Swing->Background moim wczytanym obrazkiem

Męczę się cały czas nad tym, aby wczytać mój obrazek, jako tło okienka, czyli background okna, pod panelem menu. Probowałem wrzucić kod z tej stronki: http://javastart.pl/grafika_awt_swing/pobieranie-i-wyswietlanie-obrazow/ ale mi coś nie za bardzo idzie. Czy ktoś mógłby mi zedytować ten kod, aby tło było moim wczytanym obrazkiem:

package menu;

import javax.swing.JFrame;
import javax.swing.GroupLayout.Alignment;
import javax.swing.GroupLayout;
import java.awt.Color;
import javax.swing.UIManager;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

/**
 *
 * @author Paul
 */
public class JFrameGlowna extends JFrame {

    /**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	/**
     * Creates new form JFrameGlowna
     */
    public JFrameGlowna() {
		getContentPane().setBackground(UIManager.getColor("MenuItem.selectionBackground"));
        initComponents();
    }
    public void sow(){
        //System.out.println("Pawelo");
    }
    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    
    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
    private void initComponents() {

        jPanel1 = new javax.swing.JPanel();
        jPanel2 = new javax.swing.JPanel();
        jButton1 = new javax.swing.JButton();
        jButton2 = new javax.swing.JButton();
        jButton3 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel2.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "MENU", javax.swing.border.TitledBorder.CENTER, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Arial", 0, 24))); // NOI18N

        jButton1.setText("Pong");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jButton2.setText("Scorched");

        jButton3.setText("Tron");
        jButton3.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton3ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
        jPanel2.setLayout(jPanel2Layout);
        jPanel2Layout.setHorizontalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jButton1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(jButton2, javax.swing.GroupLayout.DEFAULT_SIZE, 374, Short.MAX_VALUE)
                    .addComponent(jButton3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addContainerGap())
        );
        jPanel2Layout.setVerticalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addGap(19, 19, 19)
                .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jButton2, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jButton3, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(26, Short.MAX_VALUE))
        );

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1Layout.setHorizontalGroup(
        	jPanel1Layout.createParallelGroup(Alignment.LEADING)
        		.addGroup(jPanel1Layout.createSequentialGroup()
        			.addContainerGap()
        			.addComponent(jPanel2, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
        			.addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        jPanel1Layout.setVerticalGroup(
        	jPanel1Layout.createParallelGroup(Alignment.LEADING)
        		.addGroup(jPanel1Layout.createSequentialGroup()
        			.addComponent(jPanel2, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
        			.addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        jPanel1.setLayout(jPanel1Layout);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        layout.setHorizontalGroup(
        	layout.createParallelGroup(Alignment.TRAILING)
        		.addGroup(layout.createSequentialGroup()
        			.addContainerGap(108, Short.MAX_VALUE)
        			.addComponent(jPanel1, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
        			.addGap(106))
        );
        layout.setVerticalGroup(
        	layout.createParallelGroup(Alignment.TRAILING)
        		.addGroup(layout.createSequentialGroup()
        			.addContainerGap(168, Short.MAX_VALUE)
        			.addComponent(jPanel1, GroupLayout.PREFERRED_SIZE, 217, GroupLayout.PREFERRED_SIZE)
        			.addGap(21))
        );
        getContentPane().setLayout(layout);

        pack();
    }// </editor-fold>//GEN-END:initComponents

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
        sow();
    }//GEN-LAST:event_jButton1ActionPerformed

    private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton3ActionPerformed
        // TODO add your handling code here:
    }//GEN-LAST:event_jButton3ActionPerformed

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(JFrameGlowna.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(JFrameGlowna.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(JFrameGlowna.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(JFrameGlowna.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new JFrameGlowna().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JButton jButton3;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    // End of variables declaration//GEN-END:variables
}

Używałeś Mataisse?

A co to w ogóle jest? Bo nie spotkałem się jeszcze z taką nazwą.

Ja to robię w ten sposób że Panel tła tworze nową klase z konstruktorem w którym wczytuje zdjęcie i overide paintComponent robię. Póżniej dodajesz elementy już na nowym Panelu

np

//Tutaj kod Twojego Fram'a
tloimg = ImageIO.read(new File(file));
ImageIcon tloIcon=new ImageIcon( tloimg);

JPodPanel= new JPodPanel(tloIcon);



// Dalej kod

//A tutaj kod klasy JPodPanel

 class JPodPanel extends JPanel{
     
    private Image imga;
    
    JPodPanel(ImageIcon img){
    
        
    imga=img.getImage();    
    repaint();
        
    }

    
    
    @Override
  protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    //Wyrysowujesz zdjecie tak zeby zajelo caly obszar
    g.drawImage(imga, 0, 0, getWidth(), getHeight(), this);
  }
}

I teraz na Swojego Frame dodajesz najpierw JPodPanel a dopiero na niego całą reszte komponentów ;)

Nie wiem czy to do końca eleganckie i ładne ale działa ;-)

Ewentualnie zawsze można użyć jako formę dla backcgroundowego obrazka JLabel i później resztę obiektów rozmieszczać właśnie na nim.