import Foundation import UIKit import Display import AsyncDisplayKit import Postbox import TelegramCore import SyncCore import SwiftSignalKit import TelegramPresentationData import MergeLists import ItemListUI import PresentationDataUtils import AccountContext import ShareController import SearchBarNode import SearchUI import ActivityIndicator private enum LanguageListSection: ItemListSectionId { case official case unofficial } private enum LanguageListEntryId: Hashable { case search case localization(String) } private enum LanguageListEntryType { case official case unofficial } private enum LanguageListEntry: Comparable, Identifiable { case localization(index: Int, info: LocalizationInfo, type: LanguageListEntryType, selected: Bool, activity: Bool, revealed: Bool, editing: Bool) var stableId: LanguageListEntryId { switch self { case let .localization(_, info, _, _, _, _, _): return .localization(info.languageCode) } } private func index() -> Int { switch self { case let .localization(index, _, _, _, _, _, _): return index } } static func <(lhs: LanguageListEntry, rhs: LanguageListEntry) -> Bool { return lhs.index() < rhs.index() } func item(presentationData: PresentationData, searchMode: Bool, openSearch: @escaping () -> Void, selectLocalization: @escaping (LocalizationInfo) -> Void, setItemWithRevealedOptions: @escaping (String?, String?) -> Void, removeItem: @escaping (String) -> Void) -> ListViewItem { switch self { case let .localization(_, info, type, selected, activity, revealed, editing): return LocalizationListItem(presentationData: ItemListPresentationData(presentationData), id: info.languageCode, title: info.title, subtitle: info.localizedTitle, checked: selected, activity: activity, editing: LocalizationListItemEditing(editable: !selected && !searchMode && !info.isOfficial, editing: editing, revealed: !selected && revealed, reorderable: false), sectionId: type == .official ? LanguageListSection.official.rawValue : LanguageListSection.unofficial.rawValue, alwaysPlain: searchMode, action: { selectLocalization(info) }, setItemWithRevealedOptions: setItemWithRevealedOptions, removeItem: removeItem) } } } private struct LocalizationListSearchContainerTransition { let deletions: [ListViewDeleteItem] let insertions: [ListViewInsertItem] let updates: [ListViewUpdateItem] let isSearching: Bool } private func preparedLanguageListSearchContainerTransition(presentationData: PresentationData, from fromEntries: [LanguageListEntry], to toEntries: [LanguageListEntry], selectLocalization: @escaping (LocalizationInfo) -> Void, isSearching: Bool, forceUpdate: Bool) -> LocalizationListSearchContainerTransition { let (deleteIndices, indicesAndItems, updateIndices) = mergeListsStableWithUpdates(leftList: fromEntries, rightList: toEntries, allUpdated: forceUpdate) let deletions = deleteIndices.map { ListViewDeleteItem(index: $0, directionHint: nil) } let insertions = indicesAndItems.map { ListViewInsertItem(index: $0.0, previousIndex: $0.2, item: $0.1.item(presentationData: presentationData, searchMode: true, openSearch: {}, selectLocalization: selectLocalization, setItemWithRevealedOptions: { _, _ in }, removeItem: { _ in }), directionHint: nil) } let updates = updateIndices.map { ListViewUpdateItem(index: $0.0, previousIndex: $0.2, item: $0.1.item(presentationData: presentationData, searchMode: true, openSearch: {}, selectLocalization: selectLocalization, setItemWithRevealedOptions: { _, _ in }, removeItem: { _ in }), directionHint: nil) } return LocalizationListSearchContainerTransition(deletions: deletions, insertions: insertions, updates: updates, isSearching: isSearching) } private final class LocalizationListSearchContainerNode: SearchDisplayControllerContentNode { private let dimNode: ASDisplayNode private let listNode: ListView private var enqueuedTransitions: [LocalizationListSearchContainerTransition] = [] private var hasValidLayout = false private let searchQuery = Promise() private let searchDisposable = MetaDisposable() private var presentationData: PresentationData private var presentationDataDisposable: Disposable? private let presentationDataPromise: Promise public override var hasDim: Bool { return true } init(context: AccountContext, listState: LocalizationListState, selectLocalization: @escaping (LocalizationInfo) -> Void, applyingCode: Signal) { let