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.annotation.SuppressLint; import android.arch.lifecycle.Lifecycle; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v4.app.Fragment; import android.support.v4.util.Pair; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.FrameLayout; import java.util.ArrayList; import java.util.List; /** * A support fragment that collects all of its events. */ @SuppressLint("ValidFragment") public class CollectingSupportFragment extends Fragment implements CollectingLifecycleOwner { private final List<Pair<TestEvent, Lifecycle.Event>> mCollectedEvents = new ArrayList<>(); private TestObserver mTestObserver = new TestObserver(mCollectedEvents); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Lifecycle.Event.ON_CREATE)); getLifecycle().addObserver(mTestObserver); } @Nullable @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { //noinspection ConstantConditions FrameLayout layout = new FrameLayout(container.getContext()); layout.setId(R.id.child_fragment_container); return layout; } /** * Runs a replace fragment transaction with 'fragment' on this Fragment. */ public void replaceFragment(Fragment fragment) { getChildFragmentManager().beginTransaction().add(R.id.child_fragment_container, fragment).commitNow(); } @Override public void onStart() { super.onStart(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Lifecycle.Event.ON_START)); } @Override public void onResume() { super.onResume(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Lifecycle.Event.ON_RESUME)); } @Override public void onDestroy() { super.onDestroy(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Lifecycle.Event.ON_DESTROY)); } @Override public void onStop() { super.onStop(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Lifecycle.Event.ON_STOP)); } @Override public void onPause() { super.onPause(); mCollectedEvents.add(new Pair<>(OWNER_CALLBACK, Lifecycle.Event.ON_PAUSE)); } @Override public List<Pair<TestEvent, Lifecycle.Event>> copyCollectedEvents() { return new ArrayList<>(mCollectedEvents); } }