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 "dolphin_export.h"
  27 #include "kitemset.h"
  28
  29 #include <QObject>
  30 #include <QPointF>
  31
  32 class QTimer;
  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 QInputMethodEvent;
  44 class QKeyEvent;
  45 class QTransform;
  46
  47 /**
  48  * @brief Controls the view, model and selection of an item-list.
  49  *
  50  * For a working item-list it is mandatory to set a compatible view and model
  51  * with KItemListController::setView() and KItemListController::setModel().
  52  *
  53  * @see KItemListView
  54  * @see KItemModelBase
  55  * @see KItemListSelectionManager
  56  */
  57 class DOLPHIN_EXPORT KItemListController : public QObject
  58 {
  59     Q_OBJECT
  60     Q_PROPERTY(KItemModelBase* model READ model WRITE setModel)
  61     Q_PROPERTY(KItemListView *view READ view WRITE setView)
  62     Q_PROPERTY(SelectionBehavior selectionBehavior READ selectionBehavior WRITE setSelectionBehavior)
  63     Q_PROPERTY(AutoActivationBehavior autoActivationBehavior READ autoActivationBehavior WRITE setAutoActivationBehavior)
  64     Q_PROPERTY(MouseDoubleClickAction mouseDoubleClickAction READ mouseDoubleClickAction WRITE setMouseDoubleClickAction)
  65
  66 public:
  67     enum SelectionBehavior {
  68         NoSelection,
  69         SingleSelection,
  70         MultiSelection
  71     };
  72     Q_ENUM(SelectionBehavior)
  73
  74     enum AutoActivationBehavior {
  75         ActivationAndExpansion,
  76         ExpansionOnly
  77     };
  78
  79     enum MouseDoubleClickAction {
  80         ActivateAndExpandItem,
  81         ActivateItemOnly
  82     };
  83
  84     /**
  85      * @param model  Model of the controller. The ownership is passed to the controller.
  86      * @param view   View of the controller. The ownership is passed to the controller.
  87      * @param parent Optional parent object.
  88      */
  89     KItemListController(KItemModelBase* model, KItemListView* view, QObject* parent = nullptr);
  90     ~KItemListController() override;
  91
  92     void setModel(KItemModelBase* model);
  93     KItemModelBase* model() const;
  94
  95     void setView(KItemListView* view);
  96     KItemListView* view() const;
  97
  98     KItemListSelectionManager* selectionManager() const;
  99
 100     void setSelectionBehavior(SelectionBehavior behavior);
 101     SelectionBehavior selectionBehavior() const;
 102
 103     void setAutoActivationBehavior(AutoActivationBehavior behavior);
 104     AutoActivationBehavior autoActivationBehavior() const;
 105
 106     void setMouseDoubleClickAction(MouseDoubleClickAction action);
 107     MouseDoubleClickAction mouseDoubleClickAction() const;
 108
 109     int indexCloseToMousePressedPosition() const;
 110
 111     /**
 112      * Sets the delay in milliseconds when dragging an object above an item
 113      * until the item gets activated automatically. A value of -1 indicates
 114      * that no automatic activation will be done at all (= default value).
 115      *
 116      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
 117      * otherwise the automatic activation is not available.
 118      *
 119      * After activating the item the signal itemActivated() will be
 120      * emitted. If the view supports the expanding of items
 121      * (KItemListView::supportsItemExpanding() returns true) and the item
 122      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 123      * of activating the item it gets expanded instead (see
 124      * KItemModelBase::setExpanded()).
 125      */
 126     void setAutoActivationDelay(int delay);
 127     int autoActivationDelay() const;
 128
 129     /**
 130      * If set to true, the signals itemActivated() and itemsActivated() are emitted
 131      * after a single-click of the left mouse button. If set to false (the default),
 132      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
 133      */
 134     void setSingleClickActivationEnforced(bool singleClick);
 135     bool singleClickActivationEnforced() const;
 136
 137     virtual bool keyPressEvent(QKeyEvent* event);
 138     virtual bool inputMethodEvent(QInputMethodEvent* event);
 139     virtual bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 140     virtual bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 141     virtual bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 142     virtual bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 143     virtual bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 144     virtual bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 145     virtual bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 146     virtual bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 147     virtual bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 148     virtual bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 149     virtual bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 150     virtual bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
 151     virtual bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
 152     virtual bool processEvent(QEvent* event, const QTransform& transform);
 153
 154 signals:
 155     /**
 156      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 157      * or by pressing Return/Enter.
 158      */
 159     void itemActivated(int index);
 160
 161     /**
 162      * Is emitted if more than one item has been activated by pressing Return/Enter
 163      * when having a selection.
 164      */
 165     void itemsActivated(const KItemSet& indexes);
 166
 167     void itemMiddleClicked(int index);
 168
 169     /**
 170      * Emitted if a context-menu is requested for the item with
 171      * the index \a index. It is assured that the index is valid.
 172      */
 173     void itemContextMenuRequested(int index, const QPointF& pos);
 174
 175     /**
 176      * Emitted if a context-menu is requested for the KItemListView.
 177      */
 178     void viewContextMenuRequested(const QPointF& pos);
 179
 180     /**
 181      * Emitted if a context-menu is requested for the header of the KItemListView.
