[PATCH] ClickPad support v4

Kevin O'Connor kevin at koconnor.net
Sat Dec 25 10:48:50 PST 2010

Hi Chris,

I noticed this message on the xorg-devel mailing list:

> Thank for detailed reply.  Do you mind helping me understand how
> touchpad is being used when jumps occur?  Is use case:
> * Move cursor to area you want to click with 1 finger.  Pick up 1
> finger.  Click in button area with 1 finger.
> or
> * Move cursor to area you want to cick with 1 finger.  Leave 1 finger
> on pad.  Click in button area with 2nd finger.
> First case would move cursor a little bit because of how sensitive
> touchpads are and lots of X/Y can be sent between time of touch and
> button press completed.  But it should not be large jump.  We may need
> to add a gesture style delay when touching in button area so we can
> tell difference between button press and real movement.

I have an hp-mini notebook with a clickpad device.  The problem I most
run into is the first issue - when applying pressure to the pad to
active the "click button" the cursor will move slightly making it
difficult to click small buttons.  However, I rarely attempt to click
with a second finger.

It would be nice to be able to use the full touchpad area for
movements, but if I had to trade between jumpy button presses or
smaller touchpad area, I'd choose having a smaller touchpad area.

> Second case seems more likely to cause a jump but a) synpatics
> hardware continues to report 1st finger's X/Y during double touch and
> b) we have code to expect a jump just in case during that second touch
> based on either doubletap or finger width.  Are you working with
> non-synaptics clickpads?
> Is there any chance you could reproduce basic sequence when jumps
> occur but using evtest and send me the output?
> This is one of those problems really buggy me for some reason and I'd
> like to help resolve it.

I'm not familiar with xorg development, but I am happy to help.  If
you're still interested in this info I'll see if I can get evtest


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