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     void setSelectionMode(bool enabled);
 130     bool selectionMode() const;
 131
 132     bool processEvent(QEvent* event, const QTransform& transform);
 133
 134 Q_SIGNALS:
 135     /**
 136      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 137      * or by pressing Return/Enter.
 138      */
 139     void itemActivated(int index);
 140
 141     /**
 142      * Is emitted if more than one item has been activated by pressing Return/Enter
 143      * when having a selection.
 144      */
 145     void itemsActivated(const KItemSet &indexes);
 146
 147     void itemMiddleClicked(int index);
 148
 149     /**
 150      * Emitted if a context-menu is requested for the item with
 151      * the index \a index. It is assured that the index is valid.
 152      */
 153     void itemContextMenuRequested(int index, const QPointF& pos);
 154
 155     /**
 156      * Emitted if a context-menu is requested for the KItemListView.
 157      */
 158     void viewContextMenuRequested(const QPointF& pos);
 159
 160     /**
 161      * Emitted if a context-menu is requested for the header of the KItemListView.
 162      */
 163     void headerContextMenuRequested(const QPointF& pos);
 164
 165     /**
 166      * Is emitted if the item with the index \p index gets hovered.
 167      */
 168     void itemHovered(int index);
 169
 170     /**
 171      * Is emitted if the item with the index \p index gets unhovered.
 172      * It is assured that the signal itemHovered() for this index
 173      * has been emitted before.
 174      */
 175     void itemUnhovered(int index);
 176
 177     /**
 178      * Is emitted if a mouse-button has been pressed above an item.
 179      * If the index is smaller than 0, the mouse-button has been pressed
 180      * above the viewport.
 181      */
 182     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 183
 184     /**
 185      * Is emitted if a mouse-button has been released above an item.
 186      * It is assured that the signal mouseButtonPressed() has been emitted before.
 187      * If the index is smaller than 0, the mouse-button has been pressed
 188      * above the viewport.
 189      */
 190     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 191
 192     void itemExpansionToggleClicked(int index);
 193
 194     /**
 195      * Is emitted if a drop event is done above the item with the index
 196      * \a index. If \a index is < 0 the drop event is done above an
 197      * empty area of the view.
 198      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 199      *       which is emitted if the drop event occurs on an empty area in
 200      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 201      */
 202     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 203
 204     /**
 205      * Is emitted if a drop event is done between the item with the index
 206      * \a index and the previous item.
 207      */
 208     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 209
 210     /**
 211      * Is emitted if the Escape key is pressed.
 212      */
 213     void escapePressed();
 214
 215     /**
 216      * Is emitted if left click is pressed down for a long time without moving the cursor too much.
 217      * Moving the cursor would either trigger an item drag if the click was initiated on top of an item
 218      * or a selection rectangle if the click was not initiated on top of an item.
 219      * So long press is only emitted if there wasn't a lot of cursor movement.
 220      */
 221     void selectionModeRequested();
 222
 223     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 224     void viewChanged(KItemListView* current, KItemListView* previous);
 225
 226     void selectedItemTextPressed(int index);
 227
 228     void scrollerStop();
 229     void increaseZoom();
 230     void decreaseZoom();
 231     void swipeUp();
 232
 233 public Q_SLOTS:
 234     void slotStateChanged(QScroller::State newState);
 235
 236 private Q_SLOTS:
 237     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 238
 239     /**
 240      * Is invoked when the rubberband boundaries have been changed and will select
 241      * all items that are touched by the rubberband.
 242      */
 243     void slotRubberBandChanged();
 244
 245     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
 246
 247     void slotAutoActivationTimeout();
 248
 249 private:
 250     /**
 251      * Creates a QDrag object and initiates a drag-operation.
 252      */
 253     void startDragging();
 254
 255     /**
 256      * @return Widget that is currently in the hovered state. 0 is returned
 257      *         if no widget is marked as hovered.
 258      */
 259     KItemListWidget* hoveredWidget() const;
 260
 261     /**
 262      * @return Widget that is below the position \a pos. 0 is returned
 263      *         if no widget is below the position.
 264      */
 265     KItemListWidget* widgetForPos(const QPointF& pos) const;
 266
 267     /**
 268      * @return Widget that should receive a drop event if an item is dropped at \a pos. 0 is returned
 269      *         if no widget should receive a drop event at the position.
 270      *
 271      * While widgetForPos() returns a widget if \a pos is anywhere inside the hover highlight area of the widget,
 272      * widgetForDropPos() only returns a widget if \a pos is directly above the widget (widget->contains(pos) == true).
