Gtk - How to set box size?

Question

I have the following window on my project:

And this is basically the code that configure the main boxes:

add(main_box);
// Add boxes
main_box.pack_start(function_box, Gtk::PACK_SHRINK, 10);
main_box.pack_start(viewport_box);

I would to like to expand the viewport_box to ocupe a width larger than the half of the window. How can I do this?

Answer 1

You can either change PACK_SHRINK to PACK_EXPAND_WIDGET or use that version of pack_start, which accepts boolean expand and fill parameters