dropdown menüadded not functional

app/src/main/java/com/example/smart_watch_android/BLE/BleManager.kt

@@ -29,6 +29,7 @@ import java.util.UUID
 import kotlin.time.Duration.Companion.milliseconds
 
 class BleManager(private val context: Context) {
+    val deviceAddress = "10:BD:A3:8F:01:0E"
     val currentDate: LocalDate? = LocalDate.now()
     val deviceUUIDs = DeviceUUIDs
     private var bluetoothGatt: BluetoothGatt? = null
@@ -39,11 +40,30 @@ class BleManager(private val context: Context) {
     var isConnected by mutableStateOf(false)
         private set
 
+
+
     @RequiresPermission(Manifest.permission.BLUETOOTH_CONNECT)
     fun init() {
         bluetoothManager = context.getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
         bluetoothAdapter = bluetoothManager?.adapter
-        checkCurrentConnectionState("10:BD:A3:8F:01:0E")
+
+        if (bluetoothAdapter == null) return
+
+        try {
+            val device = bluetoothAdapter?.getRemoteDevice(deviceAddress)
+            if (device != null) {
+                val state = bluetoothManager!!.getConnectionState(device, BluetoothProfile.GATT)
+                if (state == BluetoothProfile.STATE_CONNECTED) {
+                    Log.d("ESP32_BLE", "App restarted: device still connected. rebuild GATT-connection...")
+                    connectToEsp32(deviceAddress)
+                } else {
+                    isConnected = false
+                    Log.d("ESP32_BLE", "App restarted: not connected.")
+                }
+            }
+        } catch (e: Exception) {
+            Log.d("ESP32_BLE", "error while checking the status: ${e.message}")
+        }
     }
     @RequiresPermission(Manifest.permission.BLUETOOTH_CONNECT)
     fun checkCurrentConnectionState(deviceAddress: String) {

app/src/main/java/com/example/smart_watch_android/MainViewModel.kt

@@ -1,6 +1,9 @@
 package com.example.smart_watch_android
 
+import android.Manifest
 import android.app.Application
+import android.content.Context
+import androidx.annotation.RequiresPermission
 import androidx.lifecycle.AndroidViewModel
 import com.example.smart_watch_android.BLE.BleManager
 
@@ -11,7 +14,8 @@ class MainViewModel(
     lateinit var bleManager: BleManager
         private set
 
-    fun initBleManager(activityContext: android.content.Context) {
+    @RequiresPermission(Manifest.permission.BLUETOOTH_CONNECT)
+    fun initBleManager(activityContext: Context) {
         if (!::bleManager.isInitialized) {
             bleManager = BleManager(context = activityContext)
             bleManager.init()

app/src/main/java/com/example/smart_watch_android/Screens/AppNavigation.kt

@@ -1,6 +1,7 @@
 package com.example.smart_watch_android.Screens
 
 import android.Manifest
+import android.R
 import androidx.annotation.RequiresPermission
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
@@ -41,10 +42,7 @@ fun AppNavigation(bleManager: BleManager) {
         // Connect Screen
         composable("connect") {
             ConnectScreen(
-                isConnected = bleManager.isConnected,
-                onConnectClicked = {
-                    bleManager.connectToEsp32("10:BD:A3:8F:01:0E")
-                }
+                bleManager = bleManager
             )
         }
 

app/src/main/java/com/example/smart_watch_android/Screens/ConnectScreen.kt

@@ -1,35 +1,81 @@
 package com.example.smart_watch_android.Screens
 
+import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.DropdownMenu
+import androidx.compose.material3.DropdownMenuItem
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import com.example.smart_watch_android.BLE.BleManager
 
 @Composable
-fun ConnectScreen(isConnected: Boolean, onConnectClicked: () -> Unit) {
-    Box(
-        modifier = Modifier.fillMaxSize(),
-        contentAlignment = Alignment.Center
-    ) {
-        Button(
-            onClick = onConnectClicked,
-            modifier = Modifier.size(300.dp),
-            shape = CircleShape,
-            colors = ButtonDefaults.buttonColors(containerColor = Color(0xFF5E18BE))
-        ) {
-            Text(
-                text = "Connect",
-                fontSize = 30.sp
+fun ConnectScreen(bleManager: BleManager) {
+    var expanded by remember { mutableStateOf(false) }
+    var selectedDevice by remember { mutableStateOf("device") }
+    val items = listOf("Option 1", "Option 2", "Option 3")
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .padding(16.dp),
+        verticalArrangement = Arrangement.Center,
+        horizontalAlignment = Alignment.CenterHorizontally
+    )
+    {
+            Button(
+                onClick = { expanded = !expanded },
+                shape = RoundedCornerShape(4.dp),
+                modifier = Modifier.width(400.dp)
+            ) {
+                Text(selectedDevice)
+            }
+            DropdownMenu(
+                expanded = expanded,
+                onDismissRequest = { expanded = false }
+            ) {
+                items.forEach { item ->
+                    DropdownMenuItem(
+                        text = { Text(item) },
+                        onClick = {
+                            selectedDevice = item
+                            expanded = false
+                        }
+                    )
+                }
+            }
+
+        Spacer(modifier = Modifier.height(64.dp))
+
+            Button(
+                onClick = { bleManager.connectToEsp32(deviceAddress = "10:BD:A3:8F:01:0E") },
+                modifier = Modifier.size(400.dp),
+                shape = CircleShape,
+                colors = ButtonDefaults.buttonColors(containerColor = Color(0xFF5E18BE))
+            ) {
+                Text(
+                    text = "Connect",
+                    fontSize = 32.sp
                 )
-        }
+            }
     }
 }