Re: Mac emacs scroll bars

[YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>]

>>>>> On Thu, 8 Jul 2004 09:05:31 -0700, Steven Tamm <steventamm@mac.com> said:

> I'm not sure one can do it at the lisp level. The particular problem
> is that holding down the mouse button doesn't generate the same kind
> of events on the mac that holding down a key would (i.e. autorepeat
> events).  Because of the event model, read-event hangs until you
> move the mouse.

One can tell whether an event has been available by examining the
return value of sit-for.  Here is an example:

(defun mac-scroll-down-line ()
  (track-mouse
    (let ((done nil)
	  event type)
      (while (not done)
	(scroll-down 1)
	(unless (sit-for mouse-delay) ;; possibly have initial and subsequent delays
	  (setq event (read-event))
	  (setq type (event-basic-type event))
	  (cond ((eq type 'mouse-1)
		 (setq done t))
		((eq type 'mouse-movement)
		 ;; should do something
		 )))))))

Maybe some subtle cases should be added to the above cond-expression.

> I checked in a change similar to this.  I forgot to add drag-mouse-1
> to the list of ignorable events, though.

Perhaps the following is simpler.  (I should have noticed that.)

(defun mac-scroll-ignore-events ()
  ;; Ignore confusing non-mouse events
  (while (not (eq (event-basic-type (read-event)) 'mouse-1))
    nil))

				     YAMAMOTO Mitsuharu
				mituharu@math.s.chiba-u.ac.jp