File indexing completed on 2025-04-27 03:58:23

 /* ============================================================
  *
  * This file is a part of digiKam project
  * https://www.digikam.org
  *
  * Date        : 2011-03-04
  * Description : A simple item to click, drag and release
  *
  * SPDX-FileCopyrightText: 2010-2011 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
  *
  * SPDX-License-Identifier: GPL-2.0-or-later
  *
  * ============================================================ */
 
 #include "clickdragreleaseitem.h"
 
 // Qt includes
 
 #include <QApplication>
 #include <QGraphicsSceneMouseEvent>
 #include <QKeyEvent>
 #include <QObject>
 #include <QPointF>
 
 // Local includes
 
 #include "digikam_debug.h"
 #include "itemvisibilitycontroller.h"
 
 namespace Digikam
 {
 
 enum ClickDragState
 {
     HoverState,
     PressedState,
     PressDragState,
     ClickedMoveState
 };
 
 class Q_DECL_HIDDEN ClickDragReleaseItem::Private
 {
 public:
 
     explicit Private()
         : state(HoverState)
     {
     }
 
     template <class Event> bool isDrag(Event* e)
     {
         return ((pressPos - e->scenePos()).manhattanLength() > QApplication::startDragDistance());
     }
 
     template <class Event> QRectF rect(Event* e)
     {
         return QRectF(pressPos, e->scenePos()).normalized();
     }
 
 public:
 
     ClickDragState state;
     QPointF        pressPos;
 };
 
 // ----------------------------------------------------------------------------
 
 ClickDragReleaseItem::ClickDragReleaseItem(QGraphicsItem* const parent)
     : QGraphicsObject(parent),
       d              (new Private)
 {
     setCursor(Qt::CrossCursor);
     setFlags(ItemIsFocusable | ItemHasNoContents);
 }
 
 ClickDragReleaseItem::~ClickDragReleaseItem()
 {
     delete d;
 }
 
 QRectF ClickDragReleaseItem::boundingRect() const
 {
     if (parentItem())
     {
         return QRectF(QPointF(0, 0), parentItem()->boundingRect().size());
     }
 
     return QRectF();
 }
 
 void ClickDragReleaseItem::paint(QPainter*, const QStyleOptionGraphicsItem*, QWidget*)
 {
 }
 
 /**
  * 1) Press - Drag - Release:
  *    mousePress, PressedState -> mouseMoveEvent over threshold, PressDragState -> mouseReleaseEvent, finished
  * 2) Click - Move - Click:
  *    mousePressEvent, PressedState -> mouseReleaseEvent, ClickedMoveState ->
  *    hoverMoveEvent -> mouseReleaseEvent, finished
  */
 
 void ClickDragReleaseItem::mousePressEvent(QGraphicsSceneMouseEvent* e)
 {
     if (e->button() != Qt::LeftButton)
     {
         Q_EMIT cancelled();
         return;
     }
 
     if (d->state == HoverState)
     {
         d->pressPos = e->scenePos();
         d->state    = PressedState;
         Q_EMIT started(e->scenePos());
     }
 }
 
 void ClickDragReleaseItem::mouseMoveEvent(QGraphicsSceneMouseEvent* e)
 {
     if (d->state == PressedState && d->isDrag(e))
     {
         d->state = PressDragState;
         setCursor(Qt::SizeFDiagCursor);
     }
 
     if (d->state == PressDragState)
     {
         Q_EMIT moving(d->rect(e));
     }
 }
 
 void ClickDragReleaseItem::hoverMoveEvent(QGraphicsSceneHoverEvent* e)
 {
     if (d->state == ClickedMoveState)
     {
         Q_EMIT moving(d->rect(e));
     }
 }
 
 void ClickDragReleaseItem::mouseReleaseEvent(QGraphicsSceneMouseEvent* e)
 {
     if      (d->state == PressedState)
     {
         // click-move-click mode first click.
         // It cannot be over the drag threshold in this state, would be caught in moveEvent.
 
         d->state = ClickedMoveState;
         setCursor(Qt::SizeFDiagCursor);
         setAcceptHoverEvents(true);
     }
     else if (d->state == ClickedMoveState)
     {
         // click-move-click mode second click
 
         d->state = HoverState;
         setCursor(Qt::CrossCursor);
         setAcceptHoverEvents(false);
         Q_EMIT finished(d->rect(e));
     }
     else if (d->state == PressDragState)
     {
         if (d->isDrag(e))
         {
             Q_EMIT finished(d->rect(e));
         }
         else
         {
             Q_EMIT cancelled();
         }
 
         d->state = HoverState;
         setCursor(Qt::CrossCursor);
         setAcceptHoverEvents(false);
     }
 }
 
 void ClickDragReleaseItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent* e)
 {
     e->ignore();
 }
 
 void ClickDragReleaseItem::keyPressEvent(QKeyEvent* e)
 {
     qCDebug(DIGIKAM_WIDGETS_LOG) << e;
 
     switch (e->key())
     {
         case Qt::Key_Backspace:
         case Qt::Key_Escape:
             Q_EMIT cancelled();
             break;
 
         default:
             e->ignore();
             break;
     }
 }
 
 } // namespace Digikam
 
 #include "moc_clickdragreleaseitem.cpp"