Re: ISSUE-153 (wheel delta): Converting wheel events to mousewheel and DOMMouseScroll [DOM3 Events]

Hi David,

Upon further investigation, this conversion is not accurate. Delta values of browsers' proprietary scroll events are sometimes tied to OS scroll settings. As such, there's no reliable formula for converting between these values. Additionally, it's not a goal of DOM L3 Events to document these proprietary events. 

After discussing this in the 2/4/2011 telecon, we've decided to remove these conversion formulas from the spec altogether (and the spec has been updated). Let me know if you have comments/concerns with this change.



From: David Flanagan <>
Date: Wed, 13 Oct 2010 14:36:53 -0700
Message-ID: <>
The current Editor's draft includes the following formulas for 
converting wheel events to mousewheel and DOMMouseScroll events:

mousewheel.wheelDelta = -(WheelEvent.deltaY) / 120

DOMMouseScroll.detail = WheelEvent.deltaY / 3

Shouldn't those division signs be multiplication signs?  Everything I 
read says that IE returns a wheelDelta of +120 or -120 for a single 
wheel "click", and that Firefox returns a detail field of plus or minus 3.

	David Flanagan

Received on Wednesday, 3 August 2011 16:58:58 UTC