File indexing completed on 2024-04-28 05:45:07

 /*
  * SPDX-FileCopyrightText: 2011 Peter Penz <peter.penz19@gmail.com>
  *
  * Based on the Itemviews NG project from Trolltech Labs
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
 #ifndef KITEMLISTCONTROLLER_H
 #define KITEMLISTCONTROLLER_H
 
 #include <optional>
 
 #include "dolphin_export.h"
 #include "kitemset.h"
 
 #include <QObject>
 #include <QPointF>
 #include <QScroller>
 
 class QTimer;
 class KItemModelBase;
 class KItemListKeyboardSearchManager;
 class KItemListSelectionManager;
 class KItemListView;
 class KItemListWidget;
 class QContextMenuEvent;
 class QGestureEvent;
 class QGraphicsSceneHoverEvent;
 class QGraphicsSceneDragDropEvent;
 class QGraphicsSceneMouseEvent;
 class QGraphicsSceneResizeEvent;
 class QGraphicsSceneWheelEvent;
 class QInputMethodEvent;
 class QKeyEvent;
 class QTapGesture;
 class QTransform;
 class QTouchEvent;
 
 /**
  * @brief Controls the view, model and selection of an item-list.
  *
  * For a working item-list it is mandatory to set a compatible view and model
  * with KItemListController::setView() and KItemListController::setModel().
  *
  * @see KItemListView
  * @see KItemModelBase
  * @see KItemListSelectionManager
  */
 class DOLPHIN_EXPORT KItemListController : public QObject
 {
     Q_OBJECT
     Q_PROPERTY(KItemModelBase *model READ model WRITE setModel NOTIFY modelChanged)
     Q_PROPERTY(KItemListView *view READ view WRITE setView NOTIFY viewChanged)
 
 public:
     enum SelectionBehavior { NoSelection, SingleSelection, MultiSelection };
     Q_ENUM(SelectionBehavior)
 
     enum AutoActivationBehavior { ActivationAndExpansion, ExpansionOnly };
 
     enum MouseDoubleClickAction { ActivateAndExpandItem, ActivateItemOnly };
 
     /**
      * @param model  Model of the controller. The ownership is passed to the controller.
      * @param view   View of the controller. The ownership is passed to the controller.
      * @param parent Optional parent object.
      */
     KItemListController(KItemModelBase *model, KItemListView *view, QObject *parent = nullptr);
     ~KItemListController() override;
 
     void setModel(KItemModelBase *model);
     KItemModelBase *model() const;
 
     void setView(KItemListView *view);
     KItemListView *view() const;
 
     KItemListSelectionManager *selectionManager() const;
 
     void setSelectionBehavior(SelectionBehavior behavior);
     SelectionBehavior selectionBehavior() const;
 
     void setAutoActivationBehavior(AutoActivationBehavior behavior);
     AutoActivationBehavior autoActivationBehavior() const;
 
     void setMouseDoubleClickAction(MouseDoubleClickAction action);
     MouseDoubleClickAction mouseDoubleClickAction() const;
 
     int indexCloseToMousePressedPosition() const;
 
     /**
      * Sets the delay in milliseconds when dragging an object above an item
      * until the item gets activated automatically. A value of -1 indicates
      * that no automatic activation will be done at all (= default value).
      *
      * The hovered item must support dropping (see KItemModelBase::supportsDropping()),
      * otherwise the automatic activation is not available.
      *
      * After activating the item the signal itemActivated() will be
      * emitted. If the view supports the expanding of items
      * (KItemListView::supportsItemExpanding() returns true) and the item
      * itself is expandable (see KItemModelBase::isExpandable()) then instead
      * of activating the item it gets expanded instead (see
      * KItemModelBase::setExpanded()).
      */
     void setAutoActivationDelay(int delay);
     int autoActivationDelay() const;
 
     /**
      * If set to true, the signals itemActivated() and itemsActivated() are emitted
      * after a single-click of the left mouse button. If set to false (the default),
      * the setting from style()->styleHint(QStyle::SH_ItemView_ActivateItemOnSingleClick) is used.
      */
     void setSingleClickActivationEnforced(bool singleClick);
     bool singleClickActivationEnforced() const;
 
     /**
      * Setting the selection mode to enabled will make selecting and deselecting easier by acting
      * kind of similar to when the Control Key is held down.
      */
     void setSelectionModeEnabled(bool enabled);
     bool selectionMode() const;
 
     /**
      * @return \c true if search as you type is active, or \c false otherwise.
      */
     bool isSearchAsYouTypeActive() const;
 
     bool processEvent(QEvent *event, const QTransform &transform);
 
 Q_SIGNALS:
     /**
      * Is emitted if exactly one item has been activated by e.g. a mouse-click
      * or by pressing Return/Enter.
      */
     void itemActivated(int index);
 
