src/kitemviews/kitemlistcontroller.h

   1 /*
   2  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
   3  *
   4  * Based on the Itemviews NG project from Trolltech Labs
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #ifndef KITEMLISTCONTROLLER_H
  10 #define KITEMLISTCONTROLLER_H
  11
  12 #include <optional>
  13
  14 #include "dolphin_export.h"
  15 #include "kitemset.h"
  16
  17 #include <QObject>
  18 #include <QPointF>
  19 #include <QScroller>
  20
  21 class QTimer;
  22 class KItemModelBase;
  23 class KItemListKeyboardSearchManager;
  24 class KItemListSelectionManager;
  25 class KItemListView;
  26 class KItemListWidget;
  27 class QGestureEvent;
  28 class QGraphicsSceneHoverEvent;
  29 class QGraphicsSceneDragDropEvent;
  30 class QGraphicsSceneMouseEvent;
  31 class QGraphicsSceneResizeEvent;
  32 class QGraphicsSceneWheelEvent;
  33 class QInputMethodEvent;
  34 class QKeyEvent;
  35 class QTapGesture;
  36 class QTransform;
  37 class QTouchEvent;
  38
  39 /**
  40  * @brief Controls the view, model and selection of an item-list.
  41  *
  42  * For a working item-list it is mandatory to set a compatible view and model
  43  * with KItemListController::setView() and KItemListController::setModel().
  44  *
  45  * @see KItemListView
  46  * @see KItemModelBase
  47  * @see KItemListSelectionManager
  48  */
  49 class DOLPHIN_EXPORT KItemListController : public QObject
  50 {
  51     Q_OBJECT
  52     Q_PROPERTY(KItemModelBase* model READ model WRITE setModel)
  53     Q_PROPERTY(KItemListView *view READ view WRITE setView)
  54     Q_PROPERTY(SelectionBehavior selectionBehavior READ selectionBehavior WRITE setSelectionBehavior)
  55     Q_PROPERTY(AutoActivationBehavior autoActivationBehavior READ autoActivationBehavior WRITE setAutoActivationBehavior)
  56     Q_PROPERTY(MouseDoubleClickAction mouseDoubleClickAction READ mouseDoubleClickAction WRITE setMouseDoubleClickAction)
  57
  58 public:
  59     enum SelectionBehavior {
  60         NoSelection,
  61         SingleSelection,
  62         MultiSelection
  63     };
  64     Q_ENUM(SelectionBehavior)
  65
  66     enum AutoActivationBehavior {
  67         ActivationAndExpansion,
  68         ExpansionOnly
  69     };
  70
  71     enum MouseDoubleClickAction {
  72         ActivateAndExpandItem,
  73         ActivateItemOnly
  74     };
  75
  76     /**
  77      * @param model  Model of the controller. The ownership is passed to the controller.
  78      * @param view   View of the controller. The ownership is passed to the controller.
  79      * @param parent Optional parent object.
  80      */
  81     KItemListController(KItemModelBase* model, KItemListView* view, QObject* parent = nullptr);
  82     ~KItemListController() override;
  83
  84     void setModel(KItemModelBase* model);
  85     KItemModelBase* model() const;
  86
  87     void setView(KItemListView* view);
  88     KItemListView* view() const;
  89
  90     KItemListSelectionManager* selectionManager() const;
  91
  92     void setSelectionBehavior(SelectionBehavior behavior);
  93     SelectionBehavior selectionBehavior() const;
  94
  95     void setAutoActivationBehavior(AutoActivationBehavior behavior);
  96     AutoActivationBehavior autoActivationBehavior() const;
  97
  98     void setMouseDoubleClickAction(MouseDoubleClickAction action);
  99     MouseDoubleClickAction mouseDoubleClickAction() const;
 100
 101     int indexCloseToMousePressedPosition() const;
 102
 103     /**
 104      * Sets the delay in milliseconds when dragging an object above an item
 105      * until the item gets activated automatically. A value of -1 indicates
 106      * that no automatic activation will be done at all (= default value).
