SUMMARY When I turn off touch painting in the configuration, Krita still receives events from my palm resting on the canvas. I suspect Android+Qt is transforming these touch events as mouse pointer events. We might need to block mouse-events on the canvas as well. The tablet tester, nor the tablet logging give any good feedback here (both on my laptop and on the android device, touch is given as a mouse event), we might need to adjust them to tell us about touch events too. STEPS TO REPRODUCE 1. Turn off touch painting in the settings. 2. Draw something on canvas. OBSERVED RESULT Observe how spikes will appear between palm and stylus, due to krita not blocking the palm/touch event. EXPECTED RESULT Expected result happens when turning off touch system-wise. SOFTWARE/OS VERSIONS Android 9 tablet. Google play version.
I tried reproducing this and I could reproduce it (the spikes). But, I think this might something other than mouse events being sent, I'm not sure though. When I rest my palm on tablet, the canvas rotates/zooms a few degrees which causes "On-Canvas Message" to pop up and if you start drawing at the same time, while the message is still visible, your stroke would be ended interrupted when the message disappears. There is a bug which causes events to pause from coming because of the pop-up messages. So canvas technically is still in "TabletUpdate" state even when you lifted your stylus, because "TabletEnd" was never successfully sent. So, when you later start tablet events again. It starts from the `Update` state, not the `Start` state. Hence the spike :-( You can try to disable On-canvas Messages to verify if this is the case or if it is just another bug all together...
Nope, still have this with oncanvas messages turned off. Tablet end not coming, seems plausible, but it seems somehow the touch events get precedent over the stylus events, which is troublesome.
@Sharaf could reproduce, so I'm confirming this.
Can confirm this on 4.3.0, Ubuntu 20.04, X11, Lenovo Yoga C930. Tablet tester recognizes touch event as mouse event. I do not know whether this is Qt's fault or X11's or something else.