Blur effect behind window

I’m on a new project in Xcode.
I’dt like to add a blur effect behind the main window.

After a couple of hours spent on it, I found this Swift snippet on Github but I’m not able to convert it to AppleScriptObjC.
Can someone help me on this?

//  AppDelegate.swift
//  Swift Window Blur
//  Created by Lee Brimelow on 6/3/14.
//  Copyright (c) 2014 Lee Brimelow. All rights reserved.
import Cocoa

class AppDelegate: NSObject, NSApplicationDelegate {
    @IBOutlet var window: NSWindow
    // define the visual effect view
    var blurryView = NSVisualEffectView(frame: NSRect(x: 0, y: 0, width: 800, height: 600))

    func applicationDidFinishLaunching(aNotification: NSNotification?) {
        // this is default value but is here for clarity
        blurryView.blendingMode = NSVisualEffectBlendingMode.BehindWindow
        // set the background to always be the dark blur
        blurryView.material = NSVisualEffectMaterial.Dark
        // set it to always be blurry regardless of window state
        blurryView.state = NSVisualEffectState.Active

    func applicationWillTerminate(aNotification: NSNotification?) {
        // Insert code here to tear down your application


Why do it in code? Just drag a Visual Effect View into the .xib view and set its properties in the Attributes inspector. Position it so that it’s a subview of the window’s content view, and the rest of the items are subviews of it.

Because I don’t get it.

Here are my settings:

All I get is a transparent window with no blur effect behind.

Click on the Attributes inspector (fourth icon from the left) to change the settings. But you won’t actually see the result until you run the app.

Also see the message in your console — you can throw that old Quark osax out.

If by run you mean press the keys command+R, I did it a hundred of times.
Here is wat I get:
capture 001

I saw this message.
I thought this Osax was installed and needed by the 2015 QuarkXpress version…

Really, I don’t understand.
Here are my settings for the Attributes inspector.
But the window stays opaque if I don’t set the window’s alphaValue.
If I do, the window is transparent but there’s no blur effect.

capture 001

I suspect you’re looking for more effect than it provides – it’s meant to be a very subtle appearance. You shouldn’t be giving it a Core Animation Layer or fiddling with its alpha – it’s meant to be self-contained.

Try removing it and see. The message says it’s not being loaded, so it’s hard to see how it could be doing anything.