Merge commit '7621e2f8dec938cf48181c8b10afc9b01f444e68' into beta

submodules/TelegramUI/Sources/ChatHistoryNode.swift

@@ -0,0 +1,36 @@
+import Foundation
+import UIKit
+import AsyncDisplayKit
+import Postbox
+import SwiftSignalKit
+import Display
+import ChatPresentationInterfaceState
+import AccountContext
+
+public enum ChatHistoryNodeLoadState: Equatable {
+    public enum EmptyType: Equatable {
+        case generic
+        case joined
+        case clearedHistory
+        case topic
+        case botInfo
+    }
+    
+    case loading(Bool)
+    case empty(EmptyType)
+    case messages
+}
+
+public protocol ChatHistoryNode: AnyObject {
+    var historyState: ValuePromise<ChatHistoryNodeHistoryState> { get }
+    var preloadPages: Bool { get set }
+    
+    var loadState: ChatHistoryNodeLoadState? { get }
+    func setLoadStateUpdated(_ f: @escaping (ChatHistoryNodeLoadState, Bool) -> Void)
+    
+    func messageInCurrentHistoryView(_ id: MessageId) -> Message?
+    func updateLayout(transition: ContainedViewLayoutTransition, updateSizeAndInsets: ListViewUpdateSizeAndInsets)
+    func forEachItemNode(_ f: (ASDisplayNode) -> Void)
+    func disconnect()
+    func scrollToEndOfHistory()
+}