expetion error

loc_chain_app/lib/util/bluetooth.dart

@@ -1,8 +1,7 @@
-import 'dart:io';
-import 'dart:math';
 import 'dart:typed_data';
 
 import 'package:flutter/material.dart';
+import 'package:flutter_udid/flutter_udid.dart';
 import 'package:nearby_connections/nearby_connections.dart';
 
 import 'package:shared_preferences/shared_preferences.dart';
@@ -11,20 +10,15 @@ import 'package:loc_chain_app/util/keyfile_manager.dart';
 import 'package:loc_chain_app/util/transaction_manager.dart';
 
 class Connect {
-  final serviceId = "com.yourdomain.appname";
-  final Strategy strategy = Strategy.P2P_STAR;
-  late final _userName;
-  final BuildContext? context;
+  static final serviceId = "com.yourdomain.appname";
+  static final Strategy strategy = Strategy.P2P_STAR;
+  static String _userName = "";
+  static BuildContext? context;
 
-  Map<String, ConnectionInfo> endpointMap = Map();
-  Map<String, Transaction> transactionMap = Map();
+  static Map<String, ConnectionInfo> endpointMap = Map();
+  static Map<String, Transaction> transactionMap = Map();
 
-  Connect({this.context}) {
-    SharedPreferences.getInstance()
-        .then((s) => _userName = s.getString('userName') ?? '0');
-  }
-
-  void showSnackbar(dynamic a) {
+  static void showSnackbar(dynamic a) {
     if (context == null) {
       return;
     }
@@ -33,78 +27,100 @@ class Connect {
     ));
   }
 
-  void startConnect() async {
+  static void stop() {
+    Nearby().stopAdvertising();
+    Nearby().stopDiscovery();
+    Nearby().stopAllEndpoints();
+  }
+
+  static void start() async {
+    _userName = await FlutterUdid.consistentUdid;
     // final prefs = await SharedPreferences.getInstance();
     // final userName = prefs.getString('userName') ?? " ";
 
-    try {
-      bool advertise = await Nearby().startAdvertising(
-        _userName,
-        strategy,
-        onConnectionInitiated: onConnectionInit,
-        onConnectionResult: (String id, Status status) async {
-          // Called when connection is accepted/rejected
-          // if connection is accepted send the transaction
-          if (status != Status.CONNECTED) {
-            return;
-          }
-          // Connected to other device, send combined hash and pub key
-          String str = await Transaction.generateHash(id);
-          Nearby().sendBytesPayload(id, Uint8List.fromList(str.codeUnits));
-        },
-        onDisconnected: (String id) {
-          // Callled whenever a discoverer disconnects from advertiser
-          // delete connection info
-          endpointMap.remove(id);
-          // delete transaction info
-          transactionMap.remove(id);
-        },
-        serviceId: serviceId, // uniquely identifies your app
-      );
+    Nearby().startAdvertising(
+      _userName,
+      strategy,
+      onConnectionInitiated: onConnectionInit,
+      onConnectionResult: (String id, Status status) async {
+        // Called when connection is accepted/rejected
+        // if connection is accepted send the transaction
+        if (status != Status.CONNECTED) {
+          return;
+        }
+        // Connected to other device, send combined hash and pub key
+        String str = await Transaction.generateHash(id);
+        print(str);
+        Nearby().sendBytesPayload(id, Uint8List.fromList(str.codeUnits));
+      },
+      onDisconnected: (String id) {
+        // Callled whenever a discoverer disconnects from advertiser
+        // delete connection info
+        endpointMap.remove(id);
+        // delete transaction info
+        transactionMap.remove(id);
+      },
+      serviceId: serviceId, // uniquely identifies your app
+    ).catchError((e) {
+      print(e);
+      return true;
+    });
 
-      bool discovery = await Nearby().startDiscovery(
-        _userName,
-        strategy,
-        onEndpointFound: (String id, String userName, String serviceId) {
-          // called when an advertiser is found
-          Nearby().requestConnection(
-            userName,
-            id,
-            onConnectionInitiated: onConnectionInit,
-            onConnectionResult: (String id, Status status) async {
-              // Called when connection is accepted/rejected
-              // if connection is accepted send the transaction
-              if (status != Status.CONNECTED) {
-                return;
-              }
-              // Connected to other device, send combined hash and pub key
-              String str = await Transaction.generateHash(id);
-              Nearby().sendBytesPayload(id, Uint8List.fromList(str.codeUnits));
-            },
-            onDisconnected: (id) {
-              endpointMap.remove(id);
-              showSnackbar(
-                  "Disconnected from: ${endpointMap[id]!.endpointName}, id $id");
-            },
-          );
-        },
-        onEndpointLost: (String? id) {
-          //called when an advertiser is lost (only if we weren't connected to it )
-        },
-        serviceId: serviceId, // uniquely identifies your app
-      );
-    } catch (exception) {
-      // platform exceptions like unable to start bluetooth or insufficient permissions
-    }
+    Nearby().startDiscovery(
+      _userName,
+      strategy,
+      onEndpointFound: (String id, String userName, String serviceId) {
+        // called when an advertiser is found
+        Nearby().requestConnection(
+          userName,
+          id,
+          onConnectionInitiated: onConnectionInit,
+          onConnectionResult: (String id, Status status) async {
+            // Called when connection is accepted/rejected
+            // if connection is accepted send the transaction
+            if (status != Status.CONNECTED) {
+              return;
+            }
+            // Connected to other device, send combined hash and pub key
+            String str = await Transaction.generateHash(id);
+            Nearby()
+                .sendBytesPayload(id, Uint8List.fromList(str.codeUnits))
+                .catchError((e) {
+              print(e);
+            });
+          },
+          onDisconnected: (id) {
+            endpointMap.remove(id);
+            print(
+                "Disconnected from: ${endpointMap[id]!.endpointName}, id $id");
+          },
+        ).catchError((e) {
+          print(e);
+          return true;
+        });
+      },
+      onEndpointLost: (String? id) {
+        //called when an advertiser is lost (only if we weren't connected to it )
+      },
+      serviceId: serviceId, // uniquely identifies your app
+    ).catchError((e) {
+      print(e);
+      return true;
+    });
   }
 
-  void onConnectionInit(String otherId, ConnectionInfo info) {
+  static void onConnectionInit(String otherId, ConnectionInfo info) {
+    print('Connection initialized with $otherId');
     // Called whenever a discoverer requests connection
     //
     // onConnectionInit
     if (endpointMap.containsKey(otherId)) {
+      print('Connection rejected to/from $otherId');
       Nearby().rejectConnection(otherId);
+      return;
     }
+    print('Connection accepted to/from $otherId');
+
     endpointMap[otherId] = info;
     Nearby().acceptConnection(
       otherId,
@@ -114,7 +130,7 @@ class Connect {
         String str = String.fromCharCodes(payload.bytes!);
         var parts = str.split(':');
         if (parts.length != 2) {
-          showSnackbar("$_otherId invalid payload: $str");
+          print("$_otherId invalid payload: $str");
           return;
         }
         // Store transaction
@@ -123,7 +139,6 @@ class Connect {
         transactionMap[_otherId] =
             Transaction(hash: combinedHash, pubKey: publicKey);
         // sign combined hash with our private key
-        showSnackbar('Received $_otherId payload: $combinedHash');
         print('Received $_otherId payload: $combinedHash:$publicKey');
         // upload hash+otherKey to firebase
       },
@@ -131,14 +146,16 @@ class Connect {
         if (payloadTransferUpdate.status == PayloadStatus.IN_PROGRESS) {
           print(payloadTransferUpdate.bytesTransferred);
         } else if (payloadTransferUpdate.status == PayloadStatus.FAILURE) {
-          print("failed");
-          showSnackbar(endid + ": FAILED to transfer file");
+          print(endid + ": FAILED to transfer file");
         } else if (payloadTransferUpdate.status == PayloadStatus.SUCCESS) {
-          showSnackbar(
+          print(
               "$endid success, total bytes = ${payloadTransferUpdate.totalBytes}");
         }
       },
-    );
+    ).catchError((e) {
+      print(e);
+      return true;
+    });
   }
 }