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 HPiano::gestureEvent(QGestureEvent *event)
{
if (QGesture *gesture = event->gesture(Qt::PinchGesture)) {
// Zoom in/out when receiving a pinch gesture
QPinchGesture *pinch = static_cast<QPinchGesture *>(gesture);
static qreal magStart = 1.0;
if (pinch->state() == Qt::GestureStarted) {
magStart = scaleVal;
}
if (pinch->changeFlags() & QPinchGesture::ScaleFactorChanged) {
// On Windows, totalScaleFactor() contains the net magnification.
// On OS X, totalScaleFactor() is 1, and scaleFactor() contains the net magnification.
qreal value = pinch->totalScaleFactor();
if (value == 1) {
value = pinch->scaleFactor();
}
// Qt 5.4 doesn't report pinch->centerPoint() correctly
setScale(magStart*value);
}
}
return true;
}
QGestureRecognizer::Result QPinchGestureRecognizer::recognize(QGesture *state,
QObject *,
QEvent *event)
{
QPinchGesture *q = static_cast<QPinchGesture *>(state);
QPinchGesturePrivate *d = q->d_func();
const QTouchEvent *ev = static_cast<const QTouchEvent *>(event);
QGestureRecognizer::Result result;
switch (event->type()) {
case QEvent::TouchBegin: {
result = QGestureRecognizer::MayBeGesture;
break;
}
case QEvent::TouchEnd: {
if (q->state() != Qt::NoGesture) {
result = QGestureRecognizer::FinishGesture;
} else {
result = QGestureRecognizer::CancelGesture;
}
break;
}
case QEvent::TouchUpdate: {
d->changeFlags = 0;
if (ev->touchPoints().size() == 2) {
QTouchEvent::TouchPoint p1 = ev->touchPoints().at(0);
QTouchEvent::TouchPoint p2 = ev->touchPoints().at(1);
d->hotSpot = p1.screenPos();
d->isHotSpotSet = true;
QPointF centerPoint = (p1.screenPos() + p2.screenPos()) / 2.0;
if (d->isNewSequence) {
d->startPosition[0] = p1.screenPos();
d->startPosition[1] = p2.screenPos();
d->lastCenterPoint = centerPoint;
} else {
d->lastCenterPoint = d->centerPoint;
}
d->centerPoint = centerPoint;
d->changeFlags |= QPinchGesture::CenterPointChanged;
if (d->isNewSequence) {
d->scaleFactor = 1.0;
d->lastScaleFactor = 1.0;
} else {
d->lastScaleFactor = d->scaleFactor;
QLineF line(p1.screenPos(), p2.screenPos());
QLineF lastLine(p1.lastScreenPos(), p2.lastScreenPos());
d->scaleFactor = line.length() / lastLine.length();
}
d->totalScaleFactor = d->totalScaleFactor * d->scaleFactor;
d->changeFlags |= QPinchGesture::ScaleFactorChanged;
qreal angle = QLineF(p1.screenPos(), p2.screenPos()).angle();
if (angle > 180)
angle -= 360;
qreal startAngle = QLineF(p1.startScreenPos(), p2.startScreenPos()).angle();
if (startAngle > 180)
startAngle -= 360;
const qreal rotationAngle = startAngle - angle;
if (d->isNewSequence)
d->lastRotationAngle = 0.0;
else
d->lastRotationAngle = d->rotationAngle;
d->rotationAngle = rotationAngle;
d->totalRotationAngle += d->rotationAngle - d->lastRotationAngle;
d->changeFlags |= QPinchGesture::RotationAngleChanged;
d->totalChangeFlags |= d->changeFlags;
d->isNewSequence = false;
result = QGestureRecognizer::TriggerGesture;
} else {
d->isNewSequence = true;
if (q->state() == Qt::NoGesture)
result = QGestureRecognizer::Ignore;
else
result = QGestureRecognizer::FinishGesture;
}
break;
}
case QEvent::MouseButtonPress:
case QEvent::MouseMove:
case QEvent::MouseButtonRelease:
result = QGestureRecognizer::Ignore;
break;
default:
result = QGestureRecognizer::Ignore;
break;
}
return result;
}
//===============================================================
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;
}
