W3C home > Mailing lists > Public > public-html-a11y@w3.org > April 2014

Re: Questions RE: Hit Regions before return to Last Call

From: Rik Cabanier <cabanier@gmail.com>
Date: Tue, 8 Apr 2014 15:38:02 -0700
Message-ID: <CAGN7qDB9dPsE46XuS+hbCtTw2T+hYHn6v0vLagpY58u6W3kt_w@mail.gmail.com>
To: Mark Sadecki <mark@w3.org>
Cc: "public-canvas-api@w3.org" <public-canvas-api@w3.org>, HTML A11Y TF Public <public-html-a11y@w3.org>, Jay Munro <jaymunro@microsoft.com>, "Rik Cabanier (cabanier@adobe.com)" <cabanier@adobe.com>, Jatinder Mann <jmann@microsoft.com>, Richard Schwerdtfeger <schwer@us.ibm.com>
Hi Mark,

thanks for sending this out!
However, the issue of event retargeting is still not solved. Since this is
so complex to implement, it is be unlikely that we will have 2 independent
implementations soon and that we won't have to make additional changes to
the spec.


On Tue, Apr 8, 2014 at 2:55 PM, Mark Sadecki <mark@w3.org> wrote:

> As we prepare to move Canvas back to LC (we have committed to get the HTML
> WG
> chairs a stable document *this* week), I reviewed the Hit Regions section
> of
> Canvas L1 ED [1] and had the following questions:
>
> # if control is null
>
> Should we have a step in "The region representing the control" [2]
> processing
> algorithm that matches Step 1 in "The region representing the ID" [3] that
> reads
> something like:
>
> "If control is null, return nothing and abort these steps."
>
> Now that control and ID are both optional, I think we should handle the
> case
> that they are not specified.
>

Yes, we've been going back and forth on that.
Since we now have the 'clearHitRegions' call and it was allowed in the
original proposal, let's allow unbacked regions with no ID.


>
> # clearHitRegions() not defined
>
> While we reference clearHitRegions() in a Note following "The region for a
> pixel" algorithm [4], we don't define a processing algorithm for this
> method.
> Suggest adding one below the removeHitRegion() definition [5].
>
> # Move Note RE: clearRect() and clearHitRegions()
>
> The note referenced above [4] would make more sense following the
> definition of
> removeHitRegion() and clearHitRegions() where we actually discuss methods
> for
> removing and/or clearing Hit Regions.
>
> # Steps 5 & 8 from addHitRegion() [6] are unclear and seem to suggest the
> opposite of their intention.
>
> Steps 5 & 8, as they are worded, seem to suggest to me that if the ID or
> control
> referenced in the arguments object are not null, and they reference the ID
> or
> control of a previous region, then the *previous* region should remain
> associated with this region.  This is in direct conflict with steps 9 & 10
> and
> the behavior we discussed on call, that adding a Hit Region that shares a
> control or ID with a previously referenced region would remove/clear the
> previous region.
>
> I also feel like steps 5 & 8 should both come before or after step 7, not
> before
> and after it.  There may be a reason for this order that I'm not aware of,
> though.
>

It is worded a bit strange but the "previous region for the id/control" is
an object that is used in steps 9 and 10.


>
> I look forward to your feedback,
>
> Mark
>
> [1]
> http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas_CR/#hit-regions
> [2]
>
> http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas_CR/#the-region-representing-the-control
> [3]
>
> http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas_CR/#the-region-identified-by-the-id
> [4]
>
> http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas_CR/#the-region-for-a-pixel
> [5]
>
> http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas_CR/#dom-context-2d-removehitregion
> [6]
>
> http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas_CR/#dom-context-2d-addhitregion
> --
> Mark Sadecki
> Web Accessibility Engineer
> World Wide Web Consortium, Web Accessibility Initiative
> Telephone: +1.617.715.4017
> Email: mark@w3.org
> Web: http://w3.org/People/mark
>
>
Received on Tuesday, 8 April 2014 22:38:33 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:05:38 UTC