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 17 /** 18 * Navigation is a framework for navigating between 'destinations' within an Android 19 * application that provides a consistent API whether destinations are implemented as 20 * {@link android.support.v4.app.Fragment Fragments}, {@link android.app.Activity Activities}, or 21 * other components. 22 * <p> 23 * There are 3 major components in Navigation. 24 * <ul> 25 * <li>{@link androidx.navigation.NavGraph}: A navigation graph encapsulates a set 26 * of {@link androidx.navigation.NavDestination destinations}. It can be created by 27 * inflating a navigation XML file, by constructing it programmatically, 28 * or a combination of the two. 29 * </li> 30 * <li>{@link androidx.navigation.NavController}: This is the main entry 31 * point for interacting with the Navigation Graph, translating calls to 32 * {@link androidx.navigation.NavController#navigate(int)}, 33 * {@link androidx.navigation.NavController#popBackStack()}, and 34 * {@link androidx.navigation.NavController#navigateUp()} into the appropriate operations. 35 * </li> 36 * <li>{@link androidx.navigation.NavHost}: The container that hosts a 37 * {@link androidx.navigation.NavController} and provides support for one or more specific 38 * types of {@link androidx.navigation.NavDestination destinations}. For example, 39 * {@link androidx.navigation.fragment.NavHostFragment} allows you to use 40 * {@link androidx.navigation.fragment.FragmentNavigator.Destination fragment destinations}. 41 * </li> 42 * </ul> 43 * Below is an example of working with a NavController. 44 * <pre class="prettyprint"> 45 * // File: HomeFragment.java 46 * public void onViewCreated(View view, {@literal @}Nullable Bundle savedInstanceState) { 47 * // For example purposes, assume our layout created in onCreateView has a Button 48 * // that should navigate the user to a destination 49 * Button b = view.findViewById(R.id.view_details); 50 * 51 * b.setOnClickListener(v -> { 52 * // Retrieve the NavController from any View within a NavHost 53 * NavController navController = Navigation.findNavController(v); 54 * navController.navigate(R.id.details)); 55 * } 56 * 57 * // Or use the convenience method in Navigation to combine the previous steps 58 * b.setOnClickListener(Navigation.createNavigateOnClickListener(R.id.details)); 59 * } 60 * </pre> 61 * <p> 62 * Please see the documentation of individual classes for details. 63 */ 64 package androidx.navigation; 65
