State restoration

Reader.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		D608238D27DE729E00D7D5F9 /* ItemListType.swift in Sources */ = {isa = PBXBuildFile; fileRef = D608238C27DE729E00D7D5F9 /* ItemListType.swift */; };
 		D65B18B22750469D004A9448 /* LoginViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B18B12750469D004A9448 /* LoginViewController.swift */; };
 		D65B18B4275048D9004A9448 /* ClientRegistration.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B18B3275048D9004A9448 /* ClientRegistration.swift */; };
 		D65B18B627504920004A9448 /* FervorController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D65B18B527504920004A9448 /* FervorController.swift */; };
@@ -116,6 +117,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		D608238C27DE729E00D7D5F9 /* ItemListType.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ItemListType.swift; sourceTree = "<group>"; };
 		D65B18B12750469D004A9448 /* LoginViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LoginViewController.swift; sourceTree = "<group>"; };
 		D65B18B3275048D9004A9448 /* ClientRegistration.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ClientRegistration.swift; sourceTree = "<group>"; };
 		D65B18B527504920004A9448 /* FervorController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FervorController.swift; sourceTree = "<group>"; };
@@ -324,6 +326,7 @@
 				D68B303527907D9200E8B3FA /* ExcerptGenerator.swift */,
 				D68B304127932ED500E8B3FA /* UserActivities.swift */,
 				D68408EE2794808E00E327D2 /* Preferences.swift */,
+				D608238C27DE729E00D7D5F9 /* ItemListType.swift */,
 				D6A8A33527766E9300CCEC72 /* CoreData */,
 				D65B18AF2750468B004A9448 /* Screens */,
 				D6C687F7272CD27700874C10 /* Assets.xcassets */,
@@ -632,6 +635,7 @@
 			files = (
 				D6A8A33427766C2800CCEC72 /* PersistentContainer.swift in Sources */,
 				D6E24357278B96E40005E546 /* Feed+CoreDataClass.swift in Sources */,
+				D608238D27DE729E00D7D5F9 /* ItemListType.swift in Sources */,
 				D65B18B627504920004A9448 /* FervorController.swift in Sources */,
 				D68B304227932ED500E8B3FA /* UserActivities.swift in Sources */,
 				D6C687EC272CD27600874C10 /* AppDelegate.swift in Sources */,

Reader/FervorController.swift

@@ -155,6 +155,17 @@ actor FervorController {
         }
     }
     
+    @MainActor
+    func fetchItem(id: String) async throws -> Item? {
+        guard let serverItem = try await client.item(id: id) else {
+            return nil
+        }
+        let item = Item(context: persistentContainer.viewContext)
+        item.updateFromServer(serverItem)
+        try persistentContainer.saveViewContext()
+        return item
+    }
+    
 }
 
 extension FervorController {

Reader/Info.plist

@@ -8,6 +8,7 @@
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.read-all</string>
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.read-feed</string>
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.read-group</string>
+		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.read-item</string>
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.preferences</string>
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.add-account</string>
 		<string>$(PRODUCT_BUNDLE_IDENTIFIER).activity.activate-account</string>

Reader/ItemListType.swift

@@ -0,0 +1,60 @@
+//
+//  ItemListType.swift
+//  Reader
+//
+//  Created by Shadowfacts on 3/13/22.
+//
+
+import Foundation
+import CoreData
+
+enum ItemListType: Hashable {
+    case unread
+    case all
+    case group(Group)
+    case feed(Feed)
+    
+    var title: String {
+        switch self {
+        case .unread:
+            return "Unread Articles"
+        case .all:
+            return "All Articles"
+        case let .group(group):
+            return group.title
+        case let .feed(feed):
+            return feed.title!
+        }
+    }
+    
+    var idFetchRequest: NSFetchRequest<NSManagedObjectID> {
+        let req = NSFetchRequest<NSManagedObjectID>(entityName: "Item")
+        req.resultType = .managedObjectIDResultType
+        switch self {
+        case .unread:
+            req.predicate = NSPredicate(format: "read = NO")
+        case .all:
+            break
+        case .group(let group):
+            req.predicate = NSPredicate(format: "feed in %@", group.feeds!)
+        case .feed(let feed):
+            req.predicate = NSPredicate(format: "feed = %@", feed)
+        }
+        return req
+    }
+    
+    var countFetchRequest: NSFetchRequest<Reader.Item>? {
+        let req = Reader.Item.fetchRequest()
+        switch self {
+        case .unread:
+            req.predicate = NSPredicate(format: "read = NO")
+        case .all:
+            return nil
+        case .group(let group):
+            req.predicate = NSPredicate(format: "read = NO AND feed in %@", group.feeds!)
+        case .feed(let feed):
+            req.predicate = NSPredicate(format: "read = NO AND feed = %@", feed)
+        }
+        return req
+    }
+}

