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 QContextMenuEvent;
  28 class QGestureEvent;
  29 class QGraphicsSceneHoverEvent;
  30 class QGraphicsSceneDragDropEvent;
  31 class QGraphicsSceneMouseEvent;
  32 class QGraphicsSceneResizeEvent;
  33 class QGraphicsSceneWheelEvent;
  34 class QInputMethodEvent;
  35 class QKeyEvent;
  36 class QTapGesture;
  37 class QTransform;
  38 class QTouchEvent;
  39
  40 /**
  41  * @brief Controls the view, model and selection of an item-list.
  42  *
  43  * For a working item-list it is mandatory to set a compatible view and model
  44  * with KItemListController::setView() and KItemListController::setModel().
  45  *
  46  * @see KItemListView
  47  * @see KItemModelBase
  48  * @see KItemListSelectionManager
  49  */
  50 class DOLPHIN_EXPORT KItemListController : public QObject
  51 {
  52     Q_OBJECT
  53     Q_PROPERTY(KItemModelBase *model READ model WRITE setModel NOTIFY modelChanged)
  54     Q_PROPERTY(KItemListView *view READ view WRITE setView NOTIFY viewChanged)
  55
  56 public:
  57     enum SelectionBehavior { NoSelection, SingleSelection, MultiSelection };
  58     Q_ENUM(SelectionBehavior)
  59
  60     enum AutoActivationBehavior { ActivationAndExpansion, ExpansionOnly };
  61
  62     enum MouseDoubleClickAction { ActivateAndExpandItem, ActivateItemOnly };
  63
  64     /**
  65      * @param model  Model of the controller. The ownership is passed to the controller.
  66      * @param view   View of the controller. The ownership is passed to the controller.
  67      * @param parent Optional parent object.
  68      */
  69     KItemListController(KItemModelBase *model, KItemListView *view, QObject *parent = nullptr);
  70     ~KItemListController() override;
  71
  72     void setModel(KItemModelBase *model);
  73     KItemModelBase *model() const;
  74
  75     void setView(KItemListView *view);
  76     KItemListView *view() const;
  77
  78     KItemListSelectionManager *selectionManager() const;
  79
  80     void setSelectionBehavior(SelectionBehavior behavior);
  81     SelectionBehavior selectionBehavior() const;
  82
  83     void setAutoActivationBehavior(AutoActivationBehavior behavior);
  84     AutoActivationBehavior autoActivationBehavior() const;
  85
  86     void setMouseDoubleClickAction(MouseDoubleClickAction action);
  87     MouseDoubleClickAction mouseDoubleClickAction() const;
  88
  89     int indexCloseToMousePressedPosition() const;
  90
  91     /**
  92      * Sets the delay in milliseconds when dragging an object above an item
  93      * until the item gets activated automatically. A value of -1 indicates
  94      * that no automatic activation will be done at all (= default value).
  95      *
  96      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
  97      * otherwise the automatic activation is not available.
  98      *
  99      * After activating the item the signal itemActivated() will be
 100      * emitted. If the view supports the expanding of items
 101      * (KItemListView::supportsItemExpanding() returns true) and the item
 102      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 103      * of activating the item it gets expanded instead (see
 104      * KItemModelBase::setExpanded()).
 105      */
 106     void setAutoActivationDelay(int delay);
 107     int autoActivationDelay() const;
 108
 109     /**
 110      * If set to true, the signals itemActivated() and itemsActivated() are emitted
 111      * after a single-click of the left mouse button. If set to false (the default),
 112      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
 113      */
 114     void setSingleClickActivationEnforced(bool singleClick);
 115     bool singleClickActivationEnforced() const;
 116
 117     /**
 118      * Setting the selection mode to enabled will make selecting and deselecting easier by acting
 119      * kind of similar to when the Control Key is held down.
 120      */
 121     void setSelectionModeEnabled(bool enabled);
 122     bool selectionMode() const;
 123
 124     /**
 125      * @return \c true if search as you type is active, or \c false otherwise.
 126      */
 127     bool isSearchAsYouTypeActive() 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     /**
 213      * Used to request either entering or leaving of selection mode
 214      * Leaving is requested by pressing Escape when no item is selected.
 215      *
 216      * Entering is requested 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 selectionModeChangeRequested(bool enabled);
 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     /**
 234      * Emitted when the view's background is double-clicked.
 235      * Used to trigger an user configured action.
 236      */
 237     void doubleClickViewBackground(Qt::MouseButton button);
 238
 239 public Q_SLOTS:
 240     void slotStateChanged(QScroller::State newState);
 241
 242 private Q_SLOTS:
 243     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 244
 245     /**
 246      * Is invoked when the rubberband boundaries have been changed and will select
 247      * all items that are touched by the rubberband.
 248      */
 249     void slotRubberBandChanged();
 250
 251     void slotChangeCurrentItem(const QString &text, bool searchFromNextItem);
 252
 253     void slotAutoActivationTimeout();
 254
 255 private:
 256     /**
 257      * Creates a QDrag object and initiates a drag-operation.
 258      */
 259     void startDragging();
 260
 261     /**
 262      * @return Widget that is currently in the hovered state. 0 is returned
 263      *         if no widget is marked as hovered.
 264      */
 265     KItemListWidget *hoveredWidget() const;
 266
 267     /**
 268      * @return Widget that is below the position \a pos. 0 is returned
 269      *         if no widget is below the position.
 270      */
 271     KItemListWidget *widgetForPos(const QPointF &pos) const;
 272
 273     /**
 274      * @return Widget that should receive a drop event if an item is dropped at \a pos. 0 is returned
 275      *         if no widget should receive a drop event at the position.
 276      *
 277      * While widgetForPos() returns a widget if \a pos is anywhere inside the hover highlight area of the widget,
 278      * widgetForDropPos() only returns a widget if \a pos is directly above the widget (widget->contains(pos) == true).
 279      */
 280     KItemListWidget *widgetForDropPos(const QPointF &pos) const;
 281
 282     /**
 283      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 284      * set, it will be adjusted to the current item. If it is set it will be
 285      * checked whether it is still valid, otherwise it will be reset to the
 286      * current item.
 287      */
 288     void updateKeyboardAnchor();
 289
 290     /**
 291      * @return Index for the next row based on \a index.
 292      *         If there is no next row \a index will be returned.
 293      */
 294     int nextRowIndex(int index) const;
 295
 296     /**
 297      * @return Index for the previous row based on  \a index.
 298      *         If there is no previous row \a index will be returned.
 299      */
 300     int previousRowIndex(int index) const;
 301
 302     /**
 303      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 304      * @return The position of the keyboard anchor for the item with the index \a index.
 305      *         If a horizontal scrolling is used the y-position of the item will be returned,
 306      *         for the vertical scrolling the x-position will be returned.
 307      */
 308     qreal keyboardAnchorPos(int index) const;
 309
 310     /**
 311      * Dependent on the selection-behavior the extendedSelectionRegion-property
 312      * of the KItemListStyleOption from the view should be adjusted: If no
 313      * rubberband selection is used the property should be enabled.
 314      */
 315     void updateExtendedSelectionRegion();
 316
 317     bool keyPressEvent(QKeyEvent *event);
 318     bool inputMethodEvent(QInputMethodEvent *event);
 319     bool mousePressEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 320     bool mouseMoveEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 321     bool mouseReleaseEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 322     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 323     bool contextMenuEvent(QContextMenuEvent *event);
 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 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_pressedMouseGlobalPos;
 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