// // MasterViewController.swift // NetNewsWire // // Created by Maurice Parker on 4/8/19. // Copyright © 2019 Ranchero Software. All rights reserved. // import UIKit import Account import Articles import RSCore import RSTree import SwiftUI class MasterFeedViewController: UITableViewController, UndoableCommandRunner { @IBOutlet private weak var markAllAsReadButton: UIBarButtonItem! @IBOutlet private weak var addNewItemButton: UIBarButtonItem! private lazy var dataSource = makeDataSource() var undoableCommands = [UndoableCommand]() weak var coordinator: SceneCoordinator! lazy var keyboardManager = KeyboardManager(type: .sidebar, coordinator: coordinator) override var keyCommands: [UIKeyCommand]? { return keyboardManager.keyCommands } override var canBecomeFirstResponder: Bool { return true } override func viewDidLoad() { super.viewDidLoad() if traitCollection.userInterfaceIdiom == .phone { navigationController?.navigationBar.prefersLargeTitles = true } navigationItem.rightBarButtonItem = editButtonItem tableView.register(MasterFeedTableViewSectionHeader.self, forHeaderFooterViewReuseIdentifier: "SectionHeader") tableView.dataSource = dataSource NotificationCenter.default.addObserver(self, selector: #selector(unreadCountDidChange(_:)), name: .UnreadCountDidChange, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(faviconDidBecomeAvailable(_:)), name: .FaviconDidBecomeAvailable, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(feedSettingDidChange(_:)), name: .FeedSettingDidChange, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(userDidAddFeed(_:)), name: .UserDidAddFeed, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(progressDidChange(_:)), name: .AccountRefreshProgressDidChange, object: nil) NotificationCenter.default.addObserver(self, selector: #selector(contentSizeCategoryDidChange), name: UIContentSizeCategory.didChangeNotification, object: nil) refreshControl = UIRefreshControl() refreshControl!.addTarget(self, action: #selector(refreshAccounts(_:)), for: .valueChanged) updateUI() applyChanges(animate: false) } override func viewWillAppear(_ animated: Bool) { navigationController?.title = NSLocalizedString("Feeds", comment: "Feeds") clearsSelectionOnViewWillAppear = coordinator.isRootSplitCollapsed super.viewWillAppear(animated) } override func viewDidAppear(_ animated: Bool) { super.viewDidAppear(animated) navigationController?.updateAccountRefreshProgressIndicator() } // MARK: Notifications @objc func unreadCountDidChange(_ note: Notification) { updateUI() guard let representedObject = note.object else { return } if let account = representedObject as? Account { if let node = coordinator.rootNode.childNodeRepresentingObject(account) { let sectionIndex = coordinator.rootNode.indexOfChild(node)! if let headerView = tableView.headerView(forSection: sectionIndex) as? MasterFeedTableViewSectionHeader { headerView.unreadCount = account.unreadCount } } return } var node: Node? = nil if let coordinator = representedObject as? SceneCoordinator, let fetcher = coordinator.timelineFetcher { node = coordinator.rootNode.descendantNodeRepresentingObject(fetcher as AnyObject) } else { node = coordinator.rootNode.descendantNodeRepresentingObject(representedObject as AnyObject) } if let node = node, coordinator.indexPathFor(node) != nil { reloadNode(node) } } @objc func faviconDidBecomeAvailable(_ note: Notification) { applyToAvailableCells(configureFavicon) } @objc func feedSettingDidChange(_ note: Notification) { guard let feed = note.object as? Feed, let key = note.userInfo?[Feed.FeedSettingUserInfoKey] as? String else { return } if key == Feed.FeedSettingKey.homePageURL || key == Feed.FeedSettingKey.faviconURL { configureCellsForRepresentedObject(feed) } } @objc func userDidAddFeed(_ notification: Notification) { guard let feed = notification.userInfo?