New timeline items (#424)

* Cleanup session verification state machine configuration

* Add support for new timeline items: loading indicators, stickers and invalid/unsupported events

* Add sticker accessibility label, fix session verification ones

* Add support for the new TimelineStart timeline item and new pagination API. Remove identifiers from individual timeline items and only set them in the TimelineTableViewController

* Add changelog

ElementX/Sources/Screens/SessionVerification/SessionVerificationStateMachine.swift

@@ -79,50 +79,54 @@ class SessionVerificationStateMachine {
     }
 
     init() {
-        stateMachine = StateMachine(state: .initial) { machine in
-            machine.addRoutes(event: .requestVerification, transitions: [.initial => .requestingVerification])
-            machine.addRoutes(event: .didAcceptVerificationRequest, transitions: [.requestingVerification => .verificationRequestAccepted])
-            machine.addRoutes(event: .startSasVerification, transitions: [.verificationRequestAccepted => .startingSasVerification])
-            machine.addRoutes(event: .didFail, transitions: [.requestingVerification => .initial])
-            machine.addRoutes(event: .restart, transitions: [.cancelled => .initial])
-            
-            // Transitions with associated values need to be handled through `addRouteMapping`
-            machine.addRouteMapping { event, fromState, _ in
-                switch (event, fromState) {
-                case (.didStartSasVerification, _):
-                    return .sasVerificationStarted
-                    
-                case (.didReceiveChallenge(let emojis), .sasVerificationStarted):
-                    return .showingChallenge(emojis: emojis)
-                case (.acceptChallenge, .showingChallenge(let emojis)):
-                    return .acceptingChallenge(emojis: emojis)
-                case (.didFail, .acceptingChallenge(let emojis)):
-                    return .showingChallenge(emojis: emojis)
+        stateMachine = StateMachine(state: .initial)
+        configure()
+    }
+    
+    // swiftlint:disable:next cyclomatic_complexity
+    private func configure() {
+        stateMachine.addRoutes(event: .requestVerification, transitions: [.initial => .requestingVerification])
+        stateMachine.addRoutes(event: .didAcceptVerificationRequest, transitions: [.requestingVerification => .verificationRequestAccepted])
+        stateMachine.addRoutes(event: .startSasVerification, transitions: [.verificationRequestAccepted => .startingSasVerification])
+        stateMachine.addRoutes(event: .didFail, transitions: [.requestingVerification => .initial])
+        stateMachine.addRoutes(event: .restart, transitions: [.cancelled => .initial])
+        
+        // Transitions with associated values need to be handled through `addRouteMapping`
+        stateMachine.addRouteMapping { event, fromState, _ in
+            switch (event, fromState) {
+            case (.didStartSasVerification, _):
+                return .sasVerificationStarted
                 
-                case (.didAcceptChallenge, .acceptingChallenge):
-                    return .verified
+            case (.didReceiveChallenge(let emojis), .sasVerificationStarted):
+                return .showingChallenge(emojis: emojis)
+            case (.acceptChallenge, .showingChallenge(let emojis)):
+                return .acceptingChallenge(emojis: emojis)
+            case (.didFail, .acceptingChallenge(let emojis)):
+                return .showingChallenge(emojis: emojis)
                 
-                case (.declineChallenge, .showingChallenge(let emojis)):
-                    return .decliningChallenge(emojis: emojis)
-                case (.didFail, .decliningChallenge(let emojis)):
-                    return .showingChallenge(emojis: emojis)
+            case (.didAcceptChallenge, .acceptingChallenge):
+                return .verified
                 
-                case (.cancel, _):
-                    return .cancelling
-                case (.didCancel, _):
-                    return .cancelled
-                    
-                default:
-                    return nil
-                }
+            case (.declineChallenge, .showingChallenge(let emojis)):
+                return .decliningChallenge(emojis: emojis)
+            case (.didFail, .decliningChallenge(let emojis)):
+                return .showingChallenge(emojis: emojis)
+                
+            case (.cancel, _):
+                return .cancelling
+            case (.didCancel, _):
+                return .cancelled
+                
+            default:
+                return nil
             }
-            
-            addTransitionHandler { context in
-                if let event = context.event {
-                    MXLog.info("Transitioning from `\(context.fromState)` to `\(context.toState)` with event `\(event)`")
-                } else {
-                    MXLog.info("Transitioning from \(context.fromState)` to `\(context.toState)`")
-                }
+        }
+        
+        addTransitionHandler { context in
+            if let event = context.event {
+                MXLog.info("Transitioning from `\(context.fromState)` to `\(context.toState)` with event `\(event)`")
+            } else {
+                MXLog.info("Transitioning from \(context.fromState)` to `\(context.toState)`")
             }
         }
     }

ElementX/Sources/Screens/SessionVerification/View/SessionVerificationScreen.swift

@@ -125,13 +125,13 @@ struct SessionVerificationScreen: View {
                     Label(ElementL10n.verificationSasMatch, systemImage: "checkmark")
                 }
                 .buttonStyle(.elementAction(.xLarge))
-                .accessibilityLabel("challengeAcceptButton")
+                .accessibilityIdentifier("challengeAcceptButton")
                 
                 Button(ElementL10n.verificationSasDoNotMatch) {
                     context.send(viewAction: .decline)
                 }
                 .font(.element.bodyBold)
-                .accessibilityLabel("challengeDeclineButton")
+                .accessibilityIdentifier("challengeDeclineButton")
             }
         
         case .verified: