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     /**
 127      * @return \c true if search as you type is active, or \c false otherwise.
 128      */
 129     bool isSearchAsYouTypeActive() const;
 130
 131     bool processEvent(QEvent *event, const QTransform &transform);
 132
 133 Q_SIGNALS:
 134     /**
 135      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 136      * or by pressing Return/Enter.
 137      */
 138     void itemActivated(int index);
 139
 140     /**
 141      * Is emitted if more than one item has been activated by pressing Return/Enter
 142      * when having a selection.
 143      */
 144     void itemsActivated(const KItemSet &indexes);
 145
 146     void itemMiddleClicked(int index);
 147
 148     /**
 149      * Emitted if a context-menu is requested for the item with
 150      * the index \a index. It is assured that the index is valid.
 151      */
 152     void itemContextMenuRequested(int index, const QPointF &pos);
 153
 154     /**
 155      * Emitted if a context-menu is requested for the KItemListView.
 156      */
 157     void viewContextMenuRequested(const QPointF &pos);
 158
 159     /**
 160      * Emitted if a context-menu is requested for the header of the KItemListView.
 161      */
 162     void headerContextMenuRequested(const QPointF &pos);
 163
 164     /**
 165      * Is emitted if the item with the index \p index gets hovered.
 166      */
 167     void itemHovered(int index);
 168
 169     /**
 170      * Is emitted if the item with the index \p index gets unhovered.
 171      * It is assured that the signal itemHovered() for this index
 172      * has been emitted before.
 173      */
 174     void itemUnhovered(int index);
 175
 176     /**
 177      * Is emitted if a mouse-button has been pressed above an item.
 178      * If the index is smaller than 0, the mouse-button has been pressed
 179      * above the viewport.
 180      */
 181     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 182
 183     /**
 184      * Is emitted if a mouse-button has been released above an item.
 185      * It is assured that the signal mouseButtonPressed() has been emitted before.
 186      * If the index is smaller than 0, the mouse-button has been pressed
 187      * above the viewport.
 188      */
 189     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 190
 191     void itemExpansionToggleClicked(int index);
 192
 193     /**
 194      * Is emitted if a drop event is done above the item with the index
 195      * \a index. If \a index is < 0 the drop event is done above an
 196      * empty area of the view.
 197      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 198      *       which is emitted if the drop event occurs on an empty area in
 199      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 200      */
 201     void itemDropEvent(int index, QGraphicsSceneDragDropEvent *event);
 202
 203     /**
 204      * Is emitted if a drop event is done between the item with the index
 205      * \a index and the previous item.
 206      */
 207     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent *event);
 208
 209     /**
 210      * Is emitted if the Escape key is pressed.
 211      */
 212     void escapePressed();
 213
 214     /**
 215      * Used to request either entering or leaving of selection mode
 216      * Leaving is requested by pressing Escape when no item is selected.
 217      *
 218      * Entering is requested if left click is pressed down for a long time without moving the cursor too much.
 219      * Moving the cursor would either trigger an item drag if the click was initiated on top of an item
 220      * or a selection rectangle if the click was not initiated on top of an item.
 221      * So long press is only emitted if there wasn't a lot of cursor movement.
 222      */
 223     void selectionModeChangeRequested(bool enabled);
 224
 225     void modelChanged(KItemModelBase *current, KItemModelBase *previous);
 226     void viewChanged(KItemListView *current, KItemListView *previous);
 227
 228     void selectedItemTextPressed(int index);
 229
 230     void scrollerStop();
 231     void increaseZoom();
 232     void decreaseZoom();
 233     void swipeUp();
 234
 235 public Q_SLOTS:
 236     void slotStateChanged(QScroller::State newState);
 237
 238 private Q_SLOTS:
 239     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 240
 241     /**
 242      * Is invoked when the rubberband boundaries have been changed and will select
 243      * all items that are touched by the rubberband.
 244      */
 245     void slotRubberBandChanged();
 246
 247     void slotChangeCurrentItem(const QString &text, bool searchFromNextItem);
 248
 249     void slotAutoActivationTimeout();
 250
 251 private:
 252     /**
 253      * Creates a QDrag object and initiates a drag-operation.
 254      */
 255     void startDragging();
 256
 257     /**
 258      * @return Widget that is currently in the hovered state. 0 is returned
 259      *         if no widget is marked as hovered.
 260      */
 261     KItemListWidget *hoveredWidget() const;
 262
 263     /**
 264      * @return Widget that is below the position \a pos. 0 is returned
 265      *         if no widget is below the position.
 266      */
 267     KItemListWidget *widgetForPos(const QPointF &pos) const;
 268
 269     /**
 270      * @return Widget that should receive a drop event if an item is dropped at \a pos. 0 is returned
 271      *         if no widget should receive a drop event at the position.