 273      */
 274     KItemListWidget* widgetForDropPos(const QPointF& pos) const;
 275
 276     /**
 277      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 278      * set, it will be adjusted to the current item. If it is set it will be
 279      * checked whether it is still valid, otherwise it will be reset to the
 280      * current item.
 281      */
 282     void updateKeyboardAnchor();
 283
 284     /**
 285      * @return Index for the next row based on \a index.
 286      *         If there is no next row \a index will be returned.
 287      */
 288     int nextRowIndex(int index) const;
 289
 290     /**
 291      * @return Index for the previous row based on  \a index.
 292      *         If there is no previous row \a index will be returned.
 293      */
 294     int previousRowIndex(int index) const;
 295
 296     /**
 297      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 298      * @return The position of the keyboard anchor for the item with the index \a index.
 299      *         If a horizontal scrolling is used the y-position of the item will be returned,
 300      *         for the vertical scrolling the x-position will be returned.
 301      */
 302     qreal keyboardAnchorPos(int index) const;
 303
 304     /**
 305      * Dependent on the selection-behavior the extendedSelectionRegion-property
 306      * of the KItemListStyleOption from the view should be adjusted: If no
 307      * rubberband selection is used the property should be enabled.
 308      */
 309     void updateExtendedSelectionRegion();
 310
 311     bool keyPressEvent(QKeyEvent* event);
 312     bool inputMethodEvent(QInputMethodEvent* event);
 313     bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 314     bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 315     bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 316     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 317     bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 318     bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 319     bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 320     bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 321     bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 322     bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 323     bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 324     bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
 325     bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
 326     bool gestureEvent(QGestureEvent* event, const QTransform& transform);
 327     bool touchBeginEvent(QTouchEvent* event, const QTransform& transform);
 328     void tapTriggered(QTapGesture* tap, const QTransform& transform);
 329     void tapAndHoldTriggered(QGestureEvent* event, const QTransform& transform);
 330     void pinchTriggered(QGestureEvent* event, const QTransform& transform);
 331     void swipeTriggered(QGestureEvent* event, const QTransform& transform);
 332     void twoFingerTapTriggered(QGestureEvent* event, const QTransform& transform);
 333     bool onPress(const QPoint& screenPos, const QPointF& pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons);
 334     bool onRelease(const QPointF& pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons, bool touch);
 335     void startRubberBand();
 336
 337 private:
 338     bool m_singleClickActivationEnforced;
 339     bool m_selectionMode;
 340     bool m_selectionTogglePressed;
 341     bool m_clearSelectionIfItemsAreNotDragged;
 342     bool m_isSwipeGesture;
 343     bool m_dragActionOrRightClick;
 344     bool m_scrollerIsScrolling;
 345     bool m_pinchGestureInProgress;
 346     bool m_mousePress;
 347     bool m_isTouchEvent;
 348     SelectionBehavior m_selectionBehavior;
 349     AutoActivationBehavior m_autoActivationBehavior;
 350     MouseDoubleClickAction m_mouseDoubleClickAction;
 351     KItemModelBase* m_model;
 352     KItemListView* m_view;
 353     KItemListSelectionManager* m_selectionManager;
 354     KItemListKeyboardSearchManager* m_keyboardManager;
 355     std::optional<int> m_pressedIndex;
 356     QPointF m_pressedMousePos;
 357
 358     QTimer* m_autoActivationTimer;
 359     QTimer* m_longPressDetectionTimer;
 360
 361     Qt::GestureType m_swipeGesture;
 362     Qt::GestureType m_twoFingerTapGesture;
 363
 364     /**
 365      * When starting a rubberband selection during a Shift- or Control-key has been
 366      * pressed the current selection should never be deleted. To be able to restore
 367      * the current selection it is remembered in m_oldSelection before the
 368      * rubberband gets activated.
 369      */
 370     KItemSet m_oldSelection;
 371
 372     /**
 373      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 374      * a maximum of 4 columns:
 375      *
 376      *  1  2  3  4
 377      *  5  6  7
 378      *  8  9 10 11
 379      * 12 13 14
 380      *
 381      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 382      * item. Now when pressing key-down again item 11 should get the current item and not
 383      * item 10. This makes it necessary to keep track of the requested column to have a
 384      * similar behavior like in a text editor:
 385      */
 386     int m_keyboardAnchorIndex;
 387     qreal m_keyboardAnchorPos;
 388 };
 389
 390 #endif
 391
 392