Convert Explore screen to use list-style collection view

Tusker.xcodeproj/project.pbxproj

@@ -97,7 +97,6 @@
 		D627943723A552C200D38C68 /* BookmarkStatusActivity.swift in Sources */ = {isa = PBXBuildFile; fileRef = D627943623A552C200D38C68 /* BookmarkStatusActivity.swift */; };
 		D627943923A553B600D38C68 /* UnbookmarkStatusActivity.swift in Sources */ = {isa = PBXBuildFile; fileRef = D627943823A553B600D38C68 /* UnbookmarkStatusActivity.swift */; };
 		D627943B23A55BA600D38C68 /* NavigableTableViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = D627943A23A55BA600D38C68 /* NavigableTableViewCell.swift */; };
-		D627943E23A564D400D38C68 /* ExploreViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D627943D23A564D400D38C68 /* ExploreViewController.swift */; };
 		D627944723A6AC9300D38C68 /* BasicTableViewCell.xib in Resources */ = {isa = PBXBuildFile; fileRef = D627944623A6AC9300D38C68 /* BasicTableViewCell.xib */; };
 		D627944A23A6AD6100D38C68 /* BookmarksTableViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D627944923A6AD6100D38C68 /* BookmarksTableViewController.swift */; };
 		D627944D23A9A03D00D38C68 /* ListTimelineViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D627944C23A9A03D00D38C68 /* ListTimelineViewController.swift */; };
@@ -272,6 +271,7 @@
 		D6C693FC2162FE6F007D6A6D /* LoadingViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6C693FB2162FE6F007D6A6D /* LoadingViewController.swift */; };
 		D6C693FE2162FEEA007D6A6D /* UIViewController+Children.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6C693FD2162FEEA007D6A6D /* UIViewController+Children.swift */; };
 		D6C7D27D22B6EBF800071952 /* AttachmentsContainerView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6C7D27C22B6EBF800071952 /* AttachmentsContainerView.swift */; };
+		D6C82B4125C5BB7E0017F1E6 /* ExploreViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6C82B4025C5BB7E0017F1E6 /* ExploreViewController.swift */; };
 		D6C82B5625C5F3F20017F1E6 /* ExpandThreadTableViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6C82B5425C5F3F20017F1E6 /* ExpandThreadTableViewCell.swift */; };
 		D6C82B5725C5F3F20017F1E6 /* ExpandThreadTableViewCell.xib in Resources */ = {isa = PBXBuildFile; fileRef = D6C82B5525C5F3F20017F1E6 /* ExpandThreadTableViewCell.xib */; };
 		D6C94D872139E62700CB5196 /* LargeImageViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6C94D862139E62700CB5196 /* LargeImageViewController.swift */; };
@@ -460,7 +460,6 @@
 		D627943623A552C200D38C68 /* BookmarkStatusActivity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BookmarkStatusActivity.swift; sourceTree = "<group>"; };
 		D627943823A553B600D38C68 /* UnbookmarkStatusActivity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UnbookmarkStatusActivity.swift; sourceTree = "<group>"; };
 		D627943A23A55BA600D38C68 /* NavigableTableViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NavigableTableViewCell.swift; sourceTree = "<group>"; };
-		D627943D23A564D400D38C68 /* ExploreViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ExploreViewController.swift; sourceTree = "<group>"; };
