Designers have to add these lines and numbers after the fact, and they don't always reflect the intent behind the layout. As screen sizes, typefaces and other layout details change, fixed numbers quickly become obsolete.
The ideal is to encode that original intent behind the layout into your program. As far as I can tell, any set of constraints simple enough to solve efficiently will not be powerful enough to model your designer's intent. The design will eventually become complex enough that your layout will need to be represented as a procedure. Once that happens, the constraint system becomes just another pointless layer of abstraction.
The ideal is to encode that original intent behind the layout into your program. As far as I can tell, any set of constraints simple enough to solve efficiently will not be powerful enough to model your designer's intent. The design will eventually become complex enough that your layout will need to be represented as a procedure. Once that happens, the constraint system becomes just another pointless layer of abstraction.