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Without redrawing the image s

Greetings to all that I am here a little. When I run the program and press the submit button, it should change 4 snapshots every 2 seconds. However, this does not redraw the images. If someone can give me a hand, it would be great. I use eclipse and the program compiles and works. Here is the code.

/** Here is the GUI of the program
 * class name SlideShowGui.java
 * @author Kiril Anastasov
 * @date 07/03/2012
 */

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;   

public class SlideShowGui extends JPanel  implements ActionListener, Runnable
{
    JLabel name, comments, images;
    JTextField namejtf, commentsjtf, captionjtf;
    JButton submit;
    ImageIcon pictures1, pictures2, pictures3, pictures4;
    //ImageIcon []pictures2 = {galileo1.jpg};


    SlideShowGui()
    {


        name = new JLabel("Name:");
        this.add(name);

        namejtf = new JTextField(15);
        this.add(namejtf);

        comments = new JLabel("Comments:");
        this.add(comments);

        commentsjtf = new JTextField(15);
        this.add(commentsjtf);

        submit = new JButton("Submit");
        this.add(submit);
        submit.addActionListener(this);


        pictures1 = new ImageIcon("galileo1.jpg");
        images = new JLabel(pictures1);
        this.add(images);


        pictures2 = new ImageIcon("galileo2.jpg");
        this.add(images);
        pictures3 = new ImageIcon("galileo3.jpg");
        this.add(images);
        pictures4 = new ImageIcon("galileo4.jpg");
        this.add(images);



        captionjtf = new JTextField(24);
        this.add(captionjtf);
        //pictures = new ImageIcon("galileo1.jpg");
       // images.setIcon(pictures);  
    }

    public void actionPerformed(ActionEvent ae)
    {
        Thread t = new Thread(this);
        t.start();

        if(ae.getSource() == submit)
        {

            int i = 0;
            boolean go = true;
            while(go)
            {

                i++;
                System.out.println(i);

                try 
                { 
                    Thread.sleep(2000);

                      if(i == 1)
                      {
                            pictures1 = new ImageIcon("galileo1.jpg");
                            images.setIcon(pictures1);                                                                                                      
                            System.out.println("picture 1 should be displayed here");
                      }
                      if(i == 2)
                      {
                            pictures2 = new ImageIcon("galileo2.jpg");
                            images.setIcon(pictures2);   
                            System.out.println("picture 2 should be displayed here");

                      }
                      if(i == 3)
                      {
                           pictures3 = new ImageIcon("galileo3.jpg");
                            images.setIcon(pictures3);   
                           System.out.println("picture 3 should be displayed here");  
                      }
                      if(i == 4)
                      {
                            pictures4 = new ImageIcon("galileo4.jpg");
                            images.setIcon(pictures4);   
                           System.out.println("picture 4 should be displayed here");  
                      }


                      if(i == 4)
                      {
                              i = 0;
                      }


                } 
                catch (InterruptedException ie) 
                {
                     System.out.println("thread exception");
                }

        }
    }

}

    public void run() 
    {

    }
}

/**The driver class of the program. Here is the JFrame 
 * class name TestSlideShow.java
 * @author Kiril Anastasov
 * @date 07/03/2012
 */

import java.awt.*;
import javax.swing.*;
public class TestSlideShow 
{
    public static void main(String[] args) 
    {
        JFrame application = new JFrame();
        SlideShowGui panel = new SlideShowGui();
        application.add(panel);
        application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        application.setSize(300,600);
        application.setLocation(400,100);
        application.setVisible(true);


    }

}
+1
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3 answers

Always use javax.swing.Timernever use Thread.sleep(...)in Swing at least. Try this code here, but replace pathwith your images:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class SlideShow extends JPanel
{
    private int i = 0;
    private Timer timer;
    private JLabel images = new JLabel();
    private Icon bg = UIManager.getIcon("OptionPane.warningIcon");
    private Icon red = UIManager.getIcon("OptionPane.errorIcon");
    private Icon blue =  UIManager.getIcon("OptionPane.informationIcon");
    private ImageIcon pictures1, pictures2, pictures3, pictures4;
    private ActionListener action = new ActionListener()
    {
        public void actionPerformed(ActionEvent ae)
        {           

            boolean go = true;

            i++;
            System.out.println(i);

            if(i == 1)
            {
                images.setIcon(bg);                                                                                                      
                System.out.println("picture 1 should be displayed here");
            }
            if(i == 2)
            {
                images.setIcon(red);   
                System.out.println("picture 2 should be displayed here");
            }
            if(i == 3)
            {
                images.setIcon(blue);   
                System.out.println("picture 3 should be displayed here");  
            }
            if(i == 4)
            {
                images.setIcon(bg);   
                System.out.println("picture 4 should be displayed here");  
            }
            if(i == 5)
            {
                go = false;
                timer.stop();
                System.exit(0);
            }
            revalidate();
            repaint();
        }
    };

    public SlideShow()
    {
        JFrame frame = new JFrame("SLIDE SHOW");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setLocationByPlatform(true);

        frame.getContentPane().add(this);

        add(images);

        frame.setSize(300, 300);
        frame.setVisible(true); 
        timer = new Timer(2000, action);    
        timer.start();  
    }

    public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                new SlideShow();
            }
        });
    }
}
+5
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The whole part if (i == ...can be simplified. Declare a static class member in SlideShowGUI:

private final static ImageIcon[] icons = {new ImageIcon("galileo1.jpg"),
                                          new ImageIcon("galileo2.jpg"),
                                          new ImageIcon("galileo3.jpg"),
                                          new ImageIcon("galileo4.jpg")};

and use it when replacing statements if:

images.setIcon(icons[i-1]);
System.printf("Picture %s should be displayed%n", i-1);
if (i == 4) {
  i = 0;
}
+4

You can simplify your code mentioned by Andreas_D.

Your current project blocks the main thread, when you call it Thread.sleep(), it will freeze your application.

If you want to update Image, you must implement the update code inside the method run().

So, if you find that the user clicks on submit JButton, create and run a new one Threadto update the interface.

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