 		D627944623A6AC9300D38C68 /* BasicTableViewCell.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = BasicTableViewCell.xib; sourceTree = "<group>"; };
 		D627944923A6AD6100D38C68 /* BookmarksTableViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BookmarksTableViewController.swift; sourceTree = "<group>"; };
 		D627944C23A9A03D00D38C68 /* ListTimelineViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ListTimelineViewController.swift; sourceTree = "<group>"; };
@@ -633,6 +632,7 @@
 		D6C693FB2162FE6F007D6A6D /* LoadingViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LoadingViewController.swift; sourceTree = "<group>"; };
 		D6C693FD2162FEEA007D6A6D /* UIViewController+Children.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIViewController+Children.swift"; sourceTree = "<group>"; };
 		D6C7D27C22B6EBF800071952 /* AttachmentsContainerView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AttachmentsContainerView.swift; sourceTree = "<group>"; };
+		D6C82B4025C5BB7E0017F1E6 /* ExploreViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ExploreViewController.swift; sourceTree = "<group>"; };
 		D6C82B5425C5F3F20017F1E6 /* ExpandThreadTableViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ExpandThreadTableViewCell.swift; sourceTree = "<group>"; };
 		D6C82B5525C5F3F20017F1E6 /* ExpandThreadTableViewCell.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = ExpandThreadTableViewCell.xib; sourceTree = "<group>"; };
 		D6C94D862139E62700CB5196 /* LargeImageViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LargeImageViewController.swift; sourceTree = "<group>"; };
@@ -910,7 +910,7 @@
 		D627943C23A5635D00D38C68 /* Explore */ = {
 			isa = PBXGroup;
 			children = (
-				D627943D23A564D400D38C68 /* ExploreViewController.swift */,
+				D6C82B4025C5BB7E0017F1E6 /* ExploreViewController.swift */,
 				D6945C3323AC6431005C403C /* AddSavedHashtagViewController.swift */,
 				D6093F9A25BDD4B9004811E6 /* HashtagSearchResultsViewController.swift */,
 				D6945C3923AC75E2005C403C /* FindInstanceViewController.swift */,
@@ -1996,7 +1996,6 @@
 				D6B053AE23BD322B00A066FA /* AssetPickerSheetContainerViewController.swift in Sources */,
 				D6C693EF216192C2007D6A6D /* TuskerNavigationDelegate.swift in Sources */,
 				D6C94D872139E62700CB5196 /* LargeImageViewController.swift in Sources */,
-				D627943E23A564D400D38C68 /* ExploreViewController.swift in Sources */,
 				D6B053AB23BD2F1400A066FA /* AssetCollectionViewCell.swift in Sources */,
 				D622757A24EE21D900B82A16 /* ComposeAttachmentRow.swift in Sources */,
 				D6434EB3215B1856001A919A /* XCBRequest.swift in Sources */,
@@ -2080,6 +2079,7 @@
 				D6D4DDD0212518A000E1C4BB /* AppDelegate.swift in Sources */,
 				D6412B0924B0291E00F5412E /* MyProfileViewController.swift in Sources */,
 				D6A6C10525B6138A00298D0F /* StatusTablePrefetching.swift in Sources */,
+				D6C82B4125C5BB7E0017F1E6 /* ExploreViewController.swift in Sources */,
 				D6B053A423BD2C8100A066FA /* AssetCollectionsListViewController.swift in Sources */,
 				D690797324A4EF9700023A34 /* UIBezierPath+Helpers.swift in Sources */,
 				D693DE5723FE1A6A0061E07D /* EnhancedNavigationViewController.swift in Sources */,

Tusker/Screens/Explore/ExploreViewController.swift

@@ -10,23 +10,22 @@ import UIKit
 import Combine
 import Pachyderm
 
-class ExploreViewController: EnhancedTableViewController {
+class ExploreViewController: UIViewController, UICollectionViewDelegate {
 
     weak var mastodonController: MastodonController!
     
-    var dataSource: DataSource!
+    private var collectionView: UICollectionView!
+    private var dataSource: UICollectionViewDiffableDataSource<Section, Item>!
     
-    var resultsController: SearchResultsViewController!
+    private(set) var resultsController: SearchResultsViewController!
-    var searchController: UISearchController!
+    private(set) var searchController: UISearchController!
     
     var searchControllerStatusOnAppearance: Bool? = nil
     
     init(mastodonController: MastodonController) {
         self.mastodonController = mastodonController
         
-        super.init(style: .insetGrouped)
+        super.init(nibName: nil, bundle: nil)
-        
-        dragEnabled = true
         
         title = NSLocalizedString("Explore", comment: "explore tab title")
         tabBarItem.image = UIImage(systemName: "magnifyingglass")
@@ -39,62 +38,18 @@ class ExploreViewController: EnhancedTableViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
 
-        tableView.register(UINib(nibName: "BasicTableViewCell", bundle: .main), forCellReuseIdentifier: "basicCell")
+        var configuration = UICollectionLayoutListConfiguration(appearance: .insetGrouped)
+        configuration.trailingSwipeActionsConfigurationProvider = self.trailingSwipeActionsForCell(at:)
+        configuration.headerMode = .supplementary
+        let layout = UICollectionViewCompositionalLayout.list(using: configuration)
+        collectionView = UICollectionView(frame: view.bounds, collectionViewLayout: layout)
+        collectionView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        collectionView.delegate = self
+        collectionView.dragDelegate = self
+        view.addSubview(collectionView)
         
-        dataSource = DataSource(tableView: tableView, cellProvider: { (tableView, indexPath, item) -> UITableViewCell? in
+        dataSource = createDataSource()
-            let cell = tableView.dequeueReusableCell(withIdentifier: "basicCell", for: indexPath)
+        applyInitialSnapshot()
-            
-            switch item {
-            case .bookmarks:
-                cell.imageView!.image = UIImage(systemName: "bookmark.fill")
-                cell.textLabel!.text = NSLocalizedString("Bookmarks", comment: "bookmarks nav item title")
-                cell.accessoryType = .disclosureIndicator
-
-            case let .list(list):
-                cell.imageView!.image = UIImage(systemName: "list.bullet")
-                cell.textLabel!.text = list.title
-                cell.accessoryType = .disclosureIndicator
-
-            case .addList:
-                cell.imageView!.image = UIImage(systemName: "plus")
-                cell.textLabel!.text = NSLocalizedString("New List...", comment: "new list nav item title")
-                cell.accessoryType = .none
-                
-            case let .savedHashtag(hashtag):
-                cell.imageView!.image = UIImage(systemName: "number")
-                cell.textLabel!.text = hashtag.name
-                cell.accessoryType = .disclosureIndicator
-                
-            case .addSavedHashtag:
-                cell.imageView!.image = UIImage(systemName: "plus")
-                cell.textLabel!.text = NSLocalizedString("Save Hashtag...", comment: "save hashtag nav item title")
-                cell.accessoryType = .none
-                
-            case let .savedInstance(url):
-                cell.imageView!.image = UIImage(systemName: "globe")
-                cell.textLabel!.text = url.host!
-                cell.accessoryType = .disclosureIndicator
-                
-            case .findInstance:
-                cell.imageView!.image = UIImage(systemName: "magnifyingglass")
-                cell.textLabel!.text = NSLocalizedString("Find An Instance...", comment: "find instance nav item title")
-                cell.accessoryType = .none
-            }
-            
-            return cell
-        })
-        dataSource.exploreController = self
-        
-        let account = mastodonController.accountInfo!
-        
-        var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
-        snapshot.appendSections([.bookmarks, .lists, .savedHashtags, .savedInstances])
-        snapshot.appendItems([.bookmarks], toSection: .bookmarks)
-        snapshot.appendItems([.addList], toSection: .lists)
-        snapshot.appendItems(SavedDataManager.shared.sortedHashtags(for: account).map { .savedHashtag($0) } + [.addSavedHashtag], toSection: .savedHashtags)
-        snapshot.appendItems(SavedDataManager.shared.savedInstances(for: account).map { .savedInstance($0) } + [.findInstance], toSection: .savedInstances)
-        // the initial, static items should not be displayed with an animation
-        dataSource.apply(snapshot, animatingDifferences: false)
         
         resultsController = SearchResultsViewController(mastodonController: mastodonController)
         resultsController.exploreNavigationController = self.navigationController!
@@ -109,8 +64,20 @@ class ExploreViewController: EnhancedTableViewController {
         
         NotificationCenter.default.addObserver(self, selector: #selector(savedHashtagsChanged), name: .savedHashtagsChanged, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(savedInstancesChanged), name: .savedInstancesChanged, object: nil)
+    }
     
