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.volume; 18 19 import android.animation.TimeInterpolator; 20 21 public class SystemUIInterpolators { 22 public static final class LogDecelerateInterpolator implements TimeInterpolator { 23 private final float mBase; 24 private final float mDrift; 25 private final float mTimeScale; 26 private final float mOutputScale; 27 28 public LogDecelerateInterpolator() { 29 this(400f, 1.4f, 0); 30 } 31 32 private LogDecelerateInterpolator(float base, float timeScale, float drift) { 33 mBase = base; 34 mDrift = drift; 35 mTimeScale = 1f / timeScale; 36 37 mOutputScale = 1f / computeLog(1f); 38 } 39 40 private float computeLog(float t) { 41 return 1f - (float) Math.pow(mBase, -t * mTimeScale) + (mDrift * t); 42 } 43 44 @Override 45 public float getInterpolation(float t) { 46 return computeLog(t) * mOutputScale; 47 } 48 } 49 50 public static final class LogAccelerateInterpolator implements TimeInterpolator { 51 private final int mBase; 52 private final int mDrift; 53 private final float mLogScale; 54 55 public LogAccelerateInterpolator() { 56 this(100, 0); 57 } 58 59 private LogAccelerateInterpolator(int base, int drift) { 60 mBase = base; 61 mDrift = drift; 62 mLogScale = 1f / computeLog(1, mBase, mDrift); 63 } 64 65 private static float computeLog(float t, int base, int drift) { 66 return (float) -Math.pow(base, -t) + 1 + (drift * t); 67 } 68 69 @Override 70 public float getInterpolation(float t) { 71 return 1 - computeLog(1 - t, mBase, mDrift) * mLogScale; 72 } 73 } 74 75 public interface Callback { 76 void onAnimatingChanged(boolean animating); 77 } 78 } 79
