class Drawing: NSView {
override func drawRect(dirtyRect: NSRect) {
    super.drawRect(dirtyRect)

    let context = NSGraphicsContext.currentContext()?.CGContext;

    CGContextBeginPath(context)
    CGContextMoveToPoint(context, 0, 0)
    CGContextAddLineToPoint(context, 100, 100)
    CGContextSetRGBStrokeColor(context, 1, 1, 1, 1)
    CGContextSetLineWidth(context, 5.0)
    CGContextStrokePath(context)

  }