Update dialer sources.

Test: Built package and system image.

This change clobbers the old source, and is an export
from an internal Google repository.

The internal repository was forked form Android in March,
and this change includes modifications since then, to
near the v8 release.

Since the fork, we've moved code from monolithic to independent modules. In addition,
we've switched to Blaze/Bazel as the build sysetm. This export, however, still uses make.

New dependencies have been added:
- Dagger
- Auto-Value
- Glide
- Libshortcutbadger

Going forward, development will still be in Google3, and the Gerrit release
will become an automated export, with the next drop happening in ~ two weeks.

Android.mk includes local modifications from ToT.

Abridged changelog:

Bug fixes
● Not able to mute, add a call when using Phone app in multiwindow mode
● Double tap on keypad triggering multiple key and tones
● Reported spam numbers not showing as spam in the call log
● Crash when user tries to block number while Phone app is not set as default
● Crash when user picks a number from search auto-complete list

Visual Voicemail (VVM) improvements
● Share Voicemail audio via standard exporting mechanisms that support file attachment
(email, MMS, etc.)
● Make phone number, email and web sites in VVM transcript clickable
● Set PIN before declining VVM Terms of Service {Carrier}
● Set client type for outbound visual voicemail SMS {Carrier}

New incoming call and incall UI on older devices
(Android M)
● Updated Phone app icon
● New incall UI (large buttons, button labels)
● New and animated Answer/Reject gestures

Accessibility
● Add custom answer/decline call buttons on answer screen for touch exploration
accessibility services
● Increase size of touch target
● Add verbal feedback when a Voicemail fails to load
● Fix pressing of Phone buttons while in a phone call using Switch Access
● Fix selecting and opening contacts in talkback mode
● Split focus for ‘Learn More’ link in caller id & spam to help distinguish similar text

Other
● Backup & Restore for App Preferences
● Prompt user to enable Wi-Fi calling if the call ends due to out of service and Wi-Fi is
connected
● Rename “Dialpad” to “Keypad”
● Show "Private number" for restricted calls
● Delete unused items (vcard, add contact, call history) from Phone menu

Change-Id: I2a7e53532a24c21bf308bf0a6d178d7ddbca4958

33 files changed, 2032 insertions, 0 deletions

diff --git a/java/com/android/incallui/answer/impl/classifier/AccelerationClassifier.java b/java/com/android/incallui/answer/impl/classifier/AccelerationClassifier.java
new file mode 100644
index 000000000..ac504444e
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/AccelerationClassifier.java
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2016 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.incallui.answer.impl.classifier;
+
+import android.util.ArrayMap;
+import android.view.MotionEvent;
+import java.util.Map;
+
+/**
+ * A classifier which looks at the speed and distance between successive points of a Stroke. It
+ * looks at two consecutive speeds between two points and calculates the ratio between them. The
+ * final result is the maximum of these values. It does the same for distances. If some speed or
+ * distance is equal to zero then the ratio between this and the next part is not calculated. To the
+ * duration of each part there is added one nanosecond so that it is always possible to calculate
+ * the speed of a part.
+ */
+class AccelerationClassifier extends StrokeClassifier {
+  private final Map<Stroke, Data> mStrokeMap = new ArrayMap<>();
+
+  public AccelerationClassifier(ClassifierData classifierData) {
+    mClassifierData = classifierData;
+  }
+
+  @Override
+  public String getTag() {
+    return "ACC";
+  }
+
+  @Override
+  public void onTouchEvent(MotionEvent event) {
+    int action = event.getActionMasked();
+
+    if (action == MotionEvent.ACTION_DOWN) {
+      mStrokeMap.clear();
+    }
+
+    for (int i = 0; i < event.getPointerCount(); i++) {
+      Stroke stroke = mClassifierData.getStroke(event.getPointerId(i));
+      Point point = stroke.getPoints().get(stroke.getPoints().size() - 1);
+      if (mStrokeMap.get(stroke) == null) {
+        mStrokeMap.put(stroke, new Data(point));
+      } else {
+        mStrokeMap.get(stroke).addPoint(point);
+      }
+    }
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    Data data = mStrokeMap.get(stroke);
+    return 2 * SpeedRatioEvaluator.evaluate(data.maxSpeedRatio);
+  }
+
+  private static class Data {
+
+    static final float MILLIS_TO_NANOS = 1e6f;
+
+    Point previousPoint;
+    float previousSpeed = 0;
+    float maxSpeedRatio = 0;
+
+    public Data(Point point) {
+      previousPoint = point;
+    }
+
+    public void addPoint(Point point) {
+      float distance = previousPoint.dist(point);
+      float duration = (float) (point.timeOffsetNano - previousPoint.timeOffsetNano + 1);
+      float speed = distance / duration;
+
+      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);
+      }
+
+      previousSpeed = speed;
+      previousPoint = point;
+    }
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/AnglesClassifier.java b/java/com/android/incallui/answer/impl/classifier/AnglesClassifier.java
new file mode 100644
index 000000000..dbfbcfc1c
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/AnglesClassifier.java
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2016 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.incallui.answer.impl.classifier;
+
+import android.util.ArrayMap;
+import android.view.MotionEvent;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A classifier which calculates the variance of differences between successive angles in a stroke.
+ * For each stroke it keeps its last three points. If some successive points are the same, it
+ * ignores the repetitions. If a new point is added, the classifier calculates the angle between the
+ * last three points. After that, it calculates the difference between this angle and the previously
+ * calculated angle. Then it calculates the variance of the differences from a stroke. To the
+ * differences there is artificially added value 0.0 and the difference between the first angle and
+ * PI (angles are in radians). It helps with strokes which have few points and punishes more strokes
+ * which are not smooth.
+ *
+ * <p>This classifier also tries to split the stroke into two parts in the place in which the
+ * biggest angle is. It calculates the angle variance of the two parts and sums them up. The reason
+ * the classifier is doing this, is because some human swipes at the beginning go for a moment in
+ * one direction and then they rapidly change direction for the rest of the stroke (like a tick).
+ * The final result is the minimum of angle variance of the whole stroke and the sum of angle
+ * variances of the two parts split up. The classifier tries the tick option only if the first part
+ * is shorter than the second part.
+ *
+ * <p>Additionally, the classifier classifies the angles as left angles (those angles which value is
+ * in [0.0, PI - ANGLE_DEVIATION) interval), straight angles ([PI - ANGLE_DEVIATION, PI +
+ * ANGLE_DEVIATION] interval) and right angles ((PI + ANGLE_DEVIATION, 2 * PI) interval) and then
+ * calculates the percentage of angles which are in the same direction (straight angles can be left
+ * angels or right angles)
+ */
+class AnglesClassifier extends StrokeClassifier {
+  private Map<Stroke, Data> mStrokeMap = new ArrayMap<>();
+
+  public AnglesClassifier(ClassifierData classifierData) {
+    mClassifierData = classifierData;
+  }
+
+  @Override
+  public String getTag() {
+    return "ANG";
+  }
+
+  @Override
+  public void onTouchEvent(MotionEvent event) {
+    int action = event.getActionMasked();
+
+    if (action == MotionEvent.ACTION_DOWN) {
+      mStrokeMap.clear();
+    }
+
+    for (int i = 0; i < event.getPointerCount(); i++) {
+      Stroke stroke = mClassifierData.getStroke(event.getPointerId(i));
+
+      if (mStrokeMap.get(stroke) == null) {
+        mStrokeMap.put(stroke, new Data());
+      }
+      mStrokeMap.get(stroke).addPoint(stroke.getPoints().get(stroke.getPoints().size() - 1));
+    }
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    Data data = mStrokeMap.get(stroke);
+    return AnglesVarianceEvaluator.evaluate(data.getAnglesVariance())
+        + AnglesPercentageEvaluator.evaluate(data.getAnglesPercentage());
+  }
+
+  private static class Data {
+    private static final float ANGLE_DEVIATION = (float) Math.PI / 20.0f;
+    private static final float MIN_MOVE_DIST_DP = .01f;
+
+    private List<Point> mLastThreePoints = new ArrayList<>();
+    private float mFirstAngleVariance;
+    private float mPreviousAngle;
+    private float mBiggestAngle;
+    private float mSumSquares;
+    private float mSecondSumSquares;
+    private float mSum;
+    private float mSecondSum;
+    private float mCount;
+    private float mSecondCount;
+    private float mFirstLength;
+    private float mLength;
+    private float mAnglesCount;
+    private float mLeftAngles;
+    private float mRightAngles;
+    private float mStraightAngles;
+
+    public Data() {
+      mFirstAngleVariance = 0.0f;
+      mPreviousAngle = (float) Math.PI;
+      mBiggestAngle = 0.0f;
+      mSumSquares = mSecondSumSquares = 0.0f;
+      mSum = mSecondSum = 0.0f;
+      mCount = mSecondCount = 1.0f;
+      mLength = mFirstLength = 0.0f;
+      mAnglesCount = mLeftAngles = mRightAngles = mStraightAngles = 0.0f;
+    }
+
+    public void addPoint(Point point) {
+      // Checking if the added point is different than the previously added point
+      // Repetitions and short distances are being ignored so that proper angles are calculated.
+      if (mLastThreePoints.isEmpty()
+          || (!mLastThreePoints.get(mLastThreePoints.size() - 1).equals(point)
+              && (mLastThreePoints.get(mLastThreePoints.size() - 1).dist(point)
+                  > MIN_MOVE_DIST_DP))) {
+        if (!mLastThreePoints.isEmpty()) {
