1/* 2 * Copyright (C) 2017 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 17package android.arch.lifecycle; 18 19import static android.arch.lifecycle.Lifecycle.State.RESUMED; 20 21import android.app.Activity; 22import android.app.Instrumentation; 23import android.app.Instrumentation.ActivityMonitor; 24import android.support.test.InstrumentationRegistry; 25import android.support.test.rule.ActivityTestRule; 26 27import java.util.concurrent.CountDownLatch; 28 29public class TestUtils { 30 31 private static final long TIMEOUT_MS = 2000; 32 33 @SuppressWarnings("unchecked") 34 public static <T extends Activity> T recreateActivity(final T activity, ActivityTestRule rule) 35 throws Throwable { 36 ActivityMonitor monitor = new ActivityMonitor( 37 activity.getClass().getCanonicalName(), null, false); 38 Instrumentation instrumentation = InstrumentationRegistry.getInstrumentation(); 39 instrumentation.addMonitor(monitor); 40 rule.runOnUiThread(activity::recreate); 41 T result; 42 43 // this guarantee that we will reinstall monitor between notifications about onDestroy 44 // and onCreate 45 //noinspection SynchronizationOnLocalVariableOrMethodParameter 46 synchronized (monitor) { 47 do { 48 // the documetation says "Block until an Activity is created 49 // that matches this monitor." This statement is true, but there are some other 50 // true statements like: "Block until an Activity is destoyed" or 51 // "Block until an Activity is resumed"... 52 53 // this call will release synchronization monitor's monitor 54 result = (T) monitor.waitForActivityWithTimeout(TIMEOUT_MS); 55 if (result == null) { 56 throw new RuntimeException("Timeout. Failed to recreate an activity"); 57 } 58 } while (result == activity); 59 } 60 return result; 61 } 62 63 static void waitTillResumed(final LifecycleActivity a, ActivityTestRule<?> activityRule) 64 throws Throwable { 65 final CountDownLatch latch = new CountDownLatch(1); 66 activityRule.runOnUiThread(() -> { 67 Lifecycle.State currentState = a.getLifecycle().getCurrentState(); 68 if (currentState == RESUMED) { 69 latch.countDown(); 70 } 71 a.getLifecycle().addObserver(new LifecycleObserver() { 72 @OnLifecycleEvent(Lifecycle.Event.ON_RESUME) 73 public void onStateChanged(LifecycleOwner provider) { 74 latch.countDown(); 75 provider.getLifecycle().removeObserver(this); 76 } 77 }); 78 }); 79 latch.await(); 80 } 81 82} 83