macOS Trackpad Gestures - Simultaneous Pinch & Pan?

[mjiggidyj]

On macOS with multitouch trackpad (so: traditional macOS desktop app utilizing Macbook trackpad, Magic Mouse, etc), I would like to handle two gestures simultaneously:

• User pinching to zoom in/out
• User moving hand (while pinching) to pan around

So, simultaneously I want my object to scale as the user pinches in/out AND follow the center point of that pinch around the screen to move it while it scales.

I find the best luck getting pinch-to-zoom data from QNativeGestureEvent:

	if event.type() == QtCore.QEvent.Type.NativeGesture and \
	  event.gestureType() == QtCore.Qt.NativeGestureType.ZoomNativeGesture:
		print("Zoom delta:", event.value())

And I can get two-finger pan gesture info from QWheelEvent:

	if event.type() == QtCore.QEvent.Type.Wheel:
		print("Wheel delta:", event.angleDelta())

However, if the user is zooming, I do not get QWheelEvents reported. And if the user is panning, I do not get the native gestures reported.

Furthermore, any positional info I get from the QNativeGestureEvent during pinch (from pos(), etc) is not updated -- it just reports the centerpoint as it was when the pinch was initiated, but does not move "live." Experimented with setMouseTracking(True) on the widget but that didn't update center points live.

[jsulm]

@mjiggidyj said in macOS Trackpad Gestures - Simulatneous Pinch & Pan?:

any positional info I get from the QNativeGestureEvent during pinch (from pos(), etc) is not updated

What about https://doc.qt.io/qt-6/qnativegestureevent.html#delta ?