KVO Support (#96)

* added @objc specificator to 'isScanning' property to make it trackable by KVO

* added @objc to internal property

* change the nature of `isScanning` property: now it's not a computed value but dynamic property which gives an ability to track it using KVO.
In `CBMCentralManagerNative` added observer that pass updates from `CBCentralManager.isScanning` to `CBMCentralManagerNative.isScanning`

* added observer for peripheral state
added `value` for async getting first value from peripheral stream

* code cleanup

---------

Co-authored-by: Nick Kibysh <nick.kibysh@gmail.com>

Author: NickKibish

CoreBluetoothMock/CBMCentralManager.swift

@@ -92,7 +92,7 @@ open class CBMCentralManager: NSObject {
 
     /// Whether or not the central is currently scanning.
     @available(iOS 9.0, *)
-    open var isScanning: Bool { return false }
+    @objc dynamic open internal(set) var isScanning: Bool = false
 
     /// The current authorization status for using Bluetooth.
     ///

CoreBluetoothMock/CBMCentralManagerMock.swift

@@ -81,7 +81,7 @@ open class CBMCentralManagerMock: CBMCentralManager {
             // ...stop scanning if state changed to any other state
             // than `.poweredOn`. Also, forget all peripherals.
             if manager.state != .poweredOn {
-                manager._isScanning = false
+                manager.isScanning = false
                 manager.scanFilter = nil
                 manager.scanOptions = nil
                 manager.peripherals.values.forEach { $0.closeManager() }
@@ -123,6 +123,7 @@ open class CBMCentralManagerMock: CBMCentralManager {
     ///   - config: Advertisement configuration to start.
     ///   - mock: The advertising mock peripheral.
     private static func startAdvertising(_ config: CBMAdvertisementConfig, for mock: CBMPeripheralSpec) {
+        
         // A valid advertising config is a single time advertisement (delay > 0),
         // or a periodic one (interval > 0) (or both - delayed periodic advertisement).
         // Not to be mistaken with "Periodic Advertisement" from Advertising Extension.
@@ -287,21 +288,17 @@ open class CBMCentralManagerMock: CBMCentralManager {
             CBMCentralManagerMock.managers.contains { $0.ref == self }
         }
     }
-    /// A flag set to true when the manager is scanning for mock Bluetooth LE devices.
-    private var _isScanning: Bool
 
     // MARK: - Initializers
 
     public init() {
-        self._isScanning = false
         self.queue = DispatchQueue.main
         super.init(true)
         initialize()
     }
 
     public init(delegate: CBMCentralManagerDelegate?,
                 queue: DispatchQueue?) {
-        self._isScanning = false
         self.queue = queue ?? DispatchQueue.main
         super.init(true)
         self.delegate = delegate
@@ -312,7 +309,6 @@ open class CBMCentralManagerMock: CBMCentralManager {
     public init(delegate: CBMCentralManagerDelegate?,
                 queue: DispatchQueue?,
                 options: [String : Any]?) {
-        self._isScanning = false
         self.queue = queue ?? DispatchQueue.main
         super.init(true)
         self.delegate = delegate
@@ -652,9 +648,7 @@ open class CBMCentralManagerMock: CBMCentralManager {
         }
         return CBMCentralManagerMock.managerState
     }
-    open override var isScanning: Bool {
-        return _isScanning
-    }
+    
 
     @available(iOS, introduced: 13.0, deprecated: 13.1)
     @available(macOS, introduced: 10.15)
@@ -685,15 +679,15 @@ open class CBMCentralManagerMock: CBMCentralManager {
                                           options: [String : Any]? = nil) {
         // Central manager must be in powered on state.
         guard ensurePoweredOn() else { return }
-        _isScanning = true
+        isScanning = true
         scanFilter = serviceUUIDs
         scanOptions = options
     }
 
     open override func stopScan() {
         // Central manager must be in powered on state.
         guard ensurePoweredOn() else { return }
-        _isScanning = false
+        isScanning = false
         scanFilter = nil
         scanOptions = nil
         peripherals.values.forEach { $0.wasScanned = false }
@@ -879,7 +873,7 @@ open class CBMCentralManagerMock: CBMCentralManager {
 /// This implementation will be used when creating peripherals by ``CBMCentralManagerMock``.
 ///
 /// Unless required, this class should not be accessed directly, but rather by the common protocol ``CBMPeripheral``.
-open class CBMPeripheralMock: CBMPeer, CBMPeripheral {
+@objc open class CBMPeripheralMock: CBMPeer, CBMPeripheral {
     /// The parent central manager.
     private let manager: CBMCentralManagerMock
     /// The dispatch queue to call delegate methods on.
@@ -923,7 +917,7 @@ open class CBMPeripheralMock: CBMPeer, CBMPeripheral {
         return _canSendWriteWithoutResponse
     }
     open private(set) var ancsAuthorized: Bool = false
-    open fileprivate(set) var state: CBMPeripheralState = .disconnected
+    @objc dynamic open fileprivate(set) var state: CBMPeripheralState = .disconnected
     open private(set) var services: [CBMService]? = nil
 
