Re: DOM events Re: PROPOSAL: User Agent Issue 190:

Charles,
1. Given your suggested device independent conditions on the implementation
of DOM level 2 event model, would it be prudent to recommend the DOM level
2 event model implementation in the user agent guidelines?

2. Is it possible to put these types of conditions of implementation in the
guidelines?

Jon




At 02:41 AM 2/15/00 -0500, Charles McCathieNevile wrote:
>Cross posted to Protocols & Formats and User Agent groups
>
>I think we should take a step back and look carefully at this again.
>
>Implementing an event model is important if we accept that the web that is
>moving into the future is going to rely on scripting and dynamic
>effects. Although there will be a requirement for some time to come that it
>be possible to use the web without these things, I believe that by ignoring
>them altogether we are hiding our heads in the sand - we must work out how
>to make them accessible.
>
>The basic requirement is to make the interactions that the user can have, as
>defined by the content itself, available to the user without requirement for
>a specific type of hardware interface. For example, relying on the presence
>of a mouse, or of a visual display of a certain size, is unreasonable.
>
>In HTML terms, what is required is that the User Agent provide some mechanism
>to programmatically trigger the event trigger attributes, and that that
>function is also available in a device-independent manner to the greatest
>extent possible.
>
>One approach to this is to look at the new DOM event set, and map the current
>HTML towards that set. (For a note on why this is a good idea, read the
>original HTML 4.0 specification at the relevant point...)
>
>Here is a possible way to handle the events:
>
>onClick, onDblClick, onKeyPress, onKeyDown, onKeyUp can all be mapped to the
>new onActivate, using a parameter where appropriate. I would suggest that the
>value of the parameter be numeric, and that we require of the DOM group that
>this event be able to take sufficient parameters to encompass a multiple
>click, or differentiating between some number of different keys (I would
>suggest that 10 is a better number than 2, for example)
>
>onMouseOver, onFocus be merged to the new equivalent, and similarly with
>onMouseOut and OnBlur.
>
>onMouseMove is a bit tricky. Where mouse things are used with X,Y parameters
>there is some careful thinking needed to work in a non-visual space - in some
>cases a more object-oriented approach will solve the problem (this is a Web
>Content Question), but there are cases where it is just very difficult - the
>same problem that arises in trying to deal with raster-based graphics.
>
>I think the rest of the events can stay as they are. Gregory has already
>pointed to the potential problems raised by ill-considered use of mutation
>events such as onChange for submitting forms, and in any event that does not
>rely on a particular type of user interface.
>
>To a certain extent this is going over old ground. Which I find extremely
>frustrating, but think is pretty important and we still need to get it right.
>
>Charles McCN
>
>On Mon, 14 Feb 2000 schwer@us.ibm.com wrote:
>
>  
>  
>  
>  This is why we were pushing the DOM2 event model as P2.
>  
>  It is unrealistic to expect the DOM WG to scrap their entire event model
>  for accessibility. We should be able to improve upon it in terms of device
>  independence. Having people start developing to the DOM 2 event model will
>  not require them to rewrite the whole thing.
>  
>  I do appreciate your concerns.
>  
>  Rich

Jon Gunderson, Ph.D., ATP
Coordinator of Assistive Communication and Information Technology
Chair, W3C WAI User Agent Working Group
Division of Rehabilitation - Education Services
College of Applied Life Studies
University of Illinois at Urbana/Champaign
1207 S. Oak Street, Champaign, IL  61820

Voice: (217) 244-5870
Fax: (217) 333-0248

E-mail: jongund@uiuc.edu

WWW: http://www.staff.uiuc.edu/~jongund
WWW: http://www.w3.org/wai/ua

Received on Tuesday, 15 February 2000 09:31:36 UTC