From c5e6658e5bd6fd9b904d78a4ed6675b62002ed0f Mon Sep 17 00:00:00 2001
From: Maurice Parker <mo@vincode.io>
Date: Thu, 9 Mar 2023 20:12:19 -0600
Subject: [PATCH] Fix mark as read on scroll

---
 .../Timeline/TimelineViewController.swift     | 44 ++++---------------
 1 file changed, 9 insertions(+), 35 deletions(-)

diff --git a/Mac/MainWindow/Timeline/TimelineViewController.swift b/Mac/MainWindow/Timeline/TimelineViewController.swift
index b7e55b9f4..8f6c57f04 100644
--- a/Mac/MainWindow/Timeline/TimelineViewController.swift
+++ b/Mac/MainWindow/Timeline/TimelineViewController.swift
@@ -141,11 +141,6 @@ final class TimelineViewController: NSViewController, UndoableCommandRunner, Unr
 
 	var undoableCommands = [UndoableCommand]()
 
-	var articlesWithManuallyChangedReadStatus: Set<Article> = Set()
-	private var firstVisibleRowIndexWhenDraggingBegan: Int = 0
-	
-	private var isScrolling = false
-	
 	private var fetchSerialNumber = 0
 	private let fetchRequestQueue = FetchRequestQueue()
 	private var exceptionArticleFetcher: ArticleFetcher?
@@ -231,6 +226,7 @@ final class TimelineViewController: NSViewController, UndoableCommandRunner, Unr
 			NotificationCenter.default.addObserver(self, selector: #selector(userDefaultsDidChange(_:)), name: UserDefaults.didChangeNotification, object: nil)
 			NotificationCenter.default.addObserver(self, selector: #selector(markStatusCommandDidDirectMarking(_:)), name: .MarkStatusCommandDidDirectMarking, object: nil)
 			NotificationCenter.default.addObserver(self, selector: #selector(markStatusCommandDidUndoDirectMarking(_:)), name: .MarkStatusCommandDidUndoDirectMarking, object: nil)
+			NotificationCenter.default.addObserver(self, selector: #selector(scrollViewDidScroll), name: NSScrollView.didLiveScrollNotification, object: tableView.enclosingScrollView)
 			didRegisterForNotifications = true
 		}
 	}
@@ -341,44 +337,22 @@ final class TimelineViewController: NSViewController, UndoableCommandRunner, Unr
 		}
 	}
 	
-	@objc func scrollViewDidScroll(notification: Notification){
-		if isScrolling {
-			scrollPositionQueue.add(self, #selector(scrollPositionDidChange))
-		}
-	}
-	
-	@objc func scrollViewWillStartLiveScroll(notification: Notification){
-		isScrolling = true
-		firstVisibleRowIndexWhenDraggingBegan = tableView.rows(in: tableView.visibleRect).location
-	}
-	
-	@objc func scrollViewDidEndLiveScroll(notification: Notification){
-		isScrolling = false
-	}
-	
-	@objc func scrollPositionDidChange(){
-		if !AppDefaults.shared.markArticlesAsReadOnScroll {
-			return
-		}
+	@objc func scrollViewDidScroll(notification: Notification) {
+		guard AppDefaults.shared.markArticlesAsReadOnScroll else { return }
 		
-		// Mark articles scrolled out of sight at the top as read
 		let firstVisibleRowIndex = tableView.rows(in: tableView.visibleRect).location
 		
-		let unreadArticlesScrolledAway = articles.articlesBetween(
-			upperPosition: firstVisibleRowIndexWhenDraggingBegan, lowerPosition: firstVisibleRowIndex).filter { !$0.status.read && !articlesWithManuallyChangedReadStatus.contains($0) }
-				
-		if unreadArticlesScrolledAway.isEmpty { return }
-
-		guard let undoManager = undoManager, let markReadCommand = MarkStatusCommand(initialArticles: unreadArticlesScrolledAway, markingRead: true, directlyMarked: false, undoManager: undoManager) else {
+		guard let article = articles.articleAtRow(firstVisibleRowIndex - 1),
+				article.status.read == false,
+				!directlyMarkedAsUnreadArticles.contains(article),
+				let undoManager = undoManager,
+				let markReadCommand = MarkStatusCommand(initialArticles: [article], markingRead: true, directlyMarked: false, undoManager: undoManager) else {
 			return
 		}
+		
 		runCommand(markReadCommand)
 	}
 	
-	func resetMarkAsReadOnScroll() {
-		articlesWithManuallyChangedReadStatus.removeAll()
-	}
-	
 	@IBAction func toggleStatusOfSelectedArticles(_ sender: Any?) {
 		guard !selectedArticles.isEmpty else {
 			return