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Re: Proposed clarification of checkpoint 9.4

From: Harvey Bingham <hbingham@acm.org>
Date: Sun, 07 May 2000 01:09:34 -0400
Message-Id: <>
To: w3c-wai-ua@w3.org
At 2000-05-05 19:40-0400, Ian wrote:
>Checkpoint 9.4 of the Proposed Recommendation [1] reads:
>   9.4 When loading content (e.g., document, image, audio,
>       video, etc.) indicate what proportion of the content has
>       loaded and whether loading has stalled. [Priority 3]
>We do not have a definition of "load". I believe that
>this means "to put in the viewport", i.e., to render, rather
>than retrieve (although delays in loading may be due
>to delays in retrieval initially). I therefore propose
>the following restatement of the requirement:
>   9.4 When rendering content (e.g., document, image, audio,
>       video, etc.), indicate what proportion of the content has
>       been rendered and whether rendering has stalled. [Priority 3]
I like that, though for images that are first coarse-displayed, and
progressively sharpened (possibly taking 4x longer for 2x more detail
in each dimension per pass), I question the value of having a separate 
proportion indicator. Often the ALT-text alone, or early coarse display
is plenty.

>We do have a definition of "rendered content".
>There is still a slight ambiguity, but I propose to not worry
>about it. The proportion (e.g., percentage) should probably
>represent the proportion of currently rendered content to the
>total rendered content. However, user agents that render
>incrementally may not know how much total rendered content
>there will be. An approximation based on the byte-size of
>the document source would be adequate. Document entity
>length may be known in advance (e.g., through the
>"Content-Length entity-header field in HTTP/1.1 [2],
>section 14.13). If I've misquoted the HTTP spec, please let
>me know.

Received on Sunday, 7 May 2000 01:14:47 UTC

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