sending of message and working connect/disconnect

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

@@ -18,6 +18,7 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.core.app.ActivityCompat
+import java.util.UUID
 
 class BleManager(private val context: Context) {
     val deviceUUIDs = DeviceUUIDs
@@ -72,11 +73,11 @@ class BleManager(private val context: Context) {
                             Log.d("ESP32_BLE", "4. Verbunden! Starte discoverServices()...")
                             gatt.discoverServices()
                         } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
-                            Log.d("ESP32_BLE", "5. Getrennt worden.")
                             isConnected = false
 
                             gatt.close()
                             bluetoothGatt = null
+                            Log.d("ESP32_BLE", "5. Getrennt worden.")
                         }
                     } else {
                         Log.d("ESP32_BLE", "Fehler in onConnectionStateChange! Status-Code: $status")
@@ -88,7 +89,7 @@ class BleManager(private val context: Context) {
                     Log.d("ESP32_BLE", "6. onServicesDiscovered aufgerufen mit Status: $status")
                     if (status == BluetoothGatt.GATT_SUCCESS) {
                         isConnected = true
-                        writeToEsp32("Hallo ESP32")
+                        writeToEsp32("Hallo ESP32", deviceUUIDs.TIME_CHARACTERISTIC_UUID, deviceUUIDs.TIME_CHARACTERISTIC_UUID)
                         Log.d("ESP32_BLE", "7. Services erfolgreich gefunden! Verbindung komplett erfolgreich.")
                     }
                 }
@@ -106,8 +107,20 @@ class BleManager(private val context: Context) {
             Log.d("ESP32_BLE", "Exception gefangen: ${e.message}")
         }
     }
+    @RequiresPermission(Manifest.permission.BLUETOOTH_CONNECT)
+    fun disconnectEsp32() {
+        // Nur den Disconnect-Befehl senden.
+        // Das Schließen (close) überlassen wir dem Callback, wenn es wirklich so weit ist!
+        if (ActivityCompat.checkSelfPermission(context, Manifest.permission.BLUETOOTH_CONNECT) == PackageManager.PERMISSION_GRANTED) {
+            bluetoothGatt?.disconnect()
+            Log.d("ESP32_BLE","disconnectEsp32")
+        }
+        else {
+            Log.d("BLE_DEBUG", "Permission BLUETOOTH_CONNECT fehlt!")
+        }
+    }
 
-    fun writeToEsp32(dataString: String) {
+    fun writeToEsp32(dataString: String, SERVICE_UUID: UUID?, TIME_CHARACTERISTIC_UUID: UUID?) {
         // Prüfen, ob die Verbindung steht und bluetoothGatt nicht null ist
         val gatt = bluetoothGatt
         if (gatt == null) {
@@ -116,14 +129,14 @@ class BleManager(private val context: Context) {
         }
 
         // 1. Service holen
-        val service = gatt.getService(deviceUUIDs.SERVICE_UUID)
+        val service = gatt.getService(SERVICE_UUID)
         if (service == null) {
             Log.d("ESP32_BLE", "Fehler: Service UUID nicht gefunden!")
             return
         }
 
         // 2. Characteristic holen
-        val characteristic = service.getCharacteristic(deviceUUIDs.TIME_CHARACTERISTIC_UUID)
+        val characteristic = service.getCharacteristic(TIME_CHARACTERISTIC_UUID)
         if (characteristic == null) {
             Log.d("ESP32_BLE", "Fehler: Characteristic UUID nicht gefunden!")
             return

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

@@ -3,6 +3,6 @@ package com.example.smart_watch_android.BLE
 import java.util.UUID
 
 object DeviceUUIDs {
-    val SERVICE_UUID = UUID.fromString("791cadd7-de87-49f9-8986-94b7ae11940b")
-    val TIME_CHARACTERISTIC_UUID = UUID.fromString("3e4eac5b-eaa2-4e0c-a705-dcac4f606e02")
+    val SERVICE_UUID: UUID? = UUID.fromString("791cadd7-de87-49f9-8986-94b7ae11940b")
+    val TIME_CHARACTERISTIC_UUID: UUID? = UUID.fromString("3e4eac5b-eaa2-4e0c-a705-dcac4f606e02")
 }

