Re: [External] : Re: master 127ab231be 1/2: Attempt to clarify Input Focus documentation

[Po Lu]

chad <yandros@gmail.com> writes:

> Back in the day, X programs knew how to distinguish between windows
> appearing/disappearing on their own and the window under the mouse
> being changed by the window manager, and focus could be managed
> appropriately.  WM's of the time also had (configurable) thresholds
> for whether such accidental movements would trigger focus changes or
> not.

"Appearing" or "disappearing" accidental movements?

The reason it is such a pain to manage is that the focus does not end up
in the toplevel window (with WM_TAKE_FOCUS messages), always follows the
mouse regardless of the value of the input flag in the window manager
hints property, and is delivered in terms of crossing events with the
focus flag set.  A single master device can also have both explicit and
implicit focus at any given time.