Make popup grabs work when an IME has a keyboard grab

[kchibisov]

Keep in mind that IME can't work with QT at all, so I just basically don't have popups until I kill anthywl or something.

You can probably just start anthywl and QT apps, like telegram won't have rmb popup on message working at all. This was not the thing a while ago, so I guess some new logic in niri broke it.

niri 0.1.0-alpha.3 (v0.1.0-alpha.3-65-g65e8649)

[kchibisov]

This is not QT specific, and relates to grabs.

[YaLTeR]

This will need some refactoring to fix properly, perhaps in Smithay. For now let's ignore popup grabs when an IME keyboard grab is active. f5642ab

[YaLTeR]

For more context, the problem is that:

• IME sets a keyboard grab to read key events.
• Popup grabs set a keyboard grab to keep the keyboard focus on the popup surface (normally the keyboard focus remains on the toplevel).
  • There's also a check when obtaining the popup grab that the keyboard focus was correct. If it wasn't, the popup grab is denied.
• Keyboard grabs in Smithay don't stack, so one of these replaces the other. Then the keyboard grab check fails and the popup grab is denied.

Now tbh I'm not sure we need the popup keyboard grab in niri, it will probably be better to refactor the keyboard focus code a bit and keep track of it ourselves. This might solve the problem.