NSString *fileType = NSFileTypeForHFSTypeCode(kToolbarDesktopFolderIcon); NSImage *desktopToolbarImage = [[NSWorkspace sharedWorkspace] iconForFileType:fileType];
If you double-click on the command (Xcode 3) or click on the command (Xcode 4) in the constant kToolbarDesktopFolderIcon , you will get to the file (IconsCore.h), which contains a whole bunch of default constants of the system icons. The special icon icons in the toolbar you are looking for are in the same group. kToolbarDownloadsFolderIcon will get you a white down arrow in a green circle, kToolbarHomeIcon will give you a house icon, etc.
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