How to paint an invisible JFrame elsewhere?

Question

I want to paint the contents of a JFrame onto another frame. Currently, I only get it to work if the JFrame is visible.
Is there a way to paint a hidden JFrame?

Addi

Answer 1

1) you have to use proper LayoutManager, not setSize() or setBounds()

2) if is there null LayoutManager used then Container returns any size after setVisible(true);

3) if is there used proper LayoutManager, then Container return its Size after call pack();, in other hands this container couldn't be visible on the screen ( meaning setVisible(true); )

4) JComponents must to returns PrefferedSize for example