Hide timeline First Unread button when detail view displayed.

iOS/Base.lproj/Main.storyboard

@@ -153,6 +153,9 @@
                     </toolbarItems>
                     <navigationItem key="navigationItem" title="Timeline" largeTitleDisplayMode="never" id="wcC-1L-ug4"/>
                     <simulatedToolbarMetrics key="simulatedBottomBarMetrics"/>
+                    <connections>
+                        <outlet property="nextUnreadButton" destination="2v2-jD-C9k" id="9rf-5I-18f"/>
+                    </connections>
                 </tableViewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="nzm-Gf-Xce" userLabel="First Responder" sceneMemberID="firstResponder"/>
             </objects>

iOS/Timeline/MasterTimelineViewController.swift

@@ -20,17 +20,11 @@ class MasterTimelineViewController: UITableViewController, UndoableCommandRunner
 		return navState?.showFeedNames ?? false ? rowHeightWithFeedName : rowHeightWithoutFeedName
 	}
 
+	@IBOutlet weak var nextUnreadButton: UIBarButtonItem!
+	
 	weak var navState: NavigationStateController?
 	var undoableCommands = [UndoableCommand]()
 	
-	var detailViewController: DetailViewController? {
-		if let split = splitViewController {
-			let controllers = split.viewControllers
-			return (controllers[controllers.count-1] as! UINavigationController).topViewController as? DetailViewController
-		}
-		return nil
-	}
-		
 	override var canBecomeFirstResponder: Bool {
 		return true
 	}
@@ -56,6 +50,8 @@ class MasterTimelineViewController: UITableViewController, UndoableCommandRunner
 		refreshControl = UIRefreshControl()
 		refreshControl!.addTarget(self, action: #selector(refreshAccounts(_:)), for: .valueChanged)
 		
+		splitViewController?.delegate = self
+		
 	}
 	
 	override func viewDidAppear(_ animated: Bool) {
@@ -339,6 +335,20 @@ class MasterTimelineViewController: UITableViewController, UndoableCommandRunner
 	
 }
 
+extension MasterTimelineViewController: UISplitViewControllerDelegate {
+	
+	func splitViewController(_ svc: UISplitViewController, willChangeTo displayMode: UISplitViewController.DisplayMode) {
+		if displayMode == .allVisible {
+			nextUnreadButton.isEnabled = false
+			nextUnreadButton.title = ""
+		} else {
+			nextUnreadButton.isEnabled = false
+			nextUnreadButton.title = NSLocalizedString("First Unread", comment: "First Unread")
+		}
+	}
+	
+}
+
 // MARK: Private
 
 private extension MasterTimelineViewController {