GingerbreadAnimatorCompatProvider.java revision 64dbe1d454f1190b3cd8426d09b9119949a10709 
1/*
2 * Copyright (C) 2015 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.support.v4.animation;
18
19import android.view.View;
20
21import java.util.ArrayList;
22import java.util.List;
23
24/**
25 * Provides similar functionality to Animators on platforms prior to Honeycomb.
26 * <p>
27 * This is not a fully implemented API which is why it is not public.
28 *
29 * @hide
30 */
31class GingerbreadAnimatorCompatProvider implements AnimatorProvider {
32
33    @Override
34    public ValueAnimatorCompat emptyValueAnimator() {
35        return new GingerbreadFloatValueAnimator();
36    }
37
38    private static class GingerbreadFloatValueAnimator implements ValueAnimatorCompat {
39
40        List<AnimatorListenerCompat> mListeners = new ArrayList<AnimatorListenerCompat>();
41        List<AnimatorUpdateListenerCompat> mUpdateListeners
42                = new ArrayList<AnimatorUpdateListenerCompat>();
43        View mTarget;
44        private long mStartTime;
45        private long mDuration = 200;
46        private float mFraction = 0f;
47
48        private boolean mStarted = false;
49        private boolean mEnded = false;
50
51        public GingerbreadFloatValueAnimator() {
52        }
53
54        private Runnable mLoopRunnable = new Runnable() {
55            @Override
56            public void run() {
57                long dt = getTime() - mStartTime;
58                float fraction = dt * 1f / mDuration;
59                if (fraction > 1f || mTarget.getParent() == null) {
60                    fraction = 1f;
61                }
62                mFraction = fraction;
63                notifyUpdateListeners();
64                if (mFraction >= 1f) {
65                    dispatchEnd();
66                } else {
67                    mTarget.postDelayed(mLoopRunnable, 16);
68                }
69            }
70        };
71
72        private void notifyUpdateListeners() {
73            for (int i = mUpdateListeners.size() - 1; i >= 0; i--) {
74                mUpdateListeners.get(i).onAnimationUpdate(this);
75            }
76        }
77
78        @Override
79        public void setTarget(View view) {
80            mTarget = view;
81        }
82
83        @Override
84        public void addListener(AnimatorListenerCompat listener) {
85            mListeners.add(listener);
86        }
87
88        @Override
89        public void setDuration(long duration) {
90            if (!mStarted) {
91                mDuration = duration;
92            }
93        }
94
95        @Override
96        public void start() {
97            if (mStarted) {
98                return;
99            }
100            mStarted = true;
101            dispatchStart();
102            mFraction = 0f;
103            mStartTime = getTime();
104            mTarget.postDelayed(mLoopRunnable, 16);
105        }
106
107        private long getTime() {
108            return mTarget.getDrawingTime();
109        }
110
111        private void dispatchStart() {
112            for (int i = mListeners.size() - 1; i >= 0; i--) {
113                mListeners.get(i).onAnimationStart(this);
114            }
115        }
116
117        private void dispatchEnd() {
118            for (int i = mListeners.size() - 1; i >= 0; i--) {
119                mListeners.get(i).onAnimationEnd(this);
120            }
121        }
122
123        private void dispatchCancel() {
124            for (int i = mListeners.size() - 1; i >= 0; i--) {
125                mListeners.get(i).onAnimationCancel(this);
126            }
127        }
128
129        @Override
130        public void cancel() {
131            if (mEnded) {
132                return;
133            }
134            mEnded = true;
135            if (mStarted) {
136                dispatchCancel();
137            }
138            dispatchEnd();
139        }
140
141        @Override
142        public void addUpdateListener(AnimatorUpdateListenerCompat animatorUpdateListener) {
143            mUpdateListeners.add(animatorUpdateListener);
144        }
145
146        @Override
147        public float getAnimatedFraction() {
148            return mFraction;
149        }
150    }
151
152    @Override
153    public void clearInterpolator(View view) {
154    }
155}
156