 272      *
 273      * While widgetForPos() returns a widget if \a pos is anywhere inside the hover highlight area of the widget,
 274      * widgetForDropPos() only returns a widget if \a pos is directly above the widget (widget->contains(pos) == true).
 275      */
 276     KItemListWidget *widgetForDropPos(const QPointF &pos) const;
 277
 278     /**
 279      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 280      * set, it will be adjusted to the current item. If it is set it will be
 281      * checked whether it is still valid, otherwise it will be reset to the
 282      * current item.
 283      */
 284     void updateKeyboardAnchor();
 285
 286     /**
 287      * @return Index for the next row based on \a index.
 288      *         If there is no next row \a index will be returned.
 289      */
 290     int nextRowIndex(int index) const;
 291
 292     /**
 293      * @return Index for the previous row based on  \a index.
 294      *         If there is no previous row \a index will be returned.
 295      */
 296     int previousRowIndex(int index) const;
 297
 298     /**
 299      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 300      * @return The position of the keyboard anchor for the item with the index \a index.
 301      *         If a horizontal scrolling is used the y-position of the item will be returned,
 302      *         for the vertical scrolling the x-position will be returned.
 303      */
 304     qreal keyboardAnchorPos(int index) const;
 305
 306     /**
 307      * Dependent on the selection-behavior the extendedSelectionRegion-property
 308      * of the KItemListStyleOption from the view should be adjusted: If no
 309      * rubberband selection is used the property should be enabled.
 310      */
 311     void updateExtendedSelectionRegion();
 312
 313     bool keyPressEvent(QKeyEvent *event);
 314     bool inputMethodEvent(QInputMethodEvent *event);
 315     bool mousePressEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 316     bool mouseMoveEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 317     bool mouseReleaseEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 318     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
 319     bool dragEnterEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 320     bool dragLeaveEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 321     bool dragMoveEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 322     bool dropEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
 323     bool hoverEnterEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 324     bool hoverMoveEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 325     bool hoverLeaveEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
 326     bool wheelEvent(QGraphicsSceneWheelEvent *event, const QTransform &transform);
 327     bool resizeEvent(QGraphicsSceneResizeEvent *event, const QTransform &transform);
 328     bool gestureEvent(QGestureEvent *event, const QTransform &transform);
 329     bool touchBeginEvent(QTouchEvent *event, const QTransform &transform);
 330     void tapTriggered(QTapGesture *tap, const QTransform &transform);
 331     void tapAndHoldTriggered(QGestureEvent *event, const QTransform &transform);
 332     void pinchTriggered(QGestureEvent *event, const QTransform &transform);
 333     void swipeTriggered(QGestureEvent *event, const QTransform &transform);
 334     void twoFingerTapTriggered(QGestureEvent *event, const QTransform &transform);
 335     bool onPress(const QPoint &screenPos, const QPointF &pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons);
 336     bool onRelease(const QPointF &pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons, bool touch);
 337     void startRubberBand();
 338
 339 private:
 340     bool m_singleClickActivationEnforced;
 341     bool m_selectionMode;
 342     bool m_selectionTogglePressed;
 343     bool m_clearSelectionIfItemsAreNotDragged;
 344     bool m_isSwipeGesture;
 345     bool m_dragActionOrRightClick;
 346     bool m_scrollerIsScrolling;
 347     bool m_pinchGestureInProgress;
 348     bool m_mousePress;
 349     bool m_isTouchEvent;
 350     SelectionBehavior m_selectionBehavior;
 351     AutoActivationBehavior m_autoActivationBehavior;
 352     MouseDoubleClickAction m_mouseDoubleClickAction;
 353     KItemModelBase *m_model;
 354     KItemListView *m_view;
 355     KItemListSelectionManager *m_selectionManager;
 356     KItemListKeyboardSearchManager *m_keyboardManager;
 357     std::optional<int> m_pressedIndex;
 358     QPointF m_pressedMousePos;
 359
 360     QTimer *m_autoActivationTimer;
 361
 362     Qt::GestureType m_swipeGesture;
 363     Qt::GestureType m_twoFingerTapGesture;
 364
 365     /**
 366      * When starting a rubberband selection during a Shift- or Control-key has been
 367      * pressed the current selection should never be deleted. To be able to restore
 368      * the current selection it is remembered in m_oldSelection before the
 369      * rubberband gets activated.
 370      */
 371     KItemSet m_oldSelection;
 372
 373     /**
 374      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 375      * a maximum of 4 columns:
 376      *
 377      *  1  2  3  4
 378      *  5  6  7
 379      *  8  9 10 11
 380      * 12 13 14
 381      *
 382      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 383      * item. Now when pressing key-down again item 11 should get the current item and not
 384      * item 10. This makes it necessary to keep track of the requested column to have a
 385      * similar behavior like in a text editor:
 386      */
 387     int m_keyboardAnchorIndex;
 388     qreal m_keyboardAnchorPos;
 389 };
 390
 391 #endif