Creating window borders for a WM

make_border.swift

var win: NSWindow!
func makeWindow() {
    let rect = NSRect(x: 1000, y: 1000, width: 400, height: 300)
    win = NSWindow(contentRect: rect, styleMask: .borderless, backing: .buffered, defer: false)
    win.center()
    win.level = .floating
    win.hasShadow = false
    win.backgroundColor = NSColor.clear
    win.animationBehavior = .none
    win.ignoresMouseEvents = true
    win.isOpaque = false  // doesn't seem needed, might hurt performance
    win.makeKeyAndOrderFront(nil)
    win.title = "HEY"
    win.contentView = Border(frame: NSRect(x: 0, y: 0, width: 400, height: 300))
    print(win.isVisible)
}

class Border: NSView {
    let thickness: CGFloat = 5

    override func draw(_ dirtyRect: NSRect) {
        let rect = NSInsetRect(frame, thickness, thickness)
        let border = NSBezierPath(roundedRect: rect, xRadius: thickness, yRadius: thickness)
        border.lineWidth = thickness
        border.stroke()
    }
}