Reader/SceneDelegate.swift

@@ -27,7 +27,7 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         window = UIWindow(windowScene: windowScene)
         window!.tintColor = .appTintColor
         
-        var activity = connectionOptions.userActivities.first
+        var activity = connectionOptions.userActivities.first ?? session.stateRestorationActivity
         
         var account = LocalData.mostRecentAccount()
         
@@ -47,7 +47,7 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
                 syncFromServer()
                 createAppUI()
                 if let activity = activity {
-                    setupUI(from: activity)
+                    await setupUI(from: activity)
                 }
                 setupSceneActivationConditions()
             }
@@ -108,39 +108,61 @@ class SceneDelegate: UIResponder, UIWindowSceneDelegate {
         // to restore the scene back to its current state.
     }
     
-    func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {
-        setupUI(from: userActivity)
+    func stateRestorationActivity(for scene: UIScene) -> NSUserActivity? {
+        return (window!.rootViewController as! AppSplitViewController).stateRestorationActivity()
     }
     
-    private func setupUI(from activity: NSUserActivity) {
+    func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {
+        Task { @MainActor in
+            await setupUI(from: userActivity)
+        }
+    }
+    
+    private func setupUI(from activity: NSUserActivity) async {
         guard let split = window?.rootViewController as? AppSplitViewController else {
             logger.error("Failed to setup UI for user activity: missing split VC")
             return
         }
         switch activity.activityType {
         case NSUserActivity.readUnreadType:
-            split.selectHomeItem(.unread)
+            split.showItemList(.unread)
         case NSUserActivity.readAllType:
-            split.selectHomeItem(.all)
+            split.showItemList(.all)
         case NSUserActivity.readFeedType:
-            guard let feedID = activity.feedID() else {
+            guard let feedID = activity.feedID else {
                 break
             }
             let req = Feed.fetchRequest()
             req.predicate = NSPredicate(format: "id = %@", feedID)
             if let feed = try? fervorController.persistentContainer.viewContext.fetch(req).first {
-                split.selectHomeItem(.feed(feed))
+                split.showItemList(.feed(feed))
             }
         case NSUserActivity.readGroupType:
-            guard let groupID = activity.groupID() else {
+            guard let groupID = activity.groupID else {
                 break
             }
             let req = Group.fetchRequest()
             req.predicate = NSPredicate(format: "id = %@", groupID)
             if let group = try? fervorController.persistentContainer.viewContext.fetch(req).first {
-                split.selectHomeItem(.group(group))
+                split.showItemList(.group(group))
             }
+        case NSUserActivity.readItemType:
+            guard let itemID = activity.itemID else {
+                break
+            }
+            let req = Item.fetchRequest()
+            req.predicate = NSPredicate(format: "id = %@", itemID)
+            var read: ReadViewController? = nil
+            if let item = try? fervorController.persistentContainer.viewContext.fetch(req).first {
+                read = split.showItem(item)
+            } else {
+                if let item = try? await fervorController.fetchItem(id: itemID) {
+                    read = split.showItem(item)
+                }
+            }
+            read?.restoreUserActivityState(activity)
         default:
+            logger.warning("Unknown user activity type: \(activity.activityType)")
             break
         }
     }

Reader/Screens/AppSplitViewController.swift

@@ -54,7 +54,28 @@ class AppSplitViewController: UISplitViewController {
         setViewController(nav, for: .compact)
     }
     
