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 #include <QScroller>
18 
19 class QTimer;
20 class KItemModelBase;
21 class KItemListKeyboardSearchManager;
22 class KItemListSelectionManager;
23 class KItemListView;
24 class KItemListWidget;
25 class QGestureEvent;
26 class QGraphicsSceneHoverEvent;
27 class QGraphicsSceneDragDropEvent;
28 class QGraphicsSceneMouseEvent;
29 class QGraphicsSceneResizeEvent;
30 class QGraphicsSceneWheelEvent;
31 class QInputMethodEvent;
32 class QKeyEvent;
33 class QTapGesture;
34 class QTransform;
35 class QTouchEvent;
36 
37 /**
38  * @brief Controls the view, model and selection of an item-list.
39  *
40  * For a working item-list it is mandatory to set a compatible view and model
41  * with KItemListController::setView() and KItemListController::setModel().
42  *
43  * @see KItemListView
44  * @see KItemModelBase
45  * @see KItemListSelectionManager
46  */
47 class DOLPHIN_EXPORT KItemListController : public QObject
48 {
49     Q_OBJECT
50     Q_PROPERTY(KItemModelBase* model READ model WRITE setModel)
51     Q_PROPERTY(KItemListView *view READ view WRITE setView)
52     Q_PROPERTY(SelectionBehavior selectionBehavior READ selectionBehavior WRITE setSelectionBehavior)
53     Q_PROPERTY(AutoActivationBehavior autoActivationBehavior READ autoActivationBehavior WRITE setAutoActivationBehavior)
54     Q_PROPERTY(MouseDoubleClickAction mouseDoubleClickAction READ mouseDoubleClickAction WRITE setMouseDoubleClickAction)
55 
56 public:
57     enum SelectionBehavior {
58         NoSelection,
59         SingleSelection,
60         MultiSelection
61     };
62     Q_ENUM(SelectionBehavior)
63 
64     enum AutoActivationBehavior {
65         ActivationAndExpansion,
66         ExpansionOnly
67     };
68 
69     enum MouseDoubleClickAction {
70         ActivateAndExpandItem,
71         ActivateItemOnly
72     };
73 
74     /**
75      * @param model  Model of the controller. The ownership is passed to the controller.
76      * @param view   View of the controller. The ownership is passed to the controller.
77      * @param parent Optional parent object.
78      */
79     KItemListController(KItemModelBase* model, KItemListView* view, QObject* parent = nullptr);
80     ~KItemListController() override;
81 
82     void setModel(KItemModelBase* model);
83     KItemModelBase* model() const;
84 
85     void setView(KItemListView* view);
86     KItemListView* view() const;
87 
88     KItemListSelectionManager* selectionManager() const;
89 
90     void setSelectionBehavior(SelectionBehavior behavior);
91     SelectionBehavior selectionBehavior() const;
92 
93     void setAutoActivationBehavior(AutoActivationBehavior behavior);
94     AutoActivationBehavior autoActivationBehavior() const;
95 
96     void setMouseDoubleClickAction(MouseDoubleClickAction action);
97     MouseDoubleClickAction mouseDoubleClickAction() const;
98 
99     int indexCloseToMousePressedPosition() const;
100 
101     /**
102      * Sets the delay in milliseconds when dragging an object above an item
103      * until the item gets activated automatically. A value of -1 indicates
104      * that no automatic activation will be done at all (= default value).
105      *
106      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
107      * otherwise the automatic activation is not available.
108      *
109      * After activating the item the signal itemActivated() will be
110      * emitted. If the view supports the expanding of items
111      * (KItemListView::supportsItemExpanding() returns true) and the item
112      * itself is expandable (see KItemModelBase::isExpandable()) then instead
113      * of activating the item it gets expanded instead (see
114      * KItemModelBase::setExpanded()).
115      */
116     void setAutoActivationDelay(int delay);
117     int autoActivationDelay() const;
118 
119     /**
120      * If set to true, the signals itemActivated() and itemsActivated() are emitted
121      * after a single-click of the left mouse button. If set to false (the default),
122      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
123      */
124     void setSingleClickActivationEnforced(bool singleClick);
125     bool singleClickActivationEnforced() const;
126 
127     bool processEvent(QEvent* event, const QTransform& transform);
128 
129 Q_SIGNALS:
130     /**
131      * Is emitted if exactly one item has been activated by e.g. a mouse-click
132      * or by pressing Return/Enter.
