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 "dolphin_export.h"
  13 #include "kitemset.h"
  14
  15 #include <QObject>
  16 #include <QPointF>
  17
  18 class QTimer;
  19 class KItemModelBase;
  20 class KItemListKeyboardSearchManager;
  21 class KItemListSelectionManager;
  22 class KItemListView;
  23 class KItemListWidget;
  24 class QGraphicsSceneHoverEvent;
  25 class QGraphicsSceneDragDropEvent;
  26 class QGraphicsSceneMouseEvent;
  27 class QGraphicsSceneResizeEvent;
  28 class QGraphicsSceneWheelEvent;
  29 class QInputMethodEvent;
  30 class QKeyEvent;
  31 class QTransform;
  32
  33 /**
  34  * @brief Controls the view, model and selection of an item-list.
  35  *
  36  * For a working item-list it is mandatory to set a compatible view and model
  37  * with KItemListController::setView() and KItemListController::setModel().
  38  *
  39  * @see KItemListView
  40  * @see KItemModelBase
  41  * @see KItemListSelectionManager
  42  */
  43 class DOLPHIN_EXPORT KItemListController : public QObject
  44 {
  45     Q_OBJECT
  46     Q_PROPERTY(KItemModelBase* model READ model WRITE setModel)
  47     Q_PROPERTY(KItemListView *view READ view WRITE setView)
  48     Q_PROPERTY(SelectionBehavior selectionBehavior READ selectionBehavior WRITE setSelectionBehavior)
  49     Q_PROPERTY(AutoActivationBehavior autoActivationBehavior READ autoActivationBehavior WRITE setAutoActivationBehavior)
  50     Q_PROPERTY(MouseDoubleClickAction mouseDoubleClickAction READ mouseDoubleClickAction WRITE setMouseDoubleClickAction)
  51
  52 public:
  53     enum SelectionBehavior {
  54         NoSelection,
  55         SingleSelection,
  56         MultiSelection
  57     };
  58     Q_ENUM(SelectionBehavior)
  59
  60     enum AutoActivationBehavior {
  61         ActivationAndExpansion,
  62         ExpansionOnly
  63     };
  64
  65     enum MouseDoubleClickAction {
  66         ActivateAndExpandItem,
  67         ActivateItemOnly
  68     };
  69
  70     /**
  71      * @param model  Model of the controller. The ownership is passed to the controller.
  72      * @param view   View of the controller. The ownership is passed to the controller.
  73      * @param parent Optional parent object.
  74      */
  75     KItemListController(KItemModelBase* model, KItemListView* view, QObject* parent = nullptr);
  76     ~KItemListController() override;
  77
  78     void setModel(KItemModelBase* model);
  79     KItemModelBase* model() const;
  80
  81     void setView(KItemListView* view);
  82     KItemListView* view() const;
  83
  84     KItemListSelectionManager* selectionManager() const;
  85
  86     void setSelectionBehavior(SelectionBehavior behavior);
  87     SelectionBehavior selectionBehavior() const;
  88
  89     void setAutoActivationBehavior(AutoActivationBehavior behavior);
  90     AutoActivationBehavior autoActivationBehavior() const;
  91
  92     void setMouseDoubleClickAction(MouseDoubleClickAction action);
  93     MouseDoubleClickAction mouseDoubleClickAction() const;
  94
  95     int indexCloseToMousePressedPosition() const;
  96
  97     /**
  98      * Sets the delay in milliseconds when dragging an object above an item
  99      * until the item gets activated automatically. A value of -1 indicates
 100      * that no automatic activation will be done at all (= default value).
 101      *
 102      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
 103      * otherwise the automatic activation is not available.
 104      *
 105      * After activating the item the signal itemActivated() will be
 106      * emitted. If the view supports the expanding of items
 107      * (KItemListView::supportsItemExpanding() returns true) and the item
 108      * itself is expandable (see KItemModelBase::isExpandable()) then instead
 109      * of activating the item it gets expanded instead (see
 110      * KItemModelBase::setExpanded()).
 111      */
 112     void setAutoActivationDelay(int delay);
 113     int autoActivationDelay() const;
 114
 115     /**
 116      * If set to true, the signals itemActivated() and itemsActivated() are emitted
 117      * after a single-click of the left mouse button. If set to false (the default),
 118      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
 119      */
 120     void setSingleClickActivationEnforced(bool singleClick);
 121     bool singleClickActivationEnforced() const;
 122
 123     bool processEvent(QEvent* event, const QTransform& transform);
 124
 125 signals:
 126     /**
 127      * Is emitted if exactly one item has been activated by e.g. a mouse-click
 128      * or by pressing Return/Enter.
 129      */
 130     void itemActivated(int index);
 131
 132     /**
 133      * Is emitted if more than one item has been activated by pressing Return/Enter
 134      * when having a selection.
 135      */
 136     void itemsActivated(const KItemSet& indexes);
 137
 138     void itemMiddleClicked(int index);
 139
 140     /**
 141      * Emitted if a context-menu is requested for the item with
 142      * the index \a index. It is assured that the index is valid.
 143      */
 144     void itemContextMenuRequested(int index, const QPointF& pos);
 145
 146     /**
 147      * Emitted if a context-menu is requested for the KItemListView.
 148      */
 149     void viewContextMenuRequested(const QPointF& pos);
 150
 151     /**
 152      * Emitted if a context-menu is requested for the header of the KItemListView.
 153      */
 154     void headerContextMenuRequested(const QPointF& pos);
 155
 156     /**
 157      * Is emitted if the item with the index \p index gets hovered.
