Setup NavHost;

Author: raheemadamboev

app/src/main/java/xyz/teamgravity/composenestednavigation/MainActivity.kt

@@ -3,13 +3,25 @@ package xyz.teamgravity.composenestednavigation
 import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material3.Button
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Surface
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.tooling.preview.Preview
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewmodel.compose.viewModel
+import androidx.navigation.NavBackStackEntry
+import androidx.navigation.NavController
+import androidx.navigation.compose.NavHost
+import androidx.navigation.compose.composable
+import androidx.navigation.compose.rememberNavController
+import androidx.navigation.navigation
 import xyz.teamgravity.composenestednavigation.ui.theme.ComposeNestedNavigationTheme
 
 class MainActivity : ComponentActivity() {
@@ -21,8 +33,112 @@ class MainActivity : ComponentActivity() {
                     modifier = Modifier.fillMaxSize(),
                     color = MaterialTheme.colorScheme.background
                 ) {
+                    val controller = rememberNavController()
+
+                    NavHost(
+                        navController = controller,
+                        startDestination = "auth"
+                    ) {
+                        navigation(
+                            route = "auth",
+                            startDestination = "login"
+                        ) {
+                            composable(route = "login") { entry ->
+                                val viewmodel = entry.sharedViewModel<AuthViewModel>(controller)
+                                GenericScreen(
+                                    text = "Login",
+                                    onClick = {
+                                        controller.navigate(
+                                            route = "profile",
+                                            builder = {
+                                                popUpTo(
+                                                    route = "auth",
+                                                    popUpToBuilder = {
+                                                        inclusive = true
+                                                    }
+                                                )
+                                            }
+                                        )
+                                    }
+                                )
+                            }
+                            composable(route = "register") { entry ->
+                                val viewmodel = entry.sharedViewModel<AuthViewModel>(controller)
+                                GenericScreen(
+                                    text = "Register",
+                                    onClick = {
+
+                                    }
+                                )
+                            }
+                            composable(route = "forgot_password") { entry ->
+                                val viewmodel = entry.sharedViewModel<AuthViewModel>(controller)
+                                GenericScreen(
+                                    text = "Forgot Password",
+                                    onClick = {
+                                        controller.navigate("about")
+                                    }
+                                )
+                            }
+                        }
+                        navigation(
+                            route = "profile",
+                            startDestination = "settings"
+                        ) {
+                            composable(route = "settings") {
+                                GenericScreen(
+                                    text = "Settings",
+                                    onClick = {
+                                        controller.navigate("forgot_password")
+                                    }
+                                )
+                            }
+                            composable(route = "goals") {
+                                GenericScreen(
+                                    text = "Goals",
+                                    onClick = {
+
+                                    }
+                                )
+                            }
+                        }
+                        composable(route = "about") {
+                            GenericScreen(
+                                text = "About",
+                                onClick = {
+
+                                }
+                            )
+                        }
+                    }
                 }
             }
         }
     }
-}
+}
+
+@Composable
+fun GenericScreen(
+    text: String,
+    onClick: () -> Unit
+) {
+    Column(
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.Center,
+        modifier = Modifier.fillMaxSize()
+    ) {
+        Text(text = text)
+        Button(onClick = onClick) {
+            Text(text = "Click me")
+        }
+    }
+}
+
+@Composable
+inline fun <reified T : ViewModel> NavBackStackEntry.sharedViewModel(controller: NavController): T {
+    val route = destination.parent?.route ?: return viewModel()
+    val entry = remember(this) { controller.getBackStackEntry(route) }
+    return viewModel(viewModelStoreOwner = entry)
+}
+
+class AuthViewModel : ViewModel()