     // MARK: Initializers

CoreBluetoothMock/CBMCentralManagerNative.swift

@@ -35,7 +35,8 @@ import CoreBluetooth
 ///
 /// This manager can only interact with physical Bluetooth LE devices.
 public class CBMCentralManagerNative: CBMCentralManager {
-    private var manager: CBCentralManager!
+    var observation: NSKeyValueObservation?
+    @objc dynamic private var manager: CBCentralManager!
     private var wrapper: CBCentralManagerDelegate!
     private var peripherals: [UUID : CBMPeripheralNative] = [:]
 
@@ -140,7 +141,12 @@ public class CBMCentralManagerNative: CBMCentralManager {
 
     @available(iOS 9.0, *)
     public override var isScanning: Bool {
-        return manager.isScanning
+        get {
+            manager.isScanning
+        }
+        set {
+            
+        }
     }
 
     @available(iOS, introduced: 13.0, deprecated: 13.1)
@@ -168,6 +174,8 @@ public class CBMCentralManagerNative: CBMCentralManager {
         self.wrapper = CBMCentralManagerDelegateWrapper(self)
         self.manager = CBCentralManager()
         self.manager.delegate = wrapper
+        
+        self.addManagerObserver()
     }
 
     public init(delegate: CBMCentralManagerDelegate?,
@@ -176,6 +184,8 @@ public class CBMCentralManagerNative: CBMCentralManager {
         self.wrapper = CBMCentralManagerDelegateWrapper(self)
         self.manager = CBCentralManager(delegate: wrapper, queue: queue)
         self.delegate = delegate
+        
+        self.addManagerObserver()
     }
 
     @available(iOS 7.0, *)
@@ -189,6 +199,8 @@ public class CBMCentralManagerNative: CBMCentralManager {
             CBMCentralManagerDelegateWrapper(self)
         self.manager = CBCentralManager(delegate: wrapper, queue: queue, options: options)
         self.delegate = delegate
+        
+        self.addManagerObserver()
     }
 
     public override func scanForPeripherals(withServices serviceUUIDs: [CBMUUID]?,
@@ -238,6 +250,15 @@ public class CBMCentralManagerNative: CBMCentralManager {
         manager.registerForConnectionEvents(options: options)
     }
     #endif
+    
+    /// Add observer for `\.CBCentralManager.isScanning`  and change `Self.isScanning` correspondingly.
+    private func addManagerObserver() {
+        observation = observe(\.manager?.isScanning, options: [.old, .new]) { _, change in
+            change.newValue?.flatMap { [weak self] new in
+                self?.isScanning = new
+            }
+        }
+    }
 }
 
 /// A native implementation of ``CBMPeripheral`` that will proxy all requests to an underlying `CBPeripheral`.
@@ -505,7 +526,7 @@ public class CBMPeripheralNative: CBMPeer, CBMPeripheral {
     }
     #endif
 
-    fileprivate let peripheral: CBPeripheral
+    public let peripheral: CBPeripheral
 
     fileprivate init(_ peripheral: CBPeripheral) {
         self.peripheral = peripheral

CoreBluetoothMock/CBMPeripheralPreview.swift

@@ -39,7 +39,7 @@ import CoreBluetooth
 /// All ``CBMService``s are available immediately, without the need for service discovery.
 /// Bluetooth LE operations are NO OP. The device does not need to be scanned to
 /// be retrievable by any ``CBMCentralManagerMock`` instance.
-open class CBMPeripheralPreview: CBMPeripheral {
+@objc open class CBMPeripheralPreview: NSObject, CBMPeripheral {
     private let mock: CBMPeripheralSpec
 
     public let identifier: UUID
@@ -49,7 +49,7 @@ open class CBMPeripheralPreview: CBMPeripheral {
     public var services: [CBMService]?
 
     public var delegate: CBMPeripheralDelegate?
-    public internal(set) var state: CBMPeripheralState
+    @objc dynamic public internal(set) var state: CBMPeripheralState
 
     public let canSendWriteWithoutResponse: Bool = true
     public let ancsAuthorized: Bool = false
@@ -63,6 +63,7 @@ open class CBMPeripheralPreview: CBMPeripheral {
         self.mock = mock
         self.identifier = mock.identifier
         self.state = state
+        super.init()
         self.services = mock.services?.map { CBMService(copy: $0, for: self) }
         CBMCentralManagerMock.registerForPreviews(self)
     }
@@ -118,7 +119,7 @@ open class CBMPeripheralPreview: CBMPeripheral {
         fatalError("Not available")
     }
 }
-
+/*
 extension CBMPeripheralPreview: Hashable {
 
     public static func == (lhs: CBMPeripheralPreview, rhs: CBMPeripheralPreview) -> Bool {
@@ -130,3 +131,4 @@ extension CBMPeripheralPreview: Hashable {
     }
 
 }
+*/