void CanvasView::gestureEvent(QGestureEvent *event)
{
QPinchGesture *pinch = static_cast<QPinchGesture*>(event->gesture(Qt::PinchGesture));
if(pinch) {
if(pinch->state() == Qt::GestureStarted) {
_gestureStartZoom = _zoom;
_gestureStartAngle = _rotate;
}
if((pinch->changeFlags() & QPinchGesture::ScaleFactorChanged))
setZoom(_gestureStartZoom * pinch->scaleFactor());
if((pinch->changeFlags() & QPinchGesture::RotationAngleChanged))
setRotation(_gestureStartAngle + pinch->rotationAngle());
}
}
//===============================================================
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;
}
