AndroidSynchronization.android.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 android.annotation.SuppressLint
import android.os.Looper
import androidx.test.platform.app.InstrumentationRegistry
import java.util.concurrent.ExecutionException
import java.util.concurrent.FutureTask
/**
* Runs the given action on the UI thread.
*
* This method is blocking until the action is complete.
*/
@SuppressLint("DocumentExceptions")
internal fun <T> runOnUiThread(action: () -> T): T {
if (isOnUiThread()) {
return action()
}
// Note: This implementation is directly taken from ActivityTestRule
val task: FutureTask<T> = FutureTask(action)
InstrumentationRegistry.getInstrumentation().runOnMainSync(task)
try {
return task.get()
} catch (e: ExecutionException) { // Expose the original exception
throw e.cause!!
}
}
/**
* Returns if the call is made on the main thread.
*/
internal fun isOnUiThread(): Boolean {
return Looper.myLooper() == Looper.getMainLooper()
}