How to get standard Mac OS X icons to use in your app?

Question

How do you get standard Mac OS X icons to use in your design / app?

By standard icons I mean toolbar icons from this screenshots:

Is there a location where those files are stored or any way to extract them from the Mac OS X app?

Answer 1

see +[NSImage imageNamed:(NSString)name] and the links in that for the different list of os defined images...

eg.

NSImage * img = [NSImage imageNamed:NSImageNameFolder];

toolbar images specifically are listed:
https://developer.apple.com/library/mac/documentation/Cocoa/Reference/ApplicationKit/Classes/NSImage_Class/index.html#//apple_ref/doc/constant_group/Toolbar_Named_Images

Answer 2

Not all of those are standard. For the ones which are, you use +[NSImage imageNamed:] with one of the system-defined image name constants, such as NSImageNameGoLeftTemplate or NSImageNameIconViewTemplate.