How to make an individual JPanel larger within a JFrame

Question

I am making a game and i have multiple panels within my frame. panel4 is supposed to contain my wheel, the problem is that panel4 is the same size as all of the other panels on the board when i need panel4 to be much larger because i want the picture of the wheel to fully display because as it stands, only the top part of the wheel is showing when i need all of it to show.

 public static void setUp() throws IOException {        
    frame=new JFrame();
    frame.setLayout(new GridLayout(7,1));
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setLocation(290, 5);
    frame.setSize(1100, 1100);
    frame.setTitle("Wheel of fortune");

    final JPanel scorePanel=new JPanel();
    final JPanel namePanel=new JPanel();
    final JPanel panel=new JPanel(new GridLayout(1,3,1,1));
    final JPanel panel1=new JPanel();
    final JPanel panel2=new JPanel();
    final JPanel panel3=new JPanel(new GridLayout(2,1,1,1));

    panel3.add(new JLabel("Dead letters/phrases:"));
    panel3.add(LettersOrPhGuessed);

    scorePanel.add(new JLabel("Score Board:"));


    final WheelGui test = new WheelGui();
    final JPanel panel4=test;
    panel4.setSize(800, 600);//this does nothing in the program


    namePanel.add(playerName);
    frame.getContentPane().add(namePanel);
    frame.getContentPane().add(scorePanel);
    frame.getContentPane().add(panel);
    frame.getContentPane().add(panel4);
    frame.getContentPane().add(panel2);
    frame.getContentPane().add(panel1);
    frame.getContentPane().add(panel3);
    frame.setVisible(true);
}

this is where i construct the essence of panel4. i have tried to make this panel larger but when i do, nothing appears to happen on the screen. Any suggestions would be great.

@SuppressWarnings("serial")
public class WheelGui extends JPanel{
ImageIcon image = new ImageIcon("WheelofFortune.JPG");    
JPanel rotationPanel;  
final int WIDTH = 800;  
final int HEIGHT = 600;  
static double degrees;  

public WheelGui()  
{  
    super();
    this.setPreferredSize(new Dimension(WIDTH,HEIGHT));  
    setBackground(Color.lightGray);  
    setLayout(null);  
    setFocusable(true);  
    rotationPanel = new JPanel(); 

    rotationPanel = new turningCanvas();  
    rotationPanel.setPreferredSize(new Dimension(image.getIconWidth(),image.getIconHeight()));  
    //rotationPanel.setSize(800,600);  
    add(rotationPanel);  
    rotationPanel.setBounds(WIDTH/8, HEIGHT/8, rotationPanel.getPreferredSize().width, rotationPanel.getPreferredSize().height);  
    degrees = 0;  
}  
public void paintComponent (Graphics g)  
{  
    super.paintComponent(g);  
}  
public class turningCanvas extends JPanel  
{  
    public void paintComponent (Graphics g)  
    {  
        super.paintComponent(g);  
        Graphics2D g2d = (Graphics2D)g;  
        g2d.rotate(Math.toRadians(degrees),image.getIconWidth()/2,image.getIconHeight()/2);  
        image.paintIcon(this, g2d, 0, 0);  

    }  
}   
public void rotate(){
    for(int i=0;i<360;i+=4){
        degrees++;
        repaint();
        try {
            Thread.sleep(10);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

Answer 1

You have a number of problems...

Firstly, you're using GridLayout. GridLayout will layout all the components in grid pattern with allocating the same amount of space to each component based on the width and height of the parent container. If you want components to have different sizes, GridLayout isn't the best choice.

Secondly, you're using setPreferredSize. This is a bad practice as you are not guarding yourself against the possibly that some other part of the application will try and change the size of the component later.

Instead, you should be overriding the getPreferredSize method where ever possible.

Personally, I would recommend a GridBagLayout, but you might want to check out A Visual Guide to Layout Managers for other choices

Update with example

The only way I know to do what you're asking is with the use of GridBagLayout, which gives you the flexibility to define how much space individual components will take from the available space. It's one of the most flexible and difficult layout managers to master...

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;

public class TestLayout25 {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }
                try {
                    setUp();
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }
        });
    }

    public static void setUp() throws IOException {
        JFrame frame = new JFrame();
        frame.setLayout(new GridBagLayout());
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(400, 400);
        frame.setLocationRelativeTo(null);
        frame.setTitle("Wheel of fortune");

        final JPanel scorePanel = new JPanel();
        final JPanel namePanel = new JPanel();
        final JPanel panel = new JPanel(new GridLayout(1, 3, 1, 1));
        final JPanel panel1 = new JPanel();
        final JPanel panel2 = new JPanel();
        final JPanel panel3 = new JPanel(new GridLayout(2, 1, 1, 1));

        panel3.add(new JLabel("Dead letters/phrases:"));
        panel3.add(createPane(Color.RED));

        scorePanel.add(new JLabel("Score Board:"));


        final WheelGui test = new WheelGui();
        final JPanel panel4 = test;
        panel4.setSize(800, 600);//this does nothing in the program

        GridBagConstraints gbc = new GridBagConstraints();
        gbc.gridwidth = GridBagConstraints.REMAINDER;
        gbc.weightx = 1;
        gbc.fill = GridBagConstraints.HORIZONTAL;

        namePanel.add(new JLabel("Blue"), gbc);
        frame.getContentPane().add(namePanel, gbc);
        frame.getContentPane().add(scorePanel, gbc);
        frame.getContentPane().add(panel, gbc);
        gbc.weighty = 1;
        gbc.fill = GridBagConstraints.BOTH;
        frame.getContentPane().add(panel4, gbc);
        gbc.weighty = 0;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        frame.getContentPane().add(panel2, gbc);
        frame.getContentPane().add(panel1, gbc);
        frame.getContentPane().add(panel3, gbc);
        frame.setVisible(true);
    }

    protected static JPanel createPane(Color color) {

        JPanel panel = new JPanel();
        panel.setBorder(new LineBorder(color));
        return panel;

    }

    public static class WheelGui extends JPanel {

        ImageIcon image = new ImageIcon("WheelofFortune.JPG");
        JPanel rotationPanel;
        final int WIDTH = 800;
        final int HEIGHT = 600;
        static double degrees;

        public WheelGui() {
            super();
            this.setPreferredSize(new Dimension(WIDTH, HEIGHT));
            setBackground(Color.lightGray);
            setLayout(null);
            setFocusable(true);
            rotationPanel = new JPanel();

            rotationPanel = new turningCanvas();
            rotationPanel.setPreferredSize(new Dimension(image.getIconWidth(), image.getIconHeight()));
            //rotationPanel.setSize(800,600);  
            add(rotationPanel);
            rotationPanel.setBounds(WIDTH / 8, HEIGHT / 8, rotationPanel.getPreferredSize().width, rotationPanel.getPreferredSize().height);
            degrees = 0;
        }

        public void paintComponent(Graphics g) {
            super.paintComponent(g);
        }

        public class turningCanvas extends JPanel {

            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                Graphics2D g2d = (Graphics2D) g;
                g2d.rotate(Math.toRadians(degrees), image.getIconWidth() / 2, image.getIconHeight() / 2);
                image.paintIcon(this, g2d, 0, 0);

            }
        }

        public void rotate() {
            for (int i = 0; i < 360; i += 4) {
                degrees++;
                repaint();
                try {
                    Thread.sleep(10);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }
}

Answer 2

You are using GridLayout. The layout takes care of size and location of each component and there is little you can do about it.

A GridLayout object places components in a grid of cells. Each component takes all the available space within its cell, and each cell is exactly the same size.

You will have to use another layout. GridBagLayout could be useful.