DMD text jump

[jabdoa2]

When adding a slide the text is sometimes off on a DMD. This seems to be caused by a race.

• Widget added to some slide
• Widget gets position, width, height from parent slide
• Widget positions based on that
• We remove the widget from the slide. Position changes
• We render the widget to the FBO (position is wrong here)
• Kivy will trigger the position change on the widget

So this is some kind of race. One solution would be to use the FBO texture as DMD output.

Same applies to display_light_player