Printing with timer

Printing with timer

[Heime]

I would like to insert the letter using a timer.  After each interval, the letter "T" is printed.
After four intervals, the characters are cleared, and the printing starts again.

Here X means whitespace

XXXX    ; After time interval t (all columns off)

TXXX    ; After time interval t (one column green)

TTXX    ; After time interval t

TTTX    ; After time interval t

TTTT    ; After time interval t

XXXX    

I have started with the following function.  Quite unsure if I should (and how)
the timer can be stopped.


(defun fire-indicator ()
  "TODO."
  (interactive)
  (insert "T")

(defun fire-clock ()
  "TODO."
  (interactive)

  (let* ( (tr (run-with-timer 3 1 (fire-indicator))) )
    ) )

Re: Printing with timer

[Jean Louis]

If you start running with timer, then you better be sure in which
buffer you want that be inserted, function should seek the proper
buffer to insert text.

-- 
Jean

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Re: Printing with timer

[Jean Louis]

* Heime <heimeborgia@protonmail.com> [2022-12-03 08:15]:
> I would like to insert the letter using a timer.  After each interval, the letter "T" is printed.
> After four intervals, the characters are cleared, and the printing starts again.
> 
> Here X means whitespace
> 
> XXXX    ; After time interval t (all columns off)
> 
> TXXX    ; After time interval t (one column green)
> 
> TTXX    ; After time interval t
> 
> TTTX    ; After time interval t
> 
> TTTT    ; After time interval t
> 
> XXXX    

If it is for the aircraft flight control system, and you do not write
in that buffer, then maybe you should designate specific character
position, and you should maybe have buffer empty, with characters
 inside, as to delete character and insert one:

(defun my-char-at-place (position char buffer)
  (set-buffer buffer)
  (goto-char position)
  (delete-char 1)
  (insert char))
TXX   
(my-char-at-place 886 "X" (current-buffer))
(my-char-at-place 886 "T" (current-buffer))
(my-char-at-place 887 "X" (current-buffer))
(my-char-at-place 888 "X" (current-buffer))

-- 
Jean

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https://www.fsf.org/campaigns

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Re: Printing with timer

[Stefan Monnier via Users list for the GNU Emacs text editor]

> (defun my-char-at-place (position char buffer)
>   (set-buffer buffer)
>   (goto-char position)
>   (delete-char 1)
>   (insert char))

As a rule of thumb, I recommend to stay clear of `set-buffer` and use
`with-current-buffer` instead.


        Stefan