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

@@ -1,46 +0,0 @@
-package com.example.smart_watch_android
-
-import androidx.compose.foundation.background
-import androidx.compose.foundation.clickable
-import androidx.compose.foundation.layout.Box
-import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.foundation.layout.size
-import androidx.compose.foundation.shape.CircleShape
-import androidx.compose.material3.Text
-import androidx.compose.runtime.Composable
-import androidx.compose.ui.Alignment
-import androidx.compose.ui.Modifier
-import androidx.compose.ui.draw.clip
-import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.unit.dp
-import androidx.compose.ui.unit.sp
-
-@Composable
-fun ConnectCircleScreen(
-    isConnected: Boolean,
-    onConnectClick: () -> Unit
-) {
-    // Ein Container, der den gesamten Bildschirm ausfüllt
-    Box(
-        modifier = Modifier.fillMaxSize(),
-        contentAlignment = Alignment.Center // Zentriert den Inhalt exakt in der Mitte
-    ) {
-        // Der Kreis-Button
-        Box(
-            modifier = Modifier
-                .size(180.dp) // Größe des Kreises
-                .clip(CircleShape) // Macht das Element zu einem perfekten Kreis
-                .background(if (isConnected) Color.Green else Color.Blue) // Grün = verbunden, Blau = Start/Verbinden
-                .clickable { onConnectClick() }, // Was passiert beim Drücken
-            contentAlignment = Alignment.Center
-        ) {
-            Text(
-                text = if (isConnected) "Verbunden" else "Connect",
-                color = Color.White,
-                fontSize = 20.sp,
-                fontWeight = FontWeight.Bold
-            )
-        }
-    }
-}

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

@@ -1,13 +1,5 @@
 package com.example.smart_watch_android
 
-import android.Manifest
-import android.bluetooth.BluetoothGatt
-import android.bluetooth.BluetoothGattCallback
-import android.bluetooth.BluetoothGattCharacteristic
-import android.bluetooth.BluetoothManager
-import android.bluetooth.BluetoothProfile
-import android.content.Context
-import android.content.pm.PackageManager
 import android.os.Build
 import android.os.Bundle
 import android.util.Log
@@ -15,8 +7,10 @@ import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
 import androidx.annotation.RequiresApi
-import androidx.annotation.RequiresPermission
-import androidx.core.app.ActivityCompat
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.ui.Modifier
 import com.example.smart_watch_android.BLE.BleManager
 
 class MainActivity : ComponentActivity() {
@@ -29,13 +23,16 @@ class MainActivity : ComponentActivity() {
         bleManager.checkAndRequestBluetoothPermissions()
         enableEdgeToEdge()
         setContent {
-            ConnectCircleScreen(
-                isConnected = bleManager.isConnected,
-                onConnectClick = {
-                    Log.d("ESP32_BLE", "Button wurde gedrückt!")
-                    bleManager.connectToEsp32("10:BD:A3:8F:01:0E")
+            MaterialTheme {
+                Surface(
+                    modifier = Modifier.fillMaxSize(),
+                    color = MaterialTheme.colorScheme.background
+                ) {
+                    // Hier wird deine AppNavigation aufgerufen,
+                    // die die Screens steuert!
+                    AppNavigation(bleManager)
                 }
-            )
+            }
         }
     }
 }

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

@@ -0,0 +1,30 @@
+package com.example.smart_watch_android.Screens
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+
+@Composable
+fun ConnectScreen(isConnected: Boolean, onConnectClicked: () -> Unit) {
+    Box(
+        modifier = Modifier.fillMaxSize(),
+        contentAlignment = Alignment.Center
+    ) {
+        Button(
+            onClick = onConnectClicked,
+            colors = if (isConnected) {
+                ButtonDefaults.buttonColors(containerColor = Color(0xFF4CAF50)) // Grün
+            } else {
+                ButtonDefaults.buttonColors()
+            }
+        ) {
+            Text(text = if (isConnected) "Verbunden" else "Connect")
+        }
+    }
+}