-    func selectHomeItem(_ item: HomeViewController.Item) {
+    func stateRestorationActivity() -> NSUserActivity? {
+        if traitCollection.horizontalSizeClass == .compact {
+            let nav = viewController(for: .compact) as! UINavigationController
+            let top = nav.topViewController!
+            if top is ReadViewController || top is ItemsViewController {
+                print(top.userActivity?.activityType)
+                return top.userActivity
+            }
+        } else {
+            if let read = secondaryNav.topViewController {
+                return read.userActivity
+            } else {
+                let homeNav = viewController(for: .primary) as! UINavigationController
+                if homeNav.topViewController is ItemsViewController {
+                    return homeNav.topViewController!.userActivity
+                }
+            }
+        }
+        return nil
+    }
+    
+    func showItemList(_ type: ItemListType) {
         let column: Column
         if traitCollection.horizontalSizeClass == .compact {
             column = .compact
@@ -63,7 +84,34 @@ class AppSplitViewController: UISplitViewController {
         }
         let nav = viewController(for: column) as! UINavigationController
         let home = nav.viewControllers.first! as! HomeViewController
-        home.selectItem(item)
+        home.selectItem(type)
+    }
+    
+    func showItem(_ item: Item) -> ReadViewController {
+        if traitCollection.horizontalSizeClass == .compact {
+            let nav = viewController(for: .compact) as! UINavigationController
+            // todo: should we try to show the right items list?
+            while nav.viewControllers.count > 2 {
+                if let current = nav.topViewController as? ReadViewController,
+                   current.item == item {
+                    return current
+                } else {
+                    nav.popViewController(animated: false)
+                }
+            }
+            let read = ReadViewController(item: item, fervorController: fervorController)
+            nav.pushViewController(read, animated: false)
+            return read
+        } else {
+            if let current = secondaryNav.topViewController as? ReadViewController,
+               current.item == item {
+                return current
+            } else {
+                let read = ReadViewController(item: item, fervorController: fervorController)
+                secondaryNav.setViewControllers([read], animated: false)
+                return read
+            }
+        }
     }
 
 }

Reader/Screens/Home/HomeViewController.swift

@@ -23,7 +23,7 @@ class HomeViewController: UIViewController {
     var enableStretchyMenu = true
     
     private var collectionView: UICollectionView!
-    private var dataSource: UICollectionViewDiffableDataSource<Section, Item>!
+    private var dataSource: UICollectionViewDiffableDataSource<Section, ItemListType>!
     private var groupResultsController: NSFetchedResultsController<Group>!
     private var feedResultsController: NSFetchedResultsController<Feed>!
     
@@ -76,7 +76,7 @@ class HomeViewController: UIViewController {
         
         dataSource = createDataSource()
         
-        var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
+        var snapshot = NSDiffableDataSourceSnapshot<Section, ItemListType>()
         snapshot.appendSections([.all, .groups, .feeds])
         snapshot.appendItems([.unread, .all], toSection: .all)
         dataSource.apply(snapshot, animatingDifferences: false)
@@ -116,14 +116,14 @@ class HomeViewController: UIViewController {
         dataSource.apply(snapshot)
     }
     
-    private func createDataSource() -> UICollectionViewDiffableDataSource<Section, Item> {
+    private func createDataSource() -> UICollectionViewDiffableDataSource<Section, ItemListType> {
         let sectionHeaderCell = UICollectionView.SupplementaryRegistration<UICollectionViewListCell>(elementKind: UICollectionView.elementKindSectionHeader) { supplementaryView, elementKind, indexPath in
             let section = self.dataSource.sectionIdentifier(for: indexPath.section)!
             var config = supplementaryView.defaultContentConfiguration()
             config.text = section.title
             supplementaryView.contentConfiguration = config
         }
-        let listCell = UICollectionView.CellRegistration<HomeCollectionViewCell, Item> { cell, indexPath, item in
+        let listCell = UICollectionView.CellRegistration<HomeCollectionViewCell, ItemListType> { cell, indexPath, item in
             var config = UIListContentConfiguration.valueCell()
             config.text = item.title
             if let req = item.countFetchRequest,
@@ -135,7 +135,7 @@ class HomeViewController: UIViewController {
             
             cell.accessories = [.disclosureIndicator()]
         }
-        let dataSource = UICollectionViewDiffableDataSource<Section, Item>(collectionView: collectionView) { collectionView, indexPath, item in
+        let dataSource = UICollectionViewDiffableDataSource<Section, ItemListType>(collectionView: collectionView) { collectionView, indexPath, item in
             return collectionView.dequeueConfiguredReusableCell(using: listCell, for: indexPath, item: item)
         }
         dataSource.supplementaryViewProvider = { collectionView, elementKind, indexPath in
@@ -206,26 +206,26 @@ class HomeViewController: UIViewController {
         }
     }
     
