Navigate with enum defines. Create new TopBarState

app/src/main/java/me/zobrist/tichucounter/MainActivity.kt

@@ -17,11 +17,8 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
-import androidx.navigation.NavDestination.Companion.hierarchy
-import androidx.navigation.NavGraph.Companion.findStartDestination
 import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
-import androidx.navigation.compose.composable
 import androidx.navigation.compose.currentBackStackEntryAsState
 import androidx.navigation.compose.rememberNavController
 import com.google.accompanist.systemuicontroller.rememberSystemUiController
@@ -106,10 +103,7 @@ class MainActivity : AppCompatActivity(), ISettingsChangeListener {
         fabAction: () -> Unit
     ) {
 
-        var topBarTitle by remember { mutableStateOf("") }
+        var topBarState by remember { mutableStateOf(TopBarState()) }
-        var topBarIcon by remember { mutableStateOf(Icons.Filled.Menu) }
-        var topBarActions by remember { mutableStateOf(emptyList<TopBarAction>()) }
-        var topBarNavigationAction by remember { mutableStateOf(NavigationAction {}) }
 
         Scaffold(
             floatingActionButton = {
@@ -120,26 +114,20 @@ class MainActivity : AppCompatActivity(), ISettingsChangeListener {
                     }
                 }
             },
-            topBar = {
+            topBar = { TopBar(topBarState) }) { paddings ->
-                TopBar(
-                    topBarTitle,
-                    topBarIcon,
-                    { topBarNavigationAction.action() },
-                    topBarActions
-                )
-            }) { paddings ->
 
             NavHost(
                 navController = navController,
-                startDestination = "counter",
+                startDestination = Route.COUNTER.name,
                 modifier = Modifier.padding(paddings)
             ) {
-                composable("counter") {
+                composable(Route.COUNTER) {
 
                     var expanded by remember { mutableStateOf(false) }
 
-                    Counter(counterViewModel)
+                    topBarState = TopBarState(
-                    topBarActions = (listOf(
+                        title = stringResource(R.string.app_name),
+                        actions = (listOf(
                             TopBarAction(
                                 Icons.Outlined.Undo,
                                 mainViewModel.isUndoActionActive,
@@ -168,28 +156,21 @@ class MainActivity : AppCompatActivity(), ISettingsChangeListener {
                             },
 
                             ))
-                    topBarIcon = Icons.Outlined.Menu
+                    ) { scope.launch { drawerState.open() } }
-                    topBarTitle = stringResource(R.string.app_name)
-                    topBarNavigationAction =
-                        NavigationAction { scope.launch { drawerState.open() } }
-                }
-                composable("history") {
 
-                    HistoryList(historyViewModel) { navController.navigate("counter") }
+                    Counter(counterViewModel)
-
-                    topBarActions = emptyList()
-                    topBarIcon = Icons.Outlined.Menu
-                    topBarTitle = stringResource(R.string.menu_history)
-                    topBarNavigationAction =
-                        NavigationAction { scope.launch { drawerState.open() } }
                 }
-                composable("settings") {
+                composable(Route.HISTORY) {
+                    topBarState =
+                        TopBarState(title = stringResource(R.string.menu_history)) { scope.launch { drawerState.open() } }
+
+                    HistoryList(historyViewModel) { navController.navigate(Route.COUNTER) }
+                }
+                composable(Route.SETTINGS) {
+                    topBarState =
+                        TopBarState(title = stringResource(R.string.menu_settings)) { scope.launch { drawerState.open() } }
+
                     SettingsView(settingsViewModel)
-                    topBarActions = emptyList()
-                    topBarIcon = Icons.Outlined.Menu
-                    topBarTitle = stringResource(R.string.menu_settings)
-                    topBarNavigationAction =
-                        NavigationAction { scope.launch { drawerState.open() } }
                 }
             }
         }
@@ -204,40 +185,27 @@ class MainActivity : AppCompatActivity(), ISettingsChangeListener {
         val navController = rememberNavController()
 
         val items = listOf(
-            Screen("counter", Icons.Outlined.Calculate, R.string.app_name),
+            Screen(Route.COUNTER, Icons.Outlined.Calculate, R.string.app_name),
-            Screen("history", Icons.Outlined.List, R.string.menu_history),
+            Screen(Route.HISTORY, Icons.Outlined.List, R.string.menu_history),
-            Screen("settings", Icons.Outlined.Settings, R.string.menu_settings)
+            Screen(Route.SETTINGS, Icons.Outlined.Settings, R.string.menu_settings)
         )
 
         val navBackStackEntry by navController.currentBackStackEntryAsState()
-        val currentDestination = navBackStackEntry?.destination
+        val currentDestination =
+            Route.valueOf(navBackStackEntry?.destination?.route ?: Route.COUNTER.name)
 
         ModalNavigationDrawer(
             drawerState = drawerState,
             gesturesEnabled = drawerState.isOpen,
             drawerContent = {
-                ModalDrawerSheet {
+                DrawerContent(
+                    screens = items,
+                    selectedScreen = items.first { it.route == currentDestination }) {
+                    scope.launch {
+                        drawerState.close()
 
