Finder file icon badging (icon overlay) on Mac OS X >= 10.6

Question

I'm searching for a solution to do File icon overlays (icon badging) (like Dropbox does it on mac) with cocoa on Mac.

Does anyone knows a way to do this?

I've searched the Xcode docs and looked into scpplugins source code which is kind of old carbon code.

Answer 1

A litte bit late, but maybe will be help someone.

I solved same problem with class NSWorkspace (see setIcon:forFile:options)

Basic idea:

1. Try to get preview of file with QLThumbnailImageCreate (if not NULL you will get thumbnail icon)

2. If you didn't get thumbnail, then get default OS X icon for file (NSWorkspace iconForFile)

3. Combine thumbnail (or default icon) with your badge

4. Set new icon to the file (NSWorkspace setIcon:forFile:options)