-        reloadLists()
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        
+        // Can't use UICollectionViewController's builtin version of this because it requires
+        // the collection view layout be passed into the constructor. Swipe actions for list collection views
+        // are created by passing a closure to the layout's configuration. This closure needs to capture
+        // `self`, so it can't be passed into the super constructor.
+        if let indexPaths = collectionView.indexPathsForSelectedItems {
+            for indexPath in indexPaths {
+                collectionView.deselectItem(at: indexPath, animated: true)
+            }
+        }
     }
     
     override func viewDidAppear(_ animated: Bool) {
@@ -125,16 +92,69 @@ class ExploreViewController: EnhancedTableViewController {
         }
     }
     
-    func reloadLists() {
+    private func createDataSource() -> UICollectionViewDiffableDataSource<Section, Item> {
+        let sectionHeaderCell = UICollectionView.SupplementaryRegistration<UICollectionViewListCell>(elementKind: UICollectionView.elementKindSectionHeader) { (headerView, collectionView, indexPath) in
+            let section = self.dataSource.snapshot().sectionIdentifiers[indexPath.section]
+            
+            var config = headerView.defaultContentConfiguration()
+            config.text = section.label
+            headerView.contentConfiguration = config
+        }
+        
+        let listCell = UICollectionView.CellRegistration<UICollectionViewListCell, Item> { (cell, indexPath, item) in
+            var config = cell.defaultContentConfiguration()
+            config.text = item.label
+            config.image = item.image
+            cell.contentConfiguration = config
+
+            switch item {
+            case .addList, .addSavedHashtag, .findInstance:
+                cell.accessories = []
+            default:
+                cell.accessories = [.disclosureIndicator()]
+            }
+        }
+        
+        let dataSource = UICollectionViewDiffableDataSource<Section, Item>(collectionView: collectionView) { (collectionView, indexPath, item) in
+            return collectionView.dequeueConfiguredReusableCell(using: listCell, for: indexPath, item: item)
+        }
+        dataSource.supplementaryViewProvider = { (collectionView, elementKind, indexPath) in
+            if elementKind == UICollectionView.elementKindSectionHeader {
+                return collectionView.dequeueConfiguredReusableSupplementary(using: sectionHeaderCell, for: indexPath)
+            } else {
+                return nil
+            }
+        }
+        return dataSource
+    }
+
+    private func applyInitialSnapshot() {
+        let account = mastodonController.accountInfo!
+        
+        var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
+        snapshot.appendSections(Section.allCases)
+        snapshot.appendItems([.bookmarks], toSection: .bookmarks)
+        snapshot.appendItems([.addList], toSection: .lists)
+        snapshot.appendItems(SavedDataManager.shared.sortedHashtags(for: account).map { .savedHashtag($0) }, toSection: .savedHashtags)
+        snapshot.appendItems([.addSavedHashtag], toSection: .savedHashtags)
+        snapshot.appendItems(SavedDataManager.shared.savedInstances(for: account).map { .savedInstance($0) }, toSection: .savedInstances)
+        snapshot.appendItems([.findInstance], toSection: .savedInstances)
+        dataSource.apply(snapshot, animatingDifferences: false)
+        
+        reloadLists()
+    }
+    
+    private func reloadLists() {
         let request = Client.getLists()
         mastodonController.run(request) { (response) in
             guard case let .success(lists, _) = response else {
-                fatalError()
+                return
             }
             
             var snapshot = self.dataSource.snapshot()
             snapshot.deleteItems(snapshot.itemIdentifiers(inSection: .lists))
-            snapshot.appendItems(lists.map { .list($0) } + [.addList], toSection: .lists)
+            snapshot.appendItems(lists.map { .list($0) }, toSection: .lists)
+            snapshot.appendItems([.addList], toSection: .lists)
             
             DispatchQueue.main.async {
                 self.dataSource.apply(snapshot)
@@ -142,26 +162,31 @@ class ExploreViewController: EnhancedTableViewController {
         }
     }
     