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

@@ -0,0 +1,76 @@
+package com.example.smart_watch_android.Screens
+
+import androidx.compose.foundation.layout.Arrangement
+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.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.OutlinedTextField
+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 com.example.smart_watch_android.BLE.BleManager
+import com.example.smart_watch_android.BLE.DeviceUUIDs
+
+@Composable
+fun ControlPanelScreen(
+    bleManager: BleManager,
+    onDisconnectClicked: () -> Unit
+) {
+    var textInput by remember { mutableStateOf("") }
+
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .padding(16.dp),
+        verticalArrangement = Arrangement.Center,
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        // Eingabefeld für Text / Uhrzeit / Befehle
+        OutlinedTextField(
+            value = textInput,
+            onValueChange = { textInput = it },
+            label = { Text("Nachricht an ESP32") },
+            modifier = Modifier.fillMaxWidth()
+        )
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        // Send Button
+        Button(
+            onClick = {
+                if (textInput.isNotEmpty()) {
+                    bleManager.writeToEsp32(
+                        textInput, DeviceUUIDs.SERVICE_UUID, DeviceUUIDs.TIME_CHARACTERISTIC_UUID
+                    )
+                    textInput = "" // Feld danach leeren
+                }
+            },
+            modifier = Modifier.fillMaxWidth()
+        ) {
+            Text("Send")
+        }
+
+        Spacer(modifier = Modifier.height(32.dp))
+
+        // Disconnect Button (z.B. in Rot, um ihn abzusetzen)
+        Button(
+            onClick = onDisconnectClicked,
+            colors = ButtonDefaults.buttonColors(containerColor = Color(0xFFE53935)),
+            modifier = Modifier.fillMaxWidth()
+        ) {
+            Text("Disconnect")
+        }
+    }
+}

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

@@ -0,0 +1,67 @@
+package com.example.smart_watch_android
+
+import android.Manifest
+import androidx.annotation.RequiresPermission
+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.material3.Button
+import androidx.compose.material3.ButtonDefaults
+import androidx.compose.material3.OutlinedTextField
+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 com.example.smart_watch_android.BLE.BleManager
+import com.example.smart_watch_android.BLE.DeviceUUIDs
+import com.example.smart_watch_android.Screens.ConnectScreen
+import com.example.smart_watch_android.Screens.ControlPanelScreen
+
+enum class Screen {
+    CONNECT,
+    CONTROL_PANEL
+}
+@RequiresPermission(Manifest.permission.BLUETOOTH_CONNECT)
+@Composable
+fun AppNavigation(BLEManager: BleManager) {
+    var currentScreen by remember { mutableStateOf(Screen.CONNECT) }
+    val bleManager = BLEManager
+
+    if (bleManager.isConnected && currentScreen == Screen.CONNECT) {
+        currentScreen = Screen.CONTROL_PANEL
+    } else if (!bleManager.isConnected && currentScreen == Screen.CONTROL_PANEL) {
+        currentScreen = Screen.CONNECT
+    }
+
+    // Je nach Zustand den entsprechenden Screen anzeigen
+    when (currentScreen) {
+        Screen.CONNECT -> {
+            ConnectScreen(
+                isConnected = bleManager.isConnected,
+                onConnectClicked = {
+                    bleManager.connectToEsp32("10:BD:A3:8F:01:0E")
+                }
+            )
+        }
+        Screen.CONTROL_PANEL -> {
+            ControlPanelScreen(
+                bleManager,
+                onDisconnectClicked = {
+                    bleManager.disconnectEsp32()
+                    // Screen wechselt automatisch über den Check oben
+                }
+            )
+        }
+    }
+}