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     Q_PROPERTY(AutoActivationBehavior autoActivationBehavior READ autoActivationBehavior WRITE setAutoActivationBehavior)
  68     Q_PROPERTY(MouseDoubleClickAction mouseDoubleClickAction READ mouseDoubleClickAction WRITE setMouseDoubleClickAction)
  69
  70 public:
  71     enum SelectionBehavior {
  72         NoSelection,
  73         SingleSelection,
  74         MultiSelection
  75     };
  76
  77     enum AutoActivationBehavior {
  78         ActivationAndExpansion,
  79         ExpansionOnly
  80     };
  81
  82     enum MouseDoubleClickAction {
  83         ActivateAndExpandItem,
  84         ActivateItemOnly
  85     };
  86
  87     /**
  88      * @param model  Model of the controller. The ownership is passed to the controller.
  89      * @param view   View of the controller. The ownership is passed to the controller.
  90      * @param parent Optional parent object.
  91      */
  92     KItemListController(KItemModelBase* model, KItemListView* view, QObject* parent = 0);
  93     virtual ~KItemListController();
  94
  95     void setModel(KItemModelBase* model);
  96     KItemModelBase* model() const;
  97
  98     void setView(KItemListView* view);
  99     KItemListView* view() const;
 100
 101     KItemListSelectionManager* selectionManager() const;
 102
 103     void setSelectionBehavior(SelectionBehavior behavior);
 104     SelectionBehavior selectionBehavior() const;
 105
 106     void setAutoActivationBehavior(AutoActivationBehavior behavior);
 107     AutoActivationBehavior autoActivationBehavior() const;
 108
 109     void setMouseDoubleClickAction(MouseDoubleClickAction action);
 110     MouseDoubleClickAction mouseDoubleClickAction() const;
 111
 112     /**
 113      * Sets the delay in milliseconds when dragging an object above an item
 114      * until the item gets activated automatically. A value of -1 indicates
 115      * that no automatic activation will be done at all (= default value).
 116      *
 117      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
 118      * otherwise the automatic activation is not available.
 119      *
 120      * After activating the item the signal itemActivated() will be
 121      * emitted. If the view supports the expanding of items
 122      * (KItemListView::supportsItemExpanding() returns true) and the item
 123      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 124      * of activating the item it gets expanded instead (see
 125      * KItemModelBase::setExpanded()).
 126      */
 127     void setAutoActivationDelay(int delay);
 128     int autoActivationDelay() const;
 129
 130     /**
 131      * If set to true, the signals itemActivated() and itemsActivated() are emitted
 132      * after a single-click of the left mouse button. If set to false, a double-click
 133      * is required. Per default the setting from KGlobalSettings::singleClick() is
 134      * used.
 135      */
 136     void setSingleClickActivation(bool singleClick);
 137     bool singleClickActivation() const;
 138
 139     virtual bool showEvent(QShowEvent* event);
 140     virtual bool hideEvent(QHideEvent* event);
 141     virtual bool keyPressEvent(QKeyEvent* event);
 142     virtual bool inputMethodEvent(QInputMethodEvent* event);
 143     virtual bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 144     virtual bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 145     virtual bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 146     virtual bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 147     virtual bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 148     virtual bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 149     virtual bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 150     virtual bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 151     virtual bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 152     virtual bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 153     virtual bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 154     virtual bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
 155     virtual bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
 156     virtual bool processEvent(QEvent* event, const QTransform& transform);
 157
 158 signals:
 159     /**
 160      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 161      * or by pressing Return/Enter.
 162      */
 163     void itemActivated(int index);
 164
 165     /**
 166      * Is emitted if more than one item has been activated by pressing Return/Enter
 167      * when having a selection.
 168      */
 169     void itemsActivated(const QSet<int>& indexes);
 170
 171     void itemMiddleClicked(int index);
 172
 173     /**
 174      * Emitted if a context-menu is requested for the item with
 175      * the index \a index. It is assured that the index is valid.
 176      */
 177     void itemContextMenuRequested(int index, const QPointF& pos);
 178
 179     /**
 180      * Emitted if a context-menu is requested for the KItemListView.
 181      */
 182     void viewContextMenuRequested(const QPointF& pos);
 183
 184     /**
 185      * Emitted if a context-menu is requested for the header of the KItemListView.
 186      */
 187     void headerContextMenuRequested(const QPointF& pos);
 188
 189     /**
 190      * Is emitted if the item with the index \p index gets hovered.
 191      */
 192     void itemHovered(int index);
 193
 194     /**
 195      * Is emitted if the item with the index \p index gets unhovered.
 196      * It is assured that the signal itemHovered() for this index
 197      * has been emitted before.
