ComposeNavigator.kt
/*
* Copyright 2020 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 androidx.navigation.compose
import androidx.compose.runtime.Composable
import androidx.navigation.NavBackStackEntry
import androidx.navigation.NavDestination
import androidx.navigation.NavOptions
import androidx.navigation.Navigator
import androidx.navigation.compose.ComposeNavigator.Destination
/**
* Navigator that navigates through [Composable]s. Every destination using this Navigator must
* set a valid [Composable] by setting it directly on an instantiated [Destination] or calling
* [composable].
*/
@Navigator.Name("composable")
public class ComposeNavigator : Navigator<Destination>() {
/**
* Get the map of transitions currently in progress from the [state].
*/
internal val transitionsInProgress get() = state.transitionsInProgress
/**
* Get the back stack from the [state].
*/
public val backStack get() = state.backStack
override fun navigate(
entries: List<NavBackStackEntry>,
navOptions: NavOptions?,
navigatorExtras: Extras?
) {
entries.forEach { entry ->
state.pushWithTransition(entry)
}
}
override fun createDestination(): Destination {
return Destination(this) { }
}
override fun popBackStack(popUpTo: NavBackStackEntry, savedState: Boolean) {
state.popWithTransition(popUpTo, savedState)
}
/**
* Callback to mark a navigation in transition as complete.
*
* This should be called in conjunction with [navigate] and [popBackStack] as those
* calls merely start a transition to the target destination, and requires manually marking
* the transition as complete by calling this method.
*
* Failing to call this method could result in entries being prevented from reaching their
* final [Lifecycle.State].
*/
public fun onTransitionComplete(entry: NavBackStackEntry) {
state.markTransitionComplete(entry)
}
/**
* NavDestination specific to [ComposeNavigator]
*/
@NavDestination.ClassType(Composable::class)
public class Destination(
navigator: ComposeNavigator,
internal val content: @Composable (NavBackStackEntry) -> Unit
) : NavDestination(navigator)
internal companion object {
internal const val NAME = "composable"
}
}