NSVisualEffectView behind NSScrollView

Question

I'm trying to get my NSScrollView (and thus a contained NSOutlineView) to use a blurred NSVisualEffectView with behind-window blending effect.

I've successfully made NSVisualEffectView the container view and placed my scroll view as a subview. This seems to work fine (as long as I make all my table cells, table, nsscrollview etc transparent).

However I've now turned 'Reduce transparency' ON under Accessibility options and all of a sudden I have a black background behind my NSScrollView. I tried subclassing the visual effect view in order to override the drawRect method so that I can draw my own background, but I've just learned this isn't possible or recommended.

How do I detect that Reduce Transparency is ON and how do I make my scrollview opaque dynamically?

Answer 1

Took me a while to find it, but there are a couple of new methods on NSWorkspace that you can use to find out about the preferences for OS X Yosemite’s new accessibility features. -[NSWorkspace accessibilityDisplayShouldReduceTransparency] is the one you want.

By Listening for NSWorkspaceAccessibilityDisplayOptionsDidChangeNotification you can find out when that preference changes. Note that you’ll have to register for that notification on the correct NSNotificationCenter, that is [[NSWorkspace sharedWorkspace] notificationCenter].

Answer 2

It seems as for now I've ended up overriding a parent NSView that contains everything and set a background color for that. This way, when Reduce Transparency is ON, the NSVisualEffectView becomes transparent and the color I end up getting is the one visible below it. This seems to work fine for now.