Add active area outside of which movements, scrolling, tapping are ignored.

On some touchpads physical buttons are located under the touchpad surface. As a
result, when users try to perform a click, by pressing that part of the surface
of the touchpad, they get a click, a movement, a tap and (in some cases) a scroll,
which can make clicks quite inaccurate.

The "Synaptics Area" property can be used to define the edges of the active area of
the touchpad so that all movement, scrolling and tapping which take place outside
of this area will be ignored. This property is disabled by default.

Fixes xorg bug #21613.

Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/properties.c b/src/properties.c
index 43bcabb..d03ea6e 100644
--- a/src/properties.c
+++ b/src/properties.c
@@ -83,6 +83,7 @@ Atom prop_grab                  = 0;
 Atom prop_gestures              = 0;
 Atom prop_capabilities          = 0;
 Atom prop_resolution            = 0;
+Atom prop_area                  = 0;
 
 static Atom
 InitAtom(DeviceIntPtr dev, char *name, int format, int nvalues, int *values)
@@ -268,6 +269,11 @@ InitDeviceProperties(LocalDevicePtr local)
     values[1] = para->resolution_horiz;
     prop_resolution = InitAtom(local->dev, SYNAPTICS_PROP_RESOLUTION, 32, 2, values);
 
+    values[0] = para->area_left_edge;
+    values[1] = para->area_right_edge;
+    values[2] = para->area_top_edge;
+    values[3] = para->area_bottom_edge;
+    prop_area = InitAtom(local->dev, SYNAPTICS_PROP_AREA, 32, 4, values);
 }
 
 int
@@ -622,6 +628,20 @@ SetProperty(DeviceIntPtr dev, Atom property, XIPropertyValuePtr prop,
     {
         /* read-only */
         return BadValue;
+    } else if (property == prop_area)
+    {
+        INT32 *area;
+        if (prop->size != 4 || prop->format != 32 || prop->type != XA_INTEGER)
+            return BadMatch;
+
+        area = (INT32*)prop->data;
+        if ((((area[0] != 0) && (area[1] != 0)) && (area[0] > area[1]) ) || (((area[2] != 0) && (area[3] != 0)) && (area[2] > area[3])))
+            return BadValue;
+
+        para->area_left_edge   = area[0];
+        para->area_right_edge  = area[1];
+        para->area_top_edge    = area[2];
+        para->area_bottom_edge = area[3];
     }
 
     return Success;