feat: close connection

android/src/main/java/id/kalanusa/flutter_zsdk/FlutterZsdkPlugin.java

@@ -95,6 +95,7 @@ public class FlutterZsdkPlugin implements FlutterPlugin, MethodCallHandler, Acti
     switch(call.method) {
       case "bluetoothOpenConnection":
       case "isConnected":
+      case "bluetoothCloseConnection":
         if (bluetoothConnectionHandler == null) {
           bluetoothConnectionHandler = new BluetoothConnectionHandler(bluetoothConnectionHolder);
         }

android/src/main/java/id/kalanusa/flutter_zsdk/bluetoothconnectionhandler/BluetoothConnectionHandler.java

@@ -34,6 +34,10 @@ public class BluetoothConnectionHandler {
             case "isConnected":
                 checkConnection(result);
                 break;
+
+            case "bluetoothCloseConnection":
+                closeConnection(result);
+                break;
         }
     }
 
@@ -68,5 +72,20 @@ public class BluetoothConnectionHandler {
         }).start();
     }
 
+    public void closeConnection(@NonNull MethodChannel.Result result) {
+        new Thread(new Runnable() {
+            @Override
+            public void run() {
+                try {
+                    bluetoothConnectionHolder.connection.close();
+                    result.success(null);
+                } catch (ConnectionException e) {
+                    Log.w("From Native (Android)", "something went wrong when closing connection");
+                    result.error("CLOSE_CONNECTION_ERROR", "Something went wrong while closing the connection", e.getMessage());
+                }
+            }
+        }).start();
+    }
+
 
 }

example/lib/main.dart

@@ -26,6 +26,7 @@ class _MyAppState extends State<MyApp> {
   String? _connectedPrinter;
   final _flutterZsdkPlugin = FlutterZsdk();
   String? _selectedBluetoothPrinterMacAddress;
+  bool _disconnecting = false;
 
   @override
   void initState() {
@@ -127,6 +128,29 @@ class _MyAppState extends State<MyApp> {
     setState(() {});
   }
 
+  Future<void> closeConnection() async {
+    print('invoked closeConnection from dart');
+    try {
+      setState(() {
+        _disconnecting = true;
+      });
+      await _flutterZsdkPlugin.closeConnection(); 
+      _connectedPrinter = null;
+      _disconnecting = false;
+      print('Connection closed successfully from dart');
+      
+    } on FlutterZsdkException catch (e) {
+      inspect(e);
+      showSnackBar(e.message);
+
+    } catch (e) {
+      inspect(e);
+      showSnackBar('Unexpected error while disconnecting bluetooth printers');
+    }
+
+    setState(() {});
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -148,6 +172,12 @@ class _MyAppState extends State<MyApp> {
             ),
             SizedBox(height: 20),
 
+            ElevatedButton(
+              child: Text(_disconnecting ? 'Disconnecting...' : 'Disconnect from $_connectedPrinter'),
+              onPressed: _connectedPrinter == null || _disconnecting ? null : closeConnection,
+            ),
+            SizedBox(height: 20),
+
             ElevatedButton(
               child: Text('Check connection status'),
               onPressed: () async {

lib/flutter_zsdk.dart

@@ -20,4 +20,8 @@ class FlutterZsdk {
   Future<bool> isConnected() {
     return FlutterZsdkPlatform.instance.isConnected();
   }
+
+  Future<void> closeConnection() {
+    return FlutterZsdkPlatform.instance.closeConnection();
+  }
 }

lib/src/flutter_zsdk_method_channel.dart

@@ -104,4 +104,13 @@ class MethodChannelFlutterZsdk extends FlutterZsdkPlatform {
 
     return isConnected;
   }
+
+  @override
+  Future<void> closeConnection() async {
+    try {
+      await methodChannel.invokeMethod('bluetoothCloseConnection');
+    } catch (e) {
+      throw FlutterZsdkException("Failed to close connection to printer: $e");
+    }
+  }
 }

lib/src/flutter_zsdk_platform_interface.dart

@@ -39,4 +39,8 @@ abstract class FlutterZsdkPlatform extends PlatformInterface {
   Future<bool> isConnected() {
     throw UnimplementedError('isConnected() has not been implemented.');
   }
+
+  Future<void> closeConnection() {
+    throw UnimplementedError('closeConnection() has not been implemented.');
+  }
 }