actionbarsherlock/src/com/actionbarsherlock/internal/nineoldandroids/animation/KeyframeSet.java

   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 com.actionbarsherlock.internal.nineoldandroids.animation;
  18
  19 import java.util.ArrayList;
  20 import java.util.Arrays;
  21 import android.view.animation.Interpolator;
  22
  23 import com.actionbarsherlock.internal.nineoldandroids.animation.Keyframe.FloatKeyframe;
  24 import com.actionbarsherlock.internal.nineoldandroids.animation.Keyframe.IntKeyframe;
  25 import com.actionbarsherlock.internal.nineoldandroids.animation.Keyframe.ObjectKeyframe;
  26
  27 /**
  28  * This class holds a collection of Keyframe objects and is called by ValueAnimator to calculate
  29  * values between those keyframes for a given animation. The class internal to the animation
  30  * package because it is an implementation detail of how Keyframes are stored and used.
  31  */
  32 @SuppressWarnings({"rawtypes", "unchecked"})
  33 class KeyframeSet {
  34
  35     int mNumKeyframes;
  36
  37     Keyframe mFirstKeyframe;
  38     Keyframe mLastKeyframe;
  39     /*Time*/Interpolator mInterpolator; // only used in the 2-keyframe case
  40     ArrayList<Keyframe> mKeyframes; // only used when there are not 2 keyframes
  41     TypeEvaluator mEvaluator;
  42
  43
  44     public KeyframeSet(Keyframe... keyframes) {
  45         mNumKeyframes = keyframes.length;
  46         mKeyframes = new ArrayList<Keyframe>();
  47         mKeyframes.addAll(Arrays.asList(keyframes));
  48         mFirstKeyframe = mKeyframes.get(0);
  49         mLastKeyframe = mKeyframes.get(mNumKeyframes - 1);
  50         mInterpolator = mLastKeyframe.getInterpolator();
  51     }
  52
  53     public static KeyframeSet ofInt(int... values) {
  54         int numKeyframes = values.length;
  55         IntKeyframe keyframes[] = new IntKeyframe[Math.max(numKeyframes,2)];
  56         if (numKeyframes == 1) {
  57             keyframes[0] = (IntKeyframe) Keyframe.ofInt(0f);
  58             keyframes[1] = (IntKeyframe) Keyframe.ofInt(1f, values[0]);
  59         } else {
  60             keyframes[0] = (IntKeyframe) Keyframe.ofInt(0f, values[0]);
  61             for (int i = 1; i < numKeyframes; ++i) {
  62                 keyframes[i] = (IntKeyframe) Keyframe.ofInt((float) i / (numKeyframes - 1), values[i]);
  63             }
  64         }
  65         return new IntKeyframeSet(keyframes);
  66     }
  67
  68     public static KeyframeSet ofFloat(float... values) {
  69         int numKeyframes = values.length;
  70         FloatKeyframe keyframes[] = new FloatKeyframe[Math.max(numKeyframes,2)];
  71         if (numKeyframes == 1) {
  72             keyframes[0] = (FloatKeyframe) Keyframe.ofFloat(0f);
  73             keyframes[1] = (FloatKeyframe) Keyframe.ofFloat(1f, values[0]);
  74         } else {
  75             keyframes[0] = (FloatKeyframe) Keyframe.ofFloat(0f, values[0]);
  76             for (int i = 1; i < numKeyframes; ++i) {
  77                 keyframes[i] = (FloatKeyframe) Keyframe.ofFloat((float) i / (numKeyframes - 1), values[i]);
  78             }
  79         }
  80         return new FloatKeyframeSet(keyframes);
  81     }
  82
  83     public static KeyframeSet ofKeyframe(Keyframe... keyframes) {
  84         // if all keyframes of same primitive type, create the appropriate KeyframeSet
  85         int numKeyframes = keyframes.length;
  86         boolean hasFloat = false;
  87         boolean hasInt = false;
  88         boolean hasOther = false;
  89         for (int i = 0; i < numKeyframes; ++i) {
  90             if (keyframes[i] instanceof FloatKeyframe) {
  91                 hasFloat = true;
  92             } else if (keyframes[i] instanceof IntKeyframe) {
  93                 hasInt = true;
  94             } else {
  95                 hasOther = true;
  96             }
  97         }
  98         if (hasFloat && !hasInt && !hasOther) {
  99             FloatKeyframe floatKeyframes[] = new FloatKeyframe[numKeyframes];
 100             for (int i = 0; i < numKeyframes; ++i) {
 101                 floatKeyframes[i] = (FloatKeyframe) keyframes[i];
 102             }
 103             return new FloatKeyframeSet(floatKeyframes);
 104         } else if (hasInt && !hasFloat && !hasOther) {
 105             IntKeyframe intKeyframes[] = new IntKeyframe[numKeyframes];
 106             for (int i = 0; i < numKeyframes; ++i) {
 107                 intKeyframes[i] = (IntKeyframe) keyframes[i];
 108             }
 109             return new IntKeyframeSet(intKeyframes);
 110         } else {
 111             return new KeyframeSet(keyframes);
 112         }
 113     }
 114
 115     public static KeyframeSet ofObject(Object... values) {
 116         int numKeyframes = values.length;
 117         ObjectKeyframe keyframes[] = new ObjectKeyframe[Math.max(numKeyframes,2)];
 118         if (numKeyframes == 1) {
 119             keyframes[0] = (ObjectKeyframe) Keyframe.ofObject(0f);
 120             keyframes[1] = (ObjectKeyframe) Keyframe.ofObject(1f, values[0]);
 121         } else {
 122             keyframes[0] = (ObjectKeyframe) Keyframe.ofObject(0f, values[0]);
 123             for (int i = 1; i < numKeyframes; ++i) {
 124                 keyframes[i] = (ObjectKeyframe) Keyframe.ofObject((float) i / (numKeyframes - 1), values[i]);
 125             }
 126         }
 127         return new KeyframeSet(keyframes);
 128     }
 129
 130     /**
 131      * Sets the TypeEvaluator to be used when calculating animated values. This object
 132      * is required only for KeyframeSets that are not either IntKeyframeSet or FloatKeyframeSet,
 133      * both of which assume their own evaluator to speed up calculations with those primitive
 134      * types.
