Background scanning and restoration

Demo/ReliaBLE Demo/ReliaBLE Demo/Central/CentralView.swift

@@ -97,15 +97,25 @@ struct CentralView: View {
                 }
                 .buttonStyle(.bordered)
             } else if case BluetoothState.ready = viewModel.currentState {
-                TextField("Enter service UUIDs (comma-separated)", text: $viewModel.servicesInput)
+                TextField("Service UUIDs (comma-separated; required for background)", text: $viewModel.servicesInput)
                     .textFieldStyle(.roundedBorder)
-                    .padding()
+                    .padding(.horizontal)
+
+                Text("Background discovery needs a non-empty service filter. Connect with Auto Reconnect on, then background/force-quit — restored connections reappear on relaunch.")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+                    .padding(.horizontal)
 
                 Button("Start Scanning") {
                     viewModel.startScanning()
                 }
                 .buttonStyle(.bordered)
             } else if case BluetoothState.scanning = viewModel.currentState {
+                Text("Scanning (continues in background when a service filter is set)")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+                    .padding(.horizontal)
+
                 Button("Stop Scanning") {
                     viewModel.stopScanning()
                 }
@@ -181,7 +191,15 @@ struct CentralView: View {
                         reliaBLE: reliaBLE
                     )
                 } label: {
-                    Text("\(device.name ?? "Unknown")")
+                    HStack {
+                        Text("\(device.name ?? "Unknown")")
+                        Spacer()
+                        if let state = viewModel.connectionStates[device.id] {
+                            Text(state.description)
+                                .font(.caption)
+                                .foregroundStyle(state.color)
+                        }
+                    }
                 }
             }
             .onDelete { offsets in
@@ -260,6 +278,13 @@ private struct DeviceDetailView: View {
 
             Toggle("Auto Reconnect:", isOn: $autoReconnect)
                 .disabled(connectionState.map { !$0.canEditAutoReconnect } ?? false)
+
+            if isActive {
+                Text("Standing connection: leave Auto Reconnect on, background or force-quit the app, then relaunch — restored state shows here via connectionStateChanges.")
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+                    .multilineTextAlignment(.center)
+            }
         }
         .padding()
     }

Demo/ReliaBLE Demo/ReliaBLE Demo/Central/CentralViewModel.swift

@@ -32,7 +32,8 @@ import ReliaBLE
 
 @Observable class CentralViewModel {
     var currentState: BluetoothState = .unknown
-    var servicesInput = ""
+    /// Defaults to the Demo peripheral service UUID so background scans have a required filter.
+    var servicesInput = "12345678-90AB-CDEF-1234-567890ABCDEF"
     var connectionStates: [String: ConnectionState] = [:]
 
     private var deviceStore: DeviceStoreActor?

Demo/ReliaBLE Demo/ReliaBLE Demo/ReliaBLE_DemoApp.swift

@@ -60,15 +60,17 @@ struct ReliaBLE_DemoApp: App {
         config.logWriters = [OSLogWriter(subsystem: "com.five3apps.relia-ble-demo", category: "BLE")]
         config.logQueue = DispatchQueue(label: "com.five3apps.relia-ble-demo.logging", qos: .utility)
         config.loggingEnabled = true
-
+        // Stable across launches so CoreBluetooth can restore scans/connections after termination.
+        config.restoreIdentifier = "com.five3apps.relia-ble-demo.central"
+
         let defaults = UserDefaults.standard
         var reconnectPolicy = ReconnectPolicy()
         reconnectPolicy.maxAttempts = defaults.object(forKey: "reconnectPolicy.maxAttempts") as? Int ?? 5
         reconnectPolicy.initialDelay = defaults.object(forKey: "reconnectPolicy.initialDelay") as? Double ?? 1.0
         reconnectPolicy.maxDelay = defaults.object(forKey: "reconnectPolicy.maxDelay") as? Double ?? 30.0
         reconnectPolicy.jitter = defaults.object(forKey: "reconnectPolicy.jitter") as? Double ?? 0.2
         config.reconnectPolicy = reconnectPolicy
-        
+
         return ReliaBLEManager(config: config)
     }()
 

Demo/ReliaBLE Demo/ReliaBLE-Demo-Info.plist

@@ -3,6 +3,10 @@
 <plist version="1.0">
 <dict>
     <key>NSBluetoothAlwaysUsageDescription</key>
-    <string>This app uses Bluetooth to advertise as a peripheral.</string>
+    <string>This app uses Bluetooth to scan for and connect to nearby peripherals, and to advertise as a peripheral.</string>
+    <key>UIBackgroundModes</key>
+    <array>
+        <string>bluetooth-central</string>
+    </array>
 </dict>
 </plist>