C++ QPanGesture::delta方法代码示例

bool View::gestureEvent(QGestureEvent* event)
{   
    //
    // pinch has precedence
    if (QGesture *pinchEvent = event->gesture(Qt::PinchGesture)) {
        QPinchGesture* pinch = static_cast<QPinchGesture*>(pinchEvent);

        //
        // only pinch if the fingers have already moved a significant amount
        qreal totalScaleFactor = pinch->totalScaleFactor();
        if((totalScaleFactor < 0.66) || (totalScaleFactor > 1.5)){
            qreal zoomDelta = pinch->scaleFactor();
            qreal resultZoom = m_zoomFactor * zoomDelta;
            if(resultZoom > s_maxZoomFactor){
                zoomDelta = s_maxZoomFactor / m_zoomFactor;
            }else if(resultZoom < s_minZoomFactor){
                zoomDelta = s_minZoomFactor / m_zoomFactor;
            }

            // scale the view
            scale(zoomDelta,zoomDelta);
            m_zoomFactor *= zoomDelta;

            return true;
        }
    }

    //
    // pan
    if (QGesture *panEvent = event->gesture(Qt::PanGesture)) {
        QPanGesture* pan = static_cast<QPanGesture*>(panEvent);
        QPointF delta = pan->delta();
        qreal factor = (1.0 / m_zoomFactor) * 0.9;

        QScrollBar* vScrollBar = verticalScrollBar();
        vScrollBar->setValue(vScrollBar->value() - int(delta.y()/factor));

        QScrollBar* hScrollBar = horizontalScrollBar();
        hScrollBar->setValue(hScrollBar->value() - int(delta.x()/factor));
    }

    return true;
}

    void gestureEvent(QGestureEvent *event)
    {
        QPanGesture *pan = static_cast<QPanGesture *>(event->gesture(Qt::PanGesture));
        if (pan) {
            switch(pan->state()) {
            case Qt::GestureStarted: qDebug() << this << "Pan: started"; break;
            case Qt::GestureFinished: qDebug() << this << "Pan: finished"; break;
            case Qt::GestureCanceled: qDebug() << this << "Pan: canceled"; break;
            case Qt::GestureUpdated: break;
            default: qDebug() << this << "Pan: <unknown state>"; break;
            }

            if (pan->state() == Qt::GestureStarted)
                outside = false;
            event->ignore();
            event->ignore(pan);
            if (outside)
                return;

            const QPointF delta = pan->delta();
            const QPointF totalOffset = pan->offset();
            QScrollBar *vbar = verticalScrollBar();
            QScrollBar *hbar = horizontalScrollBar();

            if ((vbar->value() == vbar->minimum() && totalOffset.y() > 10) ||
                (vbar->value() == vbar->maximum() && totalOffset.y() < -10)) {
                outside = true;
                return;
            }
            if ((hbar->value() == hbar->minimum() && totalOffset.x() > 10) ||
                (hbar->value() == hbar->maximum() && totalOffset.x() < -10)) {
                outside = true;
                return;
            }
            vbar->setValue(vbar->value() - delta.y());
            hbar->setValue(hbar->value() - delta.x());
            event->accept(pan);
        }
    }

bool ModelSelectionPane::event(QEvent *event)
{
#if 0
    if(event->type() == QEvent::Gesture) {
        LogManagerInst << LogManager::LogDegreeType_Normal << "QEvent::Gesture";
        QGestureEvent* gestureEvent = static_cast<QGestureEvent*>(event);
        QGesture *gesture = gestureEvent->gesture(Qt::PanGesture);
        if(NULL == gestureEvent) {
            LogManagerInst << LogManager::LogDegreeType_Error << "QEvent::Gesture is NULL";
        }else {
            QList<QGesture *> gestures = gestureEvent->gestures();
            QList<QGesture *> activeGestures = gestureEvent->activeGestures();

            LogManagerInst << "Gesture Value" << QString::number((int)gesture, 16);

