Заложена навигация с передачей параметров и сохранением состояний

app/src/main/AndroidManifest.xml

@@ -12,6 +12,7 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.Wallenc"
+        android:enableOnBackInvokedCallback="true"
         tools:targetApi="31">
         <activity
             android:name=".MainActivity"

gradle/libs.versions.toml

@@ -5,6 +5,7 @@ coreKtx = "1.15.0"
 junit = "4.13.2"
 junitVersion = "1.2.1"
 espressoCore = "3.6.1"
+kotlinReflect = "2.0.21"
 kotlinxCoroutinesCore = "1.9.0"
 kotlinxSerializationJson = "1.7.3"
 lifecycleRuntimeKtx = "2.8.7"
@@ -23,6 +24,7 @@ material = "1.12.0"
 runtimeAndroid = "1.7.5"
 
 [libraries]
+kotlin-reflect = { module = "org.jetbrains.kotlin:kotlin-reflect", version.ref = "kotlinReflect" }
 kotlinx-coroutines-core = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-core", version.ref = "kotlinxCoroutinesCore" }
 kotlinx-serialization-json = { module = "org.jetbrains.kotlinx:kotlinx-serialization-json", version.ref = "kotlinxSerializationJson" }
 navigation = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigation" }

presentation/build.gradle.kts

@@ -4,6 +4,7 @@ plugins {
     alias(libs.plugins.compose.compiler)
     alias(libs.plugins.dagger.hilt)
     alias(libs.plugins.jetbrains.kotlin.serialization)
+    id("kotlin-parcelize")
     alias(libs.plugins.ksp)
 }
 
@@ -54,6 +55,7 @@ dependencies {
     ksp(libs.dagger.hilt.compiler)
 
     implementation(libs.kotlinx.serialization.json)
+    implementation(libs.kotlin.reflect)
 
     implementation(libs.androidx.core.ktx)
     implementation(libs.androidx.lifecycle.runtime.ktx)

presentation/src/main/java/com/github/nullptroma/wallenc/presentation/WallencUi.kt

@@ -1,14 +1,30 @@
 package com.github.nullptroma.wallenc.presentation
 
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
 import androidx.compose.foundation.layout.padding
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.rounded.Menu
+import androidx.compose.material.icons.rounded.Settings
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.NavigationBar
+import androidx.compose.material3.NavigationBarItem
 import androidx.compose.material3.Scaffold
 import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Modifier
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
-import androidx.navigation.compose.rememberNavController
+import androidx.navigation.compose.currentBackStackEntryAsState
 import androidx.navigation.toRoute
+import com.github.nullptroma.wallenc.presentation.navigation.NavBarItem
+import com.github.nullptroma.wallenc.presentation.navigation.rememberNavigationState
 import com.github.nullptroma.wallenc.presentation.screens.main.MainRoute
 import com.github.nullptroma.wallenc.presentation.screens.main.MainScreen
 import com.github.nullptroma.wallenc.presentation.screens.settings.SettingsRoute
@@ -25,17 +41,70 @@ fun WallencUi() {
     }
 }
 
+@OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun WallencNavRoot() {
-    val navController = rememberNavController()
+    val navState = rememberNavigationState()
-    Scaffold { innerPaddings ->
+
-        NavHost(navController, startDestination = MainRoute()) {
+    val topLevelScreenRoutes = rememberSaveable {
-            composable<MainRoute> {
+        mutableMapOf(
+            MainRoute::class.qualifiedName!! to MainRoute(),
+            SettingsRoute::class.qualifiedName!! to SettingsRoute("Base settings")
+        )
+    }
+
+    // Все пункты меню верхнего уровня
+    val topLevelNavBarItems = remember {
+        listOf(
+            NavBarItem("Main", MainRoute::class.qualifiedName!!, Icons.Rounded.Menu),
+            NavBarItem("Settings", SettingsRoute::class.qualifiedName!!, Icons.Rounded.Settings)
+        )
+    }
+
+    Scaffold(
+        bottomBar = {
+            NavigationBar {
+                val navBackStackEntry by navState.navHostController.currentBackStackEntryAsState()
+                val currentRoute = navBackStackEntry?.destination?.route
+                topLevelNavBarItems.forEach {
+                    val routeClassName = it.screenRouteClass
+
+                    NavigationBarItem(
+                        icon = {
+                            Icon(
+                                it.icon,
+                                contentDescription = it.name
+                            )
+                        },
+                        label = { Text(it.name) },
+                        selected = currentRoute?.startsWith(routeClassName) == true,
+                        onClick = {
+                            var route = topLevelScreenRoutes[it.screenRouteClass]
+                            if(route == null)
+                                throw NoSuchElementException("Screen route of type ${it.screenRouteClass} no found")
+                            if(currentRoute?.startsWith(routeClassName) != true)
+                                navState.navigationTo(route)
+                        }
+                    )
+                }
+            }
+        }) { innerPaddings ->
+        NavHost(navState.navHostController, startDestination = topLevelScreenRoutes[MainRoute::class.qualifiedName]!!) {
+            composable<MainRoute>(enterTransition = {
+                fadeIn(tween(200))
+            }, exitTransition = {
+                fadeOut(tween(200))
+            }) {
                 MainScreen(Modifier.padding(innerPaddings), onSettingsRoute = { settingsRoute ->
-                    navController.navigate(settingsRoute)
+                    topLevelScreenRoutes[settingsRoute::class.qualifiedName!!] = settingsRoute
+                    navState.navigationTo(settingsRoute)
                 })
             }
-            composable<SettingsRoute> {
+            composable<SettingsRoute>(enterTransition = {
+                fadeIn(tween(200))
+            }, exitTransition = {
+                fadeOut(tween(200))
+            }) {
                 val route: SettingsRoute = it.toRoute()
                 SettingsScreen(Modifier.padding(innerPaddings), route.text)
             }

