Created attachment 267148 [details] [review]
window-tracker: Be more cautious when setting focus app

Since we started tracking non-interesting windows, we can no longer
assume that if we manage to find an app associated with the focus window,
it should appear focused - we now can find apps for docks, the DESKTOP
window etc.
To restore the old behavior, make sure that the focus window or one of
its parents is "interesting".

Review of attachment 267148 [details] [review]:

::: src/shell-window-tracker.c
@@ +485,3 @@
+  while (new_focus_win &&
+         !shell_window_tracker_is_window_interesting (new_focus_win))
+    new_focus_win = meta_window_get_transient_for (new_focus_win);

Hm. Is there a reason we have to track the window in window_for_app for uninteresting windows? Simply allowing the _shell_app_add_window but not the insert into window_to_app seems like a better fix for this to me.

(In reply to comment #2)
> Review of attachment 267148 [details] [review]:
> Hm. Is there a reason we have to track the window in window_for_app for
> uninteresting windows? Simply allowing the _shell_app_add_window but not the
> insert into window_to_app seems like a better fix for this to me.

I basically see three options:

 (1) track everything, handle focus-app explicitly

 (2) track interesting windows, handle focus-app explicitly

 (3) track "whatever should appear as focus-app"

I don't think (2) makes a lot of sense at all here - we end up with one set of windows that are associated with an app as far as ShellApp is concerned, a different set of windows for the win->app mapping, and yet a different set of windows associated with a "focus-app". (3) is better, but tracking "the set of windows we want to be associated with an application in the app menu" just feels a bit arbitrary (not to mention that it's bound to break again if we need to change the set of tracked windows for some reason in the future).

In the end it boils down to preference, but I quite like how the app->windows mapping stopped to be subtly different from the window->app mapping:
It's not at all obvious that "shell_window_tracker_get_window_app(tracker, window) == app" may be false for any window retrieved via "shell_app_get_windows(app)". Admittedly we have lived with this difference until very recently without many problems, so it wouldn't be the end of the world to reintroduce it. I still think it's nicer not to though.

Attachment 267148 [details] pushed as 2663e1b - window-tracker: Be more cautious when setting focus app