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
17package android.animation;
18
19import android.animation.Keyframe.IntKeyframe;
20
21import java.util.List;
22
23/**
24 * This class holds a collection of IntKeyframe 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 * float, 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 */
33class IntKeyframeSet extends KeyframeSet implements Keyframes.IntKeyframes {
34    private int firstValue;
35    private int lastValue;
36    private int deltaValue;
37    private boolean firstTime = true;
38
39    public IntKeyframeSet(IntKeyframe... keyframes) {
40        super(keyframes);
41    }
42
43    @Override
44    public Object getValue(float fraction) {
45        return getIntValue(fraction);
46    }
47
48    @Override
49    public IntKeyframeSet clone() {
50        List<Keyframe> keyframes = mKeyframes;
51        int numKeyframes = mKeyframes.size();
52        IntKeyframe[] newKeyframes = new IntKeyframe[numKeyframes];
53        for (int i = 0; i < numKeyframes; ++i) {
54            newKeyframes[i] = (IntKeyframe) keyframes.get(i).clone();
55        }
56        IntKeyframeSet newSet = new IntKeyframeSet(newKeyframes);
57        return newSet;
58    }
59
60    @Override
61    public void invalidateCache() {
62        firstTime = true;
63    }
64
65    @Override
66    public int getIntValue(float fraction) {
67        if (mNumKeyframes == 2) {
68            if (firstTime) {
69                firstTime = false;
70                firstValue = ((IntKeyframe) mKeyframes.get(0)).getIntValue();
71                lastValue = ((IntKeyframe) mKeyframes.get(1)).getIntValue();
72                deltaValue = lastValue - firstValue;
73            }
74            if (mInterpolator != null) {
75                fraction = mInterpolator.getInterpolation(fraction);
76            }
77            if (mEvaluator == null) {
78                return firstValue + (int)(fraction * deltaValue);
79            } else {
80                return ((Number)mEvaluator.evaluate(fraction, firstValue, lastValue)).intValue();
81            }
82        }
83        if (fraction <= 0f) {
84            final IntKeyframe prevKeyframe = (IntKeyframe) mKeyframes.get(0);
85            final IntKeyframe nextKeyframe = (IntKeyframe) mKeyframes.get(1);
86            int prevValue = prevKeyframe.getIntValue();
87            int nextValue = nextKeyframe.getIntValue();
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 + (int)(intervalFraction * (nextValue - prevValue)) :
97                    ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)).
98                            intValue();
99        } else if (fraction >= 1f) {
100            final IntKeyframe prevKeyframe = (IntKeyframe) mKeyframes.get(mNumKeyframes - 2);
101            final IntKeyframe nextKeyframe = (IntKeyframe) mKeyframes.get(mNumKeyframes - 1);
102            int prevValue = prevKeyframe.getIntValue();
103            int nextValue = nextKeyframe.getIntValue();
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 + (int)(intervalFraction * (nextValue - prevValue)) :
113                    ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)).intValue();
114        }
115        IntKeyframe prevKeyframe = (IntKeyframe) mKeyframes.get(0);
116        for (int i = 1; i < mNumKeyframes; ++i) {
117            IntKeyframe nextKeyframe = (IntKeyframe) mKeyframes.get(i);
118            if (fraction < nextKeyframe.getFraction()) {
119                final TimeInterpolator interpolator = nextKeyframe.getInterpolator();
120                float intervalFraction = (fraction - prevKeyframe.getFraction()) /
121                    (nextKeyframe.getFraction() - prevKeyframe.getFraction());
122                int prevValue = prevKeyframe.getIntValue();
123                int nextValue = nextKeyframe.getIntValue();
124                // Apply interpolator on the proportional duration.
125                if (interpolator != null) {
126                    intervalFraction = interpolator.getInterpolation(intervalFraction);
127                }
128                return mEvaluator == null ?
129                        prevValue + (int)(intervalFraction * (nextValue - prevValue)) :
130                        ((Number)mEvaluator.evaluate(intervalFraction, prevValue, nextValue)).
131                                intValue();
132            }
133            prevKeyframe = nextKeyframe;
134        }
135        // shouldn't get here
136        return ((Number)mKeyframes.get(mNumKeyframes - 1).getValue()).intValue();
137    }
138
139    @Override
140    public Class getType() {
141        return Integer.class;
142    }
143}
144
145