diff options
| author | Peter Hutterer <peter.hutterer@who-t.net> | 2015-06-03 12:15:51 +1000 |
|---|---|---|
| committer | Peter Hutterer <peter.hutterer@who-t.net> | 2015-06-03 14:43:58 +1000 |
| commit | df83144457176e454953d2a580a8f28e73f4a677 (patch) | |
| tree | e562f9b73cfaed6f286fdd50a961381e18353713 /doc/clickpad-softbuttons.dox | |
| parent | b2a6ead9929f8cdf0778a942ffcfd6e75bc76294 (diff) | |
| download | libinput-df83144457176e454953d2a580a8f28e73f4a677.tar.gz | |
touchpad: impose maximum distance limits on clickfingers
A common use-case for clickfinger is to use the index finger for moving the
pointer, then triggering the click with a thumb. If the index finger isn't
lifted before the click this counted as two-finger click.
To avoid this, check the distance between touches on the touchpad (on
touchpads reporting resolution values anyway). If the touches are too far
apart, don't count them together (or specifically only count those close
enough together as multi-finger).
The touch area is uneven, it's wider than high. Spreading fingers horizontally
is more common and this also makes it easier to rule out thumbs which tend to
be well below the fingers.
http://bugs.freedesktop.org/show_bug.cgi?id=90526
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Diffstat (limited to 'doc/clickpad-softbuttons.dox')
| -rw-r--r-- | doc/clickpad-softbuttons.dox | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/doc/clickpad-softbuttons.dox b/doc/clickpad-softbuttons.dox index e7c4e543..a4f2e444 100644 --- a/doc/clickpad-softbuttons.dox +++ b/doc/clickpad-softbuttons.dox @@ -64,9 +64,16 @@ software-defined button areas. @image html clickfinger.svg "One, two and three-finger click with Clickfinger behavior" -The Xorg synaptics driver uses 30% of the touchpad dimensions as threshold, -libinput does not have this restriction. If two fingers are on the pad -while clicking, that is a two-finger click. +On some touchpads, libinput imposes a limit on how the fingers may be placed +on the touchpad. In the most common use-case this allows for a user to +trigger a click with the thumb while leaving the pointer-moving finger on +the touchpad. + +@image html clickfinger-distance.svg "Illustration of the distance detection algorithm" + +In the illustration above the red area marks the proximity area around the +first finger. Since the thumb is outside of that area libinput considers the +click a single-finger click rather than a two-finger click. Clickfinger configuration can be enabled through the libinput_device_config_click_set_method() call. If clickfingers are |