Comment 23 for bug 1625846

Hm, that's correct. XMir *could* defer acting on focus lost until a timeout or focus-gained event, but that would be a heuristic.

The “Locally Active focus model” is a fairly X11-specific thing. It's from a time when applications were built in a one-X11-window-per-widget fashion, and so a textbox was an individual window that could be focused. I don't think it's going to be useful to Mir clients.

What might be useful - and would give XMir enough information here - is to augment the focus-lost event with the new focus window, if they're from the same session.

Alternatively, a “Session-focus” concept would also solve this. I seem to recall us talking about such a mechanism in the past...