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

[Matt Turner]

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.