[PATCH synaptics] On clickpads with two touchpoints, try to detect clickfinger 3 actions

[Peter Hutterer]

On Mon, Dec 16, 2013 at 01:02:41AM -0800, Matt Turner wrote:
> On Sun, Dec 15, 2013 at 3:49 PM, Peter Hutterer
> <peter.hutterer at who-t.net> wrote:
> > Some touchpads provide BTN_TOOL_TRIPLETAP but do not track more than two
> > touchpoints. For those, try to detect clickfinger3 actions as best as we can.
> >
> > Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> > ---
> >  src/synaptics.c | 22 ++++++++++++++++++++++
> >  1 file changed, 22 insertions(+)
> >
> > diff --git a/src/synaptics.c b/src/synaptics.c
> > index e391a98..a421384 100644
> > --- a/src/synaptics.c
> > +++ b/src/synaptics.c
> > @@ -2510,6 +2510,28 @@ clickpad_guess_clickfingers(SynapticsPrivate * priv,
> >          close_point >>= 1;
> >      }
> >
> > +    /* Some trackpads touchpad only track two touchpoints but announce
> > +       BTN_TOOL_TRIPLETAP (which sets hw->numFingers to 3).
> > +       This can affect clickfingers, in the following ways:
> > +       * one finger down: normal click
> > +       * two fingers down, close together: 2 finger click
> > +       * two fingers down, apart: normal click
> > +       * three fingers down, close together: 3 finger click
> > +       * three fingers down, with two grouped next to each other: should be
> > +       * 2-finger click but we can't detect this.
> > +       * so: if two detected fingers are close together and HW says three
> > +       * fingers, make it three fingers.
> > +       * if two detected fingers are apart and HW says three fingers, make
> > +       * it a two-finger click, guessing that the third finger is somewhere
> > +       * close to another finger.
> > +       */
> > +    if (hw->numFingers >= 3 && nfingers < hw->numFingers) {
> > +        if (!nfingers) /* touchpoints too far apart apart */
> 
> Doubled apart.

that's how far they are apart :)