UiThreadStatement.java
/*
* Copyright (C) 2014 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.test.internal.statement;
import static androidx.test.platform.app.InstrumentationRegistry.getInstrumentation;
import java.util.concurrent.atomic.AtomicReference;
import org.junit.runners.model.Statement;
/** {@link Statement} that executes a test on the application's main thread (or UI thread). */
public class UiThreadStatement extends Statement {
private final Statement base;
private final boolean runOnUiThread;
public UiThreadStatement(Statement base, boolean runOnUiThread) {
this.base = base;
this.runOnUiThread = runOnUiThread;
}
@Override
public void evaluate() throws Throwable {
if (runOnUiThread) {
final AtomicReference<Throwable> exceptionRef = new AtomicReference<>();
getInstrumentation()
.runOnMainSync(
new Runnable() {
@Override
public void run() {
try {
base.evaluate();
} catch (Throwable throwable) {
exceptionRef.set(throwable);
}
}
});
Throwable throwable = exceptionRef.get();
if (throwable != null) {
throw throwable;
}
} else {
base.evaluate();
}
}
}