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