-                    Spacer(Modifier.height(20.dp))
-
-                    items.forEach { screen ->
-                        NavigationDrawerItem(
-                            icon = { Icon(screen.icon, contentDescription = null) },
-                            label = { Text(stringResource(screen.resourceId)) },
-                            selected = currentDestination?.hierarchy?.any { it.route == screen.route } == true,
-                            onClick = {
-                                scope.launch { drawerState.close() }
-                                navController.navigate(screen.route) {
-                                    popUpTo(navController.graph.findStartDestination().id) {
-                                        saveState = true
-                                    }
-                                    launchSingleTop = true
-                                    restoreState = true
-                                }
-                            },
-                            modifier = Modifier.padding(NavigationDrawerItemDefaults.ItemPadding)
-                        )
                     }
+                    navController.navigate(it)
                 }
             }
         ) {
@@ -245,10 +213,34 @@ class MainActivity : AppCompatActivity(), ISettingsChangeListener {
                 drawerState,
                 scope,
                 navController,
-                counterViewModel.keyboardHidden && (currentDestination?.hierarchy?.any { it.route == "counter" } == true)
+                counterViewModel.keyboardHidden && (currentDestination == Route.COUNTER)
             ) { counterViewModel.showKeyboard() }
         }
     }
 
-    private class Screen(val route: String, val icon: ImageVector, @StringRes val resourceId: Int)
+    @OptIn(ExperimentalMaterial3Api::class)
+    @Composable
+    private fun DrawerContent(
+        screens: List<Screen>,
+        selectedScreen: Screen,
+        onElementClicked: (Route) -> Unit
+    ) {
+
+        ModalDrawerSheet {
+
+            Spacer(Modifier.height(20.dp))
+
+            screens.forEach { screen ->
+                NavigationDrawerItem(
+                    icon = { Icon(screen.icon, contentDescription = null) },
+                    label = { Text(stringResource(screen.resourceId)) },
+                    selected = screen == selectedScreen,
+                    onClick = { onElementClicked(screen.route) },
+                    modifier = Modifier.padding(NavigationDrawerItemDefaults.ItemPadding)
+                )
+            }
+        }
+    }
+
+    private class Screen(val route: Route, val icon: ImageVector, @StringRes val resourceId: Int)
 }

app/src/main/java/me/zobrist/tichucounter/domain/NavExtensions.kt

@@ -0,0 +1,18 @@
+package me.zobrist.tichucounter.domain
+
+import androidx.compose.runtime.Composable
+import androidx.navigation.*
+import androidx.navigation.compose.composable
+
+fun NavController.navigate(route: Route) {
+    this.navigate(route.name)
+}
+
+fun NavGraphBuilder.composable(
+    route: Route,
+    arguments: List<NamedNavArgument> = emptyList(),
+    deepLinks: List<NavDeepLink> = emptyList(),
+    content: @Composable (NavBackStackEntry) -> Unit
+) {
+    this.composable(route.name, arguments, deepLinks, content)
+}

app/src/main/java/me/zobrist/tichucounter/domain/NavigationAction.kt

@@ -1,3 +0,0 @@
-package me.zobrist.tichucounter.domain
-
-class NavigationAction(val action: () -> Unit)

app/src/main/java/me/zobrist/tichucounter/domain/Route.kt

@@ -0,0 +1,3 @@
+package me.zobrist.tichucounter.domain
+
+enum class Route { COUNTER, HISTORY, SETTINGS }

app/src/main/java/me/zobrist/tichucounter/domain/TopBarAction.kt

@@ -3,4 +3,9 @@ package me.zobrist.tichucounter.domain
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.graphics.vector.ImageVector
 
-class TopBarAction(val imageVector: ImageVector, val isActive: Boolean, val action: () -> Unit, val composeCode: @Composable () -> Unit = {})
+class TopBarAction(
+    val imageVector: ImageVector,
+    val isActive: Boolean,
+    val action: () -> Unit,
+    val composeCode: @Composable () -> Unit = {}
+)

app/src/main/java/me/zobrist/tichucounter/domain/TopBarState.kt

@@ -0,0 +1,12 @@
+package me.zobrist.tichucounter.domain
+
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.outlined.Menu
+import androidx.compose.ui.graphics.vector.ImageVector
+
+data class TopBarState(
+    var title: String = "",
+    var icon: ImageVector = Icons.Outlined.Menu,
+    var actions: List<TopBarAction> = emptyList(),
+    var onNavigate: () -> Unit = {}
+)

app/src/main/java/me/zobrist/tichucounter/ui/TopBar.kt

@@ -5,6 +5,17 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.text.style.TextOverflow
 import me.zobrist.tichucounter.domain.TopBarAction
+import me.zobrist.tichucounter.domain.TopBarState
+
+@Composable
+fun TopBar(topBarState: TopBarState) {
+    TopBar(
+        topBarState.title,
+        topBarState.icon,
+        topBarState.onNavigate,
+        topBarState.actions
+    )
+}
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable