Resize JPanel within a JFrame

Question

So I have a JPanel which is added to a JFrame.

The JPanel includes a large graphic, and the main part that I wish to display is 800 x 400 pixels.

There is extra on either sides, which doesn't matter.

When I resize the JFrame which contains the inner JPanel, is there a way to resize the JPanel as well so that those important pixels are still shown?

Here's what I tried:

JFrame frame = new JFrame("Simon");
Renderer renderer = new Renderer(); //this object extends JPanel, which is what i'm adding to the frame

frame.setLayout(new BorderLayout());
frame.setSize(WIDTH, HEIGHT);
frame.setResizable(true);
renderer.setPreferredSize(new Dimension(WIDTH, HEIGHT)); //want to keep it centered on this width/height because there is important content within there.
frame.add(renderer, BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);

This is not doing anything different to it than normal.

Any advice?

Edit: Adding the renderer class:

import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JPanel;

@SuppressWarnings("serial")
public class Renderer extends JPanel
{

    /* (non-Javadoc)
     * @see javax.swing.JComponent#paintComponent(java.awt.Graphics)
     */
    @Override
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);    
        Simon.simon.paint((Graphics2D) g); //Simon is the first class that holds the code all the way above
    }   
}

why are you setting preferredSize? If you remove that line what happens? — Oliver Watkins, Dec 09 '15 at 10:28
You have to give us your RenderClass as well because it works just fine when changing the type of renderer to a JPanel — Raven, Dec 09 '15 at 10:45
Normally, when using `BorderLayout.CENTER`, your JPanel resizes itself automatically. [You may also want to read this post](http://stackoverflow.com/questions/7229226/should-i-avoid-the-use-of-setpreferredmaximumminimumsize-methods-in-java-swi) — Yassin Hajaj, Dec 09 '15 at 10:48
@OliverWatkins, when I remove setPreferredSize, the JFrame becomes 0 x 0 pixels for some reason (or whatever the smallest possible size is). — John Fda, Dec 09 '15 at 16:48
are you sure? frame.setSize(WIDTH, HEIGHT); should work fine. Depending if your width and height are the values you want — Oliver Watkins, Dec 09 '15 at 16:51
@YassinHajaj, the thing is, the stuff I am painting is bigger than the WIDTH and HEIGHT already. — John Fda, Dec 09 '15 at 16:52
@OliverWatkins, yes I am sure. Not sure why, but it is acting like that. — John Fda, Dec 09 '15 at 16:53
@OliverWatkins, ahh that is happening because of frame.pack(); just figured it out — John Fda, Dec 09 '15 at 16:54
can you put your answer in the answer section to help other people out? — Oliver Watkins, Dec 10 '15 at 08:30

Resize JPanel within a JFrame

0 Answers0