[UserInfoKey.feed] as? Feed else { return } discloseFeed(feed) } @objc func progressDidChange(_ note: Notification) { navigationController?.updateAccountRefreshProgressIndicator() } @objc func contentSizeCategoryDidChange(_ note: Notification) { applyChanges(animate: false) } // MARK: Table View override func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat { guard let nameProvider = coordinator.rootNode.childAtIndex(section)?.representedObject as? DisplayNameProvider else { return 44 } let headerView = MasterFeedTableViewSectionHeader() headerView.name = nameProvider.nameForDisplay let size = headerView.sizeThatFits(CGSize(width: tableView.bounds.width, height: 0.0)) return size.height } override func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? { guard let nameProvider = coordinator.rootNode.childAtIndex(section)?.representedObject as? DisplayNameProvider else { return nil } let headerView = tableView.dequeueReusableHeaderFooterView(withIdentifier: "SectionHeader") as! MasterFeedTableViewSectionHeader headerView.name = nameProvider.nameForDisplay guard let sectionNode = coordinator.rootNode.childAtIndex(section) else { return headerView } if let account = sectionNode.representedObject as? Account { headerView.unreadCount = account.unreadCount } else { headerView.unreadCount = 0 } headerView.tag = section headerView.disclosureExpanded = coordinator.isExpanded(sectionNode) let tap = UITapGestureRecognizer(target: self, action:#selector(self.toggleSectionHeader(_:))) headerView.addGestureRecognizer(tap) return headerView } override func tableView(_ tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat { return CGFloat.leastNormalMagnitude } override func tableView(_ tableView: UITableView, viewForFooterInSection section: Int) -> UIView? { return UIView(frame: CGRect.zero) } override func tableView(_ tableView: UITableView, trailingSwipeActionsConfigurationForRowAt indexPath: IndexPath) -> UISwipeActionsConfiguration? { var actions = [UIContextualAction]() // Set up the delete action let deleteTitle = NSLocalizedString("Delete", comment: "Delete") let deleteAction = UIContextualAction(style: .normal, title: deleteTitle) { [weak self] (action, view, completionHandler) in self?.delete(indexPath: indexPath) completionHandler(true) } deleteAction.backgroundColor = UIColor.systemRed actions.append(deleteAction) // Set up the rename action let renameTitle = NSLocalizedString("Rename", comment: "Rename") let renameAction = UIContextualAction(style: .normal, title: renameTitle) { [weak self] (action, view, completionHandler) in self?.rename(indexPath: indexPath) completionHandler(true) } renameAction.backgroundColor = UIColor.systemOrange actions.append(renameAction) if let feed = coordinator.nodeFor(indexPath)?.representedObject as? Feed { let moreTitle = NSLocalizedString("More", comment: "More") let moreAction = UIContextualAction(style: .normal, title: moreTitle) { [weak self] (action, view, completionHandler) in if let self = self { let alert = UIAlertController(title: feed.name, message: nil, preferredStyle: .actionSheet) if let popoverController = alert.popoverPresentationController { popoverController.sourceView = view popoverController.sourceRect = CGRect(x: view.frame.size.width/2, y: view.frame.size.height/2, width: 1, height: 1) } if let action = self.homePageAlertAction(indexPath: indexPath, completionHandler: completionHandler) { alert.addAction(action) } if let action = self.copyFeedPageAlertAction(indexPath: indexPath, completionHandler: completionHandler) { alert.addAction(action) } if let action = self.copyHomePageAlertAction(indexPath: indexPath, completionHandler: completionHandler) { alert.addAction(action) } let cancelTitle = NSLocalizedString("Cancel", comment: "Cancel") alert.addAction(UIAlertAction(title: cancelTitle, style: .cancel) { _ in completionHandler(true) }) self.present(alert, animated: true) } } moreAction.backgroundColor = UIColor.systemGray actions.append(moreAction) } return UISwipeActionsConfiguration(actions: actions) } override func tableView(_ tableView: UITableView, contextMenuConfigurationForRowAt indexPath: IndexPath, point: CGPoint) -> UIContextMenuConfiguration? { guard let node = coordinator.nodeFor(indexPath), !