How do I get the dimensions of a GridBagLayout?

Question

I am making a calculator. I used a GridBagLayout to arrange the buttons, and so far it looks like this:

I am trying to find the exact size of the grid so I can set the size of the JFrame to match it. In the GridBagLayout API, I found three methods: maximumLayoutSize, minimumLayoutSize, and preferredLayoutSize. I tried all three and set the JFrame to each size to see how they worked:

When I looked at the dimensions returned by maximumLayoutSize, they were huge (millions and billions).

When I used the dimensions returned by minimumLayoutSize, I got width=151, height=150, which looks like this:

When I used the dimensions returned by preferredLayoutSize, I got width=220, height=180, which looks like this:

Instead, I want the dimensions of the GridBagLayout when it looks normal like it is in the first picture. How can I get these dimensions?

Answer 1

Call, JFrame#pack, it will pack the frame based on the needs of the frame decorations and the preferred size of the frames content.