src/kitemviews/kitemlistcontroller.h

   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 #ifndef KITEMLISTCONTROLLER_H
  24 #define KITEMLISTCONTROLLER_H
  25
  26 #include <libdolphin_export.h>
  27
  28 #include <QObject>
  29 #include <QPixmap>
  30 #include <QPointF>
  31 #include <QSet>
  32
  33 class KItemModelBase;
  34 class KItemListKeyboardSearchManager;
  35 class KItemListSelectionManager;
  36 class KItemListView;
  37 class KItemListWidget;
  38 class QGraphicsSceneHoverEvent;
  39 class QGraphicsSceneDragDropEvent;
  40 class QGraphicsSceneMouseEvent;
  41 class QGraphicsSceneResizeEvent;
  42 class QGraphicsSceneWheelEvent;
  43 class QHideEvent;
  44 class QInputMethodEvent;
  45 class QKeyEvent;
  46 class QMimeData;
  47 class QShowEvent;
  48 class QTransform;
  49
  50 /**
  51  * @brief Controls the view, model and selection of an item-list.
  52  *
  53  * For a working item-list it is mandatory to set a compatible view and model
  54  * with KItemListController::setView() and KItemListController::setModel().
  55  *
  56  * @see KItemListView
  57  * @see KItemModelBase
  58  * @see KItemListSelectionManager
  59  */
  60 class LIBDOLPHINPRIVATE_EXPORT KItemListController : public QObject
  61 {
  62     Q_OBJECT
  63     Q_ENUMS(SelectionBehavior)
  64     Q_PROPERTY(KItemModelBase* model READ model WRITE setModel)
  65     Q_PROPERTY(KItemListView *view READ view WRITE setView)
  66     Q_PROPERTY(SelectionBehavior selectionBehavior READ selectionBehavior WRITE setSelectionBehavior)
  67
  68 public:
  69     enum SelectionBehavior {
  70         NoSelection,
  71         SingleSelection,
  72         MultiSelection
  73     };
  74
  75     KItemListController(QObject* parent = 0);
  76     virtual ~KItemListController();
  77
  78     void setModel(KItemModelBase* model);
  79     KItemModelBase* model() const;
  80
  81     void setView(KItemListView* view);
  82     KItemListView* view() const;
  83
  84     KItemListSelectionManager* selectionManager() const;
  85
  86     void setSelectionBehavior(SelectionBehavior behavior);
  87     SelectionBehavior selectionBehavior() const;
  88
  89     /**
  90      * Sets the delay in milliseconds when dragging an object above an item
  91      * until the item gets activated automatically. A value of -1 indicates
  92      * that no automatic activation will be done at all (= default value).
  93      *
  94      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
  95      * otherwise the automatic activation is not available.
  96      *
  97      * After activating the item the signal itemActivated() will be
  98      * emitted. If the view supports the expanding of items
  99      * (KItemListView::supportsItemExpanding() returns true) and the item
 100      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 101      * of activating the item it gets expanded instead (see
 102      * KItemModelBase::setExpanded()).
 103      */
 104     void setAutoActivationDelay(int delay);
 105     int autoActivationDelay() const;
 106
 107     virtual bool showEvent(QShowEvent* event);
 108     virtual bool hideEvent(QHideEvent* event);
 109     virtual bool keyPressEvent(QKeyEvent* event);
 110     virtual bool inputMethodEvent(QInputMethodEvent* event);
 111     virtual bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 112     virtual bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 113     virtual bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 114     virtual bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 115     virtual bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 116     virtual bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 117     virtual bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 118     virtual bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 119     virtual bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 120     virtual bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 121     virtual bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 122     virtual bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
 123     virtual bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
 124     virtual bool processEvent(QEvent* event, const QTransform& transform);
 125
 126 signals:
 127     /**
 128      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 129      * or by pressing Return/Enter.
 130      */
 131     void itemActivated(int index);
 132
 133     /**
 134      * Is emitted if more than one item has been activated by pressing Return/Enter
 135      * when having a selection.
 136      */
 137     void itemsActivated(const QSet<int>& indexes);
 138
 139     void itemMiddleClicked(int index);
 140
 141     /**
 142      * Emitted if a context-menu is requested for the item with
 143      * the index \a index. It is assured that the index is valid.
 144      */
 145     void itemContextMenuRequested(int index, const QPointF& pos);
 146
 147     /**
 148      * Emitted if a context-menu is requested for the KItemListView.
