[RFC XI 2.1 - xf86-input-evdev 2/3] Add experimental XI 2.1 multitouch support

[Peter Hutterer]

On Thu, Dec 02, 2010 at 03:37:10PM +0000, Daniel Stone wrote:
> Hi,
> 
> On Thu, Dec 02, 2010 at 10:34:44AM -0500, Chase Douglas wrote:
> > On 12/02/2010 10:28 AM, Daniel Stone wrote:
> > > On Thu, Dec 02, 2010 at 10:06:01AM -0500, Chase Douglas wrote:
> > >> Instead, we could create separate input devices for the strip and the
> > >> touchscreen. The strip would be a dependent device, and would usually be
> > >> attached to the same MD as the touch screen. However, it could also be
> > >> attached to a different MD, allowing for more interesting mixing and
> > >> matching of input devices.
> > > 
> > > We could make the mode in the touch class a bitmask of direct and
> > > dependent, and let the driver tell us at touch creation time whether the
> > > touch should be direct or dependent?
> > 
> > That doesn't resolve the issue of sending two separate touch events from
> > two separate "devices" through one XI device. What if the intuos had
> > another touch strip? The touch event would have to distinguish between
> > the two strips somehow. I think the only way to do that would be through
> > a valuator, which would just be fitting a square peg into a round hole.
> 
> Indeed.  If we need to distinguish between the different touch strips,
> then the only option is having multiple devices, and at that stage I
> think we should really revisit the idea of a deeper device hierachy
> (e.g. MD #1 -> Wacom tablet #1 -> {Pen, Eraser, touch strip #1, touch
> strip #2}).

if the kernel can send it through one device, we can handle it, right?
if both are sent through the same axes (and need a serial or something to
differentiate like the wacom drivers) then yes, they need to be split up
into multiple devices.

Cheers,
  Peter