Fix First Responder Issues, Fix Custom Undo Manager

Sources/CodeEditTextView/TextView/TextView+Mouse.swift

@@ -48,10 +48,6 @@ extension TextView {
                 self?.autoscroll(with: event)
             }
         }
-
-        if !self.isFirstResponder {
-            self.window?.makeFirstResponder(self)
-        }
     }
 
     override public func mouseUp(with event: NSEvent) {

Sources/CodeEditTextView/TextView/TextView+UndoRedo.swift

@@ -10,6 +10,7 @@ import AppKit
 extension TextView {
     public func setUndoManager(_ newManager: CEUndoManager) {
         self._undoManager = newManager
+        self._undoManager?.setTextView(self)
     }
 
     override public var undoManager: UndoManager? {

Sources/CodeEditTextView/TextView/TextView.swift

@@ -326,6 +326,16 @@ public class TextView: NSView, NSTextContent {
         super.canBecomeKeyView && acceptsFirstResponder && !isHiddenOrHasHiddenAncestor
     }
 
+    /// Sent to the window's first responder when `NSWindow.makeKey()` occurs.
+    @objc private func becomeKeyWindow() {
+        _ = becomeFirstResponder()
+    }
+
+    /// Sent to the window's first responder when `NSWindow.resignKey()` occurs.
+    @objc private func resignKeyWindow() {
+        _ = resignFirstResponder()
+    }
+
     open override var needsPanelToBecomeKey: Bool {
         isSelectable || isEditable
     }
@@ -362,6 +372,23 @@ public class TextView: NSView, NSTextContent {
         updateFrameIfNeeded()
     }
 
+    // MARK: - Hit test
+
+    /// Returns the responding view for a given point.
+    /// - Parameter point: The point to find.
+    /// - Returns: A view at the given point, if any.
+    override public func hitTest(_ point: NSPoint) -> NSView? {
+        // For our purposes, cursor and line fragment views should be transparent from the point of view of
+        // all other views. So, if the normal hitTest returns one of them, we return `self` instead.
+        let hitView = super.hitTest(point)
+
+        if let hitView, hitView != self,
+            type(of: hitView) == CursorView.self || type(of: hitView) == LineFragmentView.self {
+            return self
+        }
+        return hitView
+    }
+
     // MARK: - Key Down
 
     override public func keyDown(with event: NSEvent) {
@@ -381,6 +408,15 @@ public class TextView: NSView, NSTextContent {
 
     // MARK: - Layout
 
+    open override class var isCompatibleWithResponsiveScrolling: Bool {
+        true
+    }
+
+    open override func prepareContent(in rect: NSRect) {
+        needsLayout = true
+        super.prepareContent(in: rect)
+    }
+
     override public func draw(_ dirtyRect: NSRect) {
         super.draw(dirtyRect)
         if isSelectable {

Sources/CodeEditTextView/Utils/CEUndoManager.swift

@@ -224,4 +224,12 @@ public class CEUndoManager {
     public func enable() {
         isDisabled = false
     }
+
+    // MARK: - Internal
+
+    /// Sets a new text view to use for mutation registration, undo/redo operations.
+    /// - Parameter newTextView: The new text view.
+    func setTextView(_ newTextView: TextView) {
+        self.textView = newTextView
+    }
 }