1 /*
2  * Copyright (C) 2022 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.android.systemui.media.controls.ui.animation
18 
19 import android.animation.Animator
20 import android.animation.AnimatorListenerAdapter
21 
22 /**
23  * MetadataAnimationHandler controls the current state of the MediaControlPanel's transition motion.
24  *
25  * It checks for a changed data object (artist & title from MediaControlPanel) and runs the
26  * animation if necessary. When the motion has fully transitioned the elements out, it runs the
27  * update callback to modify the view data, before the enter animation runs.
28  */
29 internal open class MetadataAnimationHandler(
30     private val exitAnimator: Animator,
31     private val enterAnimator: Animator
32 ) : AnimatorListenerAdapter() {
33 
34     private var postExitUpdate: (() -> Unit)? = null
35     private var postEnterUpdate: (() -> Unit)? = null
36     private var targetData: Any? = null
37 
38     val isRunning: Boolean
39         get() = enterAnimator.isRunning || exitAnimator.isRunning
40 
setNextnull41     fun setNext(targetData: Any, postExit: () -> Unit, postEnter: () -> Unit): Boolean {
42         if (targetData != this.targetData) {
43             this.targetData = targetData
44             postExitUpdate = postExit
45             postEnterUpdate = postEnter
46             if (!isRunning) {
47                 exitAnimator.start()
48             }
49             return true
50         }
51         return false
52     }
53 
onAnimationEndnull54     override fun onAnimationEnd(anim: Animator) {
55         if (anim === exitAnimator) {
56             postExitUpdate?.let { it() }
57             postExitUpdate = null
58             enterAnimator.start()
59         }
60 
61         if (anim === enterAnimator) {
62             // Another new update appeared while entering
63             if (postExitUpdate != null) {
64                 exitAnimator.start()
65             } else {
66                 postEnterUpdate?.let { it() }
67                 postEnterUpdate = null
68             }
69         }
70     }
71 
72     init {
73         exitAnimator.addListener(this)
74         enterAnimator.addListener(this)
75     }
76 }
77