2 files changed, 25 insertions, 0 deletions
diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp
index fef2f06..271b5d4 100644
--- a/services/inputflinger/InputReader.cpp
+++ b/services/inputflinger/InputReader.cpp
@@ -5843,6 +5843,7 @@ void TouchInputMapper::dispatchPointerStylus(nsecs_t when, uint32_t policyFlags)
         mPointerSimple.currentProperties.id = 0;
         mPointerSimple.currentProperties.toolType =
                 mCurrentCookedState.cookedPointerData.pointerProperties[index].toolType;
+        mLastStylusTime = when;
     } else {
         down = false;
         hovering = false;
@@ -5924,6 +5925,11 @@ void TouchInputMapper::dispatchPointerSimple(nsecs_t when, uint32_t policyFlags,
             mPointerController->fade(PointerControllerInterface::TRANSITION_GRADUAL);
         }
     }
+    
+    if (rejectPalm(when)) {     // stylus is currently active
+        mPointerSimple.reset();
+        return;
+    }
 
     if (mPointerSimple.down && !down) {
         mPointerSimple.down = false;
@@ -6045,6 +6051,9 @@ void TouchInputMapper::dispatchMotion(nsecs_t when, uint32_t policyFlags, uint32
         const PointerProperties* properties, const PointerCoords* coords,
         const uint32_t* idToIndex, BitSet32 idBits, int32_t changedId,
         float xPrecision, float yPrecision, nsecs_t downTime) {
+    
+    if (rejectPalm(when)) return;
+    
     PointerCoords pointerCoords[MAX_POINTERS];
     PointerProperties pointerProperties[MAX_POINTERS];
     uint32_t pointerCount = 0;
@@ -6118,6 +6127,13 @@ void TouchInputMapper::fadePointer() {
     }
 }
 
+nsecs_t TouchInputMapper::mLastStylusTime = 0;
+
+bool TouchInputMapper::rejectPalm(nsecs_t when) {
+    return (when - mLastStylusTime < mConfig.stylusPalmRejectionTime) &&
+        mPointerSimple.currentProperties.toolType != AMOTION_EVENT_TOOL_TYPE_STYLUS;
+}
+
 void TouchInputMapper::cancelTouch(nsecs_t when) {
     abortPointerUsage(when, 0 /*policyFlags*/);
     abortTouches(when, 0 /* policyFlags*/);
diff --git a/services/inputflinger/InputReader.h b/services/inputflinger/InputReader.h
index b73fe61..3b783c1 100644
--- a/services/inputflinger/InputReader.h
+++ b/services/inputflinger/InputReader.h
@@ -230,6 +230,9 @@ struct InputReaderConfiguration {
 
     // True to show the location of touches on the touch screen as spots.
     bool showTouches;
+    
+    // Ignore finger touches this long after the stylus has been used (including hover)
+    nsecs_t stylusPalmRejectionTime;
 
     InputReaderConfiguration() :
             virtualKeyQuietTime(0),
@@ -247,6 +250,7 @@ struct InputReaderConfiguration {
             pointerGestureSwipeMaxWidthRatio(0.25f),
             pointerGestureMovementSpeedRatio(0.8f),
             pointerGestureZoomSpeedRatio(0.3f),
+            stylusPalmRejectionTime(50 * 10000000LL), // 50 ms
             showTouches(false) { }
 
     bool getDisplayInfo(bool external, DisplayViewport* outViewport) const;
@@ -1787,6 +1791,9 @@ private:
     VelocityControl mPointerVelocityControl;
     VelocityControl mWheelXVelocityControl;
     VelocityControl mWheelYVelocityControl;
+    
+    // The time the stylus event was processed by any TouchInputMapper
+    static nsecs_t mLastStylusTime;
 
     void resetExternalStylus();
     void clearStylusDataPendingFlags();
@@ -1853,6 +1860,8 @@ private:
     const VirtualKey* findVirtualKeyHit(int32_t x, int32_t y);
 
     static void assignPointerIds(const RawState* last, RawState* current);
+    
+    bool rejectPalm(nsecs_t when);
 };