multi-touch-dev team mailing list archive

[Henrik Rydberg <rydberg@xxxxxxxxxxx>]

On 10/05/2010 10:22 PM, Chase Douglas wrote:
[...]

> The reason this is useful is to lower the latency when there's
> system-wide and application specific gesture recognition to be
> performed. It requires a trust of the client applications to not handle
> the events as though they owned them, but X trusts client applications
> with lots of similar things today without issue.


It seems to me that the idea of tentative events is not so much about latency as
it is about implementing user feedback which helps resolve ambiguities.

There are at least three stages in gesture recognition in this respect. In the
first stage, the engine builds up a reaction based on user input, from nothing
to something. I see no reason to send this buildup anywhere at all. In the
second stage, something is happening, and the user may need feedback from the
system to tell that something has been registered. This is equivalent to our
notion of gesture primitives, and could well be represented by tentative events,
although I see no compelling reason to change views. The third stage is to
perform a user-approved gesture, which is on a higher level than what we have
implemented so far, and could be a good target for geis.

Henrik