Navigate to the Pinned events timeline (#3139)

ElementX/Sources/Screens/PinnedEventsTimelineScreen/PinnedEventsTimelineScreenCoordinator.swift

@@ -0,0 +1,61 @@
+//
+// Copyright 2022 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Combine
+import SwiftUI
+
+struct PinnedEventsTimelineScreenCoordinatorParameters { }
+
+enum PinnedEventsTimelineScreenCoordinatorAction {
+    case dismiss
+    
+    // Consider adding CustomStringConvertible conformance if the actions contain PII
+}
+
+final class PinnedEventsTimelineScreenCoordinator: CoordinatorProtocol {
+    private let parameters: PinnedEventsTimelineScreenCoordinatorParameters
+    private let viewModel: PinnedEventsTimelineScreenViewModelProtocol
+    
+    private var cancellables = Set<AnyCancellable>()
+ 
+    private let actionsSubject: PassthroughSubject<PinnedEventsTimelineScreenCoordinatorAction, Never> = .init()
+    var actions: AnyPublisher<PinnedEventsTimelineScreenCoordinatorAction, Never> {
+        actionsSubject.eraseToAnyPublisher()
+    }
+    
+    init(parameters: PinnedEventsTimelineScreenCoordinatorParameters) {
+        self.parameters = parameters
+        
+        viewModel = PinnedEventsTimelineScreenViewModel()
+    }
+    
+    func start() {
+        viewModel.actionsPublisher.sink { [weak self] action in
+            MXLog.info("Coordinator: received view model action: \(action)")
+            
+            guard let self else { return }
+            switch action {
+            case .dismiss:
+                self.actionsSubject.send(.dismiss)
+            }
+        }
+        .store(in: &cancellables)
+    }
+        
+    func toPresentable() -> AnyView {
+        AnyView(PinnedEventsTimelineScreen(context: viewModel.context))
+    }
+}