+          mLength += mLastThreePoints.get(mLastThreePoints.size() - 1).dist(point);
+        }
+        mLastThreePoints.add(point);
+        if (mLastThreePoints.size() == 4) {
+          mLastThreePoints.remove(0);
+
+          float angle =
+              mLastThreePoints.get(1).getAngle(mLastThreePoints.get(0), mLastThreePoints.get(2));
+
+          mAnglesCount++;
+          if (angle < Math.PI - ANGLE_DEVIATION) {
+            mLeftAngles++;
+          } else if (angle <= Math.PI + ANGLE_DEVIATION) {
+            mStraightAngles++;
+          } else {
+            mRightAngles++;
+          }
+
+          float difference = angle - mPreviousAngle;
+
+          // If this is the biggest angle of the stroke so then we save the value of
+          // the angle variance so far and start to count the values for the angle
+          // variance of the second part.
+          if (mBiggestAngle < angle) {
+            mBiggestAngle = angle;
+            mFirstLength = mLength;
+            mFirstAngleVariance = getAnglesVariance(mSumSquares, mSum, mCount);
+            mSecondSumSquares = 0.0f;
+            mSecondSum = 0.0f;
+            mSecondCount = 1.0f;
+          } else {
+            mSecondSum += difference;
+            mSecondSumSquares += difference * difference;
+            mSecondCount += 1.0f;
+          }
+
+          mSum += difference;
+          mSumSquares += difference * difference;
+          mCount += 1.0f;
+          mPreviousAngle = angle;
+        }
+      }
+    }
+
+    public float getAnglesVariance(float sumSquares, float sum, float count) {
+      return sumSquares / count - (sum / count) * (sum / count);
+    }
+
+    public float getAnglesVariance() {
+      float anglesVariance = getAnglesVariance(mSumSquares, mSum, mCount);
+      if (mFirstLength < mLength / 2f) {
+        anglesVariance =
+            Math.min(
+                anglesVariance,
+                mFirstAngleVariance
+                    + getAnglesVariance(mSecondSumSquares, mSecondSum, mSecondCount));
+      }
+      return anglesVariance;
+    }
+
+    public float getAnglesPercentage() {
+      if (mAnglesCount == 0.0f) {
+        return 1.0f;
+      }
+      return (Math.max(mLeftAngles, mRightAngles) + mStraightAngles) / mAnglesCount;
+    }
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/AnglesPercentageEvaluator.java b/java/com/android/incallui/answer/impl/classifier/AnglesPercentageEvaluator.java
new file mode 100644
index 000000000..49a183596
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/AnglesPercentageEvaluator.java
@@ -0,0 +1,33 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class AnglesPercentageEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value < 1.00) {
+      evaluation++;
+    }
+    if (value < 0.90) {
+      evaluation++;
+    }
+    if (value < 0.70) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/AnglesVarianceEvaluator.java b/java/com/android/incallui/answer/impl/classifier/AnglesVarianceEvaluator.java
new file mode 100644
index 000000000..db4de6a3b
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/AnglesVarianceEvaluator.java
@@ -0,0 +1,42 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class AnglesVarianceEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value > 0.05) {
+      evaluation++;
+    }
+    if (value > 0.10) {
+      evaluation++;
+    }
+    if (value > 0.20) {
+      evaluation++;
+    }
+    if (value > 0.40) {
+      evaluation++;
+    }
+    if (value > 0.80) {
+      evaluation++;
+    }
+    if (value > 1.50) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/Classifier.java b/java/com/android/incallui/answer/impl/classifier/Classifier.java
new file mode 100644
index 000000000..c6fbff327
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/Classifier.java
@@ -0,0 +1,35 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+import android.hardware.SensorEvent;
+import android.view.MotionEvent;
+
+/** An abstract class for classifiers for touch and sensor events. */
+abstract class Classifier {
+
+  /** Contains all the information about touch events from which the classifier can query */
+  protected ClassifierData mClassifierData;
+
+  /** Informs the classifier that a new touch event has occurred */
+  public void onTouchEvent(MotionEvent event) {}
+
+  /** Informs the classifier that a sensor change occurred */
+  public void onSensorChanged(SensorEvent event) {}
+
+  public abstract String getTag();
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/ClassifierData.java b/java/com/android/incallui/answer/impl/classifier/ClassifierData.java
new file mode 100644
index 000000000..ae07d27a0
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/ClassifierData.java
@@ -0,0 +1,96 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+import android.util.SparseArray;
+import android.view.MotionEvent;
+import java.util.ArrayList;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Contains data which is used to classify interaction sequences on the lockscreen. It does, for
+ * example, provide information on the current touch state.
+ */
+class ClassifierData {
+  private SparseArray<Stroke> mCurrentStrokes = new SparseArray<>();
+  private ArrayList<Stroke> mEndingStrokes = new ArrayList<>();
+  private final float mDpi;
+  private final float mScreenHeight;
+
+  public ClassifierData(float dpi, float screenHeight) {
+    mDpi = dpi;
+    mScreenHeight = screenHeight / dpi;
+  }
+
+  public void update(MotionEvent event) {
+    mEndingStrokes.clear();
+    int action = event.getActionMasked();
+    if (action == MotionEvent.ACTION_DOWN) {
+      mCurrentStrokes.clear();
+    }
+
+    for (int i = 0; i < event.getPointerCount(); i++) {
+      int id = event.getPointerId(i);
+      if (mCurrentStrokes.get(id) == null) {
+        // TODO (keyboardr): See if there's a way to use event.getEventTimeNanos() instead
+        mCurrentStrokes.put(
+            id, new Stroke(TimeUnit.MILLISECONDS.toNanos(event.getEventTime()), mDpi));
+      }
+      mCurrentStrokes
+          .get(id)
+          .addPoint(
+              event.getX(i), event.getY(i), TimeUnit.MILLISECONDS.toNanos(event.getEventTime()));
+
+      if (action == MotionEvent.ACTION_UP
+          || action == MotionEvent.ACTION_CANCEL
+          || (action == MotionEvent.ACTION_POINTER_UP && i == event.getActionIndex())) {
+        mEndingStrokes.add(getStroke(id));
+      }
+    }
+  }
+
+  void cleanUp(MotionEvent event) {
+    mEndingStrokes.clear();
+    int action = event.getActionMasked();
+    for (int i = 0; i < event.getPointerCount(); i++) {
+      int id = event.getPointerId(i);
+      if (action == MotionEvent.ACTION_UP
+          || action == MotionEvent.ACTION_CANCEL
+          || (action == MotionEvent.ACTION_POINTER_UP && i == event.getActionIndex())) {
+        mCurrentStrokes.remove(id);
+      }
+    }
+  }
+
+  /** @return the list of Strokes which are ending in the recently added MotionEvent */
+  public ArrayList<Stroke> getEndingStrokes() {
+    return mEndingStrokes;
+  }
+
+  /**
+   * @param id the id from MotionEvent
+   * @return the Stroke assigned to the id
+   */
+  public Stroke getStroke(int id) {
+    return mCurrentStrokes.get(id);
+  }
+
+  /** @return the height of the screen in inches */
+  public float getScreenHeight() {
+    return mScreenHeight;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/DirectionClassifier.java b/java/com/android/incallui/answer/impl/classifier/DirectionClassifier.java
new file mode 100644
index 000000000..068626859
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/DirectionClassifier.java
@@ -0,0 +1,37 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+/**
