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Re: Constructor question and mouseEvents compat

From: Matt Brubeck <mbrubeck@mozilla.com>
Date: Mon, 08 Apr 2013 11:11:03 -0700
Message-ID: <51630837.7010600@mozilla.com>
To: Jacob Rossi <Jacob.Rossi@microsoft.com>, Wesley Johnston <wjohnston@mozilla.com>, "public-pointer-events@w3.org" <public-pointer-events@w3.org>
On 4/8/2013 10:49 AM, Jacob Rossi wrote:
> On Mon, Apr 8, 2013 at 9:13 AM, Matt Brubeck <mbrubeck@mozilla.com> wrote:
>> Without specifying exact arbitration rules, can we make it clear in 
>> the spec that (a) when there is more than one primary pointer, only 
>> one primary pointer at a time will generate compatibility mouse 
>> events, and (b) deciding which primary pointer generates these events 
>> is up to the implementation? Currently this is sort of implied, but 
>> confusingly. For example, the spec says, "The primary pointer is used 
>> to identify a master pointer amongst the set of active pointers. This 
>> pointer is the one that will produce compatibility mouse events." 
>> Later it says "When two or more pointer device types are being used 
>> concurrently, multiple pointers are considered primary" but does not 
>> explain how this affects behavior like "the *one* that will produce 
>> compatibility mouse events." 
> I see how that could be a bit confusing. Do you have a suggestion to clarify it? Perhaps for the first sentence:
>
> "The primary pointer is used to identify a master pointer amongst the set of active pointers for the pointer type.

This part sounds good.

>   This pointer will produce compatibility mouse events."

This is still confusing, because with multiple primary pointers active 
at once, one will generate mouse events and the others might not (or 
will not?).  Maybe it should say "Only a primary pointer can generate 
compatibility mouse events."  Then in section 8 we can expand on this 
with something like, "When more than one primary pointer is active, the 
user agent MAY choose to dispatch compatibility mouse events for only 
one of the primary pointers." (Maybe that should be a "SHOULD" or "MUST"...)

If my understanding is correct, we also need to update the mapping 
algorithms in 8.1 and 8.2 to allow the user agent to terminate the steps 
if it selects a different active pointer to generate mouse events.
Received on Monday, 8 April 2013 18:11:32 UTC

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