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 NOTIFY modelChanged)
  53     Q_PROPERTY(KItemListView *view READ view WRITE setView NOTIFY viewChanged)
  54
  55 public:
  56     enum SelectionBehavior { NoSelection, SingleSelection, MultiSelection };
  57     Q_ENUM(SelectionBehavior)
  58
  59     enum AutoActivationBehavior { ActivationAndExpansion, ExpansionOnly };
  60
  61     enum MouseDoubleClickAction { ActivateAndExpandItem, ActivateItemOnly };
  62
  63     /**
  64      * @param model  Model of the controller. The ownership is passed to the controller.
  65      * @param view   View of the controller. The ownership is passed to the controller.
  66      * @param parent Optional parent object.
  67      */
  68     KItemListController(KItemModelBase *model, KItemListView *view, QObject *parent = nullptr);
  69     ~KItemListController() override;
  70
  71     void setModel(KItemModelBase *model);
  72     KItemModelBase *model() const;
  73
  74     void setView(KItemListView *view);
  75     KItemListView *view() const;
  76
  77     KItemListSelectionManager *selectionManager() const;
  78
  79     void setSelectionBehavior(SelectionBehavior behavior);
  80     SelectionBehavior selectionBehavior() const;
  81
  82     void setAutoActivationBehavior(AutoActivationBehavior behavior);
  83     AutoActivationBehavior autoActivationBehavior() const;
  84
  85     void setMouseDoubleClickAction(MouseDoubleClickAction action);
  86     MouseDoubleClickAction mouseDoubleClickAction() const;
  87
  88     int indexCloseToMousePressedPosition() const;
  89
  90     /**
  91      * Sets the delay in milliseconds when dragging an object above an item
  92      * until the item gets activated automatically. A value of -1 indicates
  93      * that no automatic activation will be done at all (= default value).
  94      *
  95      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
  96      * otherwise the automatic activation is not available.
  97      *
  98      * After activating the item the signal itemActivated() will be
  99      * emitted. If the view supports the expanding of items
 100      * (KItemListView::supportsItemExpanding() returns true) and the item
 101      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 102      * of activating the item it gets expanded instead (see
 103      * KItemModelBase::setExpanded()).
 104      */
 105     void setAutoActivationDelay(int delay);
 106     int autoActivationDelay() const;
 107
 108     /**
 109      * If set to true, the signals itemActivated() and itemsActivated() are emitted
 110      * after a single-click of the left mouse button. If set to false (the default),
 111      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
 112      */
 113     void setSingleClickActivationEnforced(bool singleClick);
 114     bool singleClickActivationEnforced() const;
 115
 116     /**
 117      * Setting the selection mode to enabled will make selecting and deselecting easier by acting
 118      * kind of similar to when the Control Key is held down.
 119      */
 120     void setSelectionModeEnabled(bool enabled);
 121     bool selectionMode() const;
 122
 123     /**
 124      * @return \c true if search as you type is active, or \c false otherwise.
 125      */
 126     bool isSearchAsYouTypeActive() const;
 127
 128     bool processEvent(QEvent *event, const QTransform &transform);
 129
 130 Q_SIGNALS:
 131     /**
 132      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 133      * or by pressing Return/Enter.
 134      */
 135     void itemActivated(int index);
 136
 137     /**
 138      * Is emitted if more than one item has been activated by pressing Return/Enter
 139      * when having a selection.
 140      */
 141     void itemsActivated(const KItemSet &indexes);
 142
 143     void itemMiddleClicked(int index);
 144
 145     /**
 146      * Emitted if a context-menu is requested for the item with
 147      * the index \a index. It is assured that the index is valid.
 148      */
 149     void itemContextMenuRequested(int index, const QPointF &pos);
 150
 151     /**
 152      * Emitted if a context-menu is requested for the KItemListView.
 153      */
 154     void viewContextMenuRequested(const QPointF &pos);
 155
 156     /**
 157      * Emitted if a context-menu is requested for the header of the KItemListView.
 158      */
 159     void headerContextMenuRequested(const QPointF &pos);
 160
 161     /**
 162      * Is emitted if the item with the index \p index gets hovered.
 163      */
 164     void itemHovered(int index);
 165
 166     /**
 167      * Is emitted if the item with the index \p index gets unhovered.
