blink-cursor improvement suggestion

[Ulrich Neumerkel]

Cursor blinking in 21 is rather irritating to look at, because the
cursor vanishes completely making it difficult to remember its precise
position.  E.g. when comparing two windows.

On the other hand blinking is useful for locating the cursor in large
areas or when a bar is used.

It appears less distracting, if the cursor changes its background
color instead of vanishing completely.

Here is an attempt to show the
difference.  C-x C-e the following functions alternatively.
(I tried it in GNU Emacs 21.2.50.1)

(Certainly this would have to go into internal-show-cursor to be
efficient and reliable)


(defvar cursor-on t)

(modify-frame-parameters (selected-frame) '((cursor-type . bar)))
(modify-frame-parameters (selected-frame) '((cursor-type . box)))

(defun blink-cursor-timer-function ()
  "Improved but flickering timer function of timer `blink-cursor-timer'."
  (setq cursor-on (not cursor-on))
  (set-face-background
   'cursor
   (if cursor-on "black" "gray50")))

(defun blink-cursor-timer-function ()
  "Original timer function of timer `blink-cursor-timer'."
  (internal-show-cursor nil (not (internal-show-cursor-p))))