Flutter app doesn't regain focus after it is lost

[johnpryan]

It looks like once a Flutter app that handles keyboard shortcuts loses focus, it can't be regained.

Steps to reproduce:

1. Run this gist
2. Observe the arrow keys work
3. Move cursor into Codemirror
4. Click on the flutter app to regain focus
5. Observe the arrow keys don't work anymore.

[johnpryan]

cc: @csells it would be great to fix this as part of the AI work, since it's common to generate AI snippets that use the arrow keys (e.g. snake game)

[csells]

This is not limited to AI -- anyone building anything in DartPad that requires keyboard input beyond a TextField is going to have this problem.

[johnpryan]

Yeah, I just don't want the AI blamed when keyboard input isn't working...

[csells]

ha. I think I wrote that in an email when I first discovered this issue. : )