+ * A classifier which looks at the general direction of a stroke and evaluates it depending on the
+ * type of action that takes place.
+ */
+public class DirectionClassifier extends StrokeClassifier {
+  public DirectionClassifier(ClassifierData classifierData) {}
+
+  @Override
+  public String getTag() {
+    return "DIR";
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    Point firstPoint = stroke.getPoints().get(0);
+    Point lastPoint = stroke.getPoints().get(stroke.getPoints().size() - 1);
+    return DirectionEvaluator.evaluate(lastPoint.x - firstPoint.x, lastPoint.y - firstPoint.y);
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/DirectionEvaluator.java b/java/com/android/incallui/answer/impl/classifier/DirectionEvaluator.java
new file mode 100644
index 000000000..cdc1cfe1e
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/DirectionEvaluator.java
@@ -0,0 +1,23 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class DirectionEvaluator {
+  public static float evaluate(float xDiff, float yDiff) {
+    return Math.abs(yDiff) < Math.abs(xDiff) ? 5.5f : 0.0f;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/DurationCountClassifier.java b/java/com/android/incallui/answer/impl/classifier/DurationCountClassifier.java
new file mode 100644
index 000000000..0b9f1138d
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/DurationCountClassifier.java
@@ -0,0 +1,35 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+/**
+ * A classifier which looks at the ratio between the duration of the stroke and its number of
+ * points.
+ */
+class DurationCountClassifier extends StrokeClassifier {
+  public DurationCountClassifier(ClassifierData classifierData) {}
+
+  @Override
+  public String getTag() {
+    return "DUR";
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    return DurationCountEvaluator.evaluate(stroke.getDurationSeconds() / stroke.getCount());
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/DurationCountEvaluator.java b/java/com/android/incallui/answer/impl/classifier/DurationCountEvaluator.java
new file mode 100644
index 000000000..5b232fe95
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/DurationCountEvaluator.java
@@ -0,0 +1,39 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class DurationCountEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value < 0.0105) {
+      evaluation++;
+    }
+    if (value < 0.00909) {
+      evaluation++;
+    }
+    if (value < 0.00667) {
+      evaluation++;
+    }
+    if (value > 0.0333) {
+      evaluation++;
+    }
+    if (value > 0.0500) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/EndPointLengthClassifier.java b/java/com/android/incallui/answer/impl/classifier/EndPointLengthClassifier.java
new file mode 100644
index 000000000..95b317638
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/EndPointLengthClassifier.java
@@ -0,0 +1,36 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+/**
+ * A classifier which looks at the distance between the first and the last point from the stroke.
+ */
+class EndPointLengthClassifier extends StrokeClassifier {
+  public EndPointLengthClassifier(ClassifierData classifierData) {
+    mClassifierData = classifierData;
+  }
+
+  @Override
+  public String getTag() {
+    return "END_LNGTH";
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    return EndPointLengthEvaluator.evaluate(stroke.getEndPointLength());
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/EndPointLengthEvaluator.java b/java/com/android/incallui/answer/impl/classifier/EndPointLengthEvaluator.java
new file mode 100644
index 000000000..74bfffba4
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/EndPointLengthEvaluator.java
@@ -0,0 +1,42 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class EndPointLengthEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value < 0.05) {
+      evaluation += 2.0f;
+    }
+    if (value < 0.1) {
+      evaluation += 2.0f;
+    }
+    if (value < 0.2) {
+      evaluation += 2.0f;
+    }
+    if (value < 0.3) {
+      evaluation += 2.0f;
+    }
+    if (value < 0.4) {
+      evaluation += 2.0f;
+    }
+    if (value < 0.5) {
+      evaluation += 2.0f;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/EndPointRatioClassifier.java b/java/com/android/incallui/answer/impl/classifier/EndPointRatioClassifier.java
new file mode 100644
index 000000000..01a35c126
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/EndPointRatioClassifier.java
@@ -0,0 +1,43 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+/**
+ * A classifier which looks at the ratio between the total length covered by the stroke and the
+ * distance between the first and last point from this stroke.
+ */
+class EndPointRatioClassifier extends StrokeClassifier {
+  public EndPointRatioClassifier(ClassifierData classifierData) {
+    mClassifierData = classifierData;
+  }
+
+  @Override
+  public String getTag() {
+    return "END_RTIO";
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    float ratio;
+    if (stroke.getTotalLength() == 0.0f) {
+      ratio = 1.0f;
+    } else {
+      ratio = stroke.getEndPointLength() / stroke.getTotalLength();
+    }
+    return EndPointRatioEvaluator.evaluate(ratio);
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/EndPointRatioEvaluator.java b/java/com/android/incallui/answer/impl/classifier/EndPointRatioEvaluator.java
new file mode 100644
index 000000000..1d64bea8e
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/EndPointRatioEvaluator.java
@@ -0,0 +1,42 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class EndPointRatioEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value < 0.85) {
+      evaluation++;
+    }
+    if (value < 0.75) {
+      evaluation++;
+    }
+    if (value < 0.65) {
+      evaluation++;
+    }
+    if (value < 0.55) {
+      evaluation++;
+    }
+    if (value < 0.45) {
+      evaluation++;
+    }
+    if (value < 0.35) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/FalsingManager.java b/java/com/android/incallui/answer/impl/classifier/FalsingManager.java
new file mode 100644
index 000000000..fdcc0a3f9
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/FalsingManager.java
@@ -0,0 +1,140 @@
+/*
+ * Copyright (C) 2016 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.incallui.answer.impl.classifier;
+
+import android.content.Context;
+import android.hardware.Sensor;
+import android.hardware.SensorEvent;
+import android.hardware.SensorEventListener;
+import android.hardware.SensorManager;
+import android.os.PowerManager;
+import android.view.MotionEvent;
+import android.view.accessibility.AccessibilityManager;
+
+/**
+ * When the phone is locked, listens to touch, sensor and phone events and sends them to
+ * HumanInteractionClassifier to determine if touches are coming from a human.
+ */
+public class FalsingManager implements SensorEventListener {
+  private static final int[] CLASSIFIER_SENSORS =
+      new int[] {
+        Sensor.TYPE_PROXIMITY,
+      };
+
+  private final SensorManager mSensorManager;
+  private final HumanInteractionClassifier mHumanInteractionClassifier;
+  private final AccessibilityManager mAccessibilityManager;
+
+  private boolean mSessionActive = false;
+  private boolean mScreenOn;
+
+  public FalsingManager(Context context) {
+    mSensorManager = context.getSystemService(SensorManager.class);
+    mAccessibilityManager = context.getSystemService(AccessibilityManager.class);
+    mHumanInteractionClassifier = new HumanInteractionClassifier(context);
+    mScreenOn = context.getSystemService(PowerManager.class).isInteractive();
+  }
+
+  /** Returns {@code true} iff the FalsingManager is enabled and able to classify touches */
+  public boolean isEnabled() {
+    return mHumanInteractionClassifier.isEnabled();
