 	}
 
 	var drawingTransform: CGAffineTransform {
-		guard let scene = self.scene else { return CGAffineTransform.identity }
+		guard let scene = self.scene else { return .identity }
 		let targetRect = contentView.convert(self.contentView.bounds, to: self.mtkView)
 		let transform0 = CGAffineTransform(translationX: 0, y: self.contentView.bounds.height).scaledBy(x: 1, y: -1)
 		let transform1 = scene.bounds.transform(to: targetRect)


		// posting notification when zoomed, scrolled or resized
		typealias T = RenderView
		NotificationCenter.default.addObserver(self, selector: #selector(T.scrollContentDidChange(_:)),
					name: NSNotification.Name.NSViewBoundsDidChange, object: nil)
		scrollView.allowsMagnification = true
		scrollView.maxMagnification = 4
		scrollView.minMagnification = 1

		self.bringSubview(toFront: self.drawView)
		self.bringSubview(toFront: self.scrollView)

        let contentSize = scene?.contentSize ?? bounds.size

        self.scrollView.documentView?.frame = CGRect(origin: .zero, size: contentSize)

		self.contentView.translatesAutoresizingMaskIntoConstraints = false
		self.contentView.autoresizingMask = [.viewMaxXMargin, /*.viewMinYMargin,*/ .viewMaxYMargin]
		self.setNeedsDisplay()
