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     bool processEvent(QEvent* event, const QTransform& transform);
 138
 139 signals:
 140     /**
 141      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 142      * or by pressing Return/Enter.
 143      */
 144     void itemActivated(int index);
 145
 146     /**
 147      * Is emitted if more than one item has been activated by pressing Return/Enter
 148      * when having a selection.
 149      */
 150     void itemsActivated(const KItemSet& indexes);
 151
 152     void itemMiddleClicked(int index);
 153
 154     /**
 155      * Emitted if a context-menu is requested for the item with
 156      * the index \a index. It is assured that the index is valid.
 157      */
 158     void itemContextMenuRequested(int index, const QPointF& pos);
 159
 160     /**
 161      * Emitted if a context-menu is requested for the KItemListView.
 162      */
 163     void viewContextMenuRequested(const QPointF& pos);
 164
 165     /**
 166      * Emitted if a context-menu is requested for the header of the KItemListView.
 167      */
 168     void headerContextMenuRequested(const QPointF& pos);
 169
 170     /**
 171      * Is emitted if the item with the index \p index gets hovered.
 172      */
 173     void itemHovered(int index);
 174
 175     /**
 176      * Is emitted if the item with the index \p index gets unhovered.
 177      * It is assured that the signal itemHovered() for this index
 178      * has been emitted before.
 179      */
 180     void itemUnhovered(int index);
 181
 182     /**
 183      * Is emitted if a mouse-button has been pressed above an item.
 184      * If the index is smaller than 0, the mouse-button has been pressed
 185      * above the viewport.
 186      */
 187     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 188
 189     /**
 190      * Is emitted if a mouse-button has been released above an item.
 191      * It is assured that the signal mouseButtonPressed() has been emitted before.
 192      * If the index is smaller than 0, the mouse-button has been pressed
 193      * above the viewport.
 194      */
 195     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 196
 197     void itemExpansionToggleClicked(int index);
 198
 199     /**
 200      * Is emitted if a drop event is done above the item with the index
 201      * \a index. If \a index is < 0 the drop event is done above an
 202      * empty area of the view.
 203      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 204      *       which is emitted if the drop event occurs on an empty area in
 205      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 206      */
 207     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 208
 209     /**
 210      * Is emitted if a drop event is done between the item with the index
 211      * \a index and the previous item.
 212      */
 213     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 214
 215     /**
 216      * Is emitted if the Escape key is pressed.
 217      */
 218     void escapePressed();
 219
 220     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 221     void viewChanged(KItemListView* current, KItemListView* previous);
 222
 223     void selectedItemTextPressed(int index);
 224
 225 private slots:
 226     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 227
 228     /**
 229      * Is invoked when the rubberband boundaries have been changed and will select
 230      * all items that are touched by the rubberband.
 231      */
 232     void slotRubberBandChanged();
 233
 234     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
 235
 236     void slotAutoActivationTimeout();
 237
 238 private:
 239     /**
 240      * Creates a QDrag object and initiates a drag-operation.
 241      */
 242     void startDragging();
 243
 244     /**
 245      * @return Widget that is currently in the hovered state. 0 is returned
 246      *         if no widget is marked as hovered.
 247      */
 248     KItemListWidget* hoveredWidget() const;
 249
 250     /**
 251      * @return Widget that is below the position \a pos. 0 is returned
 252      *         if no widget is below the position.
 253      */
 254     KItemListWidget* widgetForPos(const QPointF& pos) const;
 255
 256     /**
 257      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 258      * set, it will be adjusted to the current item. If it is set it will be
 259      * checked whether it is still valid, otherwise it will be reset to the
 260      * current item.
 261      */
 262     void updateKeyboardAnchor();
 263
 264     /**
 265      * @return Index for the next row based on \a index.
 266      *         If there is no next row \a index will be returned.
 267      */
 268     int nextRowIndex(int index) const;
 269
 270     /**
 271      * @return Index for the previous row based on  \a index.
 272      *         If there is no previous row \a index will be returned.
 273      */
 274     int previousRowIndex(int index) const;
 275
 276     /**
 277      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 278      * @return The position of the keyboard anchor for the item with the index \a index.
 279      *         If a horizontal scrolling is used the y-position of the item will be returned,
 280      *         for the vertical scrolling the x-position will be returned.
 281      */
 282     qreal keyboardAnchorPos(int index) const;
 283
 284     /**
 285      * Dependent on the selection-behavior the extendedSelectionRegion-property
 286      * of the KItemListStyleOption from the view should be adjusted: If no
 287      * rubberband selection is used the property should be enabled.
 288      */
 289     void updateExtendedSelectionRegion();
 290
 291     bool keyPressEvent(QKeyEvent* event);
 292     bool inputMethodEvent(QInputMethodEvent* event);
 293     bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 294     bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 295     bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 296     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 297     bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 298     bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 299     bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 300     bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 301     bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 302     bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 303     bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 304     bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
 305     bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
 306
 307 private:
 308     bool m_singleClickActivationEnforced;
 309     bool m_selectionTogglePressed;
 310     bool m_clearSelectionIfItemsAreNotDragged;
 311     SelectionBehavior m_selectionBehavior;
 312     AutoActivationBehavior m_autoActivationBehavior;
 313     MouseDoubleClickAction m_mouseDoubleClickAction;
 314     KItemModelBase* m_model;
 315     KItemListView* m_view;
 316     KItemListSelectionManager* m_selectionManager;
 317     KItemListKeyboardSearchManager* m_keyboardManager;
 318     int m_pressedIndex;
 319     QPointF m_pressedMousePos;
 320
 321     QTimer* m_autoActivationTimer;
 322
 323     /**
 324      * When starting a rubberband selection during a Shift- or Control-key has been
 325      * pressed the current selection should never be deleted. To be able to restore
 326      * the current selection it is remembered in m_oldSelection before the
 327      * rubberband gets activated.
 328      */
 329     KItemSet m_oldSelection;
 330
 331     /**
 332      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 333      * a maximum of 4 columns:
 334      *
 335      *  1  2  3  4
 336      *  5  6  7
 337      *  8  9 10 11
 338      * 12 13 14
 339      *
 340      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 341      * item. Now when pressing key-down again item 11 should get the current item and not
 342      * item 10. This makes it necessary to keep track of the requested column to have a
 343      * similar behavior like in a text editor:
 344      */
 345     int m_keyboardAnchorIndex;
 346     qreal m_keyboardAnchorPos;
 347 };
 348
 349 #endif
 350
 351