Hi Nathan,

It is true that Safari now emits mousewheel events in increments of 120 for 
compatibility reasons.  However, there is no loss of granularity in the sense 
that events are generated on fractional wheel ticks and are accelerated on 
platforms that support it.  The only difference is that you will see increments 
of 120 rather than increments of 1.  It's been a few months since I've checked 
(and I can't look at the URL you attached on my phone), but I believe you'll 
see the same behavior in Chrome and IE.

I would also point out that in DOM Level 3 Events, mousewheel events are 
considered deprecated and the unit of wheelDelta is left up to the implementor. 
 IE set this increment to 120 some time ago, and we chose to match this 
behavior to be compatible with sites that expect it.  As you can imagine, the 
opposite problem occurs on those sites (extremely slow scrolling).  
Unfortunately any decision we made here was bound to break some sites.

-Andy

Sent from my iPhone

On Jun 8, 2010, at 19:09, Nathan Vander Wilt <[email protected]> wrote:

> In Safari 4, the following event handler would log nice smooth values when 
> scrolling:
> // logs: -3, -9, -6, -48, ...
> document.addEventListener("mousewheel", function(e) { 
> console.log(e.wheelDeltaY); });
> 
> In Safari 5, the mousewheel events have lost all precision, and are now big 
> ugly integral multiples of 120:
> // logs: -120, -240, -120, -480, ... (no correspondence with above values, of 
> course)
> document.addEventListener("mousewheel", function(e) { 
> console.log(e.wheelDeltaY); });
> 
> This is a serious loss of precision, and brings us back to the primitive days 
> when a mouse a had 1-axis clicky scroll wheel if it had one at all, and 
> Firefox was the top browser. Compare the smooth, precise scroll zooming of 
> http://calftrail.com/Share/multitouch/ in Safari 4 to the jerky, way-too-fast 
> zooming in Safari 5.
> 
> Is this a regression introduced directly in recent WebKit builds, or is it 
> Safari-specific? If the former, was it really necessary and can it please be 
> rolled back?
> 
> thanks,
> -natevw
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