+  }
+
+  /**
+   * Returns {@code true} iff the classifier determined that this is not a human interacting with
+   * the phone.
+   */
+  public boolean isFalseTouch() {
+    // Touch exploration triggers false positives in the classifier and
+    // already sufficiently prevents false unlocks.
+    return !mAccessibilityManager.isTouchExplorationEnabled()
+        && mHumanInteractionClassifier.isFalseTouch();
+  }
+
+  /**
+   * Should be called when the screen turns on and the related Views become visible. This will start
+   * tracking changes if the manager is enabled.
+   */
+  public void onScreenOn() {
+    mScreenOn = true;
+    sessionEntrypoint();
+  }
+
+  /**
+   * Should be called when the screen turns off or the related Views are no longer visible. This
+   * will cause the manager to stop tracking changes.
+   */
+  public void onScreenOff() {
+    mScreenOn = false;
+    sessionExitpoint();
+  }
+
+  /**
+   * Should be called when a new touch event has been received and should be classified.
+   *
+   * @param event MotionEvent to be classified as human or false.
+   */
+  public void onTouchEvent(MotionEvent event) {
+    if (mSessionActive) {
+      mHumanInteractionClassifier.onTouchEvent(event);
+    }
+  }
+
+  @Override
+  public synchronized void onSensorChanged(SensorEvent event) {
+    mHumanInteractionClassifier.onSensorChanged(event);
+  }
+
+  @Override
+  public void onAccuracyChanged(Sensor sensor, int accuracy) {}
+
+  private boolean shouldSessionBeActive() {
+    return isEnabled() && mScreenOn;
+  }
+
+  private boolean sessionEntrypoint() {
+    if (!mSessionActive && shouldSessionBeActive()) {
+      onSessionStart();
+      return true;
+    }
+    return false;
+  }
+
+  private void sessionExitpoint() {
+    if (mSessionActive && !shouldSessionBeActive()) {
+      mSessionActive = false;
+      mSensorManager.unregisterListener(this);
+    }
+  }
+
+  private void onSessionStart() {
+    mSessionActive = true;
+
+    if (mHumanInteractionClassifier.isEnabled()) {
+      registerSensors(CLASSIFIER_SENSORS);
+    }
+  }
+
+  private void registerSensors(int[] sensors) {
+    for (int sensorType : sensors) {
+      Sensor s = mSensorManager.getDefaultSensor(sensorType);
+      if (s != null) {
+        mSensorManager.registerListener(this, s, SensorManager.SENSOR_DELAY_GAME);
+      }
+    }
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/GestureClassifier.java b/java/com/android/incallui/answer/impl/classifier/GestureClassifier.java
new file mode 100644
index 000000000..afd7ea0e7
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/GestureClassifier.java
@@ -0,0 +1,31 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+/**
+ * An abstract class for classifiers which classify the whole gesture (all the strokes which
+ * occurred from DOWN event to UP/CANCEL event)
+ */
+abstract class GestureClassifier extends Classifier {
+
+  /**
+   * @return a non-negative value which is used to determine whether the most recent gesture is a
+   *     false interaction; the bigger the value the greater the chance that this a false
+   *     interaction.
+   */
+  public abstract float getFalseTouchEvaluation();
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/HistoryEvaluator.java b/java/com/android/incallui/answer/impl/classifier/HistoryEvaluator.java
new file mode 100644
index 000000000..3f302c65f
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/HistoryEvaluator.java
@@ -0,0 +1,115 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+import android.os.SystemClock;
+
+import java.util.ArrayList;
+
+/**
+ * Holds the evaluations for ended strokes and gestures. These values are decreased through time.
+ */
+class HistoryEvaluator {
+  private static final float INTERVAL = 50.0f;
+  private static final float HISTORY_FACTOR = 0.9f;
+  private static final float EPSILON = 1e-5f;
+
+  private final ArrayList<Data> mStrokes = new ArrayList<>();
+  private final ArrayList<Data> mGestureWeights = new ArrayList<>();
+  private long mLastUpdate;
+
+  public HistoryEvaluator() {
+    mLastUpdate = SystemClock.elapsedRealtime();
+  }
+
+  public void addStroke(float evaluation) {
+    decayValue();
+    mStrokes.add(new Data(evaluation));
+  }
+
+  public void addGesture(float evaluation) {
+    decayValue();
+    mGestureWeights.add(new Data(evaluation));
+  }
+
+  /** Calculates the weighted average of strokes and adds to it the weighted average of gestures */
+  public float getEvaluation() {
+    return weightedAverage(mStrokes) + weightedAverage(mGestureWeights);
+  }
+
+  private float weightedAverage(ArrayList<Data> list) {
+    float sumValue = 0.0f;
+    float sumWeight = 0.0f;
+    int size = list.size();
+    for (int i = 0; i < size; i++) {
+      Data data = list.get(i);
+      sumValue += data.evaluation * data.weight;
+      sumWeight += data.weight;
+    }
+
+    if (sumWeight == 0.0f) {
+      return 0.0f;
+    }
+
+    return sumValue / sumWeight;
+  }
+
+  private void decayValue() {
+    long time = SystemClock.elapsedRealtime();
+
+    if (time <= mLastUpdate) {
+      return;
+    }
+
+    // All weights are multiplied by HISTORY_FACTOR after each INTERVAL milliseconds.
+    float factor = (float) Math.pow(HISTORY_FACTOR, (time - mLastUpdate) / INTERVAL);
+
+    decayValue(mStrokes, factor);
+    decayValue(mGestureWeights, factor);
+    mLastUpdate = time;
+  }
+
+  private void decayValue(ArrayList<Data> list, float factor) {
+    int size = list.size();
+    for (int i = 0; i < size; i++) {
+      list.get(i).weight *= factor;
+    }
+
+    // Removing evaluations with such small weights that they do not matter anymore
+    while (!list.isEmpty() && isZero(list.get(0).weight)) {
+      list.remove(0);
+    }
+  }
+
+  private boolean isZero(float x) {
+    return x <= EPSILON && x >= -EPSILON;
+  }
+
+  /**
+   * For each stroke it holds its initial value and the current weight. Initially the weight is set
+   * to 1.0
+   */
+  private static class Data {
+    public float evaluation;
+    public float weight;
+
+    public Data(float evaluation) {
+      this.evaluation = evaluation;
+      weight = 1.0f;
+    }
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/HumanInteractionClassifier.java b/java/com/android/incallui/answer/impl/classifier/HumanInteractionClassifier.java
new file mode 100644
index 000000000..1d3d7ef22
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/HumanInteractionClassifier.java
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2016 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.incallui.answer.impl.classifier;
+
+import android.content.Context;
+import android.hardware.SensorEvent;
+import android.util.DisplayMetrics;
+import android.view.MotionEvent;
+import com.android.dialer.common.ConfigProviderBindings;
+
+/** An classifier trying to determine whether it is a human interacting with the phone or not. */
+class HumanInteractionClassifier extends Classifier {
+
+  private static final String CONFIG_ANSWER_FALSE_TOUCH_DETECTION_ENABLED =
+      "answer_false_touch_detection_enabled";
+
+  private final StrokeClassifier[] mStrokeClassifiers;
+  private final GestureClassifier[] mGestureClassifiers;
+  private final HistoryEvaluator mHistoryEvaluator;
+  private final boolean mEnabled;
+
+  HumanInteractionClassifier(Context context) {
+    DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
+
+    // If the phone is rotated to landscape, the calculations would be wrong if xdpi and ydpi
+    // were to be used separately. Due negligible differences in xdpi and ydpi we can just
+    // take the average.
+    // Note that xdpi and ydpi are the physical pixels per inch and are not affected by scaling.
