main.cpp Example File

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 #include <QtCore>
 #include <QtGui>
 #include "fingerswipegesture.h"

 /*!
     \class RectObject
     A QGraphicsObject that grabs and reacts on the swipe gesture.
     Note that it needs to be a QGraphicsObject or else the gestures will not work correctly.
 */
 class RectObject :  public QGraphicsObject
 {
     Q_OBJECT

 public:

     RectObject( qreal x, qreal y, qreal width, qreal height, QBrush brush)
         : m_rect(x, y, width, height)
         , m_pen(brush.color().lighter(), 3.0)
         , m_brush(brush)
         , m_striken(false)
     {
 // ![0]
         if (!fingerSwipeGestureType)
             fingerSwipeGestureType = QGestureRecognizer::registerRecognizer( new FingerSwipeGestureRecognizer() );

         grabGesture(fingerSwipeGestureType);
 // ![0]
     }

     /*!
       \reimp
       */
     QRectF boundingRect() const
     {
         qreal halfpw = m_pen.widthF() / 2;
         QRectF rect = m_rect;
         if (halfpw > 0.0)
             rect.adjust(-halfpw, -halfpw, halfpw, halfpw);

         return rect;
     }

     bool sceneEvent(QEvent *e)
     {
 // ![1]
         if (e->type() == QEvent::TouchBegin) {
             e->accept();
             return true;
         }
 // ![1]
 // ![2]
         if (e->type() == QEvent::Gesture) {
              QGestureEvent *ge = static_cast<QGestureEvent*>(e);

              if (QGesture *gesture = ge->gesture(fingerSwipeGestureType)) {
                  FingerSwipeGesture *swipe = static_cast<FingerSwipeGesture*>(gesture);
                  if (swipe->state() == Qt::GestureFinished) {
                      m_striken = swipe->isLeftToRight();
                      update();
                  }
                  ge->setAccepted(gesture, true);
                  return true;
              }
         }
 // ![2]
         return QGraphicsObject::sceneEvent(e);
     }

     /*! \reimp
       */
     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
     {
         Q_UNUSED(option);
         Q_UNUSED(widget);
         painter->setPen(m_pen);
         painter->setBrush(m_brush);
         painter->drawRect(m_rect);

         if (m_striken) {
             QPen strikePen(Qt::red, 10.0);
             painter->setPen(strikePen);
             painter->drawLine(m_rect.left() + m_rect.width() / 10,
                               m_rect.center().y(),
                               m_rect.right() - m_rect.width() / 10,
                               m_rect.center().y());
         }
     }

     static Qt::GestureType fingerSwipeGestureType;

     QRectF m_rect;

     QPen m_pen;
     QBrush m_brush;
     bool m_striken;
 };

 Qt::GestureType RectObject::fingerSwipeGestureType = (Qt::GestureType)0;

 class MainWindow : public QMainWindow
 {
     Q_OBJECT

 public:
     MainWindow()
     {
         QGraphicsScene *scene = new QGraphicsScene();

 // ![3]
         RectObject *rect1 = new RectObject( 10, 10, 200, 100, QBrush( Qt::gray ) );
         RectObject *rect2 = new RectObject( 100, 200, 200, 200, QBrush( Qt::green ) );
         RectObject *rect3 = new RectObject( 400, 300, 300, 80, QBrush( Qt::yellow ) );

         scene->addItem(rect1);
         scene->addItem(rect2);
         scene->addItem(rect3);
 // ![3]

         QGraphicsView *view = new QGraphicsView();
         view->setScene(scene);

         setCentralWidget(view);

         setWindowTitle(tr("Gesture example"));
   }
 };

 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     MainWindow mw;
     mw.show();
     return app.exec();
 }

 #include "main.moc"