- From: Arthur Barstow <art.barstow@nokia.com>
- Date: Wed, 06 Feb 2013 06:56:16 -0500
- To: ext Rick Byers <rbyers@google.com>, Jacob Rossi <Jacob.Rossi@microsoft.com>
- CC: "public-pointer-events@w3.org" <public-pointer-events@w3.org>
On 2/5/13 7:58 PM, ext Rick Byers wrote: > On Monday, February 4, 2013, Jacob Rossi wrote: > > Hey folks, > > We took a second look at this issue and have a suggested tweak to > the change we made [1]. In most pen enabled applications, mouse > generally emulates /half/ the maximum pressure of pen. As an > example, Paint provides half the stroke width when using a mouse > as compared with maximum pressure of a pen. This is generally in > line with guidance Microsoft has given for pen drawing for quite > some time: minimum pressure should be 50% stroke width, half-way > pressure is 100% (e.g. what mouse should produce), and maximum > pressure is 150% [2]. > > Given that, I reactivated this bug for us to consider making the > value 0.5 rather than 1 when the device is in the active buttons > state. > > > Having the default be intermediate between minimum and maximum makes > sense to me, and will probably result in better behaving apps in general. > > Similar to the pressure issue, the spec currently allows > implementations to provide a width/height that’s “typical of the > device type” when the hardware doesn’t support contact geometry > [3]. But it doesn’t require it. IE10 does not simulate > width/height for devices that do not provide geometry. But I think > we’d probably make IE do so in our next release, similar to > emulating pressure. I’d like to consider making the MAY (optional) > a SHOULD (recommended) in the spec for emulating width/height. I > think the emulation we’d use in IE is: > > Mouse, Pen – 1x1 width > > Touch without hw support for geometry – about 40x40 CSS pixels *** > > > Yes, I like this change (the less UA-defined-behavior the better). Are > you aware of any sites today that treat no-radius differently from > some reasonable default radius (eg. I could imagine some UI features > changing slightly when it's known that radius information is > available)? If so then we may need to consider some mechanism to > determine pointer capabilities, but without a compelling use case it's > probably not worth the complexity. Thanks Rick. Jacob - I think we now have sufficient support for your proposal,so please implement it. -Thanks, Art > This “smart default” approach should also apply to tiltX/tiltY, > but the existing default of 0 seems appropriate for those (e.g. > the stylus is normal to the screen). > > -Jacob > > *** Adjusted for zoom. 40 CSS pixels is approximately 11mm, the > average width of a touch contact [4]. > > [1] http://dvcs.w3.org/hg/pointerevents/rev/47212a0ea91c > > [2] http://msdn.microsoft.com/en-us/subscriptions/cc300776.aspx#S11 > > [3] > https://dvcs.w3.org/hg/pointerevents/raw-file/tip/pointerEvents.html#widl-PointerEvent-width > > > [4] http://bit.ly/win8touchguidance >
Received on Wednesday, 6 February 2013 11:56:28 UTC