 107      *
 108      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
 109      * otherwise the automatic activation is not available.
 110      *
 111      * After activating the item the signal itemActivated() will be
 112      * emitted. If the view supports the expanding of items
 113      * (KItemListView::supportsItemExpanding() returns true) and the item
 114      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 115      * of activating the item it gets expanded instead (see
 116      * KItemModelBase::setExpanded()).
 117      */
 118     void setAutoActivationDelay(int delay);
 119     int autoActivationDelay() const;
 120
 121     /**
 122      * If set to true, the signals itemActivated() and itemsActivated() are emitted
 123      * after a single-click of the left mouse button. If set to false (the default),
 124      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
 125      */
 126     void setSingleClickActivationEnforced(bool singleClick);
 127     bool singleClickActivationEnforced() const;
 128
 129     /**
 130      * Setting the selection mode to enabled will make selecting and deselecting easier by acting
 131      * kind of similar to when the Control Key is held down.
 132      */
 133     void setSelectionModeEnabled(bool enabled);
 134     bool selectionMode() const;
 135
 136     bool processEvent(QEvent* event, const QTransform& transform);
 137
 138 Q_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     /**
 220      * Used to request either entering or leaving of selection mode
 221      * Leaving is requested by pressing Escape when no item is selected.
 222      *
 223      * Entering is requested if left click is pressed down for a long time without moving the cursor too much.
 224      * Moving the cursor would either trigger an item drag if the click was initiated on top of an item
 225      * or a selection rectangle if the click was not initiated on top of an item.
 226      * So long press is only emitted if there wasn't a lot of cursor movement.
 227      */
 228     void selectionModeChangeRequested(bool enabled);
 229
 230     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 231     void viewChanged(KItemListView* current, KItemListView* previous);
 232
 233     void selectedItemTextPressed(int index);
 234
 235     void scrollerStop();
 236     void increaseZoom();
 237     void decreaseZoom();
 238     void swipeUp();
 239
 240 public Q_SLOTS:
 241     void slotStateChanged(QScroller::State newState);
 242
 243 private Q_SLOTS:
 244     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 245
 246     /**
 247      * Is invoked when the rubberband boundaries have been changed and will select
 248      * all items that are touched by the rubberband.
 249      */
 250     void slotRubberBandChanged();
 251
 252     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
 253
 254     void slotAutoActivationTimeout();
 255
 256 private:
 257     /**
 258      * Creates a QDrag object and initiates a drag-operation.
 259      */
 260     void startDragging();
 261
 262     /**
 263      * @return Widget that is currently in the hovered state. 0 is returned
 264      *         if no widget is marked as hovered.
 265      */
 266     KItemListWidget* hoveredWidget() const;
 267
 268     /**
 269      * @return Widget that is below the position \a pos. 0 is returned
 270      *         if no widget is below the position.
 271      */
 272     KItemListWidget* widgetForPos(const QPointF& pos) const;
 273
 274     /**
 275      * @return Widget that should receive a drop event if an item is dropped at \a pos. 0 is returned
 276      *         if no widget should receive a drop event at the position.
 277      *
 278      * While widgetForPos() returns a widget if \a pos is anywhere inside the hover highlight area of the widget,
 279      * widgetForDropPos() only returns a widget if \a pos is directly above the widget (widget->contains(pos) == true).
 280      */
 281     KItemListWidget* widgetForDropPos(const QPointF& pos) const;
 282
 283     /**
 284      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 285      * set, it will be adjusted to the current item. If it is set it will be
 286      * checked whether it is still valid, otherwise it will be reset to the
 287      * current item.
 288      */
 289     void updateKeyboardAnchor();
 290
 291     /**
 292      * @return Index for the next row based on \a index.
 293      *         If there is no next row \a index will be returned.
