Add mechanism for opening up a threaded timeline

ElementX/Sources/Screens/ThreadTimelineScreen/ThreadTimelineScreenViewModel.swift

@@ -0,0 +1,31 @@
+//
+// Copyright 2022-2024 New Vector Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+// Please see LICENSE files in the repository root for full details.
+//
+
+import Combine
+import SwiftUI
+
+typealias ThreadTimelineScreenViewModelType = StateStoreViewModel<ThreadTimelineScreenViewState, ThreadTimelineScreenViewAction>
+
+class ThreadTimelineScreenViewModel: ThreadTimelineScreenViewModelType, ThreadTimelineScreenViewModelProtocol {
+    private let actionsSubject: PassthroughSubject<ThreadTimelineScreenViewModelAction, Never> = .init()
+    var actionsPublisher: AnyPublisher<ThreadTimelineScreenViewModelAction, Never> {
+        actionsSubject.eraseToAnyPublisher()
+    }
+
+    init() {
+        super.init(initialViewState: ThreadTimelineScreenViewState())
+    }
+    
+    // MARK: - Public
+    
+    override func process(viewAction: ThreadTimelineScreenViewAction) { }
+    
+    func stop() {
+        // Work around QLPreviewController dismissal issues, see the InteractiveQuickLookModifier.
+        state.bindings.mediaPreviewViewModel = nil
+    }
+}