(node.representedObject is PseudoFeed) else { return nil } if node.representedObject is Feed { return makeFeedContextMenu(indexPath: indexPath, includeDeleteRename: true) } else { return makeFolderContextMenu(indexPath: indexPath) } } override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) { becomeFirstResponder() coordinator.selectFeed(indexPath) } override func tableView(_ tableView: UITableView, targetIndexPathForMoveFromRowAt sourceIndexPath: IndexPath, toProposedIndexPath proposedDestinationIndexPath: IndexPath) -> IndexPath { // Adjust the index path so that it will never be in the smart feeds area let destIndexPath: IndexPath = { if proposedDestinationIndexPath.section == 0 { return IndexPath(row: 0, section: 1) } return coordinator.cappedIndexPath(proposedDestinationIndexPath) }() guard let draggedNode = coordinator.nodeFor(sourceIndexPath), let destNode = coordinator.nodeFor(destIndexPath), let parentNode = destNode.parent else { assertionFailure("This should never happen") return sourceIndexPath } // If this is a folder and isn't expanded or doesn't have any entries, let the users drop on it if destNode.representedObject is Folder && (destNode.numberOfChildNodes == 0 || !coordinator.isExpanded(destNode)) { let movementAdjustment = sourceIndexPath > destIndexPath ? 1 : 0 return IndexPath(row: destIndexPath.row + movementAdjustment, section: destIndexPath.section) } // If we are dragging around in the same container, just return the original source if parentNode.childNodes.contains(draggedNode) { return sourceIndexPath } // Suggest to the user the best place to drop the feed // Revisit if the tree controller can ever be sorted in some other way. let nodes = parentNode.childNodes + [draggedNode] var sortedNodes = nodes.sortedAlphabeticallyWithFoldersAtEnd() let index = sortedNodes.firstIndex(of: draggedNode)! if index == 0 { if parentNode.representedObject is Account { return IndexPath(row: 0, section: destIndexPath.section) } else { return coordinator.indexPathFor(parentNode)! } } else { sortedNodes.remove(at: index) let movementAdjustment = sourceIndexPath < destIndexPath ? 1 : 0 let adjustedIndex = index - movementAdjustment if adjustedIndex >= sortedNodes.count { let lastSortedIndexPath = coordinator.indexPathFor(sortedNodes[sortedNodes.count - 1])! return IndexPath(row: lastSortedIndexPath.row + 1, section: lastSortedIndexPath.section) } else { return coordinator.indexPathFor(sortedNodes[adjustedIndex])! } } } // MARK: Actions @IBAction func settings(_ sender: UIBarButtonItem) { coordinator.showSettings() } @IBAction func markAllAsRead(_ sender: Any) { let title = NSLocalizedString("Mark All Read", comment: "Mark All Read") let message = NSLocalizedString("Mark all articles in all accounts as read?", comment: "Mark all articles") let alertController = UIAlertController(title: title, message: message, preferredStyle: .alert) let cancelTitle = NSLocalizedString("Cancel", comment: "Cancel") let cancelAction = UIAlertAction(title: cancelTitle, style: .cancel) alertController.addAction(cancelAction) let markTitle = NSLocalizedString("Mark All Read", comment: "Mark All Read") let markAction = UIAlertAction(title: markTitle, style: .default) { [weak self] (action) in self?.coordinator.markAllAsRead() } alertController.addAction(markAction) present(alertController, animated: true) } @IBAction func add(_ sender: UIBarButtonItem) { coordinator.showAdd() } @objc func toggleSectionHeader(_ sender: UITapGestureRecognizer) { guard let sectionIndex = sender.view?.tag, let sectionNode = coordinator.rootNode.childAtIndex(sectionIndex), let headerView = sender.view as? MasterFeedTableViewSectionHeader else { return } if coordinator.isExpanded(sectionNode) { headerView.disclosureExpanded = false coordinator.collapse(section: sectionIndex) self.applyChanges(animate: true) } else { headerView.disclosureExpanded = true coordinator.expand(section: sectionIndex) self.applyChanges(animate: true) } } @objc func refreshAccounts(_ sender: Any) { refreshControl?.endRefreshing() // This is a hack to make sure that an error dialog doesn't interfere with dismissing the refreshControl. // If the error dialog appears too closely to the call to endRefreshing, then the refreshControl never disappears. DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) { AccountManager.shared.refreshAll(errorHandler: ErrorHandler.present(self)) } } // MARK: Keyboard shortcuts @objc func selectNextUp(_ sender: Any?) { coordinator.selectPrevFeed() } @objc func selectNextDown(_ sender: Any?) { coordinator.selectNextFeed() } @objc func navigateToTimeline(_ sender: Any?) { coordinator.navigateToTimeline() } @objc func openInBrowser(_ sender: Any?) { coordinator.showBrowserForCurrentFeed() } // MARK: API func updateFeedSelection() { if let indexPath = coordinator.currentFeedIndexPath { if tableView.indexPathForSelectedRow != indexPath { tableView.selectRow(at: indexPath, animated: true, scrollPosition: .middle) } } else { tableView.selectRow(at: nil, animated: true, scrollPosition: .none) } } func reloadFeeds() { updateUI() // We have to reload all the visible cells because if we got here by doing a table cell move, // then the table itself is in a weird state. This is because we do unusual things like allowing // drops on a "folder" that should cause the dropped cell to disappear. applyChanges(animate: true) { [weak self] in self?.reloadAllVisibleCells() } } func ensureSectionIsExpanded(_ sectionIndex: Int, completion: (() -> Void)? = nil) { guard let sectionNode = coordinator.rootNode.childAtIndex(sectionIndex) else { return } if !coordinator.isExpanded(sectionNode) { coordinator.expand(section: sectionIndex) self.applyChanges(animate: true) { completion?() } } else { completion?() } } func discloseFeed(_ feed: Feed, completion: (() -> Void)? = nil) { guard let node = coordinator.rootNode.descendantNodeRepresentingObject(feed as AnyObject) else { return } if let indexPath = coordinator.indexPathFor(node) { tableView.scrollToRow(at: indexPath, at: .middle, animated: true) coordinator.selectFeed(indexPath) return } // It wasn't already visable, so expand its folder and try again guard let parent = node.parent, let indexPath = coordinator.indexPathFor(parent) else { return } coordinator.expand(indexPath) reloadNode(parent) self.applyChanges(animate: true) { [weak self] in if let indexPath = self?.coordinator.indexPathFor(node) { self?.tableView.scrollToRow(at: indexPath, at: .middle, animated: true) self?.coordinator.selectFeed(indexPath) completion?() } } } func focus() { becomeFirstResponder() } } // MARK: MasterTableViewCellDelegate extension MasterFeedViewController: MasterFeedTableViewCellDelegate { func disclosureSelected(_ sender: MasterFeedTableViewCell, expanding: Bool) { if expanding { expand(sender) } else { collapse(sender) } } } // MARK: Private private extension MasterFeedViewController { func updateUI() { markAllAsReadButton.isEnabled = coordinator.isAnyUnreadAvailable addNewItemButton.isEnabled = !AccountManager.shared.activeAccounts.isEmpty } func reloadNode(_ node: Node) { var snapshot = dataSource.snapshot() snapshot.reloadItems([node]) dataSource.apply(snapshot, animatingDifferences: false) { [weak self] in self?.restoreSelectionIfNecessary() } } func applyChanges(animate: Bool, completion: (() -> Void)? = nil) { var snapshot = NSDiffableDataSourceSnapshot() let sections = coordinator.allSections snapshot.appendSections(sections) for section in sections { snapshot.appendItems(coordinator.nodesFor(section: section), toSection: section) } dataSource.apply(snapshot, animatingDifferences: animate) { [weak self] in self?.restoreSelectionIfNecessary() completion?() } } func makeDataSource() -> UITableViewDiffableDataSource { return MasterFeedDataSource(coordinator: coordinator, errorHandler: ErrorHandler.present(self), tableView: tableView, cellProvider: { [weak self] tableView, indexPath, node in let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! MasterFeedTableViewCell self?.configure(cell, node) return cell }) } func configure(_ cell: MasterFeedTableViewCell, _ node: Node) { cell.delegate = self if node.parent?.representedObject is Folder { cell.indentationLevel = 1 } else { cell.indentationLevel = 0 } cell.disclosureExpanded = coordinator.isExpanded(node) cell.allowDisclosureSelection = node.canHaveChildNodes cell.name = nameFor(node) cell.unreadCount = coordinator.unreadCountFor(node) configureFavicon(cell, node) cell.shouldShowImage = node.representedObject is SmallIconProvider } func configureFavicon(_ cell: MasterFeedTableViewCell, _ node: Node) { cell.faviconImage = imageFor(node) } func imageFor(_ node: Node) -> UIImage? { if let smallIconProvider = node.representedObject as? SmallIconProvider { return smallIconProvider.smallIcon } return nil } func nameFor(_ node: Node) -> String { if