     /**
      * Is emitted if more than one item has been activated by pressing Return/Enter
      * when having a selection.
      */
     void itemsActivated(const KItemSet &indexes);
 
     void itemMiddleClicked(int index);
 
     /**
      * Emitted if a context-menu is requested for the item with
      * the index \a index. It is assured that the index is valid.
      */
     void itemContextMenuRequested(int index, const QPointF &pos);
 
     /**
      * Emitted if a context-menu is requested for the KItemListView.
      */
     void viewContextMenuRequested(const QPointF &pos);
 
     /**
      * Emitted if a context-menu is requested for the header of the KItemListView.
      */
     void headerContextMenuRequested(const QPointF &pos);
 
     /**
      * Is emitted if the item with the index \p index gets hovered.
      */
     void itemHovered(int index);
 
     /**
      * Is emitted if the item with the index \p index gets unhovered.
      * It is assured that the signal itemHovered() for this index
      * has been emitted before.
      */
     void itemUnhovered(int index);
 
     /**
      * Is emitted if a mouse-button has been pressed above an item.
      * If the index is smaller than 0, the mouse-button has been pressed
      * above the viewport.
      */
     void mouseButtonPressed(int itemIndex, Qt::MouseButtons buttons);
 
     /**
      * Is emitted if a mouse-button has been released above an item.
      * It is assured that the signal mouseButtonPressed() has been emitted before.
      * If the index is smaller than 0, the mouse-button has been pressed
      * above the viewport.
      */
     void mouseButtonReleased(int itemIndex, Qt::MouseButtons buttons);
 
     void itemExpansionToggleClicked(int index);
 
     /**
      * Is emitted if a drop event is done above the item with the index
      * \a index. If \a index is < 0 the drop event is done above an
      * empty area of the view.
      * TODO: Introduce a new signal viewDropEvent(QGraphicsSceneDragDropEvent),
      *       which is emitted if the drop event occurs on an empty area in
      *       the view, and make sure that index is always >= 0 in itemDropEvent().
      */
     void itemDropEvent(int index, QGraphicsSceneDragDropEvent *event);
 
     /**
      * Is emitted if a drop event is done between the item with the index
      * \a index and the previous item.
      */
     void aboveItemDropEvent(int index, QGraphicsSceneDragDropEvent *event);
 
     /**
      * Is emitted if the Escape key is pressed.
      */
     void escapePressed();
 
     /**
      * Used to request either entering or leaving of selection mode
      * Leaving is requested by pressing Escape when no item is selected.
      *
      * Entering is requested if left click is pressed down for a long time without moving the cursor too much.
      * Moving the cursor would either trigger an item drag if the click was initiated on top of an item
      * or a selection rectangle if the click was not initiated on top of an item.
      * So long press is only emitted if there wasn't a lot of cursor movement.
      */
     void selectionModeChangeRequested(bool enabled);
 
     void modelChanged(KItemModelBase *current, KItemModelBase *previous);
     void viewChanged(KItemListView *current, KItemListView *previous);
 
     void selectedItemTextPressed(int index);
 
     void scrollerStop();
     void increaseZoom();
     void decreaseZoom();
     void swipeUp();
 
 public Q_SLOTS:
     void slotStateChanged(QScroller::State newState);
 
 private Q_SLOTS:
     void slotViewScrollOffsetChanged(qreal current, qreal previous);
 
     /**
      * Is invoked when the rubberband boundaries have been changed and will select
      * all items that are touched by the rubberband.
      */
     void slotRubberBandChanged();
 
     void slotChangeCurrentItem(const QString &text, bool searchFromNextItem);
 
     void slotAutoActivationTimeout();
 
 private:
     /**
      * Creates a QDrag object and initiates a drag-operation.
      */
     void startDragging();
 
     /**
      * @return Widget that is currently in the hovered state. 0 is returned
      *         if no widget is marked as hovered.
      */
     KItemListWidget *hoveredWidget() const;
 
     /**
      * @return Widget that is below the position \a pos. 0 is returned
      *         if no widget is below the position.
      */
     KItemListWidget *widgetForPos(const QPointF &pos) const;
 
     /**
      * @return Widget that should receive a drop event if an item is dropped at \a pos. 0 is returned
      *         if no widget should receive a drop event at the position.
      *
      * While widgetForPos() returns a widget if \a pos is anywhere inside the hover highlight area of the widget,
      * widgetForDropPos() only returns a widget if \a pos is directly above the widget (widget->contains(pos) == true).
      */
     KItemListWidget *widgetForDropPos(const QPointF &pos) const;
 
