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 
17 package com.android.systemui.animation
18 
19 import java.util.function.Consumer
20 import org.junit.rules.RuleChain
21 import org.junit.rules.TestRule
22 import org.junit.runner.Description
23 import org.junit.runners.model.Statement
24 
25 /**
26  * A rule that wraps both [androidx.core.animation.AnimatorTestRule] and
27  * [android.animation.AnimatorTestRule] such that the clocks of the two animation handlers can be
28  * advanced together.
29  */
30 class AnimatorTestRule : TestRule {
31     private val androidxRule = androidx.core.animation.AnimatorTestRule()
32     private val platformRule = android.animation.AnimatorTestRule()
33     private val advanceAndroidXTimeBy =
34         Consumer<Long> { timeDelta -> androidxRule.advanceTimeBy(timeDelta) }
35 
36     /**
37      * Chain is for simplicity not to force a particular order; order should not matter, because
38      * each rule affects a different AnimationHandler classes, and no callbacks to code under test
39      * should be triggered by these rules
40      */
41     private val ruleChain = RuleChain.emptyRuleChain().around(androidxRule).around(platformRule)
42 
43     override fun apply(base: Statement, description: Description): Statement =
44         ruleChain.apply(base, description)
45 
46     /**
47      * Advances the animation clock by the given amount of delta in milliseconds. This call will
48      * produce an animation frame to all the ongoing animations.
49      *
50      * @param timeDelta the amount of milliseconds to advance
51      */
52     fun advanceTimeBy(timeDelta: Long) {
53         // NOTE: To avoid errors with order, we have to ensure that we advance the time within both
54         //  rules before either rule does its frame output. Failing to do this could cause the
55         //  animation from one to start later than the other.
56         platformRule.advanceTimeBy(timeDelta, advanceAndroidXTimeBy)
57     }
58 }
59