bug#61337: 29.0.60; Setting frame-title-format makes Emacs to steal focus

["Óscar Fuentes" <ofv@wanadoo.es>]

Eli Zaretskii <eliz@gnu.org> writes:

>> > Oscar meant that KWin focused the frame without changing the position of
>> > Emacs in the window stack.  That isn't the bug which was reported, Emacs
>> > being focused was.
>> 
>> Right. The part about the z-order not changing just makes the problem
>> worse.
>> 
>> For instance: let's suppose that Emacs window is hidden by some other
>> application's window, (Konsole for instance) that also has the focus.
>> When I switch desktops Emacs will steal the focus, but otherwise the
>> screen's appearence will not change, which makes me think that Konsole
>> still has the focus, then I start typing but the input go to Emacs, and
>> this too often causes a mess.
>> 
>> Same thing could happen even when Emacs' window is visible, of course.
>> After all, the user does not expect that switching desktops changes the
>> focus to certain application's window.
>
> You mean, you rely on the focus not to change while Emacs's desktop is
> not shown?  But if some idle timer causes Emacs to raise a frame, you
> will also see Emacs with focus when you switch desktops, right?
>
> I'm not sure I understand the basis for this expectation.  I'd
> certainly not even remember in which state I left the applications
> before switching away, and will look first when I switch back.

Sure, but on this case you will see that Konsole's window is covering
Emacs' (if Emacs' window is visible at all), so you assume that Konsole
has the focus. For avoiding that you must take care of looking at some
place that indicates which window has or has not focus (usually the
window's title bar) noticing that Konsole has no focus, and perform an
action to either give focus to Konsole or bring Emacs' window to the
front.

> because applications can request focus for any number of reasons.
>
> So I'm surprised that the fact that Emacs gets focus without your
> knowing is regarded as a problem at all.

Focus stealing is widely regarded as a very rude action. Imagine you are
typing on some application and suddenly some other application pops out
and starts receiving your keypresses. That's a disaster, even a gross
security issue. Modern desktop environments implement a notification
system to make possible for an application to show information or
request user attention without stealing the focus, so nowadays there is
no good reason for getting focus without the user's request. AFAIR in
Wayland it is simply not possible for an application to forcibly get the
focus.

Certainly, just switching destktops is not one good reason for stealing
the focus.