Re: Constructor question and mouseEvents compat

On 4/7/2013 10:28 AM, Jacob Rossi wrote:
>> 2.) The mouse compatibility section is a little vague to me about what to do with multi-mode input. i.e. If there's a mouse and a touch on the screen, I think we only want to send mouse events for the mouse pointer and not the touch or (I would guess) many pages will have issues with two mice on screen at once? If there's a touch and a pen, I think whichever was set active first should dispatch mouse events?
> We (Microsoft) often refer to the concept you're describing as "device arbitration." Platform-specific behavior may dictate this and may involve technologies out of scope for this spec (e.g. "Algorithms to determine unintended input (e.g. palm rejection)" [2]). We've discussed device arbitration in the group before [3], but I can elaborate a bit as the mail threads don't fully seem to capture the discussion we had (perhaps some old minutes do though).
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."

Received on Monday, 8 April 2013 16:14:16 UTC