presentation/src/main/java/com/github/nullptroma/wallenc/presentation/navigation/NavBarItem.kt

@@ -0,0 +1,5 @@
+package com.github.nullptroma.wallenc.presentation.navigation
+
+import androidx.compose.ui.graphics.vector.ImageVector
+
+data class NavBarItem(val name: String, val screenRouteClass: String, val icon: ImageVector)

presentation/src/main/java/com/github/nullptroma/wallenc/presentation/navigation/NavigationState.kt

@@ -0,0 +1,29 @@
+package com.github.nullptroma.wallenc.presentation.navigation
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.navigation.NavGraph.Companion.findStartDestination
+import androidx.navigation.NavHostController
+import androidx.navigation.compose.rememberNavController
+import com.github.nullptroma.wallenc.presentation.screens.ScreenRoute
+
+
+class NavigationState(
+    val navHostController: NavHostController
+) {
+    fun navigationTo(route: ScreenRoute) {
+        navHostController.navigate(route) {
+            popUpTo(navHostController.graph.findStartDestination().id)
+            launchSingleTop = true
+            restoreState = true
+        }
+    }
+}
+
+@Composable
+fun rememberNavigationState(
+    navHostController: NavHostController? = null
+): NavigationState {
+    val controller = navHostController ?: rememberNavController()
+    return remember { NavigationState(controller) }
+}

presentation/src/main/java/com/github/nullptroma/wallenc/presentation/screens/ScreenRoute.kt

@@ -0,0 +1,7 @@
+package com.github.nullptroma.wallenc.presentation.screens
+
+import android.os.Parcelable
+import kotlinx.serialization.Serializable
+
+@Serializable
+abstract class ScreenRoute() : Parcelable

presentation/src/main/java/com/github/nullptroma/wallenc/presentation/screens/main/MainRoute.kt

@@ -1,5 +1,9 @@
 package com.github.nullptroma.wallenc.presentation.screens.main
 
+import com.github.nullptroma.wallenc.presentation.screens.ScreenRoute
+import kotlinx.parcelize.Parcelize
 import kotlinx.serialization.Serializable
 
-@Serializable class MainRoute
+@Serializable
+@Parcelize
+class MainRoute: ScreenRoute()

presentation/src/main/java/com/github/nullptroma/wallenc/presentation/screens/main/MainScreen.kt

@@ -9,10 +9,11 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.TextField
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalFocusManager
 import androidx.hilt.navigation.compose.hiltViewModel
 import com.github.nullptroma.wallenc.presentation.screens.settings.SettingsRoute
 
@@ -22,12 +23,14 @@ fun MainScreen(modifier: Modifier = Modifier,
                viewModel: MainViewModel = hiltViewModel(),
                onSettingsRoute: (SettingsRoute) -> Unit) {
     val state = viewModel.stateFlow
-    var text by remember { mutableStateOf("") }
+    var text by rememberSaveable { mutableStateOf("") }
+    val focusManager = LocalFocusManager.current
     Column(modifier = modifier.imePadding().fillMaxSize(), horizontalAlignment = Alignment.CenterHorizontally, verticalArrangement = Arrangement.Center) {
         TextField(text, onValueChange = { s ->
             text = s
         })
         Button( onClick = {
+            focusManager.clearFocus()
             onSettingsRoute(SettingsRoute(text))
         }) {
             Text("Press Me!")

presentation/src/main/java/com/github/nullptroma/wallenc/presentation/screens/settings/SettingsRoute.kt

@@ -1,5 +1,9 @@
 package com.github.nullptroma.wallenc.presentation.screens.settings
 
+import com.github.nullptroma.wallenc.presentation.screens.ScreenRoute
+import kotlinx.parcelize.Parcelize
 import kotlinx.serialization.Serializable
 
-@Serializable class SettingsRoute(val text: String)
+@Serializable
+@Parcelize
+class SettingsRoute(val text: String): ScreenRoute()