 294      */
 295     int nextRowIndex(int index) const;
 296
 297     /**
 298      * @return Index for the previous row based on  \a index.
 299      *         If there is no previous row \a index will be returned.
 300      */
 301     int previousRowIndex(int index) const;
 302
 303     /**
 304      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 305      * @return The position of the keyboard anchor for the item with the index \a index.
 306      *         If a horizontal scrolling is used the y-position of the item will be returned,
 307      *         for the vertical scrolling the x-position will be returned.
 308      */
 309     qreal keyboardAnchorPos(int index) const;
 310
 311     /**
 312      * Dependent on the selection-behavior the extendedSelectionRegion-property
 313      * of the KItemListStyleOption from the view should be adjusted: If no
 314      * rubberband selection is used the property should be enabled.
 315      */
 316     void updateExtendedSelectionRegion();
 317
 318     bool keyPressEvent(QKeyEvent* event);
 319     bool inputMethodEvent(QInputMethodEvent* event);
 320     bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 321     bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 322     bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 323     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 324     bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 325     bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 326     bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 327     bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 328     bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 329     bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 330     bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 331     bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
 332     bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
 333     bool gestureEvent(QGestureEvent* event, const QTransform& transform);
 334     bool touchBeginEvent(QTouchEvent* event, const QTransform& transform);
 335     void tapTriggered(QTapGesture* tap, const QTransform& transform);
 336     void tapAndHoldTriggered(QGestureEvent* event, const QTransform& transform);
 337     void pinchTriggered(QGestureEvent* event, const QTransform& transform);
 338     void swipeTriggered(QGestureEvent* event, const QTransform& transform);
 339     void twoFingerTapTriggered(QGestureEvent* event, const QTransform& transform);
 340     bool onPress(const QPoint& screenPos, const QPointF& pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons);
 341     bool onRelease(const QPointF& pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons, bool touch);
 342     void startRubberBand();
 343
 344 private:
 345     bool m_singleClickActivationEnforced;
 346     bool m_selectionMode;
 347     bool m_selectionTogglePressed;
 348     bool m_clearSelectionIfItemsAreNotDragged;
 349     bool m_isSwipeGesture;
 350     bool m_dragActionOrRightClick;
 351     bool m_scrollerIsScrolling;
 352     bool m_pinchGestureInProgress;
 353     bool m_mousePress;
 354     bool m_isTouchEvent;
 355     SelectionBehavior m_selectionBehavior;
 356     AutoActivationBehavior m_autoActivationBehavior;
 357     MouseDoubleClickAction m_mouseDoubleClickAction;
 358     KItemModelBase* m_model;
 359     KItemListView* m_view;
 360     KItemListSelectionManager* m_selectionManager;
 361     KItemListKeyboardSearchManager* m_keyboardManager;
 362     std::optional<int> m_pressedIndex;
 363     QPointF m_pressedMousePos;
 364
 365     QTimer* m_autoActivationTimer;
 366
 367     Qt::GestureType m_swipeGesture;
 368     Qt::GestureType m_twoFingerTapGesture;
 369
 370     /**
 371      * When starting a rubberband selection during a Shift- or Control-key has been
 372      * pressed the current selection should never be deleted. To be able to restore
 373      * the current selection it is remembered in m_oldSelection before the
 374      * rubberband gets activated.
 375      */
 376     KItemSet m_oldSelection;
 377
 378     /**
 379      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 380      * a maximum of 4 columns:
 381      *
 382      *  1  2  3  4
 383      *  5  6  7
 384      *  8  9 10 11
 385      * 12 13 14
 386      *
 387      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 388      * item. Now when pressing key-down again item 11 should get the current item and not
 389      * item 10. This makes it necessary to keep track of the requested column to have a
 390      * similar behavior like in a text editor:
 391      */
 392     int m_keyboardAnchorIndex;
 393     qreal m_keyboardAnchorPos;
 394 };
 395
 396 #endif
 397
 398