+    float dpi = (displayMetrics.xdpi + displayMetrics.ydpi) / 2.0f;
+    mClassifierData = new ClassifierData(dpi, displayMetrics.heightPixels);
+    mHistoryEvaluator = new HistoryEvaluator();
+    mEnabled =
+        ConfigProviderBindings.get(context)
+            .getBoolean(CONFIG_ANSWER_FALSE_TOUCH_DETECTION_ENABLED, true);
+
+    mStrokeClassifiers =
+        new StrokeClassifier[] {
+          new AnglesClassifier(mClassifierData),
+          new SpeedClassifier(mClassifierData),
+          new DurationCountClassifier(mClassifierData),
+          new EndPointRatioClassifier(mClassifierData),
+          new EndPointLengthClassifier(mClassifierData),
+          new AccelerationClassifier(mClassifierData),
+          new SpeedAnglesClassifier(mClassifierData),
+          new LengthCountClassifier(mClassifierData),
+          new DirectionClassifier(mClassifierData)
+        };
+
+    mGestureClassifiers =
+        new GestureClassifier[] {
+          new PointerCountClassifier(mClassifierData), new ProximityClassifier(mClassifierData)
+        };
+  }
+
+  @Override
+  public void onTouchEvent(MotionEvent event) {
+
+    // If the user is dragging down the notification, they might want to drag it down
+    // enough to see the content, read it for a while and then lift the finger to open
+    // the notification. This kind of motion scores very bad in the Classifier so the
+    // MotionEvents which are close to the current position of the finger are not
+    // sent to the classifiers until the finger moves far enough. When the finger if lifted
+    // up, the last MotionEvent which was far enough from the finger is set as the final
+    // MotionEvent and sent to the Classifiers.
+    addTouchEvent(event);
+  }
+
+  private void addTouchEvent(MotionEvent event) {
+    mClassifierData.update(event);
+
+    for (StrokeClassifier c : mStrokeClassifiers) {
+      c.onTouchEvent(event);
+    }
+
+    for (GestureClassifier c : mGestureClassifiers) {
+      c.onTouchEvent(event);
+    }
+
+    int size = mClassifierData.getEndingStrokes().size();
+    for (int i = 0; i < size; i++) {
+      Stroke stroke = mClassifierData.getEndingStrokes().get(i);
+      float evaluation = 0.0f;
+      for (StrokeClassifier c : mStrokeClassifiers) {
+        float e = c.getFalseTouchEvaluation(stroke);
+        evaluation += e;
+      }
+
+      mHistoryEvaluator.addStroke(evaluation);
+    }
+
+    int action = event.getActionMasked();
+    if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
+      float evaluation = 0.0f;
+      for (GestureClassifier c : mGestureClassifiers) {
+        float e = c.getFalseTouchEvaluation();
+        evaluation += e;
+      }
+      mHistoryEvaluator.addGesture(evaluation);
+    }
+
+    mClassifierData.cleanUp(event);
+  }
+
+  @Override
+  public void onSensorChanged(SensorEvent event) {
+    for (Classifier c : mStrokeClassifiers) {
+      c.onSensorChanged(event);
+    }
+
+    for (Classifier c : mGestureClassifiers) {
+      c.onSensorChanged(event);
+    }
+  }
+
+  boolean isFalseTouch() {
+    float evaluation = mHistoryEvaluator.getEvaluation();
+    return evaluation >= 5.0f;
+  }
+
+  public boolean isEnabled() {
+    return mEnabled;
+  }
+
+  @Override
+  public String getTag() {
+    return "HIC";
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/LengthCountClassifier.java b/java/com/android/incallui/answer/impl/classifier/LengthCountClassifier.java
new file mode 100644
index 000000000..7dd2ab674
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/LengthCountClassifier.java
@@ -0,0 +1,39 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+/**
+ * A classifier which looks at the ratio between the length of the stroke and its number of points.
+ * The number of points is subtracted by 2 because the UP event comes in with some delay and it
+ * should not influence the ratio and also strokes which are long and have a small number of points
+ * are punished more (these kind of strokes are usually bad ones and they tend to score well in
+ * other classifiers).
+ */
+class LengthCountClassifier extends StrokeClassifier {
+  public LengthCountClassifier(ClassifierData classifierData) {}
+
+  @Override
+  public String getTag() {
+    return "LEN_CNT";
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    return LengthCountEvaluator.evaluate(
+        stroke.getTotalLength() / Math.max(1.0f, stroke.getCount() - 2));
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/LengthCountEvaluator.java b/java/com/android/incallui/answer/impl/classifier/LengthCountEvaluator.java
new file mode 100644
index 000000000..2a2225a00
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/LengthCountEvaluator.java
@@ -0,0 +1,45 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+/**
+ * A classifier which looks at the ratio between the length of the stroke and its number of points.
+ */
+class LengthCountEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value < 0.09) {
+      evaluation++;
+    }
+    if (value < 0.05) {
+      evaluation++;
+    }
+    if (value < 0.02) {
+      evaluation++;
+    }
+    if (value > 0.6) {
+      evaluation++;
+    }
+    if (value > 0.9) {
+      evaluation++;
+    }
+    if (value > 1.2) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/Point.java b/java/com/android/incallui/answer/impl/classifier/Point.java
new file mode 100644
index 000000000..5ea48b4ce
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/Point.java
@@ -0,0 +1,95 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class Point {
+  public float x;
+  public float y;
+  public long timeOffsetNano;
+
+  public Point(float x, float y) {
+    this.x = x;
+    this.y = y;
+    this.timeOffsetNano = 0;
+  }
+
+  public Point(float x, float y, long timeOffsetNano) {
+    this.x = x;
+    this.y = y;
+    this.timeOffsetNano = timeOffsetNano;
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (!(other instanceof Point)) {
+      return false;
+    }
+    Point otherPoint = ((Point) other);
+    return x == otherPoint.x && y == otherPoint.y;
+  }
+
+  @Override
+  public int hashCode() {
+    int result = (x != +0.0f ? Float.floatToIntBits(x) : 0);
+    result = 31 * result + (y != +0.0f ? Float.floatToIntBits(y) : 0);
+    return result;
+  }
+
+  public float dist(Point a) {
+    return (float) Math.hypot(a.x - x, a.y - y);
+  }
+
+  /**
+   * Calculates the cross product of vec(this, a) and vec(this, b) where vec(x,y) is the vector from
+   * point x to point y
+   */
+  public float crossProduct(Point a, Point b) {
+    return (a.x - x) * (b.y - y) - (a.y - y) * (b.x - x);
+  }
+
+  /**
+   * Calculates the dot product of vec(this, a) and vec(this, b) where vec(x,y) is the vector from
+   * point x to point y
+   */
+  public float dotProduct(Point a, Point b) {
+    return (a.x - x) * (b.x - x) + (a.y - y) * (b.y - y);
+  }
+
+  /**
+   * Calculates the angle in radians created by points (a, this, b). If any two of these points are
+   * the same, the method will return 0.0f
+   *
+   * @return the angle in radians
+   */
+  public float getAngle(Point a, Point b) {
+    float dist1 = dist(a);
+    float dist2 = dist(b);
+
+    if (dist1 == 0.0f || dist2 == 0.0f) {
+      return 0.0f;
+    }
+
+    float crossProduct = crossProduct(a, b);
+    float dotProduct = dotProduct(a, b);
+    float cos = Math.min(1.0f, Math.max(-1.0f, dotProduct / dist1 / dist2));
+    float angle = (float) Math.acos(cos);
+    if (crossProduct < 0.0) {
+      angle = 2.0f * (float) Math.PI - angle;
+    }
+    return angle;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/PointerCountClassifier.java b/java/com/android/incallui/answer/impl/classifier/PointerCountClassifier.java