 158      */
 159     void itemHovered(int index);
 160
 161     /**
 162      * Is emitted if the item with the index \p index gets unhovered.
 163      * It is assured that the signal itemHovered() for this index
 164      * has been emitted before.
 165      */
 166     void itemUnhovered(int index);
 167
 168     /**
 169      * Is emitted if a mouse-button has been pressed above an item.
 170      * If the index is smaller than 0, the mouse-button has been pressed
 171      * above the viewport.
 172      */
 173     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 174
 175     /**
 176      * Is emitted if a mouse-button has been released above an item.
 177      * It is assured that the signal mouseButtonPressed() has been emitted before.
 178      * If the index is smaller than 0, the mouse-button has been pressed
 179      * above the viewport.
 180      */
 181     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 182
 183     void itemExpansionToggleClicked(int index);
 184
 185     /**
 186      * Is emitted if a drop event is done above the item with the index
 187      * \a index. If \a index is < 0 the drop event is done above an
 188      * empty area of the view.
 189      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
 190      *       which is emitted if the drop event occurs on an empty area in
 191      *       the view, and make sure that index is always >= 0 in itemDropEvent().
 192      */
 193     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 194
 195     /**
 196      * Is emitted if a drop event is done between the item with the index
 197      * \a index and the previous item.
 198      */
 199     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
 200
 201     /**
 202      * Is emitted if the Escape key is pressed.
 203      */
 204     void escapePressed();
 205
 206     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
 207     void viewChanged(KItemListView* current, KItemListView* previous);
 208
 209     void selectedItemTextPressed(int index);
 210
 211 private slots:
 212     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 213
 214     /**
 215      * Is invoked when the rubberband boundaries have been changed and will select
 216      * all items that are touched by the rubberband.
 217      */
 218     void slotRubberBandChanged();
 219
 220     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
 221
 222     void slotAutoActivationTimeout();
 223
 224 private:
 225     /**
 226      * Creates a QDrag object and initiates a drag-operation.
 227      */
 228     void startDragging();
 229
 230     /**
 231      * @return Widget that is currently in the hovered state. 0 is returned
 232      *         if no widget is marked as hovered.
 233      */
 234     KItemListWidget* hoveredWidget() const;
 235
 236     /**
 237      * @return Widget that is below the position \a pos. 0 is returned
 238      *         if no widget is below the position.
 239      */
 240     KItemListWidget* widgetForPos(const QPointF& pos) const;
 241
 242     /**
 243      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
 244      * set, it will be adjusted to the current item. If it is set it will be
 245      * checked whether it is still valid, otherwise it will be reset to the
 246      * current item.
 247      */
 248     void updateKeyboardAnchor();
 249
 250     /**
 251      * @return Index for the next row based on \a index.
 252      *         If there is no next row \a index will be returned.
 253      */
 254     int nextRowIndex(int index) const;
 255
 256     /**
 257      * @return Index for the previous row based on  \a index.
 258      *         If there is no previous row \a index will be returned.
 259      */
 260     int previousRowIndex(int index) const;
 261
 262     /**
 263      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
 264      * @return The position of the keyboard anchor for the item with the index \a index.
 265      *         If a horizontal scrolling is used the y-position of the item will be returned,
 266      *         for the vertical scrolling the x-position will be returned.
 267      */
 268     qreal keyboardAnchorPos(int index) const;
 269
 270     /**
 271      * Dependent on the selection-behavior the extendedSelectionRegion-property
 272      * of the KItemListStyleOption from the view should be adjusted: If no
 273      * rubberband selection is used the property should be enabled.
 274      */
 275     void updateExtendedSelectionRegion();
 276
 277     bool keyPressEvent(QKeyEvent* event);
 278     bool inputMethodEvent(QInputMethodEvent* event);
 279     bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 280     bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 281     bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 282     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
 283     bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 284     bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 285     bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 286     bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
 287     bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 288     bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 289     bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
 290     bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
 291     bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
 292
 293 private:
 294     bool m_singleClickActivationEnforced;
 295     bool m_selectionTogglePressed;
 296     bool m_clearSelectionIfItemsAreNotDragged;
 297     SelectionBehavior m_selectionBehavior;
 298     AutoActivationBehavior m_autoActivationBehavior;
 299     MouseDoubleClickAction m_mouseDoubleClickAction;
 300     KItemModelBase* m_model;
 301     KItemListView* m_view;
 302     KItemListSelectionManager* m_selectionManager;
 303     KItemListKeyboardSearchManager* m_keyboardManager;
 304     int m_pressedIndex;
 305     QPointF m_pressedMousePos;
 306
 307     QTimer* m_autoActivationTimer;
 308
 309     /**
 310      * When starting a rubberband selection during a Shift- or Control-key has been
 311      * pressed the current selection should never be deleted. To be able to restore
 312      * the current selection it is remembered in m_oldSelection before the
 313      * rubberband gets activated.
 314      */
 315     KItemSet m_oldSelection;
 316
 317     /**
 318      * Assuming a view is given with a vertical scroll-orientation, grouped items and
 319      * a maximum of 4 columns:
 320      *
 321      *  1  2  3  4
 322      *  5  6  7
 323      *  8  9 10 11
 324      * 12 13 14
 325      *
 326      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
 327      * item. Now when pressing key-down again item 11 should get the current item and not
 328      * item 10. This makes it necessary to keep track of the requested column to have a
 329      * similar behavior like in a text editor:
 330      */
 331     int m_keyboardAnchorIndex;
 332     qreal m_keyboardAnchorPos;
 333 };
 334
 335 #endif
 336
 337