- From: Mark Sadecki <mark@w3.org>
- Date: Tue, 08 Apr 2014 14:55:45 -0700
- To: "public-canvas-api@w3.org" <public-canvas-api@w3.org>
- CC: 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>
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. # 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. 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 21:55:55 UTC