1 /*
2  * Copyright (C) 2023 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 package com.android.systemui.unfold.progress
17 
18 import android.os.Looper
19 import android.view.Choreographer
20 import androidx.dynamicanimation.animation.FrameCallbackScheduler
21 import dagger.assisted.AssistedFactory
22 import dagger.assisted.AssistedInject
23 
24 /**
25  * Scheduler that posts animation progresses on a thread different than the ui one.
26  *
27  * The following is taken from [AnimationHandler.FrameCallbackScheduler16]. It is extracted here as
28  * there are no guarantees which implementation the [DynamicAnimation] class would use otherwise.
29  * This allows classes using [DynamicAnimation] to be created in any thread, but still use the
30  * scheduler for a specific thread.
31  *
32  * Technically the [AssistedInject] is not needed: it's just to have a nicer factory with a
33  * documentation snippet instead of using a plain dagger provider.
34  */
35 class UnfoldFrameCallbackScheduler @AssistedInject constructor() : FrameCallbackScheduler {
36 
37     private val choreographer = Choreographer.getInstance()
38     private val looper =
39         Looper.myLooper() ?: error("This should be created in a thread with a looper.")
40 
postFrameCallbacknull41     override fun postFrameCallback(frameCallback: Runnable) {
42         choreographer.postFrameCallback { frameCallback.run() }
43     }
44 
isCurrentThreadnull45     override fun isCurrentThread(): Boolean {
46         return looper.isCurrentThread
47     }
48 
49     @AssistedFactory
50     interface Factory {
51         /**
52          * Creates a [FrameCallbackScheduler] that uses [Choreographer] to post frame callbacks.
53          *
54          * Note that the choreographer used depends on the thread this [create] is called on, as it
55          * is get from a thread static attribute.
56          */
createnull57         fun create(): UnfoldFrameCallbackScheduler
58     }
59 }
60