Bug 81040 – mousewheel event wheelDeltaY data shows anomalies and jitter

Bug 81040 - mousewheel event wheelDeltaY data shows anomalies and jitter


Summary:	mousewheel event wheelDeltaY data shows anomalies and jitter

Status:	UNCONFIRMED

Product:	WebKit
Component:	Event Handling
Version:	528+ (Nightly build)
Platform:	Macintosh Intel Mac OS X 10.7

Importance:	P3 Normal
Assigned To:	Nobody

URL:	https://github.com/njx/mousewheel-test
Keywords:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2012-03-13 15:02 PST by Jason San Jose
Modified:	2012-03-22 15:19 PST (History)

Attachments
Graph of mousewheel event wheelDeltaY on a MacBook Air running 10.7.3 Lion (56.98 KB, image/jpeg) 2012-03-13 15:03 PST, Jason San Jose	no flags	Details
Archive of test project from https://github.com/njx/mousewheel-test (34.23 KB, application/zip) 2012-03-13 15:03 PST, Jason San Jose	no flags	Details
View All Add an attachment (proposed patch, testcase, etc.)

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Description From Jason San Jose 2012-03-13 15:02:11 PST

Steps to reproduce:
0. Requires a Mac with OSX 10.7 Lion for smooth trackpad scrolling (via laptop trackpad or external mouse/trackpad)
1. Download project from github (https://github.com/njx/mousewheel-test) or see attached zip
2. Open mousewheel-test.html
3. Follow instructions to perform a medium to large scroll
4. Observe output graph

The graph shows wheelDeltaY values for the duration of the "mousewheel". The attached sample graph shows large anomalies during acceleration and jittering towards the end of deceleration.

------- Comment #1 From Jason San Jose 2012-03-13 15:03:05 PST -------

Created an attachment (id=131718) [details]
Graph of mousewheel event wheelDeltaY on a MacBook Air running 10.7.3 Lion

------- Comment #2 From Jason San Jose 2012-03-13 15:03:49 PST -------

Created an attachment (id=131720) [details]
Archive of test project from https://github.com/njx/mousewheel-test

------- Comment #3 From Alexey Proskuryakov 2012-03-13 16:54:03 PST -------

Are you seeing this with Safari 5.1.3?

------- Comment #4 From Jason San Jose 2012-03-13 16:56:39 PST -------

Yes. Tested with Safari 5.1.4, Chrome 17.0.963.79 and Webkit nightly r110587.