 135      *
 136      * @param evaluator The TypeEvaluator to be used to calculate animated values.
 137      */
 138     public void setEvaluator(TypeEvaluator evaluator) {
 139         mEvaluator = evaluator;
 140     }
 141
 142     @Override
 143     public KeyframeSet clone() {
 144         ArrayList<Keyframe> keyframes = mKeyframes;
 145         int numKeyframes = mKeyframes.size();
 146         Keyframe[] newKeyframes = new Keyframe[numKeyframes];
 147         for (int i = 0; i < numKeyframes; ++i) {
 148             newKeyframes[i] = keyframes.get(i).clone();
 149         }
 150         KeyframeSet newSet = new KeyframeSet(newKeyframes);
 151         return newSet;
 152     }
 153
 154     /**
 155      * Gets the animated value, given the elapsed fraction of the animation (interpolated by the
 156      * animation's interpolator) and the evaluator used to calculate in-between values. This
 157      * function maps the input fraction to the appropriate keyframe interval and a fraction
 158      * between them and returns the interpolated value. Note that the input fraction may fall
 159      * outside the [0-1] bounds, if the animation's interpolator made that happen (e.g., a
 160      * spring interpolation that might send the fraction past 1.0). We handle this situation by
 161      * just using the two keyframes at the appropriate end when the value is outside those bounds.
 162      *
 163      * @param fraction The elapsed fraction of the animation
 164      * @return The animated value.
 165      */
 166     public Object getValue(float fraction) {
 167
 168         // Special-case optimization for the common case of only two keyframes
 169         if (mNumKeyframes == 2) {
 170             if (mInterpolator != null) {
 171                 fraction = mInterpolator.getInterpolation(fraction);
 172             }
 173             return mEvaluator.evaluate(fraction, mFirstKeyframe.getValue(),
 174                     mLastKeyframe.getValue());
 175         }
 176         if (fraction <= 0f) {
 177             final Keyframe nextKeyframe = mKeyframes.get(1);
 178             final /*Time*/Interpolator interpolator = nextKeyframe.getInterpolator();
 179             if (interpolator != null) {
 180                 fraction = interpolator.getInterpolation(fraction);
 181             }
 182             final float prevFraction = mFirstKeyframe.getFraction();
 183             float intervalFraction = (fraction - prevFraction) /
 184                 (nextKeyframe.getFraction() - prevFraction);
 185             return mEvaluator.evaluate(intervalFraction, mFirstKeyframe.getValue(),
 186                     nextKeyframe.getValue());
 187         } else if (fraction >= 1f) {
 188             final Keyframe prevKeyframe = mKeyframes.get(mNumKeyframes - 2);
 189             final /*Time*/Interpolator interpolator = mLastKeyframe.getInterpolator();
 190             if (interpolator != null) {
 191                 fraction = interpolator.getInterpolation(fraction);
 192             }
 193             final float prevFraction = prevKeyframe.getFraction();
 194             float intervalFraction = (fraction - prevFraction) /
 195                 (mLastKeyframe.getFraction() - prevFraction);
 196             return mEvaluator.evaluate(intervalFraction, prevKeyframe.getValue(),
 197                     mLastKeyframe.getValue());
 198         }
 199         Keyframe prevKeyframe = mFirstKeyframe;
 200         for (int i = 1; i < mNumKeyframes; ++i) {
 201             Keyframe nextKeyframe = mKeyframes.get(i);
 202             if (fraction < nextKeyframe.getFraction()) {
 203                 final /*Time*/Interpolator interpolator = nextKeyframe.getInterpolator();
 204                 if (interpolator != null) {
 205                     fraction = interpolator.getInterpolation(fraction);
 206                 }
 207                 final float prevFraction = prevKeyframe.getFraction();
 208                 float intervalFraction = (fraction - prevFraction) /
 209                     (nextKeyframe.getFraction() - prevFraction);
 210                 return mEvaluator.evaluate(intervalFraction, prevKeyframe.getValue(),
 211                         nextKeyframe.getValue());
 212             }
 213             prevKeyframe = nextKeyframe;
 214         }
 215         // shouldn't reach here
 216         return mLastKeyframe.getValue();
 217     }
 218
 219     @Override
 220     public String toString() {
 221         String returnVal = " ";
 222         for (int i = 0; i < mNumKeyframes; ++i) {
 223             returnVal += mKeyframes.get(i).getValue() + "  ";
 224         }
 225         return returnVal;
 226     }
 227 }