[Q] Extending Interface Builder to make iPhone Development easier

[David Phillip Oster]

When designing user interface on iPhone, we often use a UImageView
loaded with stretchable images. But we do this in the Objective-C
source code, because Interface Builder doesn't let you specify the
stretch offsets of a UIImage.

It would be nice if there were a subclass of UImageView and of
UIButton that let you specify stretchable images, and let you see them
as you laid out your U.I

I.B. is supposed to be extensible via plugins. I've already written a
subclass of NSImage implements stretchable images for Mac OS X. I
haven't seen any examples of writing an I.B. plugin that does Mac OS X
rendering at design time, but implements iPhone runtime classes.