Java tutorial
/* * Copyright (C) 2017 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 android.arch.lifecycle.testapp; import static android.arch.lifecycle.testapp.TestEvent.OWNER_CALLBACK; import android.arch.lifecycle.Lifecycle.Event; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.support.v4.util.Pair; import android.widget.FrameLayout; import java.util.ArrayList; import java.util.List; import java.util.concurrent.CountDownLatch; import java.util.concurrent.TimeUnit; /** * LifecycleRegistryOwner that extends FragmentActivity. */ public class CollectingSupportActivity extends FragmentActivity implements CollectingLifecycleOwner { private final List<Pair<TestEvent, Event>> mCollectedEvents = new ArrayList<>(); private TestObserver mTestObserver = new TestObserver(mCollectedEvents); private CountDownLatch mSavedStateLatch = new CountDownLatch(1); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); FrameLayout layout = new FrameLayout(this); layout.setId(R.id.fragment_container); setContentView(layout); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Event.ON_CREATE)); getLifecycle().addObserver(mTestObserver); } /** * replaces the main content fragment w/ the given fragment. */ public void replaceFragment(Fragment fragment) { getSupportFragmentManager().beginTransaction().add(R.id.fragment_container, fragment).commitNow(); } @Override protected void onStart() { super.onStart(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Event.ON_START)); } @Override protected void onResume() { super.onResume(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Event.ON_RESUME)); } @Override protected void onDestroy() { super.onDestroy(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Event.ON_DESTROY)); } @Override protected void onStop() { super.onStop(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Event.ON_STOP)); } @Override protected void onPause() { super.onPause(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Event.ON_PAUSE)); // helps with less flaky API 16 tests. overridePendingTransition(0, 0); } @Override public List<Pair<TestEvent, Event>> copyCollectedEvents() { return new ArrayList<>(mCollectedEvents); } @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); mSavedStateLatch.countDown(); } /** * Waits for onSaveInstanceState to be called. */ public boolean waitForStateSave(@SuppressWarnings("SameParameterValue") int seconds) throws InterruptedException { return mSavedStateLatch.await(seconds, TimeUnit.SECONDS); } }