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 { NoSelection, SingleSelection, MultiSelection };
  60     Q_ENUM(SelectionBehavior)
  61
  62     enum AutoActivationBehavior { ActivationAndExpansion, ExpansionOnly };
  63
  64     enum MouseDoubleClickAction { ActivateAndExpandItem, ActivateItemOnly };
  65
  66     /**
  67      * @param model  Model of the controller. The ownership is passed to the controller.
  68      * @param view   View of the controller. The ownership is passed to the controller.
  69      * @param parent Optional parent object.
  70      */
  71     KItemListController(KItemModelBase *model, KItemListView *view, QObject *parent = nullptr);
  72     ~KItemListController() override;
  73
  74     void setModel(KItemModelBase *model);
  75     KItemModelBase *model() const;
  76
  77     void setView(KItemListView *view);
  78     KItemListView *view() const;
  79
  80     KItemListSelectionManager *selectionManager() const;
  81
  82     void setSelectionBehavior(SelectionBehavior behavior);
  83     SelectionBehavior selectionBehavior() const;
  84
  85     void setAutoActivationBehavior(AutoActivationBehavior behavior);
  86     AutoActivationBehavior autoActivationBehavior() const;
  87
  88     void setMouseDoubleClickAction(MouseDoubleClickAction action);
  89     MouseDoubleClickAction mouseDoubleClickAction() const;
  90
  91     int indexCloseToMousePressedPosition() const;
  92
  93     /**
  94      * Sets the delay in milliseconds when dragging an object above an item
  95      * until the item gets activated automatically. A value of -1 indicates
  96      * that no automatic activation will be done at all (= default value).
  97      *
  98      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
  99      * otherwise the automatic activation is not available.
 100      *
 101      * After activating the item the signal itemActivated() will be
 102      * emitted. If the view supports the expanding of items
 103      * (KItemListView::supportsItemExpanding() returns true) and the item
 104      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 105      * of activating the item it gets expanded instead (see
 106      * KItemModelBase::setExpanded()).
 107      */
 108     void setAutoActivationDelay(int delay);
 109     int autoActivationDelay() const;
 110
 111     /**
 112      * If set to true, the signals itemActivated() and itemsActivated() are emitted
 113      * after a single-click of the left mouse button. If set to false (the default),
 114      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
 115      */
 116     void setSingleClickActivationEnforced(bool singleClick);
 117     bool singleClickActivationEnforced() const;
 118
 119     /**
 120      * Setting the selection mode to enabled will make selecting and deselecting easier by acting
 121      * kind of similar to when the Control Key is held down.
 122      */
 123     void setSelectionModeEnabled(bool enabled);
 124     bool selectionMode() const;
 125
 126     bool processEvent(QEvent *event, const QTransform &transform);
 127
 128 Q_SIGNALS:
 129     /**
 130      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 131      * or by pressing Return/Enter.
 132      */
 133     void itemActivated(int index);
 134
 135     /**
 136      * Is emitted if more than one item has been activated by pressing Return/Enter
 137      * when having a selection.
 138      */
 139     void itemsActivated(const KItemSet &indexes);
 140
 141     void itemMiddleClicked(int index);
 142
 143     /**
 144      * Emitted if a context-menu is requested for the item with
 145      * the index \a index. It is assured that the index is valid.
 146      */
 147     void itemContextMenuRequested(int index, const QPointF &pos);
 148
 149     /**
 150      * Emitted if a context-menu is requested for the KItemListView.
 151      */
 152     void viewContextMenuRequested(const QPointF &pos);
 153
 154     /**
 155      * Emitted if a context-menu is requested for the header of the KItemListView.
 156      */
 157     void headerContextMenuRequested(const QPointF &pos);
 158
 159     /**
 160      * Is emitted if the item with the index \p index gets hovered.
 161      */
 162     void itemHovered(int index);
 163
 164     /**
 165      * Is emitted if the item with the index \p index gets unhovered.
 166      * It is assured that the signal itemHovered() for this index
 167      * has been emitted before.
 168      */
 169     void itemUnhovered(int index);
 170
 171     /**
 172      * Is emitted if a mouse-button has been pressed above an item.
