#288 Fullscreen toggle

[William Kendrick]

A safe, obvious, easy way to switch Tux Paint to fullscreen from within the app itself, on desktop. (e.g., Alt+F / Option+F. Perhaps also responding to a window maximize event?

[William Kendrick]

Motivation: Searching for how to make Tux Paint run in fullscreen is a very common YouTube search. I often also see photos and videos of kids at schools running Tux Paint in its default window, which is a shame.