1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License
15  */
16 
17 package com.android.systemui.classifier;
18 
19 /**
20  * A classifier that looks at the speed of the stroke. It calculates the speed of a stroke in
21  * inches per second.
22  */
23 public class SpeedClassifier extends StrokeClassifier {
24     private final float NANOS_TO_SECONDS = 1e9f;
25 
SpeedClassifier(ClassifierData classifierData)26     public SpeedClassifier(ClassifierData classifierData) {
27     }
28 
29     @Override
getTag()30     public String getTag() {
31         return "SPD";
32     }
33 
34     @Override
getFalseTouchEvaluation(int type, Stroke stroke)35     public float getFalseTouchEvaluation(int type, Stroke stroke) {
36         float duration = (float) stroke.getDurationNanos() / NANOS_TO_SECONDS;
37         if (duration == 0.0f) {
38             return SpeedEvaluator.evaluate(0.0f);
39         }
40         return SpeedEvaluator.evaluate(stroke.getTotalLength() / duration);
41     }
42 }