1 /*
2  * Copyright 2019 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.testing
18 
19 import androidx.navigation.NavDestination
20 import androidx.navigation.NavGraphNavigator
21 import androidx.navigation.Navigator
22 import androidx.navigation.NavigatorProvider
23 
24 /**
25  * A [NavigatorProvider] for testing that only parses
26  * [navigation graphs][androidx.navigation.NavGraph] and [destinations][NavDestination].
27  */
28 internal class TestNavigatorProvider : NavigatorProvider() {
29 
30     /** A [Navigator] that only supports creating destinations. */
31     private val navigator =
32         object : Navigator<NavDestination>() {
createDestinationnull33             override fun createDestination() = NavDestination("test")
34         }
35 
36     init {
37         addNavigator(NavGraphNavigator(this))
38         addNavigator("test", navigator)
39     }
40 
getNavigatornull41     override fun <T : Navigator<out NavDestination>> getNavigator(name: String): T {
42         return try {
43             super.getNavigator(name)
44         } catch (_: IllegalStateException) {
45             @Suppress("UNCHECKED_CAST")
46             navigator as T
47         }
48     }
49 }
50