MonotonicFrameClockTestRule.kt
/*
* Copyright 2020 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.compose.ui.test.junit4
import androidx.compose.animation.core.AnimationClockObservable
import androidx.compose.animation.core.InternalAnimationApi
import androidx.compose.animation.core.MonotonicFrameAnimationClock
import androidx.compose.animation.core.rootAnimationClockFactory
import androidx.compose.ui.test.ExperimentalTesting
import androidx.compose.ui.test.TestAnimationClock
import androidx.compose.ui.test.junit4.android.ComposeIdlingResource.registerTestClock
import androidx.compose.ui.test.junit4.android.ComposeIdlingResource.unregisterTestClock
import kotlinx.coroutines.CoroutineScope
import org.junit.runner.Description
import org.junit.runners.model.Statement
@ExperimentalTesting
internal class MonotonicFrameClockTestRule : AnimationClockTestRule {
private lateinit var _clock: InternalClock
override val clock: TestAnimationClock get() = _clock
override fun apply(base: Statement, description: Description?): Statement {
return AnimationClockStatement(base)
}
private fun getOrCreateClock(scope: CoroutineScope): TestAnimationClock {
if (!this::_clock.isInitialized) {
_clock = InternalClock(MonotonicFrameAnimationClock(scope))
registerTestClock(_clock)
}
return _clock
}
@OptIn(InternalAnimationApi::class)
private inner class AnimationClockStatement(private val base: Statement) : Statement() {
override fun evaluate() {
val oldFactory = rootAnimationClockFactory
rootAnimationClockFactory = { getOrCreateClock(it) }
try {
base.evaluate()
} finally {
rootAnimationClockFactory = oldFactory
unregisterTestClock(clock)
}
}
}
class InternalClock(
private val clock: MonotonicFrameAnimationClock
) : TestAnimationClock, AnimationClockObservable by clock {
override val isIdle: Boolean get() = !clock.hasObservers
override val isPaused: Boolean get() = false
override fun pauseClock(): Unit = throw UnsupportedOperationException()
override fun resumeClock(): Unit = throw UnsupportedOperationException()
override fun advanceClock(milliseconds: Long): Unit = throw UnsupportedOperationException()
}
}