Bug 81040

Summary:

mousewheel event wheelDeltaY data shows anomalies and jitter

Product:

WebKit

Reporter:

Jason San Jose <jasonsj>

Component:

UI Events

Assignee:

Nobody <webkit-unassigned>

Status:

UNCONFIRMED ---

Severity:

Normal

CC:

ap, dsubrama, njaramil, simon.fraser, WebkitBugTracker

Priority:

Version:

528+ (Nightly build)

Hardware:

Mac (Intel)

OS:

OS X 10.7

URL:

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

Attachments:

Description	Flags
Graph of mousewheel event wheelDeltaY on a MacBook Air running 10.7.3 Lion	none
Archive of test project from https://github.com/njx/mousewheel-test	none

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

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 Jason San Jose 2012-03-13 15:03:05 PDT

Created attachment 131718 [details]
Graph of mousewheel event wheelDeltaY on a MacBook Air running 10.7.3 Lion

Comment 2 Jason San Jose 2012-03-13 15:03:49 PDT

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

Comment 3 Alexey Proskuryakov 2012-03-13 16:54:03 PDT

Are you seeing this with Safari 5.1.3?

Comment 4 Jason San Jose 2012-03-13 16:56:39 PDT

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