 173      * If the index is smaller than 0, the mouse-button has been pressed
 174      * above the viewport.
 175      */
 176     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 177
 178     /**
 179      * Is emitted if a mouse-button has been released above an item.
 180      * It is assured that the signal mouseButtonPressed() has been emitted before.
 181      * If the index is smaller than 0, the mouse-button has been pressed
 182      * above the viewport.
 183      */
 184     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 185
 186     void itemExpansionToggleClicked(int index);
 187
 188     /**
 189      * Is emitted if a drop event is done above the item with the index
 190      * \a index. If \a index is < 0 the drop event is done above an
 191      * empty area of the view.
 192      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 193      *       which is emitted if the drop event occurs on an empty area in
 194      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 195      */
 196     void itemDropEvent(int index, QGraphicsSceneDragDropEvent *event);
 197
 198     /**
 199      * Is emitted if a drop event is done between the item with the index
 200      * \a index and the previous item.
 201      */
 202     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent *event);
 203
 204     /**
 205      * Is emitted if the Escape key is pressed.
 206      */
 207     void escapePressed();
 208
 209     /**
 210      * Used to request either entering or leaving of selection mode
 211      * Leaving is requested by pressing Escape when no item is selected.
 212      *
 213      * Entering is requested if left click is pressed down for a long time without moving the cursor too much.
 214      * Moving the cursor would either trigger an item drag if the click was initiated on top of an item
 215      * or a selection rectangle if the click was not initiated on top of an item.
 216      * So long press is only emitted if there wasn't a lot of cursor movement.
 217      */
 218     void selectionModeChangeRequested(bool enabled);
 219
 220     void modelChanged(KItemModelBase *current, KItemModelBase *previous);
 221     void viewChanged(KItemListView *current, KItemListView *previous);
 222
 223     void selectedItemTextPressed(int index);
 224
 225     void scrollerStop();
 226     void increaseZoom();
 227     void decreaseZoom();
 228     void swipeUp();
 229
 230 public Q_SLOTS:
 231     void slotStateChanged(QScroller::State newState);
 232
 233 private Q_SLOTS:
 234     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 235
 236     /**
 237      * Is invoked when the rubberband boundaries have been changed and will select
 238      * all items that are touched by the rubberband.
 239      */
 240     void slotRubberBandChanged();
 241
 242     void slotChangeCurrentItem(const QString &text, bool searchFromNextItem);
 243
 244     void slotAutoActivationTimeout();
 245
 246 private:
 247     /**
 248      * Creates a QDrag object and initiates a drag-operation.
 249      */
 250     void startDragging();
 251
 252     /**
 253      * @return Widget that is currently in the hovered state. 0 is returned
 254      *         if no widget is marked as hovered.
 255      */
 256     KItemListWidget *hoveredWidget() const;
 257
 258     /**
 259      * @return Widget that is below the position \a pos. 0 is returned
 260      *         if no widget is below the position.
 261      */
 262     KItemListWidget *widgetForPos(const QPointF &pos) const;
 263
 264     /**
 265      * @return Widget that should receive a drop event if an item is dropped at \a pos. 0 is returned
 266      *         if no widget should receive a drop event at the position.
 267      *
 268      * While widgetForPos() returns a widget if \a pos is anywhere inside the hover highlight area of the widget,
 269      * widgetForDropPos() only returns a widget if \a pos is directly above the widget (widget->contains(pos) == true).
 270      */
 271     KItemListWidget *widgetForDropPos(const QPointF &pos) const;
 272
 273     /**
 274      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 275      * set, it will be adjusted to the current item. If it is set it will be
 276      * checked whether it is still valid, otherwise it will be reset to the
 277      * current item.
 278      */
 279     void updateKeyboardAnchor();
 280
 281     /**
 282      * @return Index for the next row based on \a index.
 283      *         If there is no next row \a index will be returned.
 284      */
 285     int nextRowIndex(int index) const;
 286
 287     /**
 288      * @return Index for the previous row based on  \a index.
 289      *         If there is no previous row \a index will be returned.
