W3C home > Mailing lists > Public > public-canvas-api@w3.org > October to December 2014

Re: hit region list

From: Richard Schwerdtfeger <schwer@us.ibm.com>
Date: Mon, 27 Oct 2014 10:48:28 -0500
To: Dominic Mazzoni <dmazzoni@google.com>
Cc: Rik Cabanier <cabanier@gmail.com>, Jatinder Mann <jmann@microsoft.com>, Canvas <public-canvas-api@w3.org>
Message-ID: <OFFD5565D2.11C49319-ON86257D7D.006489B2-86257D7E.0056D5ED@us.ibm.com>
Hi Dominic, 

Sorry, I have been traveling and missed this. 

1. My comment on scrolling: We need to make sure that when the browser 
window gets scrolled that the accessibility API location for the 
coordinates is also moved to the new location. The accessibility API are 
in screen coordinates. I agree this is not an issue for an author. This is 
a user agent issue.
2. we should look at at hitTest function for Canvas 2. 



Rich Schwerdtfeger

From:   Dominic Mazzoni <dmazzoni@google.com>
To:     Richard Schwerdtfeger/Austin/IBM@IBMUS
Cc:     Rik Cabanier <cabanier@gmail.com>, Jatinder Mann 
<jmann@microsoft.com>, Canvas <public-canvas-api@w3.org>
Date:   10/06/2014 10:25 AM
Subject:        Re: hit region list

I agree it might be useful to have an API to retrieve the hit region list. 
Might I also suggest a lightweight "hitTest" function that lets you test a 
point and determine which element would be hit? Presumably you could do 
this by constructing a MouseEvent, but this would be more straightforward.

Rich, I don't understand your comment about scrolling or moving the 
window. Canvas hit regions are defined canvas-local coordinates, so I 
don't see any reason the browser or web author would care if the window 
scrolls or moves.

On Mon, Oct 6, 2014 at 7:33 AM, Richard Schwerdtfeger <schwer@us.ibm.com> 
So, here is another example. When the browser scrolls or the window moves 
the hit region moves. Authors are not going to keep track of all that. 


Rich Schwerdtfeger

Rik Cabanier ---10/05/2014 09:12:57 PM---On Sun, Oct 5, 2014 at 5:14 AM, 
Richard Schwerdtfeger <schwer@us.ibm.com> wrote:

From: Rik Cabanier <cabanier@gmail.com>
To: Richard Schwerdtfeger/Austin/IBM@IBMUS
Cc: Canvas <public-canvas-api@w3.org>, Jatinder Mann <jmann@microsoft.com>
Date: 10/05/2014 09:12 PM
Subject: Re: hit region list

On Sun, Oct 5, 2014 at 5:14 AM, Richard Schwerdtfeger <schwer@us.ibm.com> 
Jatinder, Rik, 

I am working on the testable statements for hit regions. There is no 
programmatic way to determine the hit region list. So, when we want to 
verify that a hit region having the same id is replaced in the list we 
cannot determine if the old hit region, associated with the id, is removed 
from the list. A developer will want to be able to look at the hit region 

I filed a defect on this: 

This will need to be a canvas 2.0 item and it does restrict our ability to 
test all of canvas 1.0 hit region functionality. 

I don't see why this needs to be a feature in canvas. If a developer wants 
to keep track of the hit regions, he can do that himself.  
Received on Monday, 27 October 2014 15:52:51 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:31:57 UTC