There is no layout engine for Cocoa. If you want two elements to rest side to side, you’ll need to calculate the pixel size of the text, padding, borders, margins — then manually position the next element.
This is getting a lot better in Lion. If you browse the WWDC 2011 videos, look for Session 103 "Cocoa Autolayout".
This is getting a lot better in Lion. If you browse the WWDC 2011 videos, look for Session 103 "Cocoa Autolayout".