bug#64619: [PATCH] Add toggle-window-dedicated command

[sbaugh@catern.com]

Drew Adams <drew.adams@oracle.com> writes:

> Some minor comments.
>
>> +  (if (window-dedicated-p window)
>> +      (progn
>> +        (set-window-dedicated-p window nil)
>> +        (when interactive (message "Window can now be used to display other buffers")))
>> +    (set-window-dedicated-p window 'dedicated)
>> +    (when interactive (message "Window will now display only its current buffer"))))
>
> 1. Why _weakly_ dedicated?

AFAIK, the difference is that if you explicitly try to switch buffer
with e.g. C-x b, you succeed when the dedication is weak, and fail with
an error when the dedication is strong.  I find that if I explicitly hit
C-x b, I want to actually switch buffers in the current window, I never
want the switch to fail.  Making it fail seems useful for Lisp programs,
sometimes, but not so much interactive usage.

> 2. Why not just this?
>
> (let ((before  (window-dedicated-p window)))
>   (set-window-dedicated-p window (not before))
>   (when interactive
>     (message "Window is %s dedicated to buffer %s"
>              (if before "no longer" "now")
>              (current-buffer))))
>
> If someone might not know what it means for a
> window to be dedicated, put that info in the
> doc string, not in the message.

Will do.

> 3. The toggle, as OP proposed it, imposes weak
> dedication, and the toggle as I wrote it above
> imposes strong dedication.  What if you want
> a toggle that respects whatever non-nil FLAG
> (weak or strong) might have already been used
> for the window?
>
> IOW, what if the window is dedicated to start
> with, before you first use the toggle, and you
> want to get back that same dedicated behavior
> (weak or strong) when you toggle it back again?
> The toggle (either definition) doesn't do that.

That would be nice, but I don't see a way to do it.  At the same time, I
think it's probably fine for the user to explicitly choose whether they
want it to be weak or strong.  After all, this way it allows the user to
change the dedicated mode.

> Shouldn't the doc make clear that the toggling
> behavior is always between weak & undedicated
> (OP version) or always between strong &
> undedicated (my version, above)?  IOW, let a
> user know that any original dedicated behavior
> is lost, once you use the toggle.
>
> Or if you want to let a user specify whether
> to use weak or strong, maybe do that with a
> prefix arg?                 

Good point, I'll add a prefix arg for strong dedication.