The incredible invisible window

OSX 10.12, Xcode 8.0

I’m not entirely certain under which circumstances this is useful, but

[code language=”plain”]class invisibleWindowController: NSWindowController {

override func windowDidLoad() {

self.window?.isOpaque = false
self.window?.backgroundColor = NSColor.clear




is a thing of beauty.

If the view in the window’s contentViewController overrides override func draw(_ dirtyRect: NSRect), the effect is lost; if it merely contains elements like buttons and text fields, they will retain their opacity while the rest of the window vanishes.

This creates some interesting effects:

[code language=”plain”]class BlurView: NSView {

override func draw(_ dirtyRect: NSRect) {
alphaValue = 0.5


(I have absolutely no idea why I would want to use this, but it needed to be recorded, and I shall remember window?.backgroundColor in the future.)