-    @objc func savedHashtagsChanged() {
+    @objc private func savedHashtagsChanged() {
         let account = mastodonController.accountInfo!
         var snapshot = dataSource.snapshot()
         snapshot.deleteItems(snapshot.itemIdentifiers(inSection: .savedHashtags))
-        snapshot.appendItems(SavedDataManager.shared.sortedHashtags(for: account).map { .savedHashtag($0) } + [.addSavedHashtag], toSection: .savedHashtags)
+        snapshot.appendItems(SavedDataManager.shared.sortedHashtags(for: account).map { .savedHashtag($0) }, toSection: .savedHashtags)
+        snapshot.appendItems([.addSavedHashtag], toSection: .savedHashtags)
         dataSource.apply(snapshot)
     }
     
-    @objc func savedInstancesChanged() {
+    @objc private func savedInstancesChanged() {
         let account = mastodonController.accountInfo!
         var snapshot = dataSource.snapshot()
         snapshot.deleteItems(snapshot.itemIdentifiers(inSection: .savedInstances))
-        snapshot.appendItems(SavedDataManager.shared.savedInstances(for: account).map { .savedInstance($0) } + [.findInstance], toSection: .savedInstances)
+        snapshot.appendItems(SavedDataManager.shared.savedInstances(for: account).map { .savedInstance($0) }, toSection: .savedInstances)
+        snapshot.appendItems([.findInstance], toSection: .savedInstances)
         dataSource.apply(snapshot)
     }
     
-    func deleteList(_ list: List) {
+    private func deleteList(_ list: List, completion: @escaping (Bool) -> Void) {
-        let title = String(format: NSLocalizedString("Are you sure want to delete the '%@' list?", comment: "delete list alert title"), list.title)
+        let titleFormat = NSLocalizedString("Are you sure you want to delete the '%@' list?", comment: "delete list alert title")
+        let title = String(format: titleFormat, list.title)
         let alert = UIAlertController(title: title, message: nil, preferredStyle: .alert)
-        alert.addAction(UIAlertAction(title: NSLocalizedString("Cancel", comment: "delete list alert cancel button"), style: .cancel, handler: nil))
+        alert.addAction(UIAlertAction(title: NSLocalizedString("Cancel", comment: "delete list alert cancel button"), style: .cancel, handler: { (_) in
+            completion(false)
+        }))
         alert.addAction(UIAlertAction(title: NSLocalizedString("Delete List", comment: "delete list alert confirm button"), style: .destructive, handler: { (_) in
             
             let request = List.delete(list)
@@ -174,6 +199,7 @@ class ExploreViewController: EnhancedTableViewController {
                 snapshot.deleteItems([.list(list)])
                 DispatchQueue.main.async {
                     self.dataSource.apply(snapshot)
+                    completion(true)
                 }
             }
         }))
@@ -190,9 +216,38 @@ class ExploreViewController: EnhancedTableViewController {
         SavedDataManager.shared.remove(instance: instanceURL, for: account)
     }
     
-    // MARK: - Table view delegate
+    private func trailingSwipeActionsForCell(at indexPath: IndexPath) -> UISwipeActionsConfiguration? {
+        let handler: UIContextualAction.Handler
+        switch dataSource.itemIdentifier(for: indexPath) {
+        case let .list(list):
+            handler = { (_, _, completion) in
+                self.deleteList(list, completion: completion)
+            }
             
-    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
+        case let .savedHashtag(hashtag):
+            handler = { (_, _, completion) in
+                self.removeSavedHashtag(hashtag)
+                completion(true)
+            }
+            
+        case let .savedInstance(url):
+            handler = { (_, _, completion) in
+                self.removeSavedInstance(url)
+                completion(true)
+            }
+        
+        default:
+            return nil
+        }
+        
+        return UISwipeActionsConfiguration(actions: [
+            UIContextualAction(style: .destructive, title: NSLocalizedString("Delete", comment: "delete swipe action title"), handler: handler)
+        ])
+    }
+    
+    // MARK: - Collection View Delegate
+    
+    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
         switch dataSource.itemIdentifier(for: indexPath) {
         case nil:
             return
@@ -204,7 +259,7 @@ class ExploreViewController: EnhancedTableViewController {
             show(ListTimelineViewController(for: list, mastodonController: mastodonController), sender: nil)
             
