bug: Dropdowns incorrectly positioned on PyGFX + Qt

[gselzer]

For some reason, the Qt dropdowns are translated across the screen when I'm using PyGFX canvases (in the video, they're in the bottom right corner):

20250206-1932-55.7974582.mp4

For some reason, it does not happen if I instead use VisPy.

For what it's worth, I'm using PyQt6 v6.8.0.

@tlambert03 can you replicate?

The only hint I have here is that when I run PyGFX, I see logged to the terminal

QWindowsWindow::setGeometry: Unable to set geometry 600x666+0+0 (frame: 600x666+0+0) on QWidgetWindow/"QWidgetClassWindow" on "DELL U2713H". Resulting geometry: 600x666+2160+1072 (frame: 600x666+2160+1072) margins: 0, 0, 0, 0)

So maybe it pertains to my monitor? If I launch from the other monitor, I see something different (this bug I've actually noticed before, but now it's more annoying):

20250206-1943-09.1451113.mp4

Maybe it's a bug in the pygfx qt backend (cc @almarklein)? Maybe this would be fixed with rendercanvas? I'll have to debug more...

[almarklein]

I would definitely recommend using rendercanvas, because wgpu.gui is going to be deprecated at some point.

Also make sure you use the QRenderWidget (rendercanvas) / QWgpuWidget (wgpu.gui). That one is meant as a widget and does not have the logic to behave as a main window.

[tlambert03]

Using render canvas elsewhere… need to update here as well 👍

(And also learned that bit about the widget vs main window and need to apply here). @gselzer, some of these lessons are in the scenex experiment for now, need to bring in here

[tlambert03]

@fdrgsp ... here's the issue we observed a couple days ago