     /**
      * Updates m_keyboardAnchorIndex and m_keyboardAnchorPos. If no anchor is
      * set, it will be adjusted to the current item. If it is set it will be
      * checked whether it is still valid, otherwise it will be reset to the
      * current item.
      */
     void updateKeyboardAnchor();
 
     /**
      * @return Index for the next row based on \a index.
      *         If there is no next row \a index will be returned.
      */
     int nextRowIndex(int index) const;
 
     /**
      * @return Index for the previous row based on  \a index.
      *         If there is no previous row \a index will be returned.
      */
     int previousRowIndex(int index) const;
 
     /**
      * Helper method for updateKeyboardAnchor(), previousRowIndex() and nextRowIndex().
      * @return The position of the keyboard anchor for the item with the index \a index.
      *         If a horizontal scrolling is used the y-position of the item will be returned,
      *         for the vertical scrolling the x-position will be returned.
      */
     qreal keyboardAnchorPos(int index) const;
 
     /**
      * Dependent on the selection-behavior the extendedSelectionRegion-property
      * of the KItemListStyleOption from the view should be adjusted: If no
      * rubberband selection is used the property should be enabled.
      */
     void updateExtendedSelectionRegion();
 
     bool keyPressEvent(QKeyEvent *event);
     bool inputMethodEvent(QInputMethodEvent *event);
     bool mousePressEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
     bool mouseMoveEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
     bool mouseReleaseEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
     bool mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event, const QTransform &transform);
     bool contextMenuEvent(QContextMenuEvent *event);
     bool dragEnterEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
     bool dragLeaveEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
     bool dragMoveEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
     bool dropEvent(QGraphicsSceneDragDropEvent *event, const QTransform &transform);
     bool hoverEnterEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
     bool hoverMoveEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
     bool hoverLeaveEvent(QGraphicsSceneHoverEvent *event, const QTransform &transform);
     bool wheelEvent(QGraphicsSceneWheelEvent *event, const QTransform &transform);
     bool resizeEvent(QGraphicsSceneResizeEvent *event, const QTransform &transform);
     bool gestureEvent(QGestureEvent *event, const QTransform &transform);
     bool touchBeginEvent(QTouchEvent *event, const QTransform &transform);
     void tapTriggered(QTapGesture *tap, const QTransform &transform);
     void tapAndHoldTriggered(QGestureEvent *event, const QTransform &transform);
     void pinchTriggered(QGestureEvent *event, const QTransform &transform);
     void swipeTriggered(QGestureEvent *event, const QTransform &transform);
     void twoFingerTapTriggered(QGestureEvent *event, const QTransform &transform);
     bool onPress(const QPoint &screenPos, const QPointF &pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons);
     bool onRelease(const QPointF &pos, const Qt::KeyboardModifiers modifiers, const Qt::MouseButtons buttons, bool touch);
     void startRubberBand();
 
 private:
     bool m_singleClickActivationEnforced;
     bool m_selectionMode;
     bool m_selectionTogglePressed;
     bool m_clearSelectionIfItemsAreNotDragged;
     bool m_isSwipeGesture;
     bool m_dragActionOrRightClick;
     bool m_scrollerIsScrolling;
     bool m_pinchGestureInProgress;
     bool m_mousePress;
     bool m_isTouchEvent;
     SelectionBehavior m_selectionBehavior;
     AutoActivationBehavior m_autoActivationBehavior;
     MouseDoubleClickAction m_mouseDoubleClickAction;
     KItemModelBase *m_model;
     KItemListView *m_view;
     KItemListSelectionManager *m_selectionManager;
     KItemListKeyboardSearchManager *m_keyboardManager;
     std::optional<int> m_pressedIndex;
     QPointF m_pressedMouseGlobalPos;
 
     QTimer *m_autoActivationTimer;
 
     Qt::GestureType m_swipeGesture;
     Qt::GestureType m_twoFingerTapGesture;
 
     /**
      * When starting a rubberband selection during a Shift- or Control-key has been
      * pressed the current selection should never be deleted. To be able to restore
      * the current selection it is remembered in m_oldSelection before the
      * rubberband gets activated.
      */
     KItemSet m_oldSelection;
 
     /**
      * Assuming a view is given with a vertical scroll-orientation, grouped items and
      * a maximum of 4 columns:
      *
      *  1  2  3  4
      *  5  6  7
      *  8  9 10 11
      * 12 13 14
      *
      * If the current index is on 4 and key-down is pressed, then item 7 gets the current
      * item. Now when pressing key-down again item 11 should get the current item and not
      * item 10. This makes it necessary to keep track of the requested column to have a
      * similar behavior like in a text editor:
      */
     int m_keyboardAnchorIndex;
     qreal m_keyboardAnchorPos;
 };
 
 #endif