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.design.widget;
18
19import android.animation.Animator;
20import android.animation.AnimatorListenerAdapter;
21import android.animation.ValueAnimator;
22import android.util.StateSet;
23
24import java.util.ArrayList;
25
26final class StateListAnimator {
27
28    private final ArrayList<Tuple> mTuples = new ArrayList<>();
29
30    private Tuple mLastMatch = null;
31    ValueAnimator mRunningAnimator = null;
32
33    private final ValueAnimator.AnimatorListener mAnimationListener =
34            new AnimatorListenerAdapter() {
35                @Override
36                public void onAnimationEnd(Animator animator) {
37                    if (mRunningAnimator == animator) {
38                        mRunningAnimator = null;
39                    }
40                }
41            };
42
43    /**
44     * Associates the given Animation with the provided drawable state specs so that it will be run
45     * when the View's drawable state matches the specs.
46     *
47     * @param specs    The drawable state specs to match against
48     * @param animator The animator to run when the specs match
49     */
50    public void addState(int[] specs, ValueAnimator animator) {
51        Tuple tuple = new Tuple(specs, animator);
52        animator.addListener(mAnimationListener);
53        mTuples.add(tuple);
54    }
55
56    /**
57     * Called by View
58     */
59    void setState(int[] state) {
60        Tuple match = null;
61        final int count = mTuples.size();
62        for (int i = 0; i < count; i++) {
63            final Tuple tuple = mTuples.get(i);
64            if (StateSet.stateSetMatches(tuple.mSpecs, state)) {
65                match = tuple;
66                break;
67            }
68        }
69        if (match == mLastMatch) {
70            return;
71        }
72        if (mLastMatch != null) {
73            cancel();
74        }
75
76        mLastMatch = match;
77
78        if (match != null) {
79            start(match);
80        }
81    }
82
83    private void start(Tuple match) {
84        mRunningAnimator = match.mAnimator;
85        mRunningAnimator.start();
86    }
87
88    private void cancel() {
89        if (mRunningAnimator != null) {
90            mRunningAnimator.cancel();
91            mRunningAnimator = null;
92        }
93    }
94
95    /**
96     * If there is an animation running for a recent state change, ends it.
97     *
98     * <p>This causes the animation to assign the end value(s) to the View.</p>
99     */
100    public void jumpToCurrentState() {
101        if (mRunningAnimator != null) {
102            mRunningAnimator.end();
103            mRunningAnimator = null;
104        }
105    }
106
107    static class Tuple {
108        final int[] mSpecs;
109        final ValueAnimator mAnimator;
110
111        Tuple(int[] specs, ValueAnimator animator) {
112            mSpecs = specs;
113            mAnimator = animator;
114        }
115    }
116}