Re: [PATCH] input: Add a detailed multi-touch finger data report protocol

Henrik Rydberg
2008-11-08T12:03:03Z

>> The minimum set of data is TOUCH, POSITION_X and POSITION_Y. If touch
>> pressure information is not given in trackpad dimension units, use a
>> specific range.
>
> The Elantech touchpad does not seem to be able to report pressure, only
> finger coordinates.

I was envisioning a binary TOUCH value, but it is arguably redundant.

>> I believe all current drivers are able to produce this data.
>
> The Elantech driver is not... :)

So only POSITION_X and POSITION_Y for elantech, then :-)

>> It is designed to bring advanced gestures to the linux desktop.
>
> Certainly. Have you already thought about the rest of the path from driver
> to application, ie kernel driver -> X.org driver -> X events -> toolkit
> events -> application?

I am involved in the synaptics Xorg driver. I have an experimental Xorg
driver utilizing the multi-touch interface. The plan is to map stable
gestures to the existing toolkit events, removing the need for programs
like syndaemon.

> For instance does the X.org driver interpret the data and emit a zoom or
> rotate event based on the finger position and movement? As far as I know
> those event do not exist and would have to be added to X.org as well as the
> toolkits like GTK+ and Qt. It could be a long implementation process... :(

Every journey begins with a step.

Henrik