted by the role given by \a current.
      * Usually the most efficient way is to emit a
      * itemsRemoved() signal for all items, reorder the items internally and to emit a
      * itemsInserted() signal afterwards.
      * The implementation should resort only if \a resortItems is true.
      */
     virtual void onSortRoleChanged(const QByteArray &current, const QByteArray &previous, bool resortItems = true);
 
     /**
      * Is invoked if the sort order has been changed by KItemModelBase::setSortOrder(). Allows
      * to react on the changed sort order before the signal sortOrderChanged() will be emitted.
      * The implementation must assure that the items are sorted by the order given by \a current.
      * Usually the most efficient way is to emit a
      * itemsRemoved() signal for all items, reorder the items internally and to emit a
      * itemsInserted() signal afterwards.
      */
     virtual void onSortOrderChanged(Qt::SortOrder current, Qt::SortOrder previous);
 
 private:
     bool m_groupedSorting;
     QByteArray m_sortRole;
     Qt::SortOrder m_sortOrder;
 };
 
 inline Qt::SortOrder KItemModelBase::sortOrder() const
 {
     return m_sortOrder;
 }
 
 #endif