let displayNameProvider = node.representedObject as? DisplayNameProvider { return displayNameProvider.nameForDisplay } return "" } func configureCellsForRepresentedObject(_ representedObject: AnyObject) { applyToCellsForRepresentedObject(representedObject, configure) } func applyToCellsForRepresentedObject(_ representedObject: AnyObject, _ callback: (MasterFeedTableViewCell, Node) -> Void) { applyToAvailableCells { (cell, node) in if node.representedObject === representedObject { callback(cell, node) } } } func applyToAvailableCells(_ callback: (MasterFeedTableViewCell, Node) -> Void) { tableView.visibleCells.forEach { cell in guard let indexPath = tableView.indexPath(for: cell), let node = coordinator.nodeFor(indexPath) else { return } callback(cell as! MasterFeedTableViewCell, node) } } private func reloadAllVisibleCells() { let visibleNodes = tableView.indexPathsForVisibleRows!.compactMap { return coordinator.nodeFor($0) } reloadCells(visibleNodes) } private func reloadCells(_ nodes: [Node]) { var snapshot = dataSource.snapshot() snapshot.reloadItems(nodes) dataSource.apply(snapshot, animatingDifferences: false) } private func accountForNode(_ node: Node) -> Account? { if let account = node.representedObject as? Account { return account } if let folder = node.representedObject as? Folder { return folder.account } if let feed = node.representedObject as? Feed { return feed.account } return nil } func expand(_ cell: MasterFeedTableViewCell) { guard let indexPath = tableView.indexPath(for: cell) else { return } coordinator.expand(indexPath) self.applyChanges(animate: true) } func collapse(_ cell: MasterFeedTableViewCell) { guard let indexPath = tableView.indexPath(for: cell) else { return } coordinator.collapse(indexPath) self.applyChanges(animate: true) } func restoreSelectionIfNecessary() { guard traitCollection.userInterfaceIdiom == .pad else { return } if let indexPath = coordinator.masterFeedIndexPathForCurrentTimeline(), indexPath != tableView.indexPathForSelectedRow { tableView.selectRow(at: indexPath, animated: false, scrollPosition: .none) } } func makeFeedContextMenu(indexPath: IndexPath, includeDeleteRename: Bool) -> UIContextMenuConfiguration { return UIContextMenuConfiguration(identifier: nil, previewProvider: nil, actionProvider: { [ weak self] suggestedActions in guard let self = self else { return nil } var actions = [UIAction]() if let homePageAction = self.homePageAction(indexPath: indexPath) { actions.append(homePageAction) } if let copyFeedPageAction = self.copyFeedPageAction(indexPath: indexPath) { actions.append(copyFeedPageAction) } if let copyHomePageAction = self.copyHomePageAction(indexPath: indexPath) { actions.append(copyHomePageAction) } if includeDeleteRename { actions.append(self.deleteAction(indexPath: indexPath)) actions.append(self.renameAction(indexPath: indexPath)) } return UIMenu(title: "", children: actions) }) } func makeFolderContextMenu(indexPath: IndexPath) -> UIContextMenuConfiguration { return UIContextMenuConfiguration(identifier: nil, previewProvider: nil, actionProvider: { [weak self] suggestedActions in guard let self = self else { return nil } var actions = [UIAction]() actions.append(self.deleteAction(indexPath: indexPath)) actions.append(self.renameAction(indexPath: indexPath)) return UIMenu(title: "", children: actions) }) } func homePageAction(indexPath: IndexPath) -> UIAction? { guard coordinator.homePageURLForFeed(indexPath) != nil else { return nil } let title = NSLocalizedString("Open Home Page", comment: "Open Home Page") let action = UIAction(title: title, image: AppAssets.safariImage) { [weak self] action in self?.coordinator.showBrowserForFeed(indexPath) } return action } func homePageAlertAction(indexPath: IndexPath, completionHandler: @escaping (Bool) -> Void) -> UIAlertAction? { guard coordinator.homePageURLForFeed(indexPath) != nil else { return nil } let title = NSLocalizedString("Open Home Page", comment: "Open Home Page") let action = UIAlertAction(title: title, style: .default) { [weak self] action in self?.coordinator.showBrowserForFeed(indexPath) completionHandler(true) } return action } func copyFeedPageAction(indexPath: IndexPath) -> UIAction? { guard let node = coordinator.nodeFor(indexPath), let