Do not switch focus to the completions buffer window

Do not switch focus to the completions buffer window

[Leo Alekseyev]

Hi all,
How would I go about preventing *Completions* buffer window from receiving
focus?  I find some value in having it pop-up, but its usability is very
questionable.  Using Tomohiro Matsuyama's popwin, it is very easy to
dismiss the buffer with C-g.  What I want is for it not to even receive
focus.  I tried creating the following piece of advice; the code doesn't
work but it gives you an idea of what I'm after:

(defadvice comint-dynamic-list-filename-completions (around
unfocus-completions-buffer activate)
  (let ((cur-win (selected-window)))
    ad-do-it
    (select-window cur-win)))


Thanks,
--Leo

Re: Do not switch focus to the completions buffer window

[Michael Heerdegen]

Hi Leo,

> Hi all,
> How would I go about preventing *Completions* buffer window from receiving
> focus?  I find some value in having it pop-up, but its usability is very
> questionable.  Using Tomohiro Matsuyama's popwin, it is very easy to
> dismiss the buffer with C-g.  What I want is for it not to even receive
> focus.  I tried creating the following piece of advice; the code doesn't
> work but it gives you an idea of what I'm after:
>
> (defadvice comint-dynamic-list-filename-completions (around
> unfocus-completions-buffer activate)
>   (let ((cur-win (selected-window)))
>     ad-do-it
>     (select-window cur-win)))

The *Completions* window is never selected for me.  I tested with Emacs
23 and Emacs 24.  Even better, with the latest Emacs release, the
*Completions* pop up window is even automatically closed after
successful completion.

So I think what you see is caused by your setup, or you use a really old
Emacs version.  Or please give a recipe of what you see starting from
emacs -Q.


Regards,

Michael.

RE: Do not switch focus to the completions buffer window

[Drew Adams]

> The *Completions* window is never selected for me.  I tested with
> Emacs 23 and Emacs 24.  Even better, with the latest Emacs release,
> the *Completions* pop up window is even automatically closed after
> successful completion.
> 
> So I think what you see is caused by your setup, or you use a really
> old Emacs version.  Or please give a recipe of what you see starting
> from emacs -Q.

Perhaps Leo is doing something like this?

emacs -Q
(setq pop-up-frames t)
M-x for TAB

That's enough, on MS Windows at least, to repro the problem.

When MS Windows creates a new frame, it gives it the input
focus.  Anything you type after the TAB above will be sent
to *Completions*.

This has been a limitation of Emacs since forever, and a
limitation that I, for one, jump through some hoops to
workaround.  (And it was a problem solved by the Epoch
version of Emacs 20 years ago.)

Dunno whether this is in fact related to Leo's actual problem.
But it is one possible scenario that leads to the problem
Leo described.