Re: jumpy scrolling on the Mac

On 2024-05-21 12:23, John Selverian wrote:
> I passed SCROLLBAR_WHEELJUMP and it was the same and the vertical
> scroll disappeared.
> 
> I used SCROLLERS_DONT_TRACK and this works! It jumps by 1 line each
> time and there is no blurring/smearing...I assume that is what you
> meant.

SCROLLERS_DONT_TRACK makes the scroll area (your scrollable list, in 
this
case) ignore the SEL_CHANGED messages, and only handle the SEL_COMMAND
one.  So as you're dragging scrollbars, contents stay put until you
stop moving and release the mouse button.

SCROLLBAR_WHEELJUMP affects only mouse wheel movement.  It skips the
animation part and jump-scrolls straight to the scroll position the
wheel would ultimately land on [e.g. a whole number of wheel lines
further].  The animation serves no purpose other than user-feedback.

But the SCROLLERS_DONT_TRACK might be too much in that you won't see
interactive scrolling at all.

One note, as you're dragging the scrollbar, keep in mind that modern 
mice
may sometimes have very high report-rates.  I think the logitech g300s
I'm using right now can push up to 1000 updates/second.  For scrolling
this may be overkill as you're seeing only 60 changed images/second, or
maybe slightly more on high-refresh-rate monitors.  A few very high-end
screens may go to 120, or even 240, but I have not seen anything beyond
that.

If you can control it [you can configure it with the g300s mouse] you
can try dropping the report rate.  Things may actually work better at
lower rates...

Note, report rates and dpi rates are not the same thing.  dpi rates 
pertain
to mouse accuracy, or pixels/inch movement.  Report rate is position 
update
transfers/second.

I have an older logitech which has only like 120/second rate and it 
always
felt very smooth; higher rates just cause more workload on CPU w/o a lot
of benefit; as long as you're above screen refresh rate it works very 
well.




        -- JVZ