We don't have fine-grained security permissions for JavaFX. We require AllPermission to be granted in order enter full screen mode, although this should be its own permission.

I propose a class javafx.stage.StagePermission for named permissions. The values of this would be

"setFullScreen" - Allows setting full screen mode for a Stage
"setFullScreenWarning" - Allows disabling the full screen overlay warning

If we have a need for other permissions in the future related to the javafx.stage package, they should be new named properties on this class. Permissions related to another packages should be in a new property class in a different package.