Re: Display jpg in JPanel problem

From:

Knute Johnson <nospam@rabbitbrush.frazmtn.com>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 27 Jun 2010 09:20:07 -0700

Message-ID:

<4TKVn.1513$Hw.1479@newsfe10.iad>

On 6/27/2010 2:08 AM, jimmy wrote:

Thanks all for your help again. I didn't include the complete code for
my GUI as it was built using NetBeans and contains lots of other
buttons and panels, which were not relevant to the problem. I was
unaware of the SSCCE method of describing a problem, and I find it a
very good method. I did write an SSCCE example showing my problem, but
I fear that, as pointed out by Knute Johnson, the problems with my
code run deeper than the problem I described. I haven't fully grasped
how to work with images, therefore I am going to buy a book on Java
today (Head First Java seems to receive high praise) and spend some
time getting to grips with the basics.

Thanks Daniel Pitts for the JLabel suggestion, however I need to be
able to manipulate the images, which I believe is beyond the scope of
JLabel.

In the meantime I need to create a GUI for image analysis, so I have
started one in MATLAB (which I am much more familiar with than Java).
My intention is to create the final version in Java however.

Cheers,

Jimmy

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;

public class test extends JPanel {
     private BufferedImage image;

     public void setImage(BufferedImage bi) {
         image = bi;
         if (image != null) {
             setPreferredSize(new Dimension(
              bi.getWidth(),bi.getHeight()));
             revalidate();
             repaint();
         }
     }

     public void paintComponent(Graphics g) {
         super.paintComponent(g);
         if (image != null)
             g.drawImage(image,0,0,null);
     }

     public static void main(String[] args) {
         EventQueue.invokeLater(new Runnable() {
             public void run() {
                 final JFrame f = new JFrame();
                 f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                 final test t = new test();
                 JScrollPane sp = new JScrollPane(t);
                 f.add(sp,BorderLayout.CENTER);
                 JButton b = new JButton("Load Image");
                 b.addActionListener(new ActionListener() {
                     public void actionPerformed(ActionEvent ae) {
                         JFileChooser chooser = new JFileChooser();
                         if (chooser.showOpenDialog(f) ==
                          JFileChooser.APPROVE_OPTION) {
                             try {
                                 File file = chooser.getSelectedFile();
                                 if (file.exists())
                                     t.setImage(ImageIO.read(file));
                             } catch (IOException ioe) {
                                 JOptionPane.showMessageDialog(f,ioe);
                             }
                         }
                     }
                 });
                 f.add(b,BorderLayout.SOUTH);
                 f.setSize(400,300);
                 f.setVisible(true);
             }
         });
     }
}

--

Knute Johnson
email s/nospam/knute2010/