Say, for example, that I have a GUI library whose API solely offers functionality for drawing text boxes, buttons, labels, etc. No fancy layout utilities.
For a simple use case, one might just hard-code the size and coordinates of a certain button, or even a small bunch of them, but once the layout starts to clutter, it's a better choice to give some organization. When there is no visual GUI editor, you either make one, or code your own layout API. Either option is obviously very time consuming, and the latter doesn't tend to be very flexible.
Is there any way/standard for "programmatically" giving a layout to a gui? For example in web, I've seen how people use html, css and json to specify certain behaviors, styles and that. How could that be applied here? In my case, I'm using the raygui lib (which isn't really standalone since its meant to be a gui utility for games)