            LogManagerInst << LogManager::LogDegreeType_Normal << "Gesture Count" << QString::number(gestures.count()) << "activeGestures Count" << QString::number(activeGestures.count());
            LogManagerInst << LogManager::LogDegreeType_Normal
                << (gestureEvent->gesture(Qt::TapGesture) != NULL?"TapGesture":"")
                << (gestureEvent->gesture(Qt::TapAndHoldGesture) != NULL?"TapAndHoldGesture":"")
                << ((NULL != gesture)?"PanGesture":"")
                << (gestureEvent->gesture(Qt::PinchGesture) != NULL?"PinchGesture":"")
                << (gestureEvent->gesture(Qt::SwipeGesture) != NULL?"SwipeGesture":"") ;
        }

        LogManagerInst << (gesture == NULL?"PanGesture == NULL":"PanGesture != NULL");
        if(gesture != NULL) {
            LogManagerInst << LogManager::LogDegreeType_Normal << "Handle Pan Gesture";
            QPanGesture* panGesture = static_cast<QPanGesture*>(gesture);
            LogManagerInst << LogManager::LogDegreeType_Normal << "Acceleration" << QString::number(panGesture->acceleration());
            LogManagerInst << LogManager::LogDegreeType_Normal << "delta" << QString::number(panGesture->delta().x());
            LogManagerInst << LogManager::LogDegreeType_Normal << "State" << QString::number(gesture->state());
            if(gesture->state() == Qt::GestureFinished) {
                if((panGesture->acceleration() > 2) || (panGesture->delta().x() > width()/2)) {
                    FlipAnimationStart(panGesture->delta().x() > 0 ? FlipDirection_Right : FlipDirection_Left);
                }
            } else {
                LogManagerInst << LogManager::LogDegreeType_Normal << "Position" << QString::number(ui->itemsetpane->x());
                QPoint targetPos = ui->itemsetpane->pos()+QPoint(panGesture->delta().x(),0);
                if(targetPos.x() > width()/4) {
                    targetPos.setX(width()/4);
                } else if(targetPos.x() < width() - m_itemSetPaneSize.width() - width()/4) {
                    targetPos.setX(width() - m_itemSetPaneSize.width() - width()/4);
                } else {

                }
                ui->itemsetpane->move(targetPos);
            }
        }
    }
#endif

#if 1
    /*****
     * 外面是阴天，我也成了阴天
     * 狗屎的Gesture
     * Document明明图示QPanGesture是一个手指
     * 源码里却他妈的是3个
     * 你他妈的逗我么
     * 我就是个秀逗
     * 明天dota只能用秀逗了
     * 悲剧啊悲剧啊
     * 我的时间
     * 如同我的身体老去
     *****/

    bool flipAction = false;
    static float last_x = 0.0f;
    static float touchBeginLastX = 0.0f;

    int deltaX = 0;
    float acceleration = 0.0f;

    switch(event->type()) {
#if 1
    case QEvent::TouchBegin: {
        LogManagerInst << LogManager::LogDegreeType_Normal  << "TouchBegin";
        flipAction = true;
        m_time.start();
        const QTouchEvent *touchEvent = static_cast<const QTouchEvent *>(event);
        QTouchEvent::TouchPoint touchPoint = touchEvent->touchPoints().first();
        last_x = touchPoint.pos().x();
        touchBeginLastX = touchPoint.pos().x();
    }
        break;
    case QEvent::TouchUpdate: {
        LogManagerInst << LogManager::LogDegreeType_Normal  << "TouchUpdate";
        flipAction = true;
        const QTouchEvent *touchEvent = static_cast<const QTouchEvent *>(event);
        QTouchEvent::TouchPoint touchPoint = touchEvent->touchPoints().first();
        deltaX = touchPoint.pos().x() - last_x;
        last_x = touchPoint.pos().x();
    }
        break;

    case QEvent::TouchEnd: {
        LogManagerInst << LogManager::LogDegreeType_Normal  << "TouchEnd";
        flipAction = true;
        const QTouchEvent *touchEvent = static_cast<const QTouchEvent *>(event);
        QTouchEvent::TouchPoint touchPoint = touchEvent->touchPoints().first();
        int elapseTime = m_time.elapsed();
//.........这里部分代码省略.........

