KalmanMotionEventPredictor.java
/*
* Copyright 2022 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 androidx.input.motionprediction.kalman;
import static androidx.annotation.RestrictTo.Scope.LIBRARY;
import android.view.MotionEvent;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
import androidx.input.motionprediction.MotionEventPredictor;
/**
* @hide
*/
@RestrictTo(LIBRARY)
public class KalmanMotionEventPredictor implements MotionEventPredictor {
private MultiPointerPredictor mMultiPointerPredictor;
private boolean mDisposed = false;
public KalmanMotionEventPredictor() {
mMultiPointerPredictor = new MultiPointerPredictor();
// 1 may seem arbitrary, but this basically tells the predictor to
// just predict the next MotionEvent.
// This will need to change as we want to build a prediction depending
// on the expected time that the frame will arrive to the screen.
mMultiPointerPredictor.setPredictionTarget(1);
}
@Override
public void recordMovement(@NonNull MotionEvent event) {
mMultiPointerPredictor.onTouchEvent(event);
}
@Nullable
@Override
public MotionEvent predict() {
if (mDisposed) {
return null;
}
return mMultiPointerPredictor.predict();
}
@Override
public void dispose() {
mDisposed = true;
}
}