 290      */
 291     int previousRowIndex(int index) const;
 292
 293     /**
 294      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 295      * @return The position of the keyboard anchor for the item with the index \a index.
 296      *         If a horizontal scrolling is used the y-position of the item will be returned,
 297      *         for the vertical scrolling the x-position will be returned.
 298      */
 299     qreal keyboardAnchorPos(int index) const;
 300
 301     /**
 302      * Dependent on the selection-behavior the extendedSelectionRegion-property
 303      * of the KItemListStyleOption from the view should be adjusted: If no
 304      * rubberband selection is used the property should be enabled.
 305      */
 306     void updateExtendedSelectionRegion();
 307
 308     bool keyPressEvent(QKeyEvent *event);
 309     bool inputMethodEvent(QInputMethodEvent *event);
 310     bool mousePressEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 311     bool mouseMoveEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 312     bool mouseReleaseEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 313     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 314     bool dragEnterEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 315     bool dragLeaveEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 316     bool dragMoveEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 317     bool dropEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 318     bool hoverEnterEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 319     bool hoverMoveEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 320     bool hoverLeaveEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 321     bool wheelEvent(QGraphicsSceneWheelEvent *event, const QTransform &transform);
 322     bool resizeEvent(QGraphicsSceneResizeEvent *event, const QTransform &transform);
 323     bool gestureEvent(QGestureEvent *event, const QTransform &transform);
 324     bool touchBeginEvent(QTouchEvent *event, const QTransform &transform);
 325     void tapTriggered(QTapGesture *tap, const QTransform &transform);
 326     void tapAndHoldTriggered(QGestureEvent *event, const QTransform &transform);
 327     void pinchTriggered(QGestureEvent *event, const QTransform &transform);
 328     void swipeTriggered(QGestureEvent *event, const QTransform &transform);
 329     void twoFingerTapTriggered(QGestureEvent *event, const QTransform &transform);
 330     bool onPress(const QPoint &screenPos, const QPointF &pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons);
 331     bool onRelease(const QPointF &pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons, bool touch);
 332     void startRubberBand();
 333
 334 private:
 335     bool m_singleClickActivationEnforced;
 336     bool m_selectionMode;
 337     bool m_selectionTogglePressed;
 338     bool m_clearSelectionIfItemsAreNotDragged;
 339     bool m_isSwipeGesture;
 340     bool m_dragActionOrRightClick;
 341     bool m_scrollerIsScrolling;
 342     bool m_pinchGestureInProgress;
 343     bool m_mousePress;
 344     bool m_isTouchEvent;
 345     SelectionBehavior m_selectionBehavior;
 346     AutoActivationBehavior m_autoActivationBehavior;
 347     MouseDoubleClickAction m_mouseDoubleClickAction;
 348     KItemModelBase *m_model;
 349     KItemListView *m_view;
 350     KItemListSelectionManager *m_selectionManager;
 351     KItemListKeyboardSearchManager *m_keyboardManager;
 352     std::optional<int> m_pressedIndex;
 353     QPointF m_pressedMousePos;
 354
 355     QTimer *m_autoActivationTimer;
 356
 357     Qt::GestureType m_swipeGesture;
 358     Qt::GestureType m_twoFingerTapGesture;
 359
 360     /**
 361      * When starting a rubberband selection during a Shift- or Control-key has been
 362      * pressed the current selection should never be deleted. To be able to restore
 363      * the current selection it is remembered in m_oldSelection before the
 364      * rubberband gets activated.
 365      */
 366     KItemSet m_oldSelection;
 367
 368     /**
 369      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 370      * a maximum of 4 columns:
 371      *
 372      *  1  2  3  4
 373      *  5  6  7
 374      *  8  9 10 11
 375      * 12 13 14
 376      *
 377      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 378      * item. Now when pressing key-down again item 11 should get the current item and not
 379      * item 10. This makes it necessary to keep track of the requested column to have a
 380      * similar behavior like in a text editor:
 381      */
 382     int m_keyboardAnchorIndex;
 383     qreal m_keyboardAnchorPos;
 384 };
 385
 386 #endif