Add a minimum physical threshold for freeform gesture on touchpad
Currently, TouchInputMapper uses the product of the size of the touchpad
and a ratio (currently 0.25) to determine a two finger gesture is a
freeform gesture or a swipe, that when the distance of two pointers is
greater than the calculated value, it is a freeform gesture, otherwise,
it is a swipe gesture. However, on a really small touch pad, such as
Sony Dualshock4's, due to the common size of human fingers, almost all
two finger gestures are decided to be freeform. Adding a minimun
physical value for the freeform gesture, 30 mm, can solve the problem.
Bug: 197146318
Test: manual test
Change-Id: Ia4ff521cb2f47b587fa55a5d753b90d023a648ef
diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.h b/services/inputflinger/reader/mapper/TouchInputMapper.h
index 714ad3f..3042be6 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.h
@@ -527,7 +527,9 @@
float mPointerXZoomScale;
float mPointerYZoomScale;
- // The maximum swipe width.
+ // The maximum swipe width between pointers to detect a swipe gesture
+ // in the number of pixels.Touches that are wider than this are translated
+ // into freeform gestures.
float mPointerGestureMaxSwipeWidth;
struct PointerDistanceHeapElement {