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