presentationData = context.sharedContext.currentPresentationData.with { $0 } self.presentationData = presentationData self.presentationDataPromise = Promise(self.presentationData) self.dimNode = ASDisplayNode() self.dimNode.backgroundColor = UIColor.black.withAlphaComponent(0.5) self.listNode = ListView() self.listNode.accessibilityPageScrolledString = { row, count in return presentationData.strings.VoiceOver_ScrollStatus(row, count).0 } super.init() self.listNode.backgroundColor = self.presentationData.theme.chatList.backgroundColor self.listNode.isHidden = true self.addSubnode(self.dimNode) self.addSubnode(self.listNode) let foundItems = self.searchQuery.get() |> mapToSignal { query -> Signal<[LocalizationInfo]?, NoError> in if let query = query, !query.isEmpty { let normalizedQuery = query.lowercased() var result: [LocalizationInfo] = [] var uniqueIds = Set() for info in listState.availableSavedLocalizations + listState.availableOfficialLocalizations { if info.title.lowercased().hasPrefix(normalizedQuery) || info.localizedTitle.lowercased().hasPrefix(normalizedQuery) { if uniqueIds.contains(info.languageCode) { continue } uniqueIds.insert(info.languageCode) result.append(info) } } return .single(result) } else { return .single(nil) } } let previousEntriesHolder = Atomic<([LanguageListEntry], PresentationTheme, PresentationStrings)?>(value: nil) self.searchDisposable.set(combineLatest(queue: .mainQueue(), foundItems, self.presentationDataPromise.get(), applyingCode).start(next: { [weak self] items, presentationData, applyingCode in guard let strongSelf = self else { return } var entries: [LanguageListEntry] = [] if let items = items { for item in items { entries.append(.localization(index: entries.count, info: item, type: .official, selected: presentationData.strings.primaryComponent.languageCode == item.languageCode, activity: applyingCode == item.languageCode, revealed: false, editing: false)) } } let previousEntriesAndPresentationData = previousEntriesHolder.swap((entries, presentationData.theme, presentationData.strings)) let transition = preparedLanguageListSearchContainerTransition(presentationData: presentationData, from: previousEntriesAndPresentationData?.0 ?? [], to: entries, selectLocalization: selectLocalization, isSearching: items != nil, forceUpdate: previousEntriesAndPresentationData?.1 !== presentationData.theme || previousEntriesAndPresentationData?.2 !== presentationData.strings) strongSelf.enqueueTransition(transition) })) self.presentationDataDisposable = (context.sharedContext.presentationData |> deliverOnMainQueue).start(next: { [weak self] presentationData in if let strongSelf = self { let previousTheme = strongSelf.presentationData.theme let previousStrings = strongSelf.presentationData.strings strongSelf.presentationData = presentationData if previousTheme !== presentationData.theme || previousStrings !== presentationData.strings { strongSelf.updateThemeAndStrings(theme: presentationData.theme, strings: presentationData.strings) strongSelf.presentationDataPromise.set(.single(presentationData)) } } }) self.listNode.beganInteractiveDragging = { [weak self] in self?.dismissInput?() } } deinit { self.searchDisposable.dispose() self.presentationDataDisposable?.dispose() } override func didLoad() { super.didLoad() self.dimNode.view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(self.dimTapGesture(_:)))) } func updateThemeAndStrings(theme: PresentationTheme, strings: PresentationStrings) { self.listNode.backgroundColor = theme.chatList.backgroundColor } override func searchTextUpdated(text: String) { if text.isEmpty { self.searchQuery.set(.single(nil)) } else { self.searchQuery.set(.single(text)) } } private func enqueueTransition(_ transition: LocalizationListSearchContainerTransition) { self.enqueuedTransitions.append(transition) if self.hasValidLayout { while !self.enqueuedTransitions.isEmpty { self.dequeueTransitions() } } } private func dequeueTransitions() { if let transition = self.enqueuedTransitions.first { self.enqueuedTransitions.remove(at: 0) var options = ListViewDeleteAndInsertOptions() options.insert(.PreferSynchronousDrawing) let isSearching = transition.isSearching self.listNode.transaction(deleteIndices: transition.deletions, insertIndicesAndItems: transition.insertions, updateIndicesAndItems: transition.updates, options: