Add Jump to Present VoiceOver action

Closes #288

Tusker/Screens/Timeline/TimelineViewController.swift

@@ -114,6 +114,19 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
             self.reapplyFilters(actionsChanged: actionsChanged)
         }
         
+        let jumpToPresentName = NSMutableAttributedString("Jump to Present")
+        // otherwise it pronounces it as 'pɹizˈənt'
+        // its IPA is also bad, this should be an alveolar approximant not a trill
+        jumpToPresentName.addAttribute(.accessibilitySpeechIPANotation, value: "ˈprɛ.zənt", range: NSRange(location: "Jump to ".count, length: "Present".count))
+        accessibilityCustomActions = [
+            UIAccessibilityCustomAction(attributedName: jumpToPresentName, actionHandler: { [unowned self] _ in
+                Task {
+                    await self.checkPresent(jumpImmediately: true)
+                }
+                return true
+            })
+        ]
+        
         NotificationCenter.default.addObserver(self, selector: #selector(sceneWillEnterForeground), name: UIScene.willEnterForegroundNotification, object: nil)
     }
     
@@ -192,7 +205,7 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
         if case .notLoadedInitial = controller.state {
             if doRestore() {
                 Task {
-                    await checkPresent()
+                    await checkPresent(jumpImmediately: false)
                 }
             } else {
                 Task {
@@ -376,7 +389,7 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
             return
         }
         Task {
-            await checkPresent()
+            await checkPresent(jumpImmediately: false)
         }
     }
     
@@ -405,10 +418,20 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
         }
     }
     
-    private func checkPresent() async {
+    private func checkPresent(jumpImmediately: Bool) async {
         if case .idle = controller.state,
-           let presentItems = try? await loadInitial() {
-            insertPresentItemsIfNecessary(presentItems)
+           let presentItems = try? await loadInitial(),
+           !presentItems.isEmpty {
+            if jumpImmediately {
+                var snapshot = NSDiffableDataSourceSnapshot<Section, Item>()
+                snapshot.appendSections([.statuses])
+                snapshot.appendItems(presentItems.map { .status(id: $0, collapseState: .unknown, filterState: .unknown) }, toSection: .statuses)
+                dataSource.apply(snapshot, animatingDifferences: true) {
+                    UIAccessibility.post(notification: .screenChanged, argument: self.collectionView.cellForItem(at: IndexPath(row: 0, section: 0)))
+                }
+            } else {
+                insertPresentItemsIfNecessary(presentItems)
+            }
         }
     }