HIC: Improve AccelerationClassifier

am: 6b312a09fc

Change-Id: Ic0e0db4d8c0cdd507352b18904fb5fb0747168e9

packages/SystemUI/src/com/android/systemui/classifier/AccelerationClassifier.java

@@ -62,36 +62,36 @@ public class AccelerationClassifier extends StrokeClassifier {
     @Override
     public float getFalseTouchEvaluation(int type, Stroke stroke) {
         Data data = mStrokeMap.get(stroke);
-        return SpeedRatioEvaluator.evaluate(data.maxSpeedRatio)
+        return 2 * SpeedRatioEvaluator.evaluate(data.maxSpeedRatio);
-                + DistanceRatioEvaluator.evaluate(data.maxDistanceRatio);
     }
 
     private static class Data {
-        public Point previousPoint;
+
-        public float previousSpeed;
+        static final float MILLIS_TO_NANOS = 1e6f;
-        public float previousDistance;
+
-        public float maxSpeedRatio;
+        Point previousPoint;
-        public float maxDistanceRatio;
+        float previousSpeed = 0;
+        float maxSpeedRatio = 0;
 
         public Data(Point point) {
             previousPoint = point;
-            previousSpeed = previousDistance = 0.0f;
-            maxDistanceRatio = maxSpeedRatio = 0.0f;
         }
 
         public void addPoint(Point point) {
             float distance = previousPoint.dist(point);
             float duration = (float) (point.timeOffsetNano - previousPoint.timeOffsetNano + 1);
             float speed = distance / duration;
-            if (previousDistance != 0.0f) {
-                maxDistanceRatio = Math.max(maxDistanceRatio, distance / previousDistance);
-            }
 
+            if (duration > 20 * MILLIS_TO_NANOS || duration < 5 * MILLIS_TO_NANOS) {
+                // reject this segment and ensure we won't use data about it in the next round.
+                previousSpeed = 0;
+                previousPoint = point;
+                return;
+            }
             if (previousSpeed != 0.0f) {
                 maxSpeedRatio = Math.max(maxSpeedRatio, speed / previousSpeed);
             }
 
-            previousDistance = distance;
             previousSpeed = speed;
             previousPoint = point;
         }

packages/SystemUI/src/com/android/systemui/classifier/DistanceRatioEvaluator.java

@@ -1,29 +0,0 @@
-/*
- * Copyright (C) 2015 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License
- */
-
-package com.android.systemui.classifier;
-
-public class DistanceRatioEvaluator {
-    public static float evaluate(float value) {
-        float evaluation = 0.0f;
-        if (value <= 1.0) evaluation++;
-        if (value <= 0.5) evaluation++;
-        if (value > 4.0) evaluation++;
-        if (value > 7.0) evaluation++;
-        if (value > 14.0) evaluation++;
-        return evaluation;
-    }
-}

packages/SystemUI/src/com/android/systemui/classifier/SpeedRatioEvaluator.java

@@ -19,6 +19,7 @@ package com.android.systemui.classifier;
 public class SpeedRatioEvaluator {
     public static float evaluate(float value) {
         float evaluation = 0.0f;
+        if (value == 0) return 0;
         if (value <= 1.0) evaluation++;
         if (value <= 0.5) evaluation++;
         if (value > 9.0) evaluation++;