Re: [DOM3Events] WheelEvent and zoom

Thanks for response.  So in what scenarios do you envision a UA ever
setting deltaZ to non-zero?  Is this just future-proofing for some
not-yet-popular hardware?

FWIW, I'd LOVE to see D3E define a zoom event.  If Indie UI
UIManipulationRequestEvent gets traction with implementations then that
would be even better.  In the meantime we continue to get requests to solve
this scenario now ;-)

Thanks,
   Rick


On Thu, Sep 12, 2013 at 10:22 PM, Masayuki Nakano <masayuki@d-toybox.com>wrote:

> I don't think browsers should set deltaZ even when the default action is
> zoom-in/out.
>
> The spec just said that "The user's *environment* might be configured to
> associate zooming with rotation along the z-axis.".
>
> So, zooming by Ctrl + y-axis wheel rotation is *just* a default action of
> some browsers. So, web applications should be able to handle the raw level
> action such as "Ctrl + y-axis wheel rotation" rather than operation for
> zoom.
>
> If web application needs to handle zoom action, D3E or UI Events should
> define "zoom" event.
>
>
> On 2013/09/12 22:56, Rick Byers wrote:
>
>> Hi,
>> We'd like to use the 'wheel' event in blink to communicate zoom requests
>> from the user, distinct from pan (eg. on a trackpad 2-finger scroll vs.
>> pinch).  The spec
>> (http://www.w3.org/TR/DOM-**Level-3-Events/#events-**wheelevents<http://www.w3.org/TR/DOM-Level-3-Events/#events-wheelevents>)
>> has a
>> suggestion to use deltaZ for this:
>>
>> "The user's environment might be configured to associate vertical
>> scrolling with rotation along the y-axis, horizontal scrolling with
>> rotation along the x-axis, and zooming with rotation along the z-axis."
>>
>> I was looking into doing this in blink (http://crbug.com/289887), but it
>> seems no other browser behaves this way.  IE10 and Firefox appear to
>> instead use deltaY with the ctrl modifier set for zooms (pinch on a
>> trackpad).  Any advice on how this should be handled?  With IE and
>> Firefox already in agreement, I think it's better to follow their lead
>> then to follow the suggestion in the spec.  Perhaps the suggestion
>> should be updated to match implementations?
>>
>> One problem with either approach is that it's not clear how an app can
>> detect that a device that supports zooming distinct from panning is
>> being used.  For example, a mapping site probably wants the wheel on a
>> physical mouse to control zoom (since panning can be accomplished with
>> click and drag), but panning on a trackpad to pan the map instead of
>> zoom it (since pinching can zoom it).  Any tips on how a UA should
>> advertise that zooming is supported?  It's unfortunate, for example,
>> that deltaZ isn't permitted to be undefined when not supported by the
>> input device.
>>
>> Thanks,
>>     Rick
>>
>
>
> --
> Masayuki Nakano <masayuki@d-toybox.com>
> Manager, Internationalization, Mozilla Japan.
>