new file mode 100644
index 000000000..070de6c9b
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/PointerCountClassifier.java
@@ -0,0 +1,51 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+import android.view.MotionEvent;
+
+/** A classifier which looks at the total number of traces in the whole gesture. */
+class PointerCountClassifier extends GestureClassifier {
+  private int mCount;
+
+  public PointerCountClassifier(ClassifierData classifierData) {
+    mCount = 0;
+  }
+
+  @Override
+  public String getTag() {
+    return "PTR_CNT";
+  }
+
+  @Override
+  public void onTouchEvent(MotionEvent event) {
+    int action = event.getActionMasked();
+
+    if (action == MotionEvent.ACTION_DOWN) {
+      mCount = 1;
+    }
+
+    if (action == MotionEvent.ACTION_POINTER_DOWN) {
+      ++mCount;
+    }
+  }
+
+  @Override
+  public float getFalseTouchEvaluation() {
+    return PointerCountEvaluator.evaluate(mCount);
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/PointerCountEvaluator.java b/java/com/android/incallui/answer/impl/classifier/PointerCountEvaluator.java
new file mode 100644
index 000000000..aa972da8c
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/PointerCountEvaluator.java
@@ -0,0 +1,23 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class PointerCountEvaluator {
+  public static float evaluate(int value) {
+    return (value - 1) * (value - 1);
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/ProximityClassifier.java b/java/com/android/incallui/answer/impl/classifier/ProximityClassifier.java
new file mode 100644
index 000000000..28701ea6d
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/ProximityClassifier.java
@@ -0,0 +1,97 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+import android.hardware.Sensor;
+import android.hardware.SensorEvent;
+import android.view.MotionEvent;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * A classifier which looks at the proximity sensor during the gesture. It calculates the percentage
+ * the proximity sensor showing the near state during the whole gesture
+ */
+class ProximityClassifier extends GestureClassifier {
+  private long mGestureStartTimeNano;
+  private long mNearStartTimeNano;
+  private long mNearDuration;
+  private boolean mNear;
+  private float mAverageNear;
+
+  public ProximityClassifier(ClassifierData classifierData) {}
+
+  @Override
+  public String getTag() {
+    return "PROX";
+  }
+
+  @Override
+  public void onSensorChanged(SensorEvent event) {
+    if (event.sensor.getType() == Sensor.TYPE_PROXIMITY) {
+      update(event.values[0] < event.sensor.getMaximumRange(), event.timestamp);
+    }
+  }
+
+  @Override
+  public void onTouchEvent(MotionEvent event) {
+    int action = event.getActionMasked();
+
+    if (action == MotionEvent.ACTION_DOWN) {
+      mGestureStartTimeNano = TimeUnit.MILLISECONDS.toNanos(event.getEventTime());
+      mNearStartTimeNano = TimeUnit.MILLISECONDS.toNanos(event.getEventTime());
+      mNearDuration = 0;
+    }
+
+    if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
+      update(mNear, TimeUnit.MILLISECONDS.toNanos(event.getEventTime()));
+      long duration = TimeUnit.MILLISECONDS.toNanos(event.getEventTime()) - mGestureStartTimeNano;
+
+      if (duration == 0) {
+        mAverageNear = mNear ? 1.0f : 0.0f;
+      } else {
+        mAverageNear = (float) mNearDuration / (float) duration;
+      }
+    }
+  }
+
+  /**
+   * @param near is the sensor showing the near state right now
+   * @param timestampNano time of this event in nanoseconds
+   */
+  private void update(boolean near, long timestampNano) {
+    // This if is necessary because MotionEvents and SensorEvents do not come in
+    // chronological order
+    if (timestampNano > mNearStartTimeNano) {
+      // if the state before was near then add the difference of the current time and
+      // mNearStartTimeNano to mNearDuration.
+      if (mNear) {
+        mNearDuration += timestampNano - mNearStartTimeNano;
+      }
+
+      // if the new state is near, set mNearStartTimeNano equal to this moment.
+      if (near) {
+        mNearStartTimeNano = timestampNano;
+      }
+    }
+    mNear = near;
+  }
+
+  @Override
+  public float getFalseTouchEvaluation() {
+    return ProximityEvaluator.evaluate(mAverageNear);
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/ProximityEvaluator.java b/java/com/android/incallui/answer/impl/classifier/ProximityEvaluator.java
new file mode 100644
index 000000000..14636c644
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/ProximityEvaluator.java
@@ -0,0 +1,28 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class ProximityEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    float threshold = 0.1f;
+    if (value >= threshold) {
+      evaluation += 2.0f;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/SpeedAnglesClassifier.java b/java/com/android/incallui/answer/impl/classifier/SpeedAnglesClassifier.java
new file mode 100644
index 000000000..36ae3ad7c
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/SpeedAnglesClassifier.java
@@ -0,0 +1,147 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+import android.util.ArrayMap;
+import android.view.MotionEvent;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * A classifier which for each point from a stroke, it creates a point on plane with coordinates
+ * (timeOffsetNano, distanceCoveredUpToThisPoint) (scaled by DURATION_SCALE and LENGTH_SCALE) and
+ * then it calculates the angle variance of these points like the class {@link AnglesClassifier}
+ * (without splitting it into two parts). The classifier ignores the last point of a stroke because
+ * the UP event comes in with some delay and this ruins the smoothness of this curve. Additionally,
+ * the classifier classifies calculates the percentage of angles which value is in [PI -
+ * ANGLE_DEVIATION, 2* PI) interval. The reason why the classifier does that is because the speed of
+ * a good stroke is most often increases, so most of these angels should be in this interval.
+ */
+class SpeedAnglesClassifier extends StrokeClassifier {
+  private Map<Stroke, Data> mStrokeMap = new ArrayMap<>();
+
+  public SpeedAnglesClassifier(ClassifierData classifierData) {
+    mClassifierData = classifierData;
+  }
+
+  @Override
+  public String getTag() {
+    return "SPD_ANG";
+  }
+
+  @Override
+  public void onTouchEvent(MotionEvent event) {
+    int action = event.getActionMasked();
+
+    if (action == MotionEvent.ACTION_DOWN) {
+      mStrokeMap.clear();
+    }
+
+    for (int i = 0; i < event.getPointerCount(); i++) {
+      Stroke stroke = mClassifierData.getStroke(event.getPointerId(i));
+
+      if (mStrokeMap.get(stroke) == null) {
+        mStrokeMap.put(stroke, new Data());
+      }
+
+      if (action != MotionEvent.ACTION_UP
+          && action != MotionEvent.ACTION_CANCEL
+          && !(action == MotionEvent.ACTION_POINTER_UP && i == event.getActionIndex())) {
+        mStrokeMap.get(stroke).addPoint(stroke.getPoints().get(stroke.getPoints().size() - 1));
+      }
+    }
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    Data data = mStrokeMap.get(stroke);
+    return SpeedVarianceEvaluator.evaluate(data.getAnglesVariance())
+        + SpeedAnglesPercentageEvaluator.evaluate(data.getAnglesPercentage());
+  }
+
+  private static class Data {
+    private static final float DURATION_SCALE = 1e8f;
+    private static final float LENGTH_SCALE = 1.0f;
+    private static final float ANGLE_DEVIATION = (float) Math.PI / 10.0f;
+
+    private List<Point> mLastThreePoints = new ArrayList<>();
+    private Point mPreviousPoint;
+    private float mPreviousAngle;
+    private float mSumSquares;
+    private float mSum;
+    private float mCount;
