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.List; 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 implements Keyframes.FloatKeyframes { 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 final List<Keyframe> keyframes = mKeyframes; 51 final 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 @Override 61 public void invalidateCache() { 62 firstTime = true; 63 } 64 65 @Override 66 public float getFloatValue(float fraction) { 67 if (mNumKeyframes == 2) { 68 if (firstTime) { 69 firstTime = false; 70 firstValue = ((FloatKeyframe) mKeyframes.get(0)).getFloatValue(); 71 lastValue = ((FloatKeyframe) mKeyframes.get(1)).getFloatValue(); 72 deltaValue = lastValue - firstValue; 73 } 74 if (mInterpolator != null) { 75 fraction = mInterpolator.getInterpolation(fraction); 76 } 77 if (mEvaluator == null) { 78 return firstValue + fraction * deltaValue; 79 } else { 80 return ((Number)mEvaluator.evaluate(fraction, firstValue, lastValue)).floatValue(); 81 } 82 } 83 if (fraction <= 0f) { 84 final FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(0); 85 final FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(1); 86 float prevValue = prevKeyframe.getFloatValue(); 87 float nextValue = nextKeyframe.getFloatValue(); 88 float prevFraction = prevKeyframe.getFraction(); 89 float nextFraction = nextKeyframe.getFraction(); 90 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 91 if (interpolator != null) { 92 fraction = interpolator.getInterpolation(fraction); 93 } 94 float intervalFraction = (fraction - prevFraction) / (nextFraction - prevFraction); 95 return mEvaluator == null ? 96 prevValue + intervalFraction * (nextValue - prevValue) : 97 ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)). 98 floatValue(); 99 } else if (fraction >= 1f) { 100 final FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(mNumKeyframes - 2); 101 final FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(mNumKeyframes - 1); 102 float prevValue = prevKeyframe.getFloatValue(); 103 float nextValue = nextKeyframe.getFloatValue(); 104 float prevFraction = prevKeyframe.getFraction(); 105 float nextFraction = nextKeyframe.getFraction(); 106 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 107 if (interpolator != null) { 108 fraction = interpolator.getInterpolation(fraction); 109 } 110 float intervalFraction = (fraction - prevFraction) / (nextFraction - prevFraction); 111 return mEvaluator == null ? 112 prevValue + intervalFraction * (nextValue - prevValue) : 113 ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)). 114 floatValue(); 115 } 116 FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(0); 117 for (int i = 1; i < mNumKeyframes; ++i) { 118 FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(i); 119 if (fraction < nextKeyframe.getFraction()) { 120 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 121 float intervalFraction = (fraction - prevKeyframe.getFraction()) / 122 (nextKeyframe.getFraction() - prevKeyframe.getFraction()); 123 float prevValue = prevKeyframe.getFloatValue(); 124 float nextValue = nextKeyframe.getFloatValue(); 125 // Apply interpolator on the proportional duration. 126 if (interpolator != null) { 127 intervalFraction = interpolator.getInterpolation(intervalFraction); 128 } 129 return mEvaluator == null ? 130 prevValue + intervalFraction * (nextValue - prevValue) : 131 ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)). 132 floatValue(); 133 } 134 prevKeyframe = nextKeyframe; 135 } 136 // shouldn't get here 137 return ((Number)mKeyframes.get(mNumKeyframes - 1).getValue()).floatValue(); 138 } 139 140 @Override 141 public Class getType() { 142 return Float.class; 143 } 144 } 145 146
