Home | History | Annotate | Download | only in classifier 
      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 
     26     public SpeedClassifier(ClassifierData classifierData) {
     27     }
     28 
     29     @Override
     30     public String getTag() {
     31         return "SPD";
     32     }
     33 
     34     @Override
     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 }