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Re: Clarifications to definition of "active element"

From: Jon Gunderson <jongund@uiuc.edu>
Date: Mon, 29 Jan 2001 11:20:20 -0600
Message-Id: <>
To: Ian Jacobs <ij@w3.org>, w3c-wai-ua@w3.org
Comment in JRG:
At 07:33 PM 1/25/2001 -0500, Ian Jacobs wrote:
>Based on some comments from Eric, I've attempted to clarify
>the definition of active element. The key clarifications are:
>   1) Content determines what is an active element.
>   2) The state of the user's interaction with the document may
>      limit which elements are active (examples are given).
>   3) Not all user interactions involve active elements (e.g.,
>      text selection and copying to the clipboard).
>   4) The role of "active element" is subject to applicability.
>The full definition follows.
>  - Ian
>An active element is a piece of content with associated
>behaviors, that the user may trigger (or, "activate") either
>through the user interface or through an API.
>Content always determines what constitutes an active element. For
>instance, the HTML 4 [HTML4] specification defines a number of
>active elements: links, image maps, form controls, element
>instances with a value for the "longdesc" attribute, and element
>instances with scripts (event handlers) explicitly associated
>with them (e.g., through the various "on" attributes). The role
>of an element as an active element is subject to applicability.

JRG: May need to discuss event bubbling here, since that can also cause an 
element to be active.

>The state of the user's interaction with that content may limit
>which elements are active. For instance, an element may be
>"deactivated" by a script as the result of the user's interaction
>with the content. Or, an element may only be active during a
>given time period (e.g., during part of a SMIL 1.0 [SMIL]
>presentation). Or, the user may be viewing content in "read-only"
>mode, which may deactivate some elements.
>The user may interact with content without necessarily activating
>active elements. For example, selecting an element's text and
>copying it to the clipboard is clearly user interaction but does
>not make that element an active element. (The element may also be
>an active element, but only by virtue of how the author has
>encoded it, not by virtue of the selection functionality provided
>by the user agent.)
>The consequence of triggering an active element depends on the
>element. For instance, when a link is activated, the user agent
>generally retrieves the linked Web resource. When a form control
>is activated, it may change state (e.g., check boxes) or may take
>user input (e.g., a text entry field). See also the definition of
>event handler.
>Most operating environments use the content focus to indicate
>which active element will be triggered on user demand.
>Ian Jacobs (jacobs@w3.org)   http://www.w3.org/People/Jacobs
>Tel:                         +1 831 457-2842
>Cell:                        +1 917 450-8783

Jon Gunderson, Ph.D., ATP
Coordinator of Assistive Communication and Information Technology
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 Monday, 29 January 2001 12:18:18 UTC

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