feed = node.representedObject as? Feed, let url = URL(string: feed.url) else { return nil } let title = NSLocalizedString("Copy Feed URL", comment: "Copy Feed URL") let action = UIAction(title: title, image: AppAssets.copyImage) { action in UIPasteboard.general.url = url } return action } func copyFeedPageAlertAction(indexPath: IndexPath, completionHandler: @escaping (Bool) -> Void) -> UIAlertAction? { guard let node = coordinator.nodeFor(indexPath), let feed = node.representedObject as? Feed, let url = URL(string: feed.url) else { return nil } let title = NSLocalizedString("Copy Feed URL", comment: "Copy Feed URL") let action = UIAlertAction(title: title, style: .default) { action in UIPasteboard.general.url = url completionHandler(true) } return action } func copyHomePageAction(indexPath: IndexPath) -> UIAction? { guard let node = coordinator.nodeFor(indexPath), let feed = node.representedObject as? Feed, let homePageURL = feed.homePageURL, let url = URL(string: homePageURL) else { return nil } let title = NSLocalizedString("Copy Home Page URL", comment: "Copy Home Page URL") let action = UIAction(title: title, image: AppAssets.copyImage) { action in UIPasteboard.general.url = url } return action } func copyHomePageAlertAction(indexPath: IndexPath, completionHandler: @escaping (Bool) -> Void) -> UIAlertAction? { guard let node = coordinator.nodeFor(indexPath), let feed = node.representedObject as? Feed, let homePageURL = feed.homePageURL, let url = URL(string: homePageURL) else { return nil } let title = NSLocalizedString("Copy Home Page URL", comment: "Copy Home Page URL") let action = UIAlertAction(title: title, style: .default) { action in UIPasteboard.general.url = url completionHandler(true) } return action } func deleteAction(indexPath: IndexPath) -> UIAction { let title = NSLocalizedString("Delete", comment: "Delete") let action = UIAction(title: title, image: AppAssets.trashImage) { [weak self] action in self?.delete(indexPath: indexPath) } return action } func renameAction(indexPath: IndexPath) -> UIAction { let title = NSLocalizedString("Rename", comment: "Rename") let action = UIAction(title: title, image: AppAssets.editImage) { [weak self] action in self?.rename(indexPath: indexPath) } return action } func rename(indexPath: IndexPath) { let name = (coordinator.nodeFor(indexPath)?.representedObject as? DisplayNameProvider)?.nameForDisplay ?? "" let formatString = NSLocalizedString("Rename “%@”", comment: "Feed finder") let title = NSString.localizedStringWithFormat(formatString as NSString, name) as String let alertController = UIAlertController(title: title, message: nil, preferredStyle: .alert) let cancelTitle = NSLocalizedString("Cancel", comment: "Cancel") alertController.addAction(UIAlertAction(title: cancelTitle, style: .cancel)) let renameTitle = NSLocalizedString("Rename", comment: "Rename") let renameAction = UIAlertAction(title: renameTitle, style: .default) { [weak self] action in guard let node = self?.coordinator.nodeFor(indexPath), let name = alertController.textFields?[0].text, !name.isEmpty else { return } if let feed = node.representedObject as? Feed { feed.rename(to: name) { result in switch result { case .success: self?.reloadNode(node) case .failure(let error): self?.presentError(error) } } } else if let folder = node.representedObject as? Folder { folder.rename(to: name) { result in switch result { case .success: self?.reloadNode(node) case .failure(let error): self?.presentError(error) } } } } alertController.addAction(renameAction) alertController.addTextField() { textField in textField.placeholder = NSLocalizedString("Name", comment: "Name") } self.present(alertController, animated: true) { } } func delete(indexPath: IndexPath) { guard let undoManager = undoManager, let deleteNode = coordinator.nodeFor(indexPath), let deleteCommand = DeleteCommand(nodesToDelete: [deleteNode], undoManager: undoManager, errorHandler: ErrorHandler.present(self)) else { return } if let folder = deleteNode.representedObject as? Folder { ActivityManager.cleanUp(folder) } else if let feed = deleteNode.representedObject as? Feed { ActivityManager.cleanUp(feed) } pushUndoableCommand(deleteCommand) deleteCommand.perform() } }