From 9f550e8c3de62904db2651cacfc6685625edd41d Mon Sep 17 00:00:00 2001
From: Pete Schwamb <pete@schwamb.net>
Date: Tue, 8 Jan 2019 12:02:18 -0600
Subject: [PATCH] Allow the settings screen to update when new readings come in

---
 CGMBLEKit/TransmitterManager.swift            | 36 +++++++++++++++++++
 .../TransmitterSettingsViewController.swift   | 11 ++++++
 2 files changed, 47 insertions(+)

diff --git a/CGMBLEKit/TransmitterManager.swift b/CGMBLEKit/TransmitterManager.swift
index 1512858d..8ddfb806 100644
--- a/CGMBLEKit/TransmitterManager.swift
+++ b/CGMBLEKit/TransmitterManager.swift
@@ -41,9 +41,16 @@ public struct TransmitterManagerState: RawRepresentable, Equatable {
 }
 
 
+public protocol TransmitterManagerObserver: class {
+    func transmitterManagerDidUpdateLatestReading(_ manager: TransmitterManager)
+}
+
+
 public class TransmitterManager: TransmitterDelegate {
     private var state: TransmitterManagerState
 
+    private let observers = Locked(NSHashTable<AnyObject>.weakObjects())
+
     public required init(state: TransmitterManagerState) {
         self.state = state
         self.transmitter = Transmitter(id: state.transmitterID, passiveModeEnabled: state.passiveModeEnabled)
@@ -143,6 +150,7 @@ public class TransmitterManager: TransmitterDelegate {
             "dataIsFresh: \(dataIsFresh)",
             "providesBLEHeartbeat: \(providesBLEHeartbeat)",
             shareManager.debugDescription,
+            "observers.count: \(observers.value.count)",
             ""
         ].joined(separator: "\n")
     }
@@ -151,6 +159,8 @@ public class TransmitterManager: TransmitterDelegate {
         if let manager = self as? CGMManager {
             delegate?.cgmManager(manager, didUpdateWith: result)
         }
+
+        notifyObserversOfLatestReading()
     }
 
     // MARK: - TransmitterDelegate
@@ -221,6 +231,32 @@ public class TransmitterManager: TransmitterDelegate {
 }
 
 
+// MARK: - Observer management
+extension TransmitterManager {
+    public func addObserver(_ observer: TransmitterManagerObserver) {
+        _ = observers.mutate { (observerTable) in
+            observerTable.add(observer as AnyObject)
+        }
+    }
+
+    public func removeObserver(_ observer: TransmitterManagerObserver) {
+        _ = observers.mutate { (observerTable) in
+            observerTable.remove(observer as AnyObject)
+        }
+    }
+
+    private func notifyObserversOfLatestReading() {
+        let observers = self.observers.value.objectEnumerator()
+
+        for observer in observers {
+            if let observer = observer as? TransmitterManagerObserver {
+                observer.transmitterManagerDidUpdateLatestReading(self)
+            }
+        }
+    }
+}
+
+
 public class G5CGMManager: TransmitterManager, CGMManager {
     public static let managerIdentifier: String = "DexG5Transmitter"
 
diff --git a/CGMBLEKitUI/TransmitterSettingsViewController.swift b/CGMBLEKitUI/TransmitterSettingsViewController.swift
index 6fdde34b..0641d3ae 100644
--- a/CGMBLEKitUI/TransmitterSettingsViewController.swift
+++ b/CGMBLEKitUI/TransmitterSettingsViewController.swift
@@ -24,6 +24,8 @@ class TransmitterSettingsViewController: UITableViewController {
         self.glucoseUnit = glucoseUnit
 
         super.init(style: .grouped)
+
+        cgmManager.addObserver(self)
     }
 
     required init?(coder aDecoder: NSCoder) {
@@ -350,6 +352,15 @@ class TransmitterSettingsViewController: UITableViewController {
 }
 
 
+extension TransmitterSettingsViewController: TransmitterManagerObserver {
+    func transmitterManagerDidUpdateLatestReading(_ manager: TransmitterManager) {
+        DispatchQueue.main.async {
+            self.tableView.reloadData()
+        }
+    }
+}
+
+
 private extension UIAlertController {
     convenience init(cgmDeletionHandler handler: @escaping () -> Void) {
         self.init(