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     bool processEvent(QEvent* event, const QTransform& transform);
 130
 131 Q_SIGNALS:
 132     /**
 133      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 134      * or by pressing Return/Enter.
 135      */
 136     void itemActivated(int index);
 137
 138     /**
 139      * Is emitted if more than one item has been activated by pressing Return/Enter
 140      * when having a selection.
 141      */
 142     void itemsActivated(const KItemSet &indexes);
 143
 144     void itemMiddleClicked(int index);
 145
 146     /**
 147      * Emitted if a context-menu is requested for the item with
 148      * the index \a index. It is assured that the index is valid.
 149      */
 150     void itemContextMenuRequested(int index, const QPointF& pos);
 151
 152     /**
 153      * Emitted if a context-menu is requested for the KItemListView.
 154      */
 155     void viewContextMenuRequested(const QPointF& pos);
 156
 157     /**
 158      * Emitted if a context-menu is requested for the header of the KItemListView.
 159      */
 160     void headerContextMenuRequested(const QPointF& pos);
 161
 162     /**
 163      * Is emitted if the item with the index \p index gets hovered.
 164      */
 165     void itemHovered(int index);
 166
 167     /**
 168      * Is emitted if the item with the index \p index gets unhovered.
 169      * It is assured that the signal itemHovered() for this index
 170      * has been emitted before.
 171      */
 172     void itemUnhovered(int index);
 173
 174     /**
 175      * Is emitted if a mouse-button has been pressed above an item.
 176      * If the index is smaller than 0, the mouse-button has been pressed
 177      * above the viewport.
 178      */
 179     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 180
 181     /**
 182      * Is emitted if a mouse-button has been released above an item.
 183      * It is assured that the signal mouseButtonPressed() has been emitted before.
 184      * If the index is smaller than 0, the mouse-button has been pressed
 185      * above the viewport.
 186      */
 187     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 188
 189     void itemExpansionToggleClicked(int index);
 190
 191     /**
 192      * Is emitted if a drop event is done above the item with the index
 193      * \a index. If \a index is < 0 the drop event is done above an
 194      * empty area of the view.
 195      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 196      *       which is emitted if the drop event occurs on an empty area in
 197      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 198      */
 199     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 200
 201     /**
 202      * Is emitted if a drop event is done between the item with the index
 203      * \a index and the previous item.
 204      */
 205     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 206
 207     /**
 208      * Is emitted if the Escape key is pressed.
 209      */
 210     void escapePressed();
 211
 212     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 213     void viewChanged(KItemListView* current, KItemListView* previous);
 214
 215     void selectedItemTextPressed(int index);
 216
 217     void scrollerStop();
 218     void increaseZoom();
 219     void decreaseZoom();
 220     void swipeUp();
 221
 222 public Q_SLOTS:
 223     void slotStateChanged(QScroller::State newState);
 224
 225 private Q_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     bool gestureEvent(QGestureEvent* event, const QTransform& transform);
 307     bool touchBeginEvent(QTouchEvent* event, const QTransform& transform);
 308     void tapTriggered(QTapGesture* tap, const QTransform& transform);
 309     void tapAndHoldTriggered(QGestureEvent* event, const QTransform& transform);
 310     void pinchTriggered(QGestureEvent* event, const QTransform& transform);
 311     void swipeTriggered(QGestureEvent* event, const QTransform& transform);
 312     void twoFingerTapTriggered(QGestureEvent* event, const QTransform& transform);
 313     bool onPress(const QPoint& screenPos, const QPointF& pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons);
 314     bool onRelease(const QPointF& pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons, bool touch);
 315     void startRubberBand();
 316
 317 private:
 318     bool m_singleClickActivationEnforced;
 319     bool m_selectionTogglePressed;
 320     bool m_clearSelectionIfItemsAreNotDragged;
 321     bool m_isSwipeGesture;
 322     bool m_dragActionOrRightClick;
 323     bool m_scrollerIsScrolling;
 324     bool m_pinchGestureInProgress;
 325     bool m_mousePress;
 326     bool m_isTouchEvent;
 327     SelectionBehavior m_selectionBehavior;
 328     AutoActivationBehavior m_autoActivationBehavior;
 329     MouseDoubleClickAction m_mouseDoubleClickAction;
 330     KItemModelBase* m_model;
 331     KItemListView* m_view;
 332     KItemListSelectionManager* m_selectionManager;
 333     KItemListKeyboardSearchManager* m_keyboardManager;
 334     std::optional<int> m_pressedIndex;
 335     QPointF m_pressedMousePos;
 336
 337     QTimer* m_autoActivationTimer;
 338
 339     Qt::GestureType m_swipeGesture;
 340     Qt::GestureType m_twoFingerTapGesture;
 341
 342     /**
 343      * When starting a rubberband selection during a Shift- or Control-key has been
 344      * pressed the current selection should never be deleted. To be able to restore
 345      * the current selection it is remembered in m_oldSelection before the
 346      * rubberband gets activated.
 347      */
 348     KItemSet m_oldSelection;
 349
 350     /**
 351      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 352      * a maximum of 4 columns:
 353      *
 354      *  1  2  3  4
 355      *  5  6  7
 356      *  8  9 10 11
 357      * 12 13 14
 358      *
 359      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 360      * item. Now when pressing key-down again item 11 should get the current item and not
 361      * item 10. This makes it necessary to keep track of the requested column to have a
 362      * similar behavior like in a text editor:
 363      */
 364     int m_keyboardAnchorIndex;
 365     qreal m_keyboardAnchorPos;
 366 };
 367
 368 #endif
 369
 370