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

Answer 1

Other images/icons are available from IconServices:

/*
   Type of the predefined/generic icons. For example, the call:
      err = GetIconRef(kOnSystemDisk, kSystemIconsCreator, kHelpIcon, &iconRef);
   will retun in iconRef the IconRef for the standard help icon.
*/

/* Generic Finder icons */

public var kClipboardIcon: Int { get }
public var kClippingUnknownTypeIcon: Int { get }
public var kClippingPictureTypeIcon: Int { get }
public var kClippingTextTypeIcon: Int { get }
public var kClippingSoundTypeIcon: Int { get }
public var kDesktopIcon: Int { get }
public var kFinderIcon: Int { get }
public var kComputerIcon: Int { get }
public var kFontSuitcaseIcon: Int { get }
public var kFullTrashIcon: Int { get }
public var kGenericApplicationIcon: Int { get }
public var kGenericCDROMIcon: Int { get }
...
...

You can use NSWorkspace icon methods with the above constants:

NSWorkspace.shared.icon(forFileType: NSFileTypeForHFSTypeCode(UInt32(kGenericApplicationIcon)))