Warn for inproper use of WxRenderWidget

[almarklein]

Closes #91 cc @tlambert03

[tlambert03]

This is fine, however, there’s shouldn’t be technically anything wrong with creating an unparented widget and then reparenting it before starting the event loop right?

Thats what I had been doing and why this warning sorta misses the point (which is more that rendercanvas doesn’t support that mode of operation… even if you didn’t intend to use it as a top widget)

the key reason that that is an unsupported mode is because of operations performed by renderwidget in the init (not because of a problem with an temporarily unparented widget in wxpython). So the warning should perhaps say “render widget requires a parent at the time of instantiation” rather than assuming it was going to be a top level widget

[Vipitis]

I think the same is also true for QRenderWidget I had imported that instead of RenderCanvas and I had to kill the terminal to recover.

[almarklein]

there’s shouldn’t be technically anything wrong with creating an unparented widget and then reparenting it before starting the event loop right?

Good point! I tweaked the code so that it allows a (temporary) unparented widget. Could you try and see if it works with what you were trying?