Re: [PATCH] frame.c: focus hooks

[Josh <josh@foxtail.org>]

On Tue, Nov 19, 2013 at 7:16 PM, Stefan Monnier
<monnier@iro.umontreal.ca> wrote:
>> These frame focus hooks are closely related to the select-window-hook
>> that was proposed and ultimately rejected a few years back[0].  Would
>> such a hook be accepted now if its documentation were to contain a
>> similar warning?
>
> Personally, I think such a hook is not in itself a problem.  But I also
> think it's ill-advised.  The main reason is that select-window is an
> operation used internally, so it can be called many times within
> a single command, even if the command might end up "staying in the same
> window".

Yes, that's a fair point.  Is there some way we could distinguish
between such ephemeral selected-window changes and transitions from
one steady state to another?

> A pre/post-command-hook that compares selected-window with the previous one
> will provide a behavior closer to what users want, I think.
> Of course, it could still be called select-window-hook, tho that name
> would be a bit misleading.

Such a hook would be an improvement but not ideal, since some
selected-window changes of interest may not result from a user
command, e.g. those due to a non-nil compilation-auto-jump-to-first-error.