1 /* 2 * Copyright 2018 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 package androidx.navigation; 18 19 import android.os.Bundle; 20 import android.support.annotation.NonNull; 21 import android.view.View; 22 23 /** 24 * A host is a single context or container for navigation via a {@link NavController}. 25 * <p> 26 * Navigation hosts must: 27 * <ul> 28 * <li>Handle {@link NavController#saveState() saving} and 29 * {@link NavController#restoreState(Bundle) restoring} their controller's state</li> 30 * <li>Call {@link Navigation#setViewNavController(View, NavController)} on their root view</li> 31 * </ul> 32 */ 33 public interface NavHost { 34 35 /** 36 * Returns the {@link NavController navigation controller} for this navigation host. 37 * 38 * @return this host's navigation controller 39 */ 40 @NonNull 41 NavController getNavController(); 42 } 43
