Universal app with pdf's, how to config UIButton and constraints programmatically?

All,

I'd like to use the "universal" pdfs instead of as usual creating lots of multiscale png's but as is obvioiusly known the UIButton doesn't come with a texture, it has to be added as a .custom

So I'm running into a similar problem as this

h ttp://stackoverflow.com/questions/34714690/swift-problems-with-programmatically-positioning-uibutton-universal

and this

h ttps://stackoverflow.com/questions/33778134/resizing-universal-pdf-image-asset-in-swift-produces-a-blurry-image

i can scale the image with a transform but the underlying view does not scale. I've tried scaling the frame, the view but nothing seems to work.

any help?

Xcode 8.3.1 not 9