-    private func itemsViewController(for item: Item) -> ItemsViewController {
-        let vc = ItemsViewController(fetchRequest: item.idFetchRequest, fervorController: fervorController)
-        vc.title = item.title
+    private func itemsViewController(for item: ItemListType) -> ItemsViewController {
+        let vc = ItemsViewController(type: item, fervorController: fervorController)
         vc.delegate = itemsDelegate
-        switch item {
-        case .all:
-            vc.userActivity = .readAll(account: fervorController.account!)
-        case .unread:
-            vc.userActivity = .readUnread(account: fervorController.account!)
-        case .group(let group):
-            vc.userActivity = .readGroup(group, account: fervorController.account!)
-        case .feed(let feed):
-            vc.userActivity = .readFeed(feed, account: fervorController.account!)
-        }
         return vc
     }
     
-    func selectItem(_ item: Item) {
-        navigationController!.popToRootViewController(animated: false)
-        navigationController!.pushViewController(itemsViewController(for: item), animated: false)
+    func selectItem(_ item: ItemListType) {
+        guard let navigationController = navigationController else {
+            return
+        }
+        if navigationController.viewControllers.count >= 2,
+           let second = navigationController.viewControllers[1] as? ItemsViewController,
+           second.type == item {
+            while navigationController.viewControllers.count > 2 {
+                navigationController.popViewController(animated: false)
+            }
+        } else {
+            navigationController.popToRootViewController(animated: false)
+            navigationController.pushViewController(itemsViewController(for: item), animated: false)
+        }
     }
     
 }
@@ -247,56 +247,6 @@ extension HomeViewController {
             }
         }
     }
-    enum Item: Hashable {
-        case unread
-        case all
-        case group(Group)
-        case feed(Feed)
-        
-        var title: String {
-            switch self {
-            case .unread:
-                return "Unread Articles"
-            case .all:
-                return "All Articles"
-            case let .group(group):
-                return group.title
-            case let .feed(feed):
-                return feed.title!
-            }
-        }
-        
-        var idFetchRequest: NSFetchRequest<NSManagedObjectID> {
-            let req = NSFetchRequest<NSManagedObjectID>(entityName: "Item")
-            req.resultType = .managedObjectIDResultType
-            switch self {
-            case .unread:
-                req.predicate = NSPredicate(format: "read = NO")
-            case .all:
-                break
-            case .group(let group):
-                req.predicate = NSPredicate(format: "feed in %@", group.feeds!)
-            case .feed(let feed):
-                req.predicate = NSPredicate(format: "feed = %@", feed)
-            }
-            return req
-        }
-        
-        var countFetchRequest: NSFetchRequest<Reader.Item>? {
-            let req = Reader.Item.fetchRequest()
-            switch self {
-            case .unread:
-                req.predicate = NSPredicate(format: "read = NO")
-            case .all:
-                return nil
-            case .group(let group):
-                req.predicate = NSPredicate(format: "read = NO AND feed in %@", group.feeds!)
-            case .feed(let feed):
-                req.predicate = NSPredicate(format: "read = NO AND feed = %@", feed)
-            }
-            return req
-        }
-    }
 }
 
 extension HomeViewController: NSFetchedResultsControllerDelegate {

Reader/Screens/Items/ItemsViewController.swift

@@ -18,20 +18,32 @@ class ItemsViewController: UIViewController {
     weak var delegate: ItemsViewControllerDelegate?
     
     let fervorController: FervorController
-    let fetchRequest: NSFetchRequest<NSManagedObjectID>
+    let type: ItemListType
+    private let fetchRequest: NSFetchRequest<NSManagedObjectID>
     
     private var collectionView: UICollectionView!
     private var dataSource: UICollectionViewDiffableDataSource<Section, NSManagedObjectID>!
     
     private var batchUpdates: [() -> Void] = []
     
