Filesystem monitor and refactor.

src/MenulessWindow.swift

@@ -0,0 +1,33 @@
+import AppKit
+import Carbon
+
+class MenulessWindow: NSWindow {
+    init(viewController: NSViewController) {
+        super.init(
+            contentRect: CGRect(x: 0, y: 0, width: 100, height: 100),
+            styleMask: [.titled, .closable],
+            backing: .buffered,
+            defer: false
+        )
+        super.contentViewController = viewController
+
+        title = ""
+        titlebarAppearsTransparent = true
+        collectionBehavior = [.managed, .fullScreenNone]
+        isReleasedWhenClosed = false
+        hidesOnDeactivate = false
+    }
+
+    override func performKeyEquivalent(with event: NSEvent) -> Bool {
+        let modifiers = event.modifierFlags.rawValue
+        let key = event.keyCode
+
+        if event.type == NSEvent.EventType.keyDown {
+            if modsContains(keys: OSCmd, in: modifiers) && key == kVK_ANSI_W {
+                performClose(nil)
+            }
+        }
+
+        return super.performKeyEquivalent(with: event)
+    }
+}