 168      * It is assured that the signal itemHovered() for this index
 169      * has been emitted before.
 170      */
 171     void itemUnhovered(int index);
 172
 173     /**
 174      * Is emitted if a mouse-button has been pressed above an item.
 175      * If the index is smaller than 0, the mouse-button has been pressed
 176      * above the viewport.
 177      */
 178     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 179
 180     /**
 181      * Is emitted if a mouse-button has been released above an item.
 182      * It is assured that the signal mouseButtonPressed() has been emitted before.
 183      * If the index is smaller than 0, the mouse-button has been pressed
 184      * above the viewport.
 185      */
 186     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 187
 188     void itemExpansionToggleClicked(int index);
 189
 190     /**
 191      * Is emitted if a drop event is done above the item with the index
 192      * \a index. If \a index is < 0 the drop event is done above an
 193      * empty area of the view.
 194      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 195      *       which is emitted if the drop event occurs on an empty area in
 196      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 197      */
 198     void itemDropEvent(int index, QGraphicsSceneDragDropEvent *event);
 199
 200     /**
 201      * Is emitted if a drop event is done between the item with the index
 202      * \a index and the previous item.
 203      */
 204     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent *event);
 205
 206     /**
 207      * Is emitted if the Escape key is pressed.
 208      */
 209     void escapePressed();
 210
 211     /**
 212      * Used to request either entering or leaving of selection mode
 213      * Leaving is requested by pressing Escape when no item is selected.
 214      *
 215      * Entering is requested if left click is pressed down for a long time without moving the cursor too much.
 216      * Moving the cursor would either trigger an item drag if the click was initiated on top of an item
 217      * or a selection rectangle if the click was not initiated on top of an item.
 218      * So long press is only emitted if there wasn't a lot of cursor movement.
 219      */
 220     void selectionModeChangeRequested(bool enabled);
 221
 222     void modelChanged(KItemModelBase *current, KItemModelBase *previous);
 223     void viewChanged(KItemListView *current, KItemListView *previous);
 224
 225     void selectedItemTextPressed(int index);
 226
 227     void scrollerStop();
 228     void increaseZoom();
 229     void decreaseZoom();
 230     void swipeUp();
 231
 232 public Q_SLOTS:
 233     void slotStateChanged(QScroller::State newState);
 234
 235 private Q_SLOTS:
 236     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 237
 238     /**
 239      * Is invoked when the rubberband boundaries have been changed and will select
 240      * all items that are touched by the rubberband.
 241      */
 242     void slotRubberBandChanged();
 243
 244     void slotChangeCurrentItem(const QString &text, bool searchFromNextItem);
 245
 246     void slotAutoActivationTimeout();
 247
 248 private:
 249     /**
 250      * Creates a QDrag object and initiates a drag-operation.
 251      */
 252     void startDragging();
 253
 254     /**
 255      * @return Widget that is currently in the hovered state. 0 is returned
 256      *         if no widget is marked as hovered.
 257      */
 258     KItemListWidget *hoveredWidget() const;
 259
 260     /**
 261      * @return Widget that is below the position \a pos. 0 is returned
 262      *         if no widget is below the position.
 263      */
 264     KItemListWidget *widgetForPos(const QPointF &pos) const;
 265
 266     /**
 267      * @return Widget that should receive a drop event if an item is dropped at \a pos. 0 is returned
 268      *         if no widget should receive a drop event at the position.
 269      *
 270      * While widgetForPos() returns a widget if \a pos is anywhere inside the hover highlight area of the widget,
 271      * widgetForDropPos() only returns a widget if \a pos is directly above the widget (widget->contains(pos) == true).
 272      */
 273     KItemListWidget *widgetForDropPos(const QPointF &pos) const;
 274
 275     /**
 276      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 277      * set, it will be adjusted to the current item. If it is set it will be
 278      * checked whether it is still valid, otherwise it will be reset to the
 279      * current item.
 280      */
 281     void updateKeyboardAnchor();
 282
 283     /**
 284      * @return Index for the next row based on \a index.
 285      *         If there is no next row \a index will be returned.
 286      */
 287     int nextRowIndex(int index) const;
 288
 289     /**
 290      * @return Index for the previous row based on  \a index.