options, updateSizeAndInsets: nil, updateOpaqueState: nil, completion: { [weak self] _ in self?.listNode.isHidden = !isSearching self?.dimNode.isHidden = isSearching }) } } override func containerLayoutUpdated(_ layout: ContainerViewLayout, navigationBarHeight: CGFloat, transition: ContainedViewLayoutTransition) { super.containerLayoutUpdated(layout, navigationBarHeight: navigationBarHeight, transition: transition) let topInset = navigationBarHeight transition.updateFrame(node: self.dimNode, frame: CGRect(origin: CGPoint(x: 0.0, y: topInset), size: CGSize(width: layout.size.width, height: layout.size.height - topInset))) let (duration, curve) = listViewAnimationDurationAndCurve(transition: transition) self.listNode.frame = CGRect(origin: CGPoint(), size: layout.size) self.listNode.transaction(deleteIndices: [], insertIndicesAndItems: [], updateIndicesAndItems: [], options: [.Synchronous], scrollToItem: nil, updateSizeAndInsets: ListViewUpdateSizeAndInsets(size: layout.size, insets: UIEdgeInsets(top: navigationBarHeight, left: layout.safeInsets.left, bottom: layout.insets(options: [.input]).bottom, right: layout.safeInsets.right), duration: duration, curve: curve), stationaryItemRange: nil, updateOpaqueState: nil, completion: { _ in }) if !self.hasValidLayout { self.hasValidLayout = true while !self.enqueuedTransitions.isEmpty { self.dequeueTransitions() } } } @objc func dimTapGesture(_ recognizer: UITapGestureRecognizer) { if case .ended = recognizer.state { self.cancel?() } } } private struct LanguageListNodeTransition { let deletions: [ListViewDeleteItem] let insertions: [ListViewInsertItem] let updates: [ListViewUpdateItem] let firstTime: Bool let isLoading: Bool let animated: Bool } private func preparedLanguageListNodeTransition(presentationData: PresentationData, from fromEntries: [LanguageListEntry], to toEntries: [LanguageListEntry], openSearch: @escaping () -> Void, selectLocalization: @escaping (LocalizationInfo) -> Void, setItemWithRevealedOptions: @escaping (String?, String?) -> Void, removeItem: @escaping (String) -> Void, firstTime: Bool, isLoading: Bool, forceUpdate: Bool, animated: Bool) -> LanguageListNodeTransition { let (deleteIndices, indicesAndItems, updateIndices) = mergeListsStableWithUpdates(leftList: fromEntries, rightList: toEntries, allUpdated: forceUpdate) let deletions = deleteIndices.map { ListViewDeleteItem(index: $0, directionHint: nil) } let insertions = indicesAndItems.map { ListViewInsertItem(index: $0.0, previousIndex: $0.2, item: $0.1.item(presentationData: presentationData, searchMode: false, openSearch: openSearch, selectLocalization: selectLocalization, setItemWithRevealedOptions: setItemWithRevealedOptions, removeItem: removeItem), directionHint: nil) } let updates = updateIndices.map { ListViewUpdateItem(index: $0.0, previousIndex: $0.2, item: $0.1.item(presentationData: presentationData, searchMode: false, openSearch: openSearch, selectLocalization: selectLocalization, setItemWithRevealedOptions: setItemWithRevealedOptions, removeItem: removeItem), directionHint: nil) } return LanguageListNodeTransition(deletions: deletions, insertions: insertions, updates: updates, firstTime: firstTime, isLoading: isLoading, animated: animated) } final class LocalizationListControllerNode: ViewControllerTracingNode { private let context: AccountContext private var presentationData: PresentationData private let navigationBar: NavigationBar private let requestActivateSearch: () -> Void private let requestDeactivateSearch: () -> Void private let present: (ViewController, Any?) -> Void private var didSetReady = false let _ready = ValuePromise() private var containerLayout: (ContainerViewLayout, CGFloat)? let listNode: ListView private var queuedTransitions: [LanguageListNodeTransition] = [] private var activityIndicator: ActivityIndicator? private var searchDisplayController: SearchDisplayController? private let presentationDataValue = Promise() private var updatedDisposable: Disposable? private var listDisposable: Disposable? private let applyDisposable = MetaDisposable() private var currentListState: LocalizationListState? private let applyingCode = Promise(nil) private let isEditing = ValuePromise(false) private var isEditingValue: Bool = false { didSet { self.isEditing.set(self.isEditingValue) } } init(context: AccountContext, presentationData: PresentationData, navigationBar: NavigationBar, requestActivateSearch: @escaping () -> Void, requestDeactivateSearch: @escaping () -> Void, updateCanStartEditing: @escaping (Bool?) -> Void, present: @escaping (ViewController, Any?) -> Void) { self.context = context self.presentationData = presentationData self.presentationDataValue.set(.single(presentationData)) self.navigationBar = navigationBar self.requestActivateSearch = requestActivateSearch self.requestDeactivateSearch = requestDeactivateSearch self.present = present self.listNode = ListView() self.listNode.keepTopItemOverscrollBackground = ListViewKeepTopItemOverscrollBackground(color: presentationData.theme.chatList.backgroundColor, direction: true) self.listNode.accessibilityPageScrolledString = { row, count in return presentationData.strings.VoiceOver_ScrollStatus(row, count).0 } super.init() self.backgroundColor = presentationData.theme.list.blocksBackgroundColor self.addSubnode(self.listNode) let openSearch: () -> Void = { requestActivateSearch() } let revealedCode = Promise(nil) var revealedCodeValue: String? let setItemWithRevealedOptions: (String?, String?) -> Void = { id, fromId in if (id == nil && fromId == revealedCodeValue) || (id != nil && fromId == nil) { revealedCodeValue = id revealedCode.set(.single(id)) } } let removeItem: (String) -> Void = { id in let _ = (context.account.postbox.transaction { transaction -> Signal in removeSavedLocalization(transaction: transaction, languageCode: id) let state = transaction.getPreferencesEntry(key: PreferencesKeys.localizationListState) as? LocalizationListState return context.sharedContext.accountManager.transaction { transaction -> LocalizationInfo? in if let settings = transaction.getSharedData(SharedDataKeys.localizationSettings) as? LocalizationSettings, let state = state { if settings.primaryComponent.languageCode == id { for item in state.availableOfficialLocalizations { if item.languageCode == "en" { return item } } } } return nil } } |> switchToLatest |> deliverOnMainQueue).start(next: { [weak self] info in if revealedCodeValue == id { revealedCodeValue = nil revealedCode.set(.single(nil)) } if let info = info { self?.selectLocalization(info) } }) } let preferencesKey: PostboxViewKey = .preferences(keys: Set([PreferencesKeys.localizationListState])) let previousEntriesHolder = Atomic<([LanguageListEntry], PresentationTheme, PresentationStrings)?>(value: nil) self.listDisposable = combineLatest(queue: .mainQueue(), context.account.postbox.combinedView(keys: [preferencesKey]), context.sharedContext.accountManager.sharedData(keys: [SharedDataKeys.localizationSettings]), self.presentationDataValue.get(), self.applyingCode.get(), revealedCode.get(), self.isEditing.get()).start(next: { [weak self] view, sharedData, presentationData, applyingCode, revealedCode, isEditing in guard let strongSelf = self else { return } var entries: [LanguageListEntry] = [] var activeLanguageCode: String? if let localizationSettings = sharedData.entries[SharedDataKeys.localizationSettings] as? LocalizationSettings { activeLanguageCode = localizationSettings.primaryComponent.languageCode } var existingIds = Set() if let localizationListState = (view.views[preferencesKey] as? PreferencesView)?.values[PreferencesKeys.localizationListState] as? LocalizationListState, !localizationListState.availableOfficialLocalizations.isEmpty { strongSelf.currentListState = localizationListState let availableSavedLocalizations = localizationListState.availableSavedLocalizations.filter({ info in !localizationListState.availableOfficialLocalizations.contains(where: { $0.languageCode == info.languageCode }) }) if availableSavedLocalizations.isEmpty { updateCanStartEditing(nil) } else { updateCanStartEditing(isEditing) } if !availableSavedLocalizations.isEmpty { for info in availableSavedLocalizations { if existingIds.contains(info.languageCode) { continue } existingIds.insert(info.languageCode) entries.append(.localization(index: entries.count, info: info, type: .unofficial, selected: info.languageCode == activeLanguageCode, activity: applyingCode == info.languageCode, revealed: revealedCode == info.languageCode, editing: isEditing)) } } for info in localizationListState.availableOfficialLocalizations { if existingIds.contains(info.languageCode) { continue } existingIds.insert(info.languageCode) entries.append(.localization(index: entries.count, info: info, type: .official, selected: info.languageCode == activeLanguageCode, activity: applyingCode == info.languageCode, revealed: revealedCode == info.languageCode, editing: false)) } } let previousEntriesAndPresentationData = previousEntriesHolder.swap((entries, presentationData.theme, presentationData.strings)) let transition = preparedLanguageListNodeTransition(presentationData: presentationData, from: previousEntriesAndPresentationData?.0 ?? [], to: entries, openSearch: openSearch, selectLocalization: { [weak self] info in self?.selectLocalization(info) }, setItemWithRevealedOptions: setItemWithRevealedOptions, removeItem: removeItem, firstTime: previousEntriesAndPresentationData == nil, isLoading: entries.isEmpty, forceUpdate: previousEntriesAndPresentationData?.1 !== presentationData.theme || previousEntriesAndPresentationData?.2 !== presentationData.strings, animated: (previousEntriesAndPresentationData?.0.count ?? 0) >= entries.count) strongSelf.enqueueTransition(transition) }) self.updatedDisposable = synchronizedLocalizationListState(postbox: context.account.postbox, network: context.account.network).start() } deinit { self.listDisposable?.dispose() self.updatedDisposable?.dispose() self.applyDisposable.dispose() } func updatePresentationData(_ presentationData: PresentationData) { self.presentationData = presentationData self.presentationDataValue.set(.single(presentationData)) self.backgroundColor = presentationData.theme.list.blocksBackgroundColor self.listNode.keepTopItemOverscrollBackground = ListViewKeepTopItemOverscrollBackground(color: presentationData.theme.chatList.backgroundColor, direction: true) self.searchDisplayController?.updatePresentationData(presentationData) } func containerLayoutUpdated(_ layout: ContainerViewLayout, navigationBarHeight: CGFloat, transition: ContainedViewLayoutTransition) { let hadValidLayout = self.containerLayout != nil self.containerLayout = (layout, navigationBarHeight) var listInsets = layout.insets(options: [.input]) listInsets.top += navigationBarHeight listInsets.left += layout.safeInsets.left listInsets.right += layout.safeInsets.right if let searchDisplayController = self.searchDisplayController { searchDisplayController.containerLayoutUpdated(layout, navigationBarHeight: navigationBarHeight, transition: transition) } self.listNode.bounds = CGRect(x: 0.0, y: 0.0, width: layout.size.width, height: layout.size.height) self.listNode.position = CGPoint(x: layout.size.width / 2.0, y: layout.size.height / 2.0) let (duration, curve) = listViewAnimationDurationAndCurve(transition: transition) let updateSizeAndInsets = ListViewUpdateSizeAndInsets(size: layout.size, insets: listInsets, duration: duration, curve: curve) self.listNode.transaction(deleteIndices: [], insertIndicesAndItems: [], updateIndicesAndItems: [], options: [.Synchronous, .LowLatency], scrollToItem: nil, updateSizeAndInsets: updateSizeAndInsets, stationaryItemRange: nil, updateOpaqueState: nil, completion: { _ in }) if let activityIndicator = self.activityIndicator { let indicatorSize = activityIndicator.measure(CGSize(width: 100.0, height: 100.0)) transition.updateFrame(node: activityIndicator, frame: CGRect(origin: CGPoint(x: floor((layout.size.width - indicatorSize.width) / 2.0), y: updateSizeAndInsets.insets.top + 50.0 + floor((layout.size.height - updateSizeAndInsets.insets.top - updateSizeAndInsets.insets.bottom - indicatorSize.height - 50.0) / 2.0)), size: indicatorSize)) } if !hadValidLayout { self.dequeueTransitions() } } private func enqueueTransition(_ transition: LanguageListNodeTransition) { self.queuedTransitions.append(transition) if self.containerLayout != nil { self.dequeueTransitions() } } private func dequeueTransitions() { guard let (layout, navigationBarHeight) = self.containerLayout else { return } while !self.queuedTransitions.isEmpty { let transition = self.queuedTransitions.removeFirst() var options = ListViewDeleteAndInsertOptions() if transition.firstTime { options.insert(.Synchronous) options.insert(.LowLatency) } else if transition.animated { options.insert(.AnimateInsertion) } self.listNode.transaction(deleteIndices: transition.deletions, insertIndicesAndItems: transition.insertions, updateIndicesAndItems: transition.updates, options: options, updateOpaqueState: nil, completion: { [weak self] _ in if let strongSelf = self { if !strongSelf.didSetReady { strongSelf.didSetReady = true strongSelf._ready.set(true) } if transition.isLoading, strongSelf.activityIndicator == nil { let activityIndicator = ActivityIndicator(type: .custom(strongSelf.presentationData.theme.list.itemAccentColor, 22.0, 1.0, false)) strongSelf.activityIndicator = activityIndicator strongSelf.insertSubnode(activityIndicator, aboveSubnode: strongSelf.listNode) strongSelf.containerLayoutUpdated(layout, navigationBarHeight: navigationBarHeight, transition: .immediate) } else if !transition.isLoading, let activityIndicator = strongSelf.activityIndicator { strongSelf.activityIndicator = nil activityIndicator.removeFromSupernode() } } }) } } private func selectLocalization(_ info: LocalizationInfo) -> Void { let applyImpl: () -> Void = { [weak self] in guard let strongSelf = self else { return } strongSelf.applyingCode.set(.single(info.languageCode)) strongSelf.applyDisposable.set((downloadAndApplyLocalization(accountManager: strongSelf.context.sharedContext.accountManager, postbox: strongSelf.context.account.postbox, network: strongSelf.context.account.network, languageCode: info.languageCode) |> deliverOnMainQueue).start(completed: { self?.applyingCode.set(.single(nil)) })) } if info.isOfficial { applyImpl() return } let controller = ActionSheetController(presentationData: presentationData) let dismissAction: () -> Void = { [weak controller] in controller?.dismissAnimated() } var items: [ActionSheetItem] = [] items.append(ActionSheetTextItem(title: info.localizedTitle)) if self.presentationData.strings.primaryComponent.languageCode != info.languageCode { items.append(ActionSheetButtonItem(title: presentationData.strings.ApplyLanguage_ChangeLanguageAction, action: { dismissAction() applyImpl() })) } items.append(ActionSheetButtonItem(title: presentationData.strings.Conversation_ContextMenuShare, action: { [weak self] in dismissAction() guard let strongSelf = self else { return } let shareController = ShareController(context: strongSelf.context, subject: .url("https://t.me/setlanguage/\(info.languageCode)")) strongSelf.present(shareController, nil) })) controller.setItemGroups([ ActionSheetItemGroup(items: items), ActionSheetItemGroup(items: [ActionSheetButtonItem(title: presentationData.strings.Common_Cancel, action: { dismissAction() })]) ]) self.view.window?.endEditing(true) self.present(controller, nil) } func toggleEditing() { self.isEditingValue = !self.isEditingValue } func activateSearch(placeholderNode: SearchBarPlaceholderNode) { guard let (containerLayout, navigationBarHeight) = self.containerLayout, self.searchDisplayController == nil else { return } self.searchDisplayController = SearchDisplayController(presentationData: self.presentationData, contentNode: LocalizationListSearchContainerNode(context: self.context, listState: self.currentListState ?? LocalizationListState.defaultSettings, selectLocalization: { [weak self] info in self?.selectLocalization(info) }, applyingCode: self.applyingCode.get()), cancel: { [weak self] in self?.requestDeactivateSearch() }) self.searchDisplayController?.containerLayoutUpdated(containerLayout, navigationBarHeight: navigationBarHeight, transition: .immediate) self.searchDisplayController?.activate(insertSubnode: { [weak self, weak placeholderNode] subnode, isSearchBar in if let strongSelf = self, let strongPlaceholderNode = placeholderNode { if isSearchBar { strongPlaceholderNode.supernode?.insertSubnode(subnode, aboveSubnode: strongPlaceholderNode) } else { strongSelf.insertSubnode(subnode, belowSubnode: strongSelf.navigationBar) } } }, placeholder: placeholderNode) } func deactivateSearch(placeholderNode: SearchBarPlaceholderNode) { if let searchDisplayController = self.searchDisplayController { searchDisplayController.deactivate(placeholder: placeholderNode) self.searchDisplayController = nil } } func scrollToTop() { self.listNode.transaction(deleteIndices: [], insertIndicesAndItems: [], updateIndicesAndItems: [], options: [.Synchronous, .LowLatency], scrollToItem: ListViewScrollToItem(index: 0, position: .top(0.0), animated: true, curve: .Default(duration: nil), directionHint: .Up), updateSizeAndInsets: nil, stationaryItemRange: nil, updateOpaqueState: nil, completion: { _ in }) } }