Re: Dedicated buffer with buttons that show messages in a central display area

[Heime <heimeborgia@protonmail.com>]

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------- Original Message -------
On Friday, November 11th, 2022 at 6:38 PM, Jean Louis <bugs@gnu.support> wrote:


> * Heime heimeborgia@protonmail.com [2022-11-11 17:35]:
> 
> > I would like to have a dedicated buffer that has a number of buttons that display messages in a central display area
> > when pressed. Can this be done?
> 
> 
> It can be done, but you do not define your desires clearly.
> 
> Each buffer in Emacs is dedicated, that I know.
> 
> "number of buttons", what kind of buttons? Do you mean like button
> links as explained in (info "(elisp) Buttons") ?
> 
> Define "central display area", do you mean center of the visible
> window? Or center of the buffer? Horizontally and vertically to window
> or buffer? Or center of the text width before wrap?

To look like MCDU (Multi-Function Control Display Unit) on aircraft.

https://www.uasc.com/home/shop/avionics/mcdu

> I have this function:
> 
> (defun rcd-button-insert (button-text action-function &optional how-many revert-key revert-value)
> "Insert button BUTTON-TEXT with ACTION-FUNCTION.
> 
> Optional number HOW-MANY adds superscript digits to BUTTON-TEXT."
> (let* ((revert-key (or revert-key "revert-key"))
> (revert-key (intern revert-key))
> (rever-value (or revert-value button-text)))
> (insert-text-button button-text
> 'action
> action-function
> 'follow-link t
> revert-key revert-value)
> (when how-many
> (insert (rcd-superscript-digits how-many)))))
> 
> Which uses this one:
> 
> (defun rcd-superscript-digits (number)
> "Return unicode digits for NUMBER."
> (let* ((string (cond ((numberp number) (number-to-string number))
> ((stringp number) number)))
> (digits (split-string string "" t " ")))
> (with-temp-buffer
> (while digits
> (insert (rcd-superscript-digit-1 (string-to-number (pop digits)))))
> (buffer-string))))
> 
> Then you go like this:
> 
> (rcd-button-insert "Display my message"
> (lambda () (message "My message"))) <-- evaluate it here
> 
> or like this:
> 
> (rcd-button-insert "Display my message"
> (lambda () (message "My message")) 21)Display my message²¹
> 
> Function is made so that buttons displayed may be reverted, but that
> is not subject of your interest now.
> 
> (defun rcd-button-revert-source (&optional revert-key)
> "Revert the button source.
> 
> REVERT-KEY is optional and by default the symbol 'REVERT-KEY. The
> value of REVERT-KEY will be returned as source."
> ;; (rcd-button-insert "Hello" (lambda (_) (message-box "Hello")) nil nil "⟦ (hyperscope 123) ⟧")
> (let ((point (point))
> (revert-key (or revert-key 'revert-key)))
> (save-excursion
> (goto-char (point-min))
> (let (my-prop)
> (while (setq my-prop
> (text-property-search-forward
> revert-key))
> (when my-prop
> (let ((begin (prop-match-beginning my-prop))
> (end (prop-match-end my-prop))
> (value (prop-match-value my-prop)))
> (set-text-properties (1- begin) end nil)
> (delete-region begin end)
> (goto-char begin)
> (insert (format "%s" value)))))))
> (goto-char point)))
> 
> --
> Jean
> 
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