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 import java.util.List; 23 24 /** 25 * This class holds a collection of FloatKeyframe objects and is called by ValueAnimator to calculate 26 * values between those keyframes for a given animation. The class internal to the animation 27 * package because it is an implementation detail of how Keyframes are stored and used. 28 * 29 * <p>This type-specific subclass of KeyframeSet, along with the other type-specific subclass for 30 * int, exists to speed up the getValue() method when there is no custom 31 * TypeEvaluator set for the animation, so that values can be calculated without autoboxing to the 32 * Object equivalents of these primitive types.</p> 33 */ 34 class FloatKeyframeSet extends KeyframeSet implements Keyframes.FloatKeyframes { 35 private float firstValue; 36 private float lastValue; 37 private float deltaValue; 38 private boolean firstTime = true; 39 40 public FloatKeyframeSet(FloatKeyframe... keyframes) { 41 super(keyframes); 42 } 43 44 @Override 45 public Object getValue(float fraction) { 46 return getFloatValue(fraction); 47 } 48 49 @Override 50 public FloatKeyframeSet clone() { 51 final List<Keyframe> keyframes = mKeyframes; 52 final int numKeyframes = mKeyframes.size(); 53 FloatKeyframe[] newKeyframes = new FloatKeyframe[numKeyframes]; 54 for (int i = 0; i < numKeyframes; ++i) { 55 newKeyframes[i] = (FloatKeyframe) keyframes.get(i).clone(); 56 } 57 FloatKeyframeSet newSet = new FloatKeyframeSet(newKeyframes); 58 return newSet; 59 } 60 61 @Override 62 public void invalidateCache() { 63 firstTime = true; 64 } 65 66 @Override 67 public float getFloatValue(float fraction) { 68 if (mNumKeyframes == 2) { 69 if (firstTime) { 70 firstTime = false; 71 firstValue = ((FloatKeyframe) mKeyframes.get(0)).getFloatValue(); 72 lastValue = ((FloatKeyframe) mKeyframes.get(1)).getFloatValue(); 73 deltaValue = lastValue - firstValue; 74 } 75 if (mInterpolator != null) { 76 fraction = mInterpolator.getInterpolation(fraction); 77 } 78 if (mEvaluator == null) { 79 return firstValue + fraction * deltaValue; 80 } else { 81 return ((Number)mEvaluator.evaluate(fraction, firstValue, lastValue)).floatValue(); 82 } 83 } 84 if (fraction <= 0f) { 85 final FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(0); 86 final FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(1); 87 float prevValue = prevKeyframe.getFloatValue(); 88 float nextValue = nextKeyframe.getFloatValue(); 89 float prevFraction = prevKeyframe.getFraction(); 90 float nextFraction = nextKeyframe.getFraction(); 91 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 92 if (interpolator != null) { 93 fraction = interpolator.getInterpolation(fraction); 94 } 95 float intervalFraction = (fraction - prevFraction) / (nextFraction - prevFraction); 96 return mEvaluator == null ? 97 prevValue + intervalFraction * (nextValue - prevValue) : 98 ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)). 99 floatValue(); 100 } else if (fraction >= 1f) { 101 final FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(mNumKeyframes - 2); 102 final FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(mNumKeyframes - 1); 103 float prevValue = prevKeyframe.getFloatValue(); 104 float nextValue = nextKeyframe.getFloatValue(); 105 float prevFraction = prevKeyframe.getFraction(); 106 float nextFraction = nextKeyframe.getFraction(); 107 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 108 if (interpolator != null) { 109 fraction = interpolator.getInterpolation(fraction); 110 } 111 float intervalFraction = (fraction - prevFraction) / (nextFraction - prevFraction); 112 return mEvaluator == null ? 113 prevValue + intervalFraction * (nextValue - prevValue) : 114 ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)). 115 floatValue(); 116 } 117 FloatKeyframe prevKeyframe = (FloatKeyframe) mKeyframes.get(0); 118 for (int i = 1; i < mNumKeyframes; ++i) { 119 FloatKeyframe nextKeyframe = (FloatKeyframe) mKeyframes.get(i); 120 if (fraction < nextKeyframe.getFraction()) { 121 final TimeInterpolator interpolator = nextKeyframe.getInterpolator(); 122 if (interpolator != null) { 123 fraction = interpolator.getInterpolation(fraction); 124 } 125 float intervalFraction = (fraction - prevKeyframe.getFraction()) / 126 (nextKeyframe.getFraction() - prevKeyframe.getFraction()); 127 float prevValue = prevKeyframe.getFloatValue(); 128 float nextValue = nextKeyframe.getFloatValue(); 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