         case .addList:
-            tableView.selectRow(at: nil, animated: true, scrollPosition: .none)
+            collectionView.deselectItem(at: indexPath, animated: true)
             let alert = UIAlertController(title: NSLocalizedString("New List", comment: "new list alert title"), message: NSLocalizedString("Choose a title for your new list", comment: "new list alert message"), preferredStyle: .alert)
             alert.addTextField(configurationHandler: nil)
             alert.addAction(UIAlertAction(title: NSLocalizedString("Cancel", comment: "new list alert cancel button"), style: .cancel, handler: nil))
@@ -232,7 +287,7 @@ class ExploreViewController: EnhancedTableViewController {
             show(HashtagTimelineViewController(for: hashtag, mastodonController: mastodonController), sender: nil)
             
         case .addSavedHashtag:
-            tableView.selectRow(at: nil, animated: true, scrollPosition: .none)
+            collectionView.deselectItem(at: indexPath, animated: true)
             let navController = UINavigationController(rootViewController: AddSavedHashtagViewController(mastodonController: mastodonController))
             present(navController, animated: true)
             
@@ -240,7 +295,7 @@ class ExploreViewController: EnhancedTableViewController {
             show(InstanceTimelineViewController(for: url, parentMastodonController: mastodonController), sender: nil)
             
         case .findInstance:
-            tableView.selectRow(at: nil, animated: true, scrollPosition: .none)
+            collectionView.deselectItem(at: indexPath, animated: true)
             let findController = FindInstanceViewController(parentMastodonController: mastodonController)
             findController.instanceTimelineDelegate = self
             let navController = UINavigationController(rootViewController: findController)
@@ -248,37 +303,6 @@ class ExploreViewController: EnhancedTableViewController {
         }
     }
     
-    override func tableView(_ tableView: UITableView, editingStyleForRowAt indexPath: IndexPath) -> UITableViewCell.EditingStyle {
-        return .delete
-    }
-    
-    override func tableView(_ tableView: UITableView, contextMenuConfigurationForRowAt indexPath: IndexPath, point: CGPoint) -> UIContextMenuConfiguration? {
-        switch dataSource.itemIdentifier(for: indexPath) {
-        case .bookmarks:
-            return UIContextMenuConfiguration(identifier: nil, previewProvider: {
-                return BookmarksTableViewController(mastodonController: self.mastodonController)
-            }, actionProvider: nil)
-            
-        case let .list(list):
-            return UIContextMenuConfiguration(identifier: nil, previewProvider: {
-                return ListTimelineViewController(for: list, mastodonController: self.mastodonController)
-            }, actionProvider: nil)
-            
-        case let .savedHashtag(hashtag):
-            return UIContextMenuConfiguration(identifier: nil, previewProvider: {
-                return HashtagTimelineViewController(for: hashtag, mastodonController: self.mastodonController)
-            }, actionProvider: nil)
-            
-        case let .savedInstance(url):
-            return UIContextMenuConfiguration(identifier: nil, previewProvider: {
-                return InstanceTimelineViewController(for: url, parentMastodonController: self.mastodonController)
-            }, actionProvider: nil)
-            
-        default:
-            return nil
-        }
-    }
-    
 }
 
 extension ExploreViewController {
@@ -287,7 +311,21 @@ extension ExploreViewController {
         case lists
         case savedHashtags
         case savedInstances
+        
+        var label: String? {
+            switch self {
+            case .bookmarks:
+                return  nil
+            case .lists:
+                return NSLocalizedString("Lists", comment: "explore lists section title")
+            case .savedHashtags:
+                return NSLocalizedString("Saved Hashtags", comment: "explore saved hashtags section title")
+            case .savedInstances:
+                return NSLocalizedString("Instance Timelines", comment: "explore instance timelines section title")
             }
+        }
+    }
+    
     enum Item: Hashable {
         case bookmarks
         case list(List)
@@ -297,7 +335,45 @@ extension ExploreViewController {
         case savedInstance(URL)
         case findInstance
         
