Embed Notice

There are couple of surprises around window interaction:

- Once a cursor starts to resize/move a window, those actions are not possible for the other one.
- One cursor can open a menu, and the other one can use it, that one works pretty well!
- Closing a window with one cursor, while the other drags it, makes the second one *disappear*! :D

I mean, these are really hard UI questions to solve! Often, it's not clear to me what the correct behavior should be!