Stretch PNGs smoothly in Cocoa AppKit

Question

In questions like this one it shows how to use UIKit's

-(UIImage *)stretchableImageWithLeftCapWidth:(NSInteger)leftCapWidth topCapHeight:(NSInteger)topCapHeight

to stretch a PNG easily, e.g when inserting text in an iChat like bubble. I would like to do the same on regular AppKit/Cocoa/desktop app using CoreGraphics or some NSImage related API but couldn't find an equivalent method. Does anybody know how to do this in AppKit?

Answer 1

Use NSDrawThreePartImage or NSDrawNinePartImage.

Answer 2

Just use -[NSImage drawInRect:fromRect:operation:fraction:], and pass NSZeroRect as the fromRect; parameter.