Re: Select completions from the minibuffer

[Juri Linkov]

>> 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 outdated value) otherwise consider if this may be simply t or nil by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)