Question

Is there a way to set, when specifying height and width of a component in Swing, that a given object should fill the available vertical/horizontal space? I.e. I would like to say setSize(*, 100) to allow horizontal fill.

Answer 1

You can call setSize with whatever you want, but in the end it is the LayoutManager of the parent Container which decides what position and what size each component gets.

So by using the correct LayoutManager you can typically succeed in letting a component take all the available width.
As you can see in the BorderLayout part of the Visual guide to LayoutManagers tutorial the PAGE_START and PAGE_END take all the available width.

By specifying the height as preferred size you will obtain the desired result