Add configureBrowserNavigation method for web targets to show a cur…

…rent route in a browser and enable browser navigation calls.

navigation/navigation-runtime/build.gradle

@@ -136,6 +136,8 @@ kotlin {
             dependsOn(jbMain)
         }
 
+        webMain.dependsOn(jbMain)
+
         targets.all { target ->
             if (target.platformType !in [
                     KotlinPlatformType.androidJvm,
@@ -147,6 +149,14 @@ kotlin {
                 }
             }
         }
+
+        targets.all { target ->
+            if (target.platformType == KotlinPlatformType.native) {
+                target.compilations["main"].defaultSourceSet.dependsOn(jbMain)
+            } else if (target.platformType in [KotlinPlatformType.js, KotlinPlatformType.wasm]) {
+                target.compilations["main"].defaultSourceSet.dependsOn(webMain)
+            }
+        }
     }
 }
 

navigation/navigation-runtime/src/jsMain/kotlin/androidx/navigation/BrowserHistory.js.kt

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2024 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
+
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
+import org.w3c.dom.PopStateEvent
+import org.w3c.dom.Window
+import org.w3c.dom.events.Event
+
+actual typealias BrowserWindow = Window
+
+actual fun configureBrowserNavigation(window: Window, navController: NavController) {
+    var initState = true
+    var updateState = true
+
+    window.addEventListener("popstate", { event: Event ->
+        if (event is PopStateEvent) { //back or forward in the browser
+            val state = event.state.toString()
+
+            val restoredRoutes = state.lines()
+            val currentBackStack = navController.currentBackStack.value
+
+            //don't handle next navigation calls
+            updateState = false
+
+            //clear current stack
+            currentBackStack.firstOrNull { it.destination !is NavGraph }?.let { root ->
+                root.destination.route?.let { navController.popBackStack(it, true) }
+            }
+            //restore stack
+            restoredRoutes.forEach { route -> navController.navigate(route) }
+        }
+    })
+
+    //global listener is fine here
+    GlobalScope.launch {
+        navController.currentBackStack.collect { stack ->
+            val routes = stack.filter { it.destination !is NavGraph }
+                .map { it.getRouteWithArgs() ?: return@collect }
+
+            val newUri = window.location.run { "$protocol//$host/${routes.last()}" }
+            val state = routes.joinToString("\n")
+
+            if (updateState) {
+                if (initState) {
+                    window.history.replaceState(state, "", newUri)
+                    initState = false
+                } else {
+                    window.history.pushState(state, "", newUri)
+                }
+            }
+            updateState = true
+        }
+    }
+}

navigation/navigation-runtime/src/wasmJsMain/kotlin/androidx/navigation/BrowserHistory.wasmJs.kt

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2024 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
+
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
+import org.w3c.dom.PopStateEvent
+import org.w3c.dom.Window
+import org.w3c.dom.events.Event
+
+actual typealias BrowserWindow = Window
+
+actual fun configureBrowserNavigation(window: Window, navController: NavController) {
+    var initState = true
+    var updateState = true
+
+    window.addEventListener("popstate", { event: Event ->
+        if (event is PopStateEvent) { //back or forward in the browser
+            val state = event.state?.unsafeCast<JsString>().toString()
+
+            val restoredRoutes = state.lines()
+            val currentBackStack = navController.currentBackStack.value
+
+            //don't handle next navigation calls
+            updateState = false
+
+            //clear current stack
+            currentBackStack.firstOrNull { it.destination !is NavGraph }?.let { root ->
+                root.destination.route?.let { navController.popBackStack(it, true) }
+            }
+            //restore stack
+            restoredRoutes.forEach { route -> navController.navigate(route) }
+        }
+    })
+
+    //global listener is fine here
+    GlobalScope.launch {
+        navController.currentBackStack.collect { stack ->
+            val routes = stack.filter { it.destination !is NavGraph }
+                .map { it.getRouteWithArgs() ?: return@collect }
+
+            val newUri = window.location.run { "$protocol//$host/${routes.last()}" }
+            val state = routes.joinToString("\n")
+
+            if (updateState) {
+                if (initState) {
+                    window.history.replaceState(state.toJsString(), "", newUri)
+                    initState = false
+                } else {
+                    window.history.pushState(state.toJsString(), "", newUri)
+                }
+            }
+            updateState = true
+        }
+    }
+}

navigation/navigation-runtime/src/webMain/kotlin/androidx/navigation/BrowserHistory.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2024 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
+
+import androidx.core.bundle.Bundle
+import androidx.navigation.NavBackStackEntry
+import androidx.navigation.NavController
+import androidx.navigation.NavGraph
+
+expect abstract class BrowserWindow
+
+/**
+ * Configures the browser navigation for the given window and navigation controller.
+ *
+ * @param window an instance of browser's window to be configured
+ * @param navController an instance of NavController handling the navigation logic
+ */
+expect fun configureBrowserNavigation(window: BrowserWindow, navController: NavController)
+
+private val argPlaceholder = Regex("""\{*.\}""")
+internal fun NavBackStackEntry.getRouteWithArgs(): String? {
+    val entry = this
+    val route = entry.destination.route ?: return null
+    if (!route.contains(argPlaceholder)) return route
+    val args = entry.arguments ?: Bundle()
+    val nameToValue = entry.destination.arguments.map { (name, arg) ->
+        val serializedTypeValue = arg.type.serializeAsValue(arg.type[args, name])
+        name to serializedTypeValue
+    }
+
+    val routeWithFilledArgs =
+        nameToValue.fold(initial = route) { acc, (argumentName: String, value: String) ->
+            acc.replace("{$argumentName}", value)
+        }
+    return routeWithFilledArgs.takeIf { !it.contains(argPlaceholder) }
+}