Refactor gutter view calculations to use scroll view consistently and mark certain properties as @mainactor for thread safety. Adjust font and text color handling to ensure layout updates properly.

Author: krzyzanowskim

Sources/STTextViewAppKit/STTextView+Gutter.swift

@@ -108,7 +108,7 @@ extension STTextView {
 
                 gutterView.containerView.addSubview(numberCell)
             }
-        } else if let viewportRange = textLayoutManager.textViewportLayoutController.viewportRange {
+        } else if let scrollView, let viewportRange = textLayoutManager.textViewportLayoutController.viewportRange {
 
             let textElements = textContentManager.textElements(
                 for: NSTextRange(
@@ -154,7 +154,7 @@ extension STTextView {
                     let lineNumber = startLineIndex + linesCount + 1
                     let locationForFirstCharacter = lineFragment.locationForCharacter(at: 0)
 
-                    var lineFragmentFrame = CGRect(origin: CGPoint(x: 0, y: layoutFragment.layoutFragmentFrame.origin.y - scrollView!.contentView.bounds.minY/*contentOffset.y*/), size: layoutFragment.layoutFragmentFrame.size)
+                    var lineFragmentFrame = CGRect(origin: CGPoint(x: 0, y: layoutFragment.layoutFragmentFrame.origin.y - scrollView.contentView.bounds.minY/*contentOffset.y*/), size: layoutFragment.layoutFragmentFrame.size)
 
                     lineFragmentFrame.origin.y += lineFragment.typographicBounds.origin.y
                     if lineFragment.isExtraLineFragment {

Sources/STTextViewAppKit/STTextView.swift

@@ -89,6 +89,7 @@ import AVFoundation
     ///
     /// Assigning a new value to this property causes the new font to be applied to the entire contents of the text view.
     /// If you want to apply the font to only a portion of the text, you must create a new attributed string with the desired style information and assign it
+    @MainActor
     @objc public var font: NSFont {
         get {
             _defaultTypingAttributes[.font] as! NSFont
@@ -100,6 +101,8 @@ import AVFoundation
             // apply to the document
             if !textLayoutManager.documentRange.isEmpty {
                 addAttributes([.font: newValue], range: textLayoutManager.documentRange)
+                needsLayout = true
+                needsDisplay = true
             }
 
             updateTypingAttributes()
@@ -109,6 +112,7 @@ import AVFoundation
     /// The text color of the text view.
     ///
     /// Default text color.
+    @MainActor
     @objc public var textColor: NSColor {
         get {
             _defaultTypingAttributes[.foregroundColor] as! NSColor
@@ -120,6 +124,7 @@ import AVFoundation
     }
 
     /// Default paragraph style.
+    @MainActor
     @objc public var defaultParagraphStyle: NSParagraphStyle {
         set {
             _defaultTypingAttributes[.paragraphStyle] = newValue
@@ -1381,6 +1386,7 @@ import AVFoundation
         }
     }
 
+    @MainActor
     private func setUp(instance: some STPlugin) -> STPluginEvents {
         // unwrap any STPluginProtocol
         let events = STPluginEvents()