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Re: Change proposal for reopening issue 131 to address chairs clarification on text baseline

From: Charles Pritchard <chuck@jumis.com>
Date: Mon, 05 Dec 2011 12:33:51 -0800
Message-ID: <4EDD2AAF.60207@jumis.com>
To: Paul Cotton <Paul.Cotton@microsoft.com>
CC: Richard Schwerdtfeger <schwer@us.ibm.com>, Frank Olivier <Frank.Olivier@microsoft.com>, "faulkner.steve@gmail.com" <faulkner.steve@gmail.com>, "dbolter@mozilla.com" <dbolter@mozilla.com>, "david.bolter@gmail.com" <david.bolter@gmail.com>, Cynthia Shelly <cyns@microsoft.com>, "public-canvas-api@w3.org" <public-canvas-api@w3.org>, "public-html-a11y@w3.org" <public-html-a11y@w3.org>
The chairs asked, primarily, that the baseline proposal be separated 
from the 131 decision.

Exactly: this specifies that baseline value of the TextMetrics object 
corresponds to the vertical anchor point as previously defined in the 
document.

The Chairs seemed confused as to what "baseline" would be used. This 
document explicitly states that the baseline
corresponds to the vertical position of the anchor point as calculated 
by the textBaseline algorithm, step 6, section 12.

http://lists.w3.org/Archives/Public/public-html-a11y/2011Dec/att-0061/canvasissue131textbaseline.html#dom-context-2d-textbaseline

"Let the anchor point be a point on the inline box, determined by the 
textAlign and textBaseline values, as follows:
.... let the anchor point's vertical position be..."

This proposal simply exposes a value that's well defined and already 
calculated by implementations supporting the textBaseline attribute.

It exposes the value within TextMetrics such that:
measureText().baseline === the anchor point's vertical position.
measureText().width is unaltered.

There is no need to gather the horizontal position of the anchor point, 
width is sufficient.

-Charles


On 12/5/11 12:28 PM, Paul Cotton wrote:
>
> >Is this clear enough to submit to the chairs to reopen issue 131 for 
> text baseline?
>
> Can you characterize the differences between this proposal and the 
> proposal endorsed by the ISSUE-131 WG Decision?
>
> Exactly what new information do you plan to provide the Chairs in 
> order to re-open ISSUE-131?
>
> /paulc
>
> Paul Cotton, Microsoft Canada
>
> 17 Eleanor Drive, Ottawa, Ontario K2E 6A3
>
> Tel: (425) 705-9596 Fax: (425) 936-7329
>
> *From:*Richard Schwerdtfeger [mailto:schwer@us.ibm.com]
> *Sent:* Sunday, December 04, 2011 2:26 PM
> *To:* Frank Olivier; chuck@jumis.com; faulkner.steve@gmail.com; 
> dbolter@mozilla.com; david.bolter@gmail.com; Cynthia Shelly
> *Cc:* public-canvas-api@w3.org; public-html-a11y@w3.org
> *Subject:* Change proposal for reopening issue 131 to address chairs 
> clarification on text baseline
>
> Frank, Cynthia, Charles, Steve, David,
>
> Is this clear enough to submit to the chairs to reopen issue 131 for 
> text baseline?
>
> http://www.w3.org/html/wg/wiki/ChangeProposals/FocusRingTextBaseline
>
>
> If not, what should be added?
>
> Thanks,
> Rich
>
> Rich Schwerdtfeger
> CTO Accessibility Software Group
>
Received on Monday, 5 December 2011 20:34:18 GMT

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