Re: [kzeitler@lucent.com: Re: Crash with mouse-avoidance-mode]

[Chong Yidong <cyd@stupidchicken.com>]

Klaus Zeitler <kzeitler@lucent.com> writes:

>>>>>> "Nick" == Nick Roberts <nickrob@snap.net.nz> writes:
>     Nick> 
>     Nick> I don't know about the haywire bit, maybe it's meant to do that, but
>     Nick> the crash was related to sit-for which Chong has already fixed.
>
> No it's not meant to do that. If you try it first with the default
> mouse-avoidance-animation-delay (0.01), you'll see how it is supposed
> to act. And it does nearly the same with the value I've been using for
> a long time (0.1). But with recent changes (I suspect sit-for) sometimes
> the mouse pointer keeps jumping around or dithering and will not stop as
> long as no new input is entered. Though I'm not sure if this is a Solaris
> specific problem or not.

I think this is an avoid.el bug that only surfaced with the new
sit-for.  mouse-avoidance-mode works by activating a timer to run
mouse-avoidance-fancy-hook every 0.1 seconds.  If the animation delay
is long, the timer can run again in the middle of the animation, which
nudges the mouse pointer in another random direction.

The way to solve this is to introduce a variable
mouse-avoidance-animating-pointer which is non-nil while animating the
mouse, and making mouse-avoidance-fancy-hook do nothing if
mouse-avoidance-animating-pointer is non-nil.

(BTW, mouse-avoidance-fancy-hook violates the naming conventions, and
should be renamed mouse-avoidance-timer-function.)

I'll check in changes to fix these issues shortly.