//===============================================================
bool MousePanNZoomNavigator::eventFilter(QObject *widget, QEvent *e) {
// according to Qt's doc, this constant has been defined by wheel mouse vendors
// we need it to interpret the value of QWheelEvent->delta()
#define WHEEL_DELTA 120
  if (e->type() == QEvent::Wheel &&
      (((QWheelEvent *) e)->orientation() == Qt::Vertical)) {

    GlMainWidget *g = (GlMainWidget *) widget;

    if(((QWheelEvent *) e)->delta() < 0 && g->getScene()->getCamera().getZoomFactor() < 0.5f) {
      return true;
    }

    g->getScene()->zoomXY(((QWheelEvent *) e)->delta() / WHEEL_DELTA,
                          ((QWheelEvent *) e)->x(), ((QWheelEvent *) e)->y());
    g->draw(false);
    return true;
  }

  if(e->type() == QEvent::Gesture) {
    GlMainWidget *g = (GlMainWidget *) widget;
    QGestureEvent* gesture = (QGestureEvent*)e;
    QPointF center;
    //swipe events and pan events are never fired, known Qt bug
    /*if(gesture->gesture(Qt::SwipeGesture)) {
      QSwipeGesture* swipe = (QSwipeGesture*)gesture->gesture(Qt::SwipeGesture);
      int x = cos(swipe->swipeAngle()) * swipe->property("velocity").toFloat();
      int y = sin(swipe->swipeAngle()) * swipe->property("velocity").toFloat();
      g->getScene()->translateCamera(x, y, 0);
    }*/

    if(gesture->gesture(Qt::PinchGesture)) {
      QPinchGesture* pinch = (QPinchGesture*)gesture->gesture(Qt::PinchGesture);
      Camera& camera = g->getScene()->getCamera();

      //store the camera scale factor when starting the gesture
      if(pinch->state() == Qt::GestureStarted) {
        cameraScaleFactor = camera.getZoomFactor();
        isGesturing = true;
      }

      if(pinch->changeFlags() & QPinchGesture::ScaleFactorChanged) {
        //only set the zoom factor if two events in a row were in the same direction (zoom in or out) to smooth a bit the effect.
        if((pinch->lastScaleFactor() > 1 && pinch->scaleFactor() > 1) || (pinch->lastScaleFactor() <= 1 && pinch->scaleFactor() <= 1)) {
          camera.setZoomFactor(cameraScaleFactor * pinch->totalScaleFactor());
        }
      }

      if(pinch->changeFlags() & QPinchGesture::RotationAngleChanged) {
        /*//backup the current camera center
              Coord oldCenter = camera.getCenter();
              Coord oldEye = camera.getEyes();
        //sets the camera center to the center of the pich gesture
              Coord rotationCenter(g->mapFromGlobal(pinch->centerPoint().toPoint()).x(), g->mapFromGlobal(pinch->centerPoint().toPoint()).y(), oldCenter.getZ());
              Coord rotationEye=camera.getEyes()+(rotationCenter-oldCenter);
              camera.setCenter(rotationCenter);
              camera.setEyes(rotationEye);*/
        //rotates the camera
        camera.rotate((pinch->rotationAngle() - pinch->lastRotationAngle())/180*M_PI, 0, 0, 1);
        /*
        //restore old camera center and eyes
              camera.setCenter(oldCenter);
              camera.setEyes(oldEye); */
      }

      if(pinch->state() == Qt::GestureFinished) {
        isGesturing = false;
      }

      if(gesture->gesture(Qt::PanGesture)) {
        QPanGesture* pan = (QPanGesture*)gesture->gesture(Qt::PanGesture);

        if(pan->state() == Qt::GestureStarted) {
          isGesturing = true;
        }

        if(pan->state() == Qt::GestureFinished) {
          isGesturing = false;
        }

        center = pan->delta();
        g->getScene()->translateCamera(pan->delta().x(), -pan->delta().y(), 0);
      }
    }

    g->draw(false);
    return true;
  }

  return false;
}