Activity Indicator Demo: Update start/stop activity button title based on state

Author: imthath-m

ios/FluentUI.Demo/FluentUI.Demo/Demos/ActivityIndicatorDemoController.swift

@@ -52,9 +52,9 @@ class ActivityIndicatorDemoController: DemoTableViewController {
                 return UITableViewCell()
             }
 
-            cell.setup(action1Title: row.title)
+            cell.setup(action1Title: activityActionButtonTitle)
             cell.action1Button.addTarget(self,
-                                         action: #selector(startStopActivity),
+                                         action: #selector(startStopActivity(_:)),
                                          for: .touchUpInside)
             cell.bottomSeparatorType = .full
             return cell
@@ -153,6 +153,8 @@ class ActivityIndicatorDemoController: DemoTableViewController {
         }
     }
 
+    private var activityActionButtonTitle: String { isAnimating ? "Stop Activity" : "Start Activity" }
+
     private var defaultColorIndicators: [MSFActivityIndicatorSize: MSFActivityIndicator] = {
         var defaultColorIndicators: [MSFActivityIndicatorSize: MSFActivityIndicator] = [:]
 
@@ -191,7 +193,7 @@ class ActivityIndicatorDemoController: DemoTableViewController {
             case .hidesWhenStopped:
                 return "Hides when stopped"
             case .startStopActivity:
-                return "Start / Stop activity"
+                return ""
             case .demoOfSize:
                 return ""
             }
@@ -233,8 +235,9 @@ class ActivityIndicatorDemoController: DemoTableViewController {
 
     private let xLargeSize: CGFloat = 36
 
-    @objc private func startStopActivity() {
+    @objc private func startStopActivity(_ sender: UIButton) {
         isAnimating.toggle()
+        sender.setTitle(activityActionButtonTitle, for: .normal)
     }
 }