 149      */
 150     void viewContextMenuRequested(const QPointF& pos);
 151
 152     /**
 153      * Emitted if a context-menu is requested for the header of the KItemListView.
 154      */
 155     void headerContextMenuRequested(const QPointF& pos);
 156
 157     /**
 158      * Is emitted if the item with the index \p index gets hovered.
 159      */
 160     void itemHovered(int index);
 161
 162     /**
 163      * Is emitted if the item with the index \p index gets unhovered.
 164      * It is assured that the signal itemHovered() for this index
 165      * has been emitted before.
 166      */
 167     void itemUnhovered(int index);
 168
 169     /**
 170      * Is emitted if a mouse-button has been pressed above an item.
 171      */
 172     void itemPressed(int index, Qt::MouseButton button);
 173
 174     /**
 175      * Is emitted if a mouse-button has been released above an item.
 176      * It is assured that the signal itemPressed() has been emitted before.
 177      */
 178     void itemReleased(int index, Qt::MouseButton button);
 179
 180     void itemExpansionToggleClicked(int index);
 181
 182     /**
 183      * Is emitted if a drop event is done above the item with the index
 184      * \a index. If \a index is < 0 the drop event is done above an
 185      * empty area of the view.
 186      */
 187     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 188
 189     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 190     void viewChanged(KItemListView* current, KItemListView* previous);
 191
 192 private slots:
 193     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 194
 195     /**
 196      * Is invoked when the rubberband boundaries have been changed and will select
 197      * all items that are touched by the rubberband.
 198      */
 199     void slotRubberBandChanged();
 200
 201     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
 202
 203     void slotAutoActivationTimeout();
 204
 205 private:
 206     /**
 207      * Creates a QDrag object and initiates a drag-operation.
 208      */
 209     void startDragging();
 210
 211     /**
 212      * @return Widget that is currently in the hovered state. 0 is returned
 213      *         if no widget is marked as hovered.
 214      */
 215     KItemListWidget* hoveredWidget() const;
 216
 217     /**
 218      * @return Widget that is below the position \a pos. 0 is returned
 219      *         if no widget is below the position.
 220      */
 221     KItemListWidget* widgetForPos(const QPointF& pos) const;
 222
 223     /**
 224      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 225      * set, it will be adjusted to the current item. If it is set it will be
 226      * checked whether it is still valid, otherwise it will be reset to the
 227      * current item.
 228      */
 229     void updateKeyboardAnchor();
 230
 231     /**
 232      * @return Index for the next row based on the current index.
 233      *         If there is no next row the current index will be returned.
 234      */
 235     int nextRowIndex() const;
 236
 237     /**
 238      * @return Index for the previous row based on the current index.
 239      *         If there is no previous row the current index will be returned.
 240      */
 241     int previousRowIndex() const;
 242
 243     /**
 244      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 245      * @return The position of the keyboard anchor for the item with the index \a index.
 246      *         If a horizontal scrolling is used the y-position of the item will be returned,
 247      *         for the vertical scrolling the x-position will be returned.
 248      */
 249     qreal keyboardAnchorPos(int index) const;
 250
 251 private:
 252     bool m_selectionTogglePressed;
 253     SelectionBehavior m_selectionBehavior;
 254     KItemModelBase* m_model;
 255     KItemListView* m_view;
 256     KItemListSelectionManager* m_selectionManager;
 257     KItemListKeyboardSearchManager* m_keyboardManager;
 258     int m_pressedIndex;
 259     QPointF m_pressedMousePos;
 260
 261     QTimer* m_autoActivationTimer;
 262
 263     /**
 264      * When starting a rubberband selection during a Shift- or Control-key has been
 265      * pressed the current selection should never be deleted. To be able to restore
 266      * the current selection it is remembered in m_oldSelection before the
 267      * rubberband gets activated.
 268      */
 269     QSet<int> m_oldSelection;
 270
 271     /**
 272      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 273      * a maximum of 4 columns:
 274      *
 275      *  1  2  3  4
 276      *  5  6  7
 277      *  8  9 10 11
 278      * 12 13 14
 279      *
 280      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 281      * item. Now when pressing key-down again item 11 should get the current item and not
 282      * item 10. This makes it necessary to keep track of the requested column to have a
 283      * similar behavior like in a text editor:
 284      */
 285     int m_keyboardAnchorIndex;
 286     qreal m_keyboardAnchorXPos;
 287 };
 288
 289 #endif
 290
 291