 182      */
 183     void headerContextMenuRequested(const QPointF& pos);
 184
 185     /**
 186      * Is emitted if the item with the index \p index gets hovered.
 187      */
 188     void itemHovered(int index);
 189
 190     /**
 191      * Is emitted if the item with the index \p index gets unhovered.
 192      * It is assured that the signal itemHovered() for this index
 193      * has been emitted before.
 194      */
 195     void itemUnhovered(int index);
 196
 197     /**
 198      * Is emitted if a mouse-button has been pressed above an item.
 199      * If the index is smaller than 0, the mouse-button has been pressed
 200      * above the viewport.
 201      */
 202     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 203
 204     /**
 205      * Is emitted if a mouse-button has been released above an item.
 206      * It is assured that the signal mouseButtonPressed() has been emitted before.
 207      * If the index is smaller than 0, the mouse-button has been pressed
 208      * above the viewport.
 209      */
 210     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 211
 212     void itemExpansionToggleClicked(int index);
 213
 214     /**
 215      * Is emitted if a drop event is done above the item with the index
 216      * \a index. If \a index is < 0 the drop event is done above an
 217      * empty area of the view.
 218      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 219      *       which is emitted if the drop event occurs on an empty area in
 220      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 221      */
 222     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 223
 224     /**
 225      * Is emitted if a drop event is done between the item with the index
 226      * \a index and the previous item.
 227      */
 228     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 229
 230     /**
 231      * Is emitted if the Escape key is pressed.
 232      */
 233     void escapePressed();
 234
 235     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 236     void viewChanged(KItemListView* current, KItemListView* previous);
 237
 238     void selectedItemTextPressed(int index);
 239
 240 private slots:
 241     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 242
 243     /**
 244      * Is invoked when the rubberband boundaries have been changed and will select
 245      * all items that are touched by the rubberband.
 246      */
 247     void slotRubberBandChanged();
 248
 249     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
 250
 251     void slotAutoActivationTimeout();
 252
 253 private:
 254     /**
 255      * Creates a QDrag object and initiates a drag-operation.
 256      */
 257     void startDragging();
 258
 259     /**
 260      * @return Widget that is currently in the hovered state. 0 is returned
 261      *         if no widget is marked as hovered.
 262      */
 263     KItemListWidget* hoveredWidget() const;
 264
 265     /**
 266      * @return Widget that is below the position \a pos. 0 is returned
 267      *         if no widget is below the position.
 268      */
 269     KItemListWidget* widgetForPos(const QPointF& pos) const;
 270
 271     /**
 272      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 273      * set, it will be adjusted to the current item. If it is set it will be
 274      * checked whether it is still valid, otherwise it will be reset to the
 275      * current item.
 276      */
 277     void updateKeyboardAnchor();
 278
 279     /**
 280      * @return Index for the next row based on \a index.
 281      *         If there is no next row \a index will be returned.
 282      */
 283     int nextRowIndex(int index) const;
 284
 285     /**
 286      * @return Index for the previous row based on  \a index.
 287      *         If there is no previous row \a index will be returned.
 288      */
 289     int previousRowIndex(int index) const;
 290
 291     /**
 292      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 293      * @return The position of the keyboard anchor for the item with the index \a index.
 294      *         If a horizontal scrolling is used the y-position of the item will be returned,
 295      *         for the vertical scrolling the x-position will be returned.
 296      */
 297     qreal keyboardAnchorPos(int index) const;
 298
 299     /**
 300      * Dependent on the selection-behavior the extendedSelectionRegion-property
 301      * of the KItemListStyleOption from the view should be adjusted: If no
 302      * rubberband selection is used the property should be enabled.
 303      */
 304     void updateExtendedSelectionRegion();
 305
 306 private:
 307     bool m_singleClickActivationEnforced;
 308     bool m_selectionTogglePressed;
 309     bool m_clearSelectionIfItemsAreNotDragged;
 310     SelectionBehavior m_selectionBehavior;
 311     AutoActivationBehavior m_autoActivationBehavior;
 312     MouseDoubleClickAction m_mouseDoubleClickAction;
 313     KItemModelBase* m_model;
 314     KItemListView* m_view;
 315     KItemListSelectionManager* m_selectionManager;
 316     KItemListKeyboardSearchManager* m_keyboardManager;
 317     int m_pressedIndex;
 318     QPointF m_pressedMousePos;
 319
 320     QTimer* m_autoActivationTimer;
 321
 322     /**
 323      * When starting a rubberband selection during a Shift- or Control-key has been
 324      * pressed the current selection should never be deleted. To be able to restore
 325      * the current selection it is remembered in m_oldSelection before the
 326      * rubberband gets activated.
 327      */
 328     KItemSet m_oldSelection;
 329
 330     /**
 331      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 332      * a maximum of 4 columns:
 333      *
 334      *  1  2  3  4
 335      *  5  6  7
 336      *  8  9 10 11
 337      * 12 13 14
 338      *
 339      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 340      * item. Now when pressing key-down again item 11 should get the current item and not
 341      * item 10. This makes it necessary to keep track of the requested column to have a
 342      * similar behavior like in a text editor:
 343      */
 344     int m_keyboardAnchorIndex;
 345     qreal m_keyboardAnchorPos;
 346 };
 347
 348 #endif
 349
 350