133      */
134     void itemActivated(int index);
135 
136     /**
137      * Is emitted if more than one item has been activated by pressing Return/Enter
138      * when having a selection.
139      */
140     void itemsActivated(const KItemSet& indexes);
141 
142     void itemMiddleClicked(int index);
143 
144     /**
145      * Emitted if a context-menu is requested for the item with
146      * the index \a index. It is assured that the index is valid.
147      */
148     void itemContextMenuRequested(int index, const QPointF& pos);
149 
150     /**
151      * Emitted if a context-menu is requested for the KItemListView.
152      */
153     void viewContextMenuRequested(const QPointF& pos);
154 
155     /**
156      * Emitted if a context-menu is requested for the header of the KItemListView.
157      */
158     void headerContextMenuRequested(const QPointF& pos);
159 
160     /**
161      * Is emitted if the item with the index \p index gets hovered.
162      */
163     void itemHovered(int index);
164 
165     /**
166      * Is emitted if the item with the index \p index gets unhovered.
167      * It is assured that the signal itemHovered() for this index
168      * has been emitted before.
169      */
170     void itemUnhovered(int index);
171 
172     /**
173      * Is emitted if a mouse-button has been pressed above an item.
174      * If the index is smaller than 0, the mouse-button has been pressed
175      * above the viewport.
176      */
177     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
178 
179     /**
180      * Is emitted if a mouse-button has been released above an item.
181      * It is assured that the signal mouseButtonPressed() has been emitted before.
182      * If the index is smaller than 0, the mouse-button has been pressed
183      * above the viewport.
184      */
185     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
186 
187     void itemExpansionToggleClicked(int index);
188 
189     /**
190      * Is emitted if a drop event is done above the item with the index
191      * \a index. If \a index is < 0 the drop event is done above an
192      * empty area of the view.
193      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
194      *       which is emitted if the drop event occurs on an empty area in
195      *       the view, and make sure that index is always >= 0 in itemDropEvent().
196      */
197     void itemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
198 
199     /**
200      * Is emitted if a drop event is done between the item with the index
201      * \a index and the previous item.
202      */
203     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent* event);
204 
205     /**
206      * Is emitted if the Escape key is pressed.
207      */
208     void escapePressed();
209 
210     void modelChanged(KItemModelBase* current, KItemModelBase* previous);
211     void viewChanged(KItemListView* current, KItemListView* previous);
212 
213     void selectedItemTextPressed(int index);
214 
215     void scrollerStop();
216     void increaseZoom();
217     void decreaseZoom();
218     void swipeUp();
219 
220 public Q_SLOTS:
221     void slotStateChanged(QScroller::State newState);
222 
223 private Q_SLOTS:
224     void slotViewScrollOffsetChanged(qreal current, qreal previous);
225 
226     /**
227      * Is invoked when the rubberband boundaries have been changed and will select
228      * all items that are touched by the rubberband.
229      */
230     void slotRubberBandChanged();
231 
232     void slotChangeCurrentItem(const QString& text, bool searchFromNextItem);
233 
234     void slotAutoActivationTimeout();
235 
236 private:
237     /**
238      * Creates a QDrag object and initiates a drag-operation.
239      */
240     void startDragging();
241 
242     /**
243      * @return Widget that is currently in the hovered state. 0 is returned
244      *         if no widget is marked as hovered.
245      */
246     KItemListWidget* hoveredWidget() const;
247 
248     /**
249      * @return Widget that is below the position \a pos. 0 is returned
250      *         if no widget is below the position.
251      */
252     KItemListWidget* widgetForPos(const QPointF& pos) const;
253 
254     /**
255      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
256      * set, it will be adjusted to the current item. If it is set it will be
257      * checked whether it is still valid, otherwise it will be reset to the
258      * current item.
259      */
260     void updateKeyboardAnchor();
261 
262     /**
263      * @return Index for the next row based on \a index.
264      *         If there is no next row \a index will be returned.
265      */
266     int nextRowIndex(int index) const;
267 
268     /**
269      * @return Index for the previous row based on  \a index.
