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  *                                                                         *
   6  *   This program is free software; you can redistribute it and/or modify  *
   7  *   it under the terms of the GNU General Public License as published by  *
   8  *   the Free Software Foundation; either version 2 of the License, or     *
   9  *   (at your option) any later version.                                   *
  10  *                                                                         *
  11  *   This program is distributed in the hope that it will be useful,       *
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  14  *   GNU General Public License for more details.                          *
  15  *                                                                         *
  16  *   You should have received a copy of the GNU General Public License     *
  17  *   along with this program; if not, write to the                         *
  18  *   Free Software Foundation, Inc.,                                       *
  19  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  20  ***************************************************************************/
  21
  22 #ifndef KITEMLISTCONTROLLER_H
  23 #define KITEMLISTCONTROLLER_H
  24
  25 #include "dolphin_export.h"
  26 #include "kitemset.h"
  27
  28 #include <QObject>
  29 #include <QPointF>
  30
  31 class QTimer;
  32 class KItemModelBase;
  33 class KItemListKeyboardSearchManager;
  34 class KItemListSelectionManager;
  35 class KItemListView;
  36 class KItemListWidget;
  37 class QGraphicsSceneHoverEvent;
  38 class QGraphicsSceneDragDropEvent;
  39 class QGraphicsSceneMouseEvent;
  40 class QGraphicsSceneResizeEvent;
  41 class QGraphicsSceneWheelEvent;
  42 class QInputMethodEvent;
  43 class QKeyEvent;
  44 class QTransform;
  45
  46 /**
  47  * @brief Controls the view, model and selection of an item-list.
  48  *
  49  * For a working item-list it is mandatory to set a compatible view and model
  50  * with KItemListController::setView() and KItemListController::setModel().
  51  *
  52  * @see KItemListView
  53  * @see KItemModelBase
  54  * @see KItemListSelectionManager
  55  */
  56 class DOLPHIN_EXPORT KItemListController : public QObject
  57 {
  58     Q_OBJECT
  59     Q_PROPERTY(KItemModelBase* model READ model WRITE setModel)
  60     Q_PROPERTY(KItemListView *view READ view WRITE setView)
  61     Q_PROPERTY(SelectionBehavior selectionBehavior READ selectionBehavior WRITE setSelectionBehavior)
  62     Q_PROPERTY(AutoActivationBehavior autoActivationBehavior READ autoActivationBehavior WRITE setAutoActivationBehavior)
  63     Q_PROPERTY(MouseDoubleClickAction mouseDoubleClickAction READ mouseDoubleClickAction WRITE setMouseDoubleClickAction)
  64
  65 public:
  66     enum SelectionBehavior {
  67         NoSelection,
  68         SingleSelection,
  69         MultiSelection
  70     };
  71     Q_ENUM(SelectionBehavior)
  72
  73     enum AutoActivationBehavior {
  74         ActivationAndExpansion,
  75         ExpansionOnly
  76     };
  77
  78     enum MouseDoubleClickAction {
  79         ActivateAndExpandItem,
  80         ActivateItemOnly
  81     };
  82
  83     /**
  84      * @param model  Model of the controller. The ownership is passed to the controller.
  85      * @param view   View of the controller. The ownership is passed to the controller.
  86      * @param parent Optional parent object.
  87      */
  88     KItemListController(KItemModelBase* model, KItemListView* view, QObject* parent = nullptr);
  89     ~KItemListController() override;
  90
  91     void setModel(KItemModelBase* model);
  92     KItemModelBase* model() const;
  93
  94     void setView(KItemListView* view);
  95     KItemListView* view() const;
  96
  97     KItemListSelectionManager* selectionManager() const;
  98
  99     void setSelectionBehavior(SelectionBehavior behavior);
 100     SelectionBehavior selectionBehavior() const;
 101
 102     void setAutoActivationBehavior(AutoActivationBehavior behavior);
 103     AutoActivationBehavior autoActivationBehavior() const;
 104
 105     void setMouseDoubleClickAction(MouseDoubleClickAction action);
 106     MouseDoubleClickAction mouseDoubleClickAction() const;
 107
 108     int indexCloseToMousePressedPosition() const;
 109
 110     /**
 111      * Sets the delay in milliseconds when dragging an object above an item
 112      * until the item gets activated automatically. A value of -1 indicates
 113      * that no automatic activation will be done at all (= default value).
 114      *
 115      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
 116      * otherwise the automatic activation is not available.
 117      *
 118      * After activating the item the signal itemActivated() will be
 119      * emitted. If the view supports the expanding of items
 120      * (KItemListView::supportsItemExpanding() returns true) and the item
 121      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 122      * of activating the item it gets expanded instead (see
 123      * KItemModelBase::setExpanded()).
 124      */
 125     void setAutoActivationDelay(int delay);
 126     int autoActivationDelay() const;
 127
 128     /**
 129      * If set to true, the signals itemActivated() and itemsActivated() are emitted
 130      * after a single-click of the left mouse button. If set to false (the default),
 131      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
 132      */
 133     void setSingleClickActivationEnforced(bool singleClick);
 134     bool singleClickActivationEnforced() const;
 135
 136     bool processEvent(QEvent* event, const QTransform& transform);
 137
 138 signals:
 139     /**
 140      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 141      * or by pressing Return/Enter.