 291      *         If there is no previous row \a index will be returned.
 292      */
 293     int previousRowIndex(int index) const;
 294
 295     /**
 296      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 297      * @return The position of the keyboard anchor for the item with the index \a index.
 298      *         If a horizontal scrolling is used the y-position of the item will be returned,
 299      *         for the vertical scrolling the x-position will be returned.
 300      */
 301     qreal keyboardAnchorPos(int index) const;
 302
 303     /**
 304      * Dependent on the selection-behavior the extendedSelectionRegion-property
 305      * of the KItemListStyleOption from the view should be adjusted: If no
 306      * rubberband selection is used the property should be enabled.
 307      */
 308     void updateExtendedSelectionRegion();
 309
 310     bool keyPressEvent(QKeyEvent *event);
 311     bool inputMethodEvent(QInputMethodEvent *event);
 312     bool mousePressEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 313     bool mouseMoveEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 314     bool mouseReleaseEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 315     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 316     bool dragEnterEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 317     bool dragLeaveEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 318     bool dragMoveEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 319     bool dropEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 320     bool hoverEnterEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 321     bool hoverMoveEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 322     bool hoverLeaveEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 323     bool wheelEvent(QGraphicsSceneWheelEvent *event, const QTransform &transform);
 324     bool resizeEvent(QGraphicsSceneResizeEvent *event, const QTransform &transform);
 325     bool gestureEvent(QGestureEvent *event, const QTransform &transform);
 326     bool touchBeginEvent(QTouchEvent *event, const QTransform &transform);
 327     void tapTriggered(QTapGesture *tap, const QTransform &transform);
 328     void tapAndHoldTriggered(QGestureEvent *event, const QTransform &transform);
 329     void pinchTriggered(QGestureEvent *event, const QTransform &transform);
 330     void swipeTriggered(QGestureEvent *event, const QTransform &transform);
 331     void twoFingerTapTriggered(QGestureEvent *event, const QTransform &transform);
 332     bool onPress(const QPoint &screenPos, const QPointF &pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons);
 333     bool onRelease(const QPointF &pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons, bool touch);
 334     void startRubberBand();
 335
 336 private:
 337     bool m_singleClickActivationEnforced;
 338     bool m_selectionMode;
 339     bool m_selectionTogglePressed;
 340     bool m_clearSelectionIfItemsAreNotDragged;
 341     bool m_isSwipeGesture;
 342     bool m_dragActionOrRightClick;
 343     bool m_scrollerIsScrolling;
 344     bool m_pinchGestureInProgress;
 345     bool m_mousePress;
 346     bool m_isTouchEvent;
 347     SelectionBehavior m_selectionBehavior;
 348     AutoActivationBehavior m_autoActivationBehavior;
 349     MouseDoubleClickAction m_mouseDoubleClickAction;
 350     KItemModelBase *m_model;
 351     KItemListView *m_view;
 352     KItemListSelectionManager *m_selectionManager;
 353     KItemListKeyboardSearchManager *m_keyboardManager;
 354     std::optional<int> m_pressedIndex;
 355     QPointF m_pressedMouseGlobalPos;
 356
 357     QTimer *m_autoActivationTimer;
 358
 359     Qt::GestureType m_swipeGesture;
 360     Qt::GestureType m_twoFingerTapGesture;
 361
 362     /**
 363      * When starting a rubberband selection during a Shift- or Control-key has been
 364      * pressed the current selection should never be deleted. To be able to restore
 365      * the current selection it is remembered in m_oldSelection before the
 366      * rubberband gets activated.
 367      */
 368     KItemSet m_oldSelection;
 369
 370     /**
 371      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 372      * a maximum of 4 columns:
 373      *
 374      *  1  2  3  4
 375      *  5  6  7
 376      *  8  9 10 11
 377      * 12 13 14
 378      *
 379      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 380      * item. Now when pressing key-down again item 11 should get the current item and not
 381      * item 10. This makes it necessary to keep track of the requested column to have a
 382      * similar behavior like in a text editor:
 383      */
 384     int m_keyboardAnchorIndex;
 385     qreal m_keyboardAnchorPos;
 386 };
 387
 388 #endif