+    private float mDist;
+    private float mAnglesCount;
+    private float mAcceleratingAngles;
+
+    public Data() {
+      mPreviousPoint = null;
+      mPreviousAngle = (float) Math.PI;
+      mSumSquares = 0.0f;
+      mSum = 0.0f;
+      mCount = 1.0f;
+      mDist = 0.0f;
+      mAnglesCount = mAcceleratingAngles = 0.0f;
+    }
+
+    public void addPoint(Point point) {
+      if (mPreviousPoint != null) {
+        mDist += mPreviousPoint.dist(point);
+      }
+
+      mPreviousPoint = point;
+      Point speedPoint =
+          new Point((float) point.timeOffsetNano / DURATION_SCALE, mDist / LENGTH_SCALE);
+
+      // Checking if the added point is different than the previously added point
+      // Repetitions are being ignored so that proper angles are calculated.
+      if (mLastThreePoints.isEmpty()
+          || !mLastThreePoints.get(mLastThreePoints.size() - 1).equals(speedPoint)) {
+        mLastThreePoints.add(speedPoint);
+        if (mLastThreePoints.size() == 4) {
+          mLastThreePoints.remove(0);
+
+          float angle =
+              mLastThreePoints.get(1).getAngle(mLastThreePoints.get(0), mLastThreePoints.get(2));
+
+          mAnglesCount++;
+          if (angle >= (float) Math.PI - ANGLE_DEVIATION) {
+            mAcceleratingAngles++;
+          }
+
+          float difference = angle - mPreviousAngle;
+          mSum += difference;
+          mSumSquares += difference * difference;
+          mCount += 1.0f;
+          mPreviousAngle = angle;
+        }
+      }
+    }
+
+    public float getAnglesVariance() {
+      return mSumSquares / mCount - (mSum / mCount) * (mSum / mCount);
+    }
+
+    public float getAnglesPercentage() {
+      if (mAnglesCount == 0.0f) {
+        return 1.0f;
+      }
+      return (mAcceleratingAngles) / mAnglesCount;
+    }
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/SpeedAnglesPercentageEvaluator.java b/java/com/android/incallui/answer/impl/classifier/SpeedAnglesPercentageEvaluator.java
new file mode 100644
index 000000000..5a8bc3556
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/SpeedAnglesPercentageEvaluator.java
@@ -0,0 +1,33 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class SpeedAnglesPercentageEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value < 1.00) {
+      evaluation++;
+    }
+    if (value < 0.90) {
+      evaluation++;
+    }
+    if (value < 0.70) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/SpeedClassifier.java b/java/com/android/incallui/answer/impl/classifier/SpeedClassifier.java
new file mode 100644
index 000000000..f3ade3f49
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/SpeedClassifier.java
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2016 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.incallui.answer.impl.classifier;
+
+/**
+ * A classifier that looks at the speed of the stroke. It calculates the speed of a stroke in inches
+ * per second.
+ */
+class SpeedClassifier extends StrokeClassifier {
+
+  public SpeedClassifier(ClassifierData classifierData) {}
+
+  @Override
+  public String getTag() {
+    return "SPD";
+  }
+
+  @Override
+  public float getFalseTouchEvaluation(Stroke stroke) {
+    float duration = stroke.getDurationSeconds();
+    if (duration == 0.0f) {
+      return SpeedEvaluator.evaluate(0.0f);
+    }
+    return SpeedEvaluator.evaluate(stroke.getTotalLength() / duration);
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/SpeedEvaluator.java b/java/com/android/incallui/answer/impl/classifier/SpeedEvaluator.java
new file mode 100644
index 000000000..4f9aace0e
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/SpeedEvaluator.java
@@ -0,0 +1,36 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class SpeedEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value < 4.0) {
+      evaluation++;
+    }
+    if (value < 2.2) {
+      evaluation++;
+    }
+    if (value > 35.0) {
+      evaluation++;
+    }
+    if (value > 50.0) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/SpeedRatioEvaluator.java b/java/com/android/incallui/answer/impl/classifier/SpeedRatioEvaluator.java
new file mode 100644
index 000000000..7ae111313
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/SpeedRatioEvaluator.java
@@ -0,0 +1,39 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+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++;
+    }
+    if (value > 18.0) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/SpeedVarianceEvaluator.java b/java/com/android/incallui/answer/impl/classifier/SpeedVarianceEvaluator.java
new file mode 100644
index 000000000..211650cbb
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/SpeedVarianceEvaluator.java
@@ -0,0 +1,36 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+class SpeedVarianceEvaluator {
+  public static float evaluate(float value) {
+    float evaluation = 0.0f;
+    if (value > 0.06) {
+      evaluation++;
+    }
+    if (value > 0.15) {
+      evaluation++;
+    }
+    if (value > 0.3) {
+      evaluation++;
+    }
+    if (value > 0.6) {
+      evaluation++;
+    }
+    return evaluation;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/Stroke.java b/java/com/android/incallui/answer/impl/classifier/Stroke.java
new file mode 100644
index 000000000..c542d0f7c
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/Stroke.java
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2016 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.incallui.answer.impl.classifier;
+
+import java.util.ArrayList;
+
+/**
+ * Contains data about a stroke (a single trace, all the events from a given id from the
+ * DOWN/POINTER_DOWN event till the UP/POINTER_UP/CANCEL event.)
+ */
+class Stroke {
+
+  private static final float NANOS_TO_SECONDS = 1e9f;
+
+  private ArrayList<Point> mPoints = new ArrayList<>();
+  private long mStartTimeNano;
+  private long mEndTimeNano;
+  private float mLength;
+  private final float mDpi;
+
+  public Stroke(long eventTimeNano, float dpi) {
+    mDpi = dpi;
+    mStartTimeNano = mEndTimeNano = eventTimeNano;
+  }
+
+  public void addPoint(float x, float y, long eventTimeNano) {
+    mEndTimeNano = eventTimeNano;
+    Point point = new Point(x / mDpi, y / mDpi, eventTimeNano - mStartTimeNano);
+    if (!mPoints.isEmpty()) {
+      mLength += mPoints.get(mPoints.size() - 1).dist(point);
+    }
+    mPoints.add(point);
+  }
+
+  public int getCount() {
+    return mPoints.size();
+  }
+
+  public float getTotalLength() {
+    return mLength;
+  }
+
+  public float getEndPointLength() {
+    return mPoints.get(0).dist(mPoints.get(mPoints.size() - 1));
+  }
+
+  public long getDurationNanos() {
+    return mEndTimeNano - mStartTimeNano;
+  }
+
+  public float getDurationSeconds() {
+    return (float) getDurationNanos() / NANOS_TO_SECONDS;
+  }
+
+  public ArrayList<Point> getPoints() {
+    return mPoints;
+  }
+}
diff --git a/java/com/android/incallui/answer/impl/classifier/StrokeClassifier.java b/java/com/android/incallui/answer/impl/classifier/StrokeClassifier.java
new file mode 100644
index 000000000..8abd7e2ec
--- /dev/null
+++ b/java/com/android/incallui/answer/impl/classifier/StrokeClassifier.java
@@ -0,0 +1,28 @@
+/*
+ * 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.incallui.answer.impl.classifier;
+
+/** An abstract class for classifiers which classify each stroke separately. */
+abstract class StrokeClassifier extends Classifier {
+
+  /**
+   * @param stroke the stroke for which the evaluation will be calculated
+   * @return a non-negative value which is used to determine whether this a false touch; the bigger
+   *     the value the greater the chance that this a false touch
+   */
+  public abstract float getFalseTouchEvaluation(Stroke stroke);
+}