 142      */
 143     void itemActivated(int index);
 144
 145     /**
 146      * Is emitted if more than one item has been activated by pressing Return/Enter
 147      * when having a selection.
 148      */
 149     void itemsActivated(const KItemSet& indexes);
 150
 151     void itemMiddleClicked(int index);
 152
 153     /**
 154      * Emitted if a context-menu is requested for the item with
 155      * the index \a index. It is assured that the index is valid.
 156      */
 157     void itemContextMenuRequested(int index, const QPointF& pos);
 158
 159     /**
 160      * Emitted if a context-menu is requested for the KItemListView.
 161      */
 162     void viewContextMenuRequested(const QPointF& pos);
 163
 164     /**
 165      * Emitted if a context-menu is requested for the header of the KItemListView.
 166      */
 167     void headerContextMenuRequested(const QPointF& pos);
 168
 169     /**
 170      * Is emitted if the item with the index \p index gets hovered.
 171      */
 172     void itemHovered(int index);
 173
 174     /**
 175      * Is emitted if the item with the index \p index gets unhovered.
 176      * It is assured that the signal itemHovered() for this index
 177      * has been emitted before.
 178      */
 179     void itemUnhovered(int index);
 180
 181     /**
 182      * Is emitted if a mouse-button has been pressed above an item.
 183      * If the index is smaller than 0, the mouse-button has been pressed
 184      * above the viewport.
 185      */
 186     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 187
 188     /**
 189      * Is emitted if a mouse-button has been released above an item.
 190      * It is assured that the signal mouseButtonPressed() has been emitted before.
 191      * If the index is smaller than 0, the mouse-button has been pressed
 192      * above the viewport.
 193      */
 194     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 195
 196     void itemExpansionToggleClicked(int index);
 197
 198     /**
 199      * Is emitted if a drop event is done above the item with the index
 200      * \a index. If \a index is < 0 the drop event is done above an
 201      * empty area of the view.
 202      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 203      *       which is emitted if the drop event occurs on an empty area in
 204      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 205      */
 206     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 207
 208     /**
 209      * Is emitted if a drop event is done between the item with the index
 210      * \a index and the previous item.
 211      */
 212     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 213
 214     /**
 215      * Is emitted if the Escape key is pressed.
 216      */
 217     void escapePressed();
 218
 219     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 220     void viewChanged(KItemListView* current, KItemListView* previous);
 221
 222     void selectedItemTextPressed(int index);
 223
 224 private slots:
 225     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 226
 227     /**
 228      * Is invoked when the rubberband boundaries have been changed and will select
 229      * all items that are touched by the rubberband.
 230      */
 231     void slotRubberBandChanged();
 232
 233     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
 234
 235     void slotAutoActivationTimeout();
 236
 237 private:
 238     /**
 239      * Creates a QDrag object and initiates a drag-operation.
 240      */
 241     void startDragging();
 242
 243     /**
 244      * @return Widget that is currently in the hovered state. 0 is returned
 245      *         if no widget is marked as hovered.
 246      */
 247     KItemListWidget* hoveredWidget() const;
 248
 249     /**
 250      * @return Widget that is below the position \a pos. 0 is returned
 251      *         if no widget is below the position.
 252      */
 253     KItemListWidget* widgetForPos(const QPointF& pos) const;
 254
 255     /**
 256      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 257      * set, it will be adjusted to the current item. If it is set it will be
 258      * checked whether it is still valid, otherwise it will be reset to the
 259      * current item.
 260      */
 261     void updateKeyboardAnchor();
 262
 263     /**
 264      * @return Index for the next row based on \a index.
 265      *         If there is no next row \a index will be returned.
 266      */
 267     int nextRowIndex(int index) const;
 268
 269     /**
 270      * @return Index for the previous row based on  \a index.
 271      *         If there is no previous row \a index will be returned.
 272      */
 273     int previousRowIndex(int index) const;
 274
 275     /**
 276      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 277      * @return The position of the keyboard anchor for the item with the index \a index.
 278      *         If a horizontal scrolling is used the y-position of the item will be returned,
 279      *         for the vertical scrolling the x-position will be returned.
 280      */
 281     qreal keyboardAnchorPos(int index) const;
 282
 283     /**
 284      * Dependent on the selection-behavior the extendedSelectionRegion-property
 285      * of the KItemListStyleOption from the view should be adjusted: If no
 286      * rubberband selection is used the property should be enabled.
 287      */
 288     void updateExtendedSelectionRegion();
 289
 290     bool keyPressEvent(QKeyEvent* event);
 291     bool inputMethodEvent(QInputMethodEvent* event);
 292     bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 293     bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 294     bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 295     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 296     bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 297     bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 298     bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 299     bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 300     bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 301     bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 302     bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 303     bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
 304     bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
 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