-        static func == (lhs: ExploreViewController.Item, rhs: ExploreViewController.Item) -> Bool {
+        var label: String {
+            switch self {
+            case .bookmarks:
+                return NSLocalizedString("Bookmarks", comment: "bookmarks nav item title")
+            case let .list(list):
+                return list.title
+            case .addList:
+                return NSLocalizedString("New List...", comment: "new list nav item title")
+            case let .savedHashtag(hashtag):
+                return hashtag.name
+            case .addSavedHashtag:
+                return NSLocalizedString("Save Hashtag...", comment: "save hashtag nav item title")
+            case let .savedInstance(url):
+                return url.host!
+            case .findInstance:
+                return NSLocalizedString("Find An Instance...", comment: "find instance nav item title")
+            }
+        }
+        
+        var image: UIImage {
+            let name: String
+            switch self {
+            case .bookmarks:
+                name = "bookmark.fill"
+            case .list(_):
+                name = "list.bullet"
+            case .addList, .addSavedHashtag:
+                name = "plus"
+            case .savedHashtag(_):
+                name = "number"
+            case .savedInstance(_):
+                name = "globe"
+            case .findInstance:
+                name = "magnifyingglass"
+            }
+            return UIImage(systemName: name)!
+        }
+        
+        static func == (lhs: Item, rhs: Item) -> Bool {
             switch (lhs, rhs) {
             case (.bookmarks, .bookmarks):
                 return true
@@ -317,6 +393,7 @@ extension ExploreViewController {
                 return false
             }
         }
+        
         func hash(into hasher: inout Hasher) {
             switch self {
             case .bookmarks:
@@ -339,57 +416,6 @@ extension ExploreViewController {
             }
         }
     }
-    
-    class DataSource: UITableViewDiffableDataSource<Section, Item> {
-        
-        weak var exploreController: ExploreViewController?
-        
-        override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
-            switch section {
-            case 1:
-                return NSLocalizedString("Lists", comment: "explore lists section title")
-            case 2:
-                return NSLocalizedString("Saved Hashtags", comment: "explore saved hashtags section title")
-            case 3:
-                return NSLocalizedString("Instance Timelines", comment: "explore instance timelines section title")
-            default:
-                return nil
-            }
-        }
-        
-        override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
-            switch itemIdentifier(for: indexPath) {
-            case .list(_):
-                return true
-            case .savedHashtag(_):
-                return true
-            case .savedInstance(_):
-                return true
-            default:
-                return false
-            }
-        }
-
-        override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
-            guard editingStyle == .delete,
-                let exploreController = exploreController else {
-                return
-            }
-            
-            switch itemIdentifier(for: indexPath) {
-            case let .list(list):
-                exploreController.deleteList(list)
-            case let .savedHashtag(hashtag):
-                exploreController.removeSavedHashtag(hashtag)
-            case let .savedInstance(url):
-                exploreController.removeSavedInstance(url)
-            default:
-                return
-            }
-
-        }
-        
-    }
 }
 
 extension ExploreViewController: InstanceTimelineViewControllerDelegate {
@@ -404,12 +430,13 @@ extension ExploreViewController: InstanceTimelineViewControllerDelegate {
     }
 }
 
-extension ExploreViewController {
+extension ExploreViewController: UICollectionViewDragDelegate {
-    override func tableView(_ tableView: UITableView, itemsForBeginning session: UIDragSession, at indexPath: IndexPath) -> [UIDragItem] {
+    func collectionView(_ collectionView: UICollectionView, itemsForBeginning session: UIDragSession, at indexPath: IndexPath) -> [UIDragItem] {
         guard let item = dataSource.itemIdentifier(for: indexPath),
               let accountID = mastodonController.accountInfo?.id else {
             return []
         }
+        
         let provider: NSItemProvider
         switch item {
         case .bookmarks:
@@ -425,11 +452,7 @@ extension ExploreViewController {
         case let .savedInstance(url):
             provider = NSItemProvider(object: url as NSURL)
             // todo: should dragging public timelines into new windows be supported?
-        case .addList:
+        case .addList, .addSavedHashtag, .findInstance:
-            return []
-        case .addSavedHashtag:
-            return []
-        case .findInstance:
             return []
         }
         return [UIDragItem(itemProvider: provider)]