How to set an image to a NSButton to be resized along with the button?

Question

I have an image (3width x 15height, the first and last pixels are rounded on the corners), and I want to create a button (the height of the button is always the same, 15px, but the width changes) that uses this image no matter what size it is, kinda like UIEdgeInsets on iOS.
I've tried to use [[button cell] setImageScaling:NSImageScaleAxesIndependently]; but the image gets distorted and loses quality.
How can I do this on OSX? Thanks!

Answer 1

You could probably create a custom subclass of NSButtonCell and use the Application Kit's NSDrawThreePartImage() function in the cell's drawInteriorWithFrame:inView: method.

For more info on how to use NSDrawThreePartImage(), see Cocoa Drawing Guide: Drawing Resizable Textures Using Images.

Answer 2

If it's possible to set this in graphical interface > Attribute Inspection > Button section Background