Re: Detect window switches?

[Dan Espen <despen@verizon.net>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Dan Espen <despen@verizon.net>
>> Date: Thu, 26 Sep 2013 15:22:58 -0400
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> >> From: Dan Espen <despen@verizon.net>
>> >> Date: Thu, 26 Sep 2013 14:22:15 -0400
>> >> 
>> >> My mode line changes color when a buffer changes from active/inactive.
>> >> Isn't that what the OP is looking for?
>> >
>> > That's done on the C level, and Lisp programs cannot hook into this.
>> 
>> Hmm, starting to sound like a bug.
>> Here's an event that Emacs acts on but doesn't make the
>> event visible to ELisp.
>
> No, Emacs doesn't act on this as an event.  What happens is that the
> next redisplay after a window switch redraws the mode line in a
> different face.  The redisplay isn't triggered by an event (because
> there is no such event), it is triggered by other means, mostly
> because Emacs becomes idle.  That could happen many seconds after the
> switch, if Emacs becomes busy calculating something, for example.

I only meant event with the meaning that something happens.

Here Emacs sees a buffer become active or inactive and thinks it's
an important enough event that it provides a visual mode line change.

Well, it also changes the physical appearance of the keyboard cursor.
Mine goes from 3 pixels wide to 1.

-- 
Dan Espen