270      *         If there is no previous row \a index will be returned.
271      */
272     int previousRowIndex(int index) const;
273 
274     /**
275      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
276      * @return The position of the keyboard anchor for the item with the index \a index.
277      *         If a horizontal scrolling is used the y-position of the item will be returned,
278      *         for the vertical scrolling the x-position will be returned.
279      */
280     qreal keyboardAnchorPos(int index) const;
281 
282     /**
283      * Dependent on the selection-behavior the extendedSelectionRegion-property
284      * of the KItemListStyleOption from the view should be adjusted: If no
285      * rubberband selection is used the property should be enabled.
286      */
287     void updateExtendedSelectionRegion();
288 
289     bool keyPressEvent(QKeyEvent* event);
290     bool inputMethodEvent(QInputMethodEvent* event);
291     bool mousePressEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
292     bool mouseMoveEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
293     bool mouseReleaseEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
294     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent* event, const QTransform& transform);
295     bool dragEnterEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
296     bool dragLeaveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
297     bool dragMoveEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
298     bool dropEvent(QGraphicsSceneDragDropEvent* event, const QTransform& transform);
299     bool hoverEnterEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
300     bool hoverMoveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
301     bool hoverLeaveEvent(QGraphicsSceneHoverEvent* event, const QTransform& transform);
302     bool wheelEvent(QGraphicsSceneWheelEvent* event, const QTransform& transform);
303     bool resizeEvent(QGraphicsSceneResizeEvent* event, const QTransform& transform);
304     bool gestureEvent(QGestureEvent* event, const QTransform& transform);
305     bool touchBeginEvent(QTouchEvent* event, const QTransform& transform);
306     void tapTriggered(QTapGesture* tap, const QTransform& transform);
307     void tapAndHoldTriggered(QGestureEvent* event, const QTransform& transform);
308     void pinchTriggered(QGestureEvent* event, const QTransform& transform);
309     void swipeTriggered(QGestureEvent* event, const QTransform& transform);
310     void twoFingerTapTriggered(QGestureEvent* event, const QTransform& transform);
311     bool onPress(const QPoint& screenPos, const QPointF& pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons);
312     bool onRelease(const QPointF& pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons, bool touch);
313     void startRubberBand();
314 
315 private:
316     bool m_singleClickActivationEnforced;
317     bool m_selectionTogglePressed;
318     bool m_clearSelectionIfItemsAreNotDragged;
319     bool m_isSwipeGesture;
320     bool m_dragActionOrRightClick;
321     bool m_scrollerIsScrolling;
322     bool m_pinchGestureInProgress;
323     bool m_mousePress;
324     bool m_isTouchEvent;
325     SelectionBehavior m_selectionBehavior;
326     AutoActivationBehavior m_autoActivationBehavior;
327     MouseDoubleClickAction m_mouseDoubleClickAction;
328     KItemModelBase* m_model;
329     KItemListView* m_view;
330     KItemListSelectionManager* m_selectionManager;
331     KItemListKeyboardSearchManager* m_keyboardManager;
332     int m_pressedIndex;
333     QPointF m_pressedMousePos;
334 
335     QTimer* m_autoActivationTimer;
336 
337     Qt::GestureType m_swipeGesture;
338     Qt::GestureType m_twoFingerTapGesture;
339 
340     /**
341      * When starting a rubberband selection during a Shift- or Control-key has been
342      * pressed the current selection should never be deleted. To be able to restore
343      * the current selection it is remembered in m_oldSelection before the
344      * rubberband gets activated.
345      */
346     KItemSet m_oldSelection;
347 
348     /**
349      * Assuming a view is given with a vertical scroll-orientation, grouped items and
350      * a maximum of 4 columns:
351      *
352      *  1  2  3  4
353      *  5  6  7
354      *  8  9 10 11
355      * 12 13 14
356      *
357      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
358      * item. Now when pressing key-down again item 11 should get the current item and not
359      * item 10. This makes it necessary to keep track of the requested column to have a
360      * similar behavior like in a text editor:
361      */
362     int m_keyboardAnchorIndex;
363     qreal m_keyboardAnchorPos;
364 };
365 
366 #endif
367 
368 
369