-    init(fetchRequest: NSFetchRequest<NSManagedObjectID>, fervorController: FervorController) {
-        precondition(fetchRequest.entityName == "Item")
-        
+    init(type: ItemListType, fervorController: FervorController) {
         self.fervorController = fervorController
-        self.fetchRequest = fetchRequest
+        self.type = type
+        self.fetchRequest = type.idFetchRequest
         
         super.init(nibName: nil, bundle: nil)
+        
+        self.title = type.title
+        switch type {
+        case .all:
+            self.userActivity = .readAll(account: fervorController.account!)
+        case .unread:
+            self.userActivity = .readUnread(account: fervorController.account!)
+        case .group(let group):
+            self.userActivity = .readGroup(group, account: fervorController.account!)
+        case .feed(let feed):
+            self.userActivity = .readFeed(feed, account: fervorController.account!)
+        }
     }
     
     required init?(coder: NSCoder) {

Reader/Screens/Read/ReadViewController.swift

@@ -9,6 +9,7 @@ import UIKit
 import WebKit
 import HTMLEntities
 import SafariServices
+import Combine
 
 class ReadViewController: UIViewController {
     
@@ -22,6 +23,10 @@ class ReadViewController: UIViewController {
     let fervorController: FervorController
     let item: Item
     
+    private let scrollPositionChangedSubject = PassthroughSubject<Void, Never>()
+    private var cancellables = Set<AnyCancellable>()
+    private var scrollTargetSelector: String?
+    
     private var webView: WKWebView!
     
     #if targetEnvironment(macCatalyst)
@@ -41,6 +46,8 @@ class ReadViewController: UIViewController {
         self.item = item
         
         super.init(nibName: nil, bundle: nil)
+        
+        self.userActivity = .readItem(item, account: fervorController.account!)
     }
     
     required init?(coder: NSCoder) {
@@ -59,6 +66,7 @@ class ReadViewController: UIViewController {
         webView.translatesAutoresizingMaskIntoConstraints = false
         webView.navigationDelegate = self
         webView.uiDelegate = self
+        webView.scrollView.delegate = self
         // transparent background required to prevent white flash in dark mode, just using .appBackground doesn't work
         webView.isOpaque = false
         webView.backgroundColor = .clear
@@ -78,6 +86,13 @@ class ReadViewController: UIViewController {
             activityItemsConfiguration = UIActivityItemsConfiguration(objects: [url as NSURL])
         }
         
+        scrollPositionChangedSubject
+            .debounce(for: .milliseconds(500), scheduler: RunLoop.main)
+            .sink { [unowned self] in
+                self.updateUserActivityScrollPosition()
+            }
+            .store(in: &cancellables)
+        
         #if targetEnvironment(macCatalyst)
         itemReadObservation = item.observe(\.read) { [unowned self] _, _ in
             self.updateToggleReadToolbarImage()
@@ -97,6 +112,44 @@ class ReadViewController: UIViewController {
         updateScrollIndicatorStyle()
     }
     
+    override func restoreUserActivityState(_ activity: NSUserActivity) {
+        if let selector = activity.topElementSelector {
+            scrollTargetSelector = selector
+            if isViewLoaded {
+                scrollToTargetSelector()
+            }
+        }
+    }
+    
+    private func scrollToTargetSelector() {
+        guard let selector = scrollTargetSelector else {
+            return
+        }
+        
+        let js = """
+        const doScroll = () => {
+            const el = document.querySelector(sel);
+            if (!el) {
+                throw new Error("not ready yet");
+            }
+            el.scrollIntoView();
+        };
+        if (document.readyState !== "complete") {
+            window.addEventListener("load", doScroll);
+        } else {
+            doScroll();
+        }
+        """
+        webView.callAsyncJavaScript(js, arguments: ["sel": selector], in: nil, in: .defaultClient) { result in
+            switch result {
+            case .failure(let error):
+                print(error)
+            case .success(_):
+                self.scrollTargetSelector = nil
+            }
+        }
+    }
+    
     private func updateScrollIndicatorStyle() {
         guard #available(iOS 15.4, *) else {
             // different workaround pre-iOS 15.4
@@ -171,6 +224,55 @@ class ReadViewController: UIViewController {
         return vc
     }
     
