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Proposed: 4.9.c visual media scaling

From: Jim Allan <allanj@tsbvi.edu>
Date: Mon, 30 Nov 2009 15:19:15 -0600
To: "'UAWG list'" <w3c-wai-ua@w3.org>
Message-ID: <000801ca7202$c4f40d30$4edc2790$@edu>
Please disregard previous message " Proposed: 4.9.d visual media scaling."
Here is a cleaner version. 
Strange, there is not an Issue or Action for this. Thanks to Mark for
brainstorming.
Jim

4.9.C Visual Multimedia Scaling

When visual multimedia content region is presented in a viewport, the user
has the option to resize the region independently of other content, within
the limits of the display, overriding any values specified by the author,
such that all of the following are true (Level A): 

* The region should support default resizing of full screen and 200%, if
within the physical size of the current screen. 

* If the region is less than full screen the user agent will reflow the
viewport content around the region (includes but not limited to flash,
canvas, video, css overflow).

===============================
Comments: 

This is a first pass. The idea is to allow the region (object, canvas, div
with css overflow, etc.) to be resizable by the user. Much like
restructuring resizing of regions in home page portals (Google, yahoo,
etc.). when a user selects 'full screen' no other interaction with the
viewport (webpage) is possible. The user should be able to expand (mouse or
keyboard control) a video or other object to scale its size much like a
window. Additionally, other content should automatically reflow.

Youtube will scale the video along with the font size. This results in text
moving off the screen to the right. The user should be able to scale these
objects independently of other content. 

With css overflow, I can envision an scenario where a div with overflow
creates a scrollable region too small to be functional (yes it is poor
design, and may fail wcag). See code below.

<div style="width: 5em; height: 5em; overflow:scroll;"> 4.9.d visual media
scaling (canvas, svg, overflow, ) When visual multimedia content region is
presented in a viewport, the user has the option to resize the region,
within the limits of the display, overriding any values specified by the
author. The region should support default resizing of full screen and 200%,
if within the physical size of the current screen. If the region is less
than full screen the user agent will reflow the viewport around the region
(includes but not limited to flash, canvas, video, css overflow).
</div>

Using browser content scaling, the div and its content scale with the page,
but the div is still unusable. It would be equally unusable for all users,
but would present a barrier to comprehension for users with cognitive or
visual impairments and a physical barrier (number of navigation keystrokes
needed) for those with motoric impairments.
Received on Monday, 30 November 2009 21:19:59 GMT

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