| /* |
| * Copyright (C) 2007 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.dreams.phototable; |
| |
| import android.view.animation.DecelerateInterpolator; |
| import android.view.animation.Interpolator; |
| import android.view.animation.LinearInterpolator; |
| |
| /** |
| * An interpolator where the rate of change starts out quickly and |
| * and then decelerates. |
| * |
| */ |
| public class SoftLandingInterpolator implements Interpolator { |
| private final LinearInterpolator fly; |
| private final DecelerateInterpolator slide; |
| private final float mI; |
| private final float mO; |
| private final float upperRange; |
| private final float bottom; |
| private final float top; |
| |
| public SoftLandingInterpolator(float i, float o) { |
| fly = new LinearInterpolator(); |
| slide = new DecelerateInterpolator(); |
| mI = i; |
| mO = o; |
| final float epsilon = Math.min(mI / 2f, (1f - mI) / 2f); |
| bottom = mI - epsilon; |
| top = mI + epsilon; |
| upperRange = 1f - bottom; |
| } |
| |
| public float getInterpolation(float input) { |
| final float f = fly.getInterpolation(input / upperRange) * mO; |
| final float s = slide.getInterpolation((input - bottom) / upperRange) * (1f - mO) + mO; |
| |
| float value; |
| if (input < bottom) { |
| value = f; |
| } else if (input < top) { |
| final float alpha = (input - bottom) / (top - bottom); |
| value = (1f - alpha) * f + alpha * s; |
| } else { |
| value = s; |
| } |
| |
| return value; |
| } |
| } |