Correctly align separator with contents of cell. Issue #2592

Mac/MainWindow/Timeline/TimelineTableRowView.swift

@@ -10,6 +10,8 @@ import AppKit
 
 class TimelineTableRowView : NSTableRowView {
 
+	private var separator: NSView?
+	
 	override var isOpaque: Bool {
 		return true
 	}
@@ -23,6 +25,7 @@ class TimelineTableRowView : NSTableRowView {
 	override var isSelected: Bool {
 		didSet {
 			cellView?.isSelected = isSelected
+			separator?.isHidden = isSelected
 		}
 	}
 	
@@ -43,4 +46,38 @@ class TimelineTableRowView : NSTableRowView {
 		return nil
 	}
 
+	override func viewDidMoveToSuperview() {
+		if #available(macOS 11.0, *) {
+			addSeparatorView()
+		} else {
+			if AppDefaults.shared.timelineShowsSeparators {
+				addSeparatorView()
+			}
+		}
+	}
+	
+	private func addSeparatorView() {
+		guard let cellView = cellView else { return }
+		separator = NSView()
+		separator!.translatesAutoresizingMaskIntoConstraints = false
+		separator!.wantsLayer = true
+		separator!.layer?.backgroundColor = NSColor.separatorColor.cgColor
+		addSubview(separator!)
+		if #available(macOS 11.0, *) {
+			NSLayoutConstraint.activate([
+				separator!.leadingAnchor.constraint(equalTo: cellView.leadingAnchor, constant: 20),
+				separator!.trailingAnchor.constraint(equalTo: cellView.trailingAnchor, constant: -4),
+				separator!.heightAnchor.constraint(equalToConstant: 1),
+				separator!.bottomAnchor.constraint(equalTo: bottomAnchor, constant: 0)
+			])
+		} else {
+			NSLayoutConstraint.activate([
+				separator!.leadingAnchor.constraint(equalTo: cellView.leadingAnchor, constant: 34),
+				separator!.trailingAnchor.constraint(equalTo: cellView.trailingAnchor, constant: -28),
+				separator!.heightAnchor.constraint(equalToConstant: 1),
+				separator!.bottomAnchor.constraint(equalTo: bottomAnchor, constant: 0)
+			])
+		}
+	}
+	
 }

Mac/MainWindow/Timeline/TimelineViewController.swift

@@ -209,11 +209,6 @@ final class TimelineViewController: NSViewController, UndoableCommandRunner, Unr
 		
 		if #available(macOS 11.0, *) {
 			tableView.style = .inset
-			tableView.gridStyleMask = .solidHorizontalGridLineMask
-		} else {
-			if AppDefaults.shared.timelineShowsSeparators {
-				tableView.gridStyleMask = .solidHorizontalGridLineMask
-			}
 		}
 		
 		if !didRegisterForNotifications {