[Bug 20217] New: Expand touch-action property to include more of the values implemented by IE?

https://www.w3.org/Bugs/Public/show_bug.cgi?id=20217

            Bug ID: 20217
           Summary: Expand touch-action property to include more of the
                    values implemented by IE?
    Classification: Unclassified
           Product: PointerEventsWG
           Version: unspecified
          Hardware: PC
                OS: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Pointer Events specification
          Assignee: jrossi@microsoft.com
          Reporter: rbyers@chromium.org
        QA Contact: dave.null@w3.org
                CC: public-pointer-events-bugzilla@w3.org

The IE implementation of pointer events specifies several different values for
touch-action:
http://msdn.microsoft.com/en-us/library/windows/apps/hh767313.aspx.  The
pointer-events draft specification currently includes only 'auto', 'none' and
'inherit'.

One important scenario where I believe additional control is essential is when
there is a scrollable list which can also be pulled side to side to trigger
some action.  Eg., imagine a google+ page where pulling horizontally switches
the stream you're viewing, but pulling vertically scrolls it.  I believe the
only way to implement this with pointer events is to use touch-action: none and
process scrolling entirely in JavaScript.  This is unaccaptable because it then
becomes very difficult to mimic the browser's native scrolling feel.  

With touch events (as implemented in iOS and chrome desktop at least) it's
possible to implement this by listening for all events on the div, but ignoring
the touchmove events corresponding to scrolling.  Once a sufficient horizontal
movement is detected, then preventDefault can be called to stop scrolling and
javascript used to implement the horizontal action.

I believe the IE implementation of pointer events can handle this scenario even
better.  By using 'touch-action: pan-y', the element can be scrolled vertically
without any involvement of javascript (and so in a completely hardware
accelerated fashion).  However if the user moves horizontally instead, events
can be generated which the application can respond to.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

Received on Monday, 3 December 2012 22:09:20 UTC