Re: Select completions from the minibuffer

[Ergus]

Hi Juri:

Yes I just confirmed, actually the pre-redisplay-function is not called
for simple commands like self-insert or moving the point and in your
case neither.

Looking at the last line in `deactivate-mark` it seems like it is a
known issue and changing such optimization in the display engine may be
probably undesirable (Eli will confirm soon hopefully), so in your case
maybe is better to force the update on demand like in deactivate-mark:

```
(defmacro with-minibuffer-completions-window (&rest body)
  "Execute the forms in BODY from the minibuffer in its completions window.
When used in a minibuffer window, select the window with completions,
and execute the forms."
  (declare (indent 0) (debug t))
  `(let ((window (or (get-buffer-window "*Completions*" 0)
                     ;; Make sure we have a completions window.
                     (progn (minibuffer-completion-help)
                            (get-buffer-window "*Completions*" 0)))))
     (when window
       (with-selected-window window
         ,@body
         (redisplay--update-cursor-face-highlight window)))))
```

This seems to work.

Is it enough?


On Thu, Mar 17, 2022 at 10:56:01PM +0200, Juri Linkov wrote:
> > > But cursor-face is not highlighted in *Completions* when the current buffer
> > > is the minibuffer.  Such highlighting is necessary when completions
> > > are navigated from the minibuffer.
>
> > Please check the change and try to set
> > cursor-face-highlight-nonselected-window unconditionally in
> > *Completions* to t when using your mode.
>
> Now it keeps highlighting in *Completions* after switching to the minibuffer,
> but still doesn't move the highlighting in *Completions* when
> completions are navigated from the minibuffer with
>
>  (defmacro with-minibuffer-completions-window (&rest body)
>    "Execute the forms in BODY from the minibuffer in its completions window.
>  When used in a minibuffer window, select the window with completions,
>  and execute the forms."
>    (declare (indent 0) (debug t))
>    `(let ((window (or (get-buffer-window "*Completions*" 0)
>                       ;; Make sure we have a completions window.
>                       (progn (minibuffer-completion-help)
>                              (get-buffer-window "*Completions*" 0)))))
>       (when window
>         (with-selected-window window
>           ,@body))))
>
>  (defun minibuffer-next-completion (&optional n)
>    "Run `next-completion' from the minibuffer in its completions window."
>    (interactive "p")
>    (with-minibuffer-completions-window
>      (next-completion n)))
>
> > If you could improve the initialization in order to use
> > cursor-in-non-selected-windows unless the user sets another value
> > manually it may be nicer (because in the general scenario the user could
> > set cursor-in-non-selected-windows latter so this variable may have an
> > outdated value) otherwise consider if this may be simply t or nil by
> > default. But at the moment it works fine for the current use cases.
>
> I think it's unrelated to cursor-in-non-selected-windows
> because the cursor in non-selected windows is displayed as
> a hollow box, but cursor-face stays the same.
> So you can set cursor-face-highlight-nonselected-window
> to nil by default.  Then commands could let-bind it like
>
>  (defun minibuffer-next-completion (&optional n)
>    "Run `next-completion' from the minibuffer in its completions window."
>    (interactive "p")
>    (let ((cursor-face-highlight-nonselected-window t))
>      (with-minibuffer-completions-window
>        (next-completion n))))
>
> (but this currently doesn't work for the same reason as above)