+    func updateUserActivityScrollPosition() {
+        // can't use needsSave and updateUserActivityState(_:) because running JS is asynchronous
+        let js = """
+        (() => {
+            function topVisibleChild(element) {
+                if (element.children.length <= 0 || element.tagName === "svg") {
+                    return element;
+                }
+                let min, minDistanceToTop;
+                for (const c of element.children) {
+                    const rect = c.getBoundingClientRect();
+                    if (!min || Math.abs(rect.top) < minDistanceToTop) {
+                        min = c;
+                        minDistanceToTop = Math.abs(rect.top);
+                    }
+                }
+                return topVisibleChild(min);
+            }
+            function uniqueSelector(self) {
+                if (!self) {
+                    return null;
+                } else if (self.tagName === "BODY") {
+                    return "body";
+                } else {
+                    let selfSel;
+                    if (self.id) {
+                        return `#${self.id}`;
+                    } else if (Array.from(self.parentNode.children).filter((e) => e.tagName === self.tagName).length === 1) {
+                        selfSel = ` > ${self.tagName.toLowerCase()}`;
+                    } else {
+                        const index = Array.from(self.parentNode.children).indexOf(self);
+                        selfSel = ` > ${self.tagName.toLowerCase()}:nth-child(${index + 1})`;
+                    }
+                    const parentSel = uniqueSelector(self.parentNode);
+                    return parentSel + selfSel;
+                }
+            }
+            return uniqueSelector(topVisibleChild(document.getElementById("item-content")));
+        })()
+        """
+        // todo: check if <source> can be scrolled into view
+        webView.evaluateJavaScript(js) { result, error in
+            guard let result = result as? String else {
+                return
+            }
+            self.userActivity?.topElementSelector = result
+        }
+    }
+    
     #if targetEnvironment(macCatalyst)
     @objc func toggleItemRead(_ item: NSToolbarItem) {
         Task {
@@ -208,6 +310,11 @@ extension ReadViewController: WKNavigationDelegate {
             return .allow
         }
     }
+    
+    func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
+        // we try to scroll after the navigation triggered by the loadHTML, since that's asynchronous but doesn't have a callback
+        scrollToTargetSelector()
+    }
 }
 
 extension ReadViewController: WKUIDelegate {
@@ -242,6 +349,15 @@ extension ReadViewController: WKUIDelegate {
     }
 }
 
+extension ReadViewController: UIScrollViewDelegate {
+    func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
+        scrollPositionChangedSubject.send()
+    }
+    func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
+        scrollPositionChangedSubject.send()
+    }
+}
+
 extension ReadViewController: StretchyMenuInteractionDelegate {
     func stretchyMenuTitle() -> String? {
         return nil

Reader/UserActivities.swift

@@ -16,6 +16,7 @@ extension NSUserActivity {
     static let readAllType = "net.shadowfacts.Reader.activity.read-all"
     static let readFeedType = "net.shadowfacts.Reader.activity.read-feed"
     static let readGroupType = "net.shadowfacts.Reader.activity.read-group"
+    static let readItemType = "net.shadowfacts.Reader.activity.read-item"
     
     func accountID() -> Data? {
         let types = [
@@ -31,7 +32,7 @@ extension NSUserActivity {
         }
     }
     
-    func feedID() -> String? {
+    var feedID: String? {
         if activityType == NSUserActivity.readFeedType {
             return userInfo?["feedID"] as? String
         } else {
@@ -39,7 +40,7 @@ extension NSUserActivity {
         }
     }
     
-    func groupID() -> String? {
+    var groupID: String? {
         if activityType == NSUserActivity.readGroupType {
             return userInfo?["groupID"] as? String
         } else {
@@ -47,6 +48,27 @@ extension NSUserActivity {
         }
     }
     
+    var itemID: String? {
+        if activityType == NSUserActivity.readItemType {
+            return userInfo?["itemID"] as? String
+        } else {
+            return nil
+        }
+    }
+    
+    var topElementSelector: String? {
+        get {
+            userInfo?["topElementSelector"] as? String
+        }
+        set {
+            if let newValue = newValue {
+                addUserInfoEntries(from: ["topElementSelector": newValue])
+            } else {
+                userInfo?.removeValue(forKey: "topElementSelector")
+            }
+        }
+    }
+
     static func preferences() -> NSUserActivity {
         return NSUserActivity(activityType: preferencesType)
     }
@@ -113,4 +135,14 @@ extension NSUserActivity {
         return activity
     }
     
+    static func readItem(_ item: Item, account: LocalData.Account) -> NSUserActivity {
+        let activity = NSUserActivity(activityType: readItemType)
+        activity.isEligibleForHandoff = true
+        activity.userInfo = [
+            "accountID": account.id,
+            "itemID": item.id!,
+        ]
+        return activity
+    }
+    
 }