 198      */
 199     void itemUnhovered(int index);
 200
 201     /**
 202      * Is emitted if a mouse-button has been pressed above an item.
 203      * If the index is smaller than 0, the mouse-button has been pressed
 204      * above the viewport.
 205      */
 206     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 207
 208     /**
 209      * Is emitted if a mouse-button has been released above an item.
 210      * It is assured that the signal mouseButtonPressed() has been emitted before.
 211      * If the index is smaller than 0, the mouse-button has been pressed
 212      * above the viewport.
 213      */
 214     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 215
 216     void itemExpansionToggleClicked(int index);
 217
 218     /**
 219      * Is emitted if a drop event is done above the item with the index
 220      * \a index. If \a index is < 0 the drop event is done above an
 221      * empty area of the view.
 222      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 223      *       which is emitted if the drop event occurs on an empty area in
 224      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 225      */
 226     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 227
 228     /**
 229      * Is emitted if a drop event is done between the item with the index
 230      * \a index and the previous item.
 231      */
 232     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 233
 234     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 235     void viewChanged(KItemListView* current, KItemListView* previous);
 236
 237 private slots:
 238     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 239
 240     /**
 241      * Is invoked when the rubberband boundaries have been changed and will select
 242      * all items that are touched by the rubberband.
 243      */
 244     void slotRubberBandChanged();
 245
 246     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
 247
 248     void slotAutoActivationTimeout();
 249
 250 private:
 251     /**
 252      * Creates a QDrag object and initiates a drag-operation.
 253      */
 254     void startDragging();
 255
 256     /**
 257      * @return Widget that is currently in the hovered state. 0 is returned
 258      *         if no widget is marked as hovered.
 259      */
 260     KItemListWidget* hoveredWidget() const;
 261
 262     /**
 263      * @return Widget that is below the position \a pos. 0 is returned
 264      *         if no widget is below the position.
 265      */
 266     KItemListWidget* widgetForPos(const QPointF& pos) const;
 267
 268     /**
 269      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 270      * set, it will be adjusted to the current item. If it is set it will be
 271      * checked whether it is still valid, otherwise it will be reset to the
 272      * current item.
 273      */
 274     void updateKeyboardAnchor();
 275
 276     /**
 277      * @return Index for the next row based on \a index.
 278      *         If there is no next row \a index will be returned.
 279      */
 280     int nextRowIndex(int index) const;
 281
 282     /**
 283      * @return Index for the previous row based on  \a index.
 284      *         If there is no previous row \a index will be returned.
 285      */
 286     int previousRowIndex(int index) const;
 287
 288     /**
 289      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 290      * @return The position of the keyboard anchor for the item with the index \a index.
 291      *         If a horizontal scrolling is used the y-position of the item will be returned,
 292      *         for the vertical scrolling the x-position will be returned.
 293      */
 294     qreal keyboardAnchorPos(int index) const;
 295
 296     /**
 297      * Dependent on the selection-behavior the extendedSelectionRegion-property
 298      * of the KItemListStyleOption from the view should be adjusted: If no
 299      * rubberband selection is used the property should be enabled.
 300      */
 301     void updateExtendedSelectionRegion();
 302
 303 private:
 304     bool m_singleClickActivation;
 305     bool m_selectionTogglePressed;
 306     bool m_clearSelectionIfItemsAreNotDragged;
 307     SelectionBehavior m_selectionBehavior;
 308     AutoActivationBehavior m_autoActivationBehavior;
 309     MouseDoubleClickAction m_mouseDoubleClickAction;
 310     KItemModelBase* m_model;
 311     KItemListView* m_view;
 312     KItemListSelectionManager* m_selectionManager;
 313     KItemListKeyboardSearchManager* m_keyboardManager;
 314     int m_pressedIndex;
 315     QPointF m_pressedMousePos;
 316
 317     QTimer* m_autoActivationTimer;
 318
 319     /**
 320      * When starting a rubberband selection during a Shift- or Control-key has been
 321      * pressed the current selection should never be deleted. To be able to restore
 322      * the current selection it is remembered in m_oldSelection before the
 323      * rubberband gets activated.
 324      */
 325     QSet<int> m_oldSelection;
 326
 327     /**
 328      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 329      * a maximum of 4 columns:
 330      *
 331      *  1  2  3  4
 332      *  5  6  7
 333      *  8  9 10 11
 334      * 12 13 14
 335      *
 336      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 337      * item. Now when pressing key-down again item 11 should get the current item and not
 338      * item 10. This makes it necessary to keep track of the requested column to have a
 339      * similar behavior like in a text editor:
 340      */
 341     int m_keyboardAnchorIndex;
 342     qreal m_keyboardAnchorPos;
 343 };
 344
 345 #endif
 346
 347