1 /* 2 * Copyright (C) 2010 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 android.animation; 18 19 import android.animation.Keyframe.FloatKeyframe; 20 21 import java.util.ArrayList; 22 23 /** 24 * This class holds a collection of FloatKeyframe objects and is called by ValueAnimator to calculate 25 * values between those keyframes for a given animation. The class internal to the animation 26 * package because it is an implementation detail of how Keyframes are stored and used. 27 * 28 * <p>This type-specific subclass of KeyframeSet, along with the other type-specific subclass for 29 * int, exists to speed up the getValue() method when there is no custom 30 * TypeEvaluator set for the animation, so that values can be calculated without autoboxing to the 31 * Object equivalents of these primitive types.</p> 32 */ 33 class FloatKeyframeSet extends KeyframeSet { 34 private float firstValue; 35 private float lastValue; 36 private float deltaValue; 37 private boolean firstTime = true; 38 39 public FloatKeyframeSet(FloatKeyframe... keyframes) { 40 super(keyframes); 41 } 42 43 @Override 44 public Object getValue(float fraction) { 45 return getFloatValue(fraction); 46 } 47 48 @Override 49 public FloatKeyframeSet clone() { 50 ArrayList<Keyframe> keyframes = mKeyframes; 51 int numKeyframes = mKeyframes.size(); 52 FloatKeyframe[] newKeyframes = new FloatKeyframe[numKeyframes]; 53 for (int i = 0; i < numKeyframes; ++i) { 54 newKeyframes[i] = (FloatKeyframe) keyframes.get(i).clone(); 55 } 56 FloatKeyframeSet newSet = new FloatKeyframeSet(newKeyframes); 57 return newSet; 58 } 59 60 public float getFloatValue(float fraction) { 61 if (mNumKeyframes == 2) { 62 if (firstTime) { 63 firstTime = false; 64 firstValue = ((FloatKeyframe) mKeyframes.get(0)).getFloatValue(); 65 lastValue = ((FloatKeyframe) mKeyframes.get(1)).getFloatValue(); 66 deltaValue = lastValue - firstValue; 67 } 68 if (mInterpolator != null) { 69 fraction = mInterpolator.getInterpolation(fraction); 70 } 71 if (mEvaluator == null) { 72 return firstValue + fraction * deltaValue; 73 } else { 74 return ((Number)mEvaluator.evaluate(fraction, firstValue, lastValue)).floatValue(); 75 } 76 } 77 if (fraction <= 0f) { 78 final FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(0); 79 final FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(1); 80 float prevValue = prevKeyframe.getFloatValue(); 81 float nextValue = nextKeyframe.getFloatValue(); 82 float prevFraction = prevKeyframe.getFraction(); 83 float nextFraction = nextKeyframe.getFraction(); 84 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 85 if (interpolator != null) { 86 fraction = interpolator.getInterpolation(fraction); 87 } 88 float intervalFraction = (fraction - prevFraction) / (nextFraction - prevFraction); 89 return mEvaluator == null ? 90 prevValue + intervalFraction * (nextValue - prevValue) : 91 ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)). 92 floatValue(); 93 } else if (fraction >= 1f) { 94 final FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(mNumKeyframes - 2); 95 final FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(mNumKeyframes - 1); 96 float prevValue = prevKeyframe.getFloatValue(); 97 float nextValue = nextKeyframe.getFloatValue(); 98 float prevFraction = prevKeyframe.getFraction(); 99 float nextFraction = nextKeyframe.getFraction(); 100 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 101 if (interpolator != null) { 102 fraction = interpolator.getInterpolation(fraction); 103 } 104 float intervalFraction = (fraction - prevFraction) / (nextFraction - prevFraction); 105 return mEvaluator == null ? 106 prevValue + intervalFraction * (nextValue - prevValue) : 107 ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)). 108 floatValue(); 109 } 110 FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(0); 111 for (int i = 1; i < mNumKeyframes; ++i) { 112 FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(i); 113 if (fraction < nextKeyframe.getFraction()) { 114 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 115 if (interpolator != null) { 116 fraction = interpolator.getInterpolation(fraction); 117 } 118 float intervalFraction = (fraction - prevKeyframe.getFraction()) / 119 (nextKeyframe.getFraction() - prevKeyframe.getFraction()); 120 float prevValue = prevKeyframe.getFloatValue(); 121 float nextValue = nextKeyframe.getFloatValue(); 122 return mEvaluator == null ? 123 prevValue + intervalFraction * (nextValue - prevValue) : 124 ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)). 125 floatValue(); 126 } 127 prevKeyframe = nextKeyframe; 128 } 129 // shouldn't get here 130 return ((Number)mKeyframes.get(mNumKeyframes - 1).getValue()).floatValue(); 131 } 132 133 } 134 135
