JLabel setIcon() not working...

[James Hodgkiss]

I am creating an image button class using JLabel and it's setIcon() method.
It also has a MouseListener, so that when the mouse goes over the button, the image changes colour.

I had it working nicely on my PC, buy when I uploaded my applet and tried it, no image would be displayed on m0useover...

It now displays no images at all regardles of where the mouse is. The code is quite simple, but I can't work out what is missing or what might be wrong. Does anyone have any ideas?...

 
import javax.swing.*;
import java.awt.Font;
import java.awt.event.ActionListener;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.MediaTracker;
import java.awt.Dimension;
 
public class Button extends JLabel implements MouseListener {
    private boolean ism0useov3r = false;
    private Image mouseAwayImage, m0useov3rImage;
    private ImageIcon mouseAwayImageIcon, m0useov3rImageIcon;
    private String text;
    
    private String m0useov3rImageLocation;
    private String mouseAwayImageLocation;
    
    public Button(Image mouseAwayImage, Image m0useov3rImage, String text) {
        this.mouseAwayImage = mouseAwayImage;
        this.m0useov3rImage = m0useov3rImage;
        this.text = text;
        
        if (mouseAwayImage == null) {
            System.out.println("mouseAwayImage is null");
        }
        else {
            System.out.println("mouseAwayImage is not null");
        }
        try {
            mouseAwayImageIcon = new ImageIcon(mouseAwayImage);
        }
        catch(Exception e) {
            System.out.println("Exception creating mouseAwayImageIcon: " + e.toString());
        }
        if (mouseAwayImageIcon == null) {
            System.out.println("mouseAwayImageIcon is null!");
        }
        else {
            System.out.println("mouseAwayImageIcon is not null");
        }
        
        if (m0useov3rImage == null) {
            System.out.println("m0useov3rImage is null");
        }
        else {
            System.out.println("m0useov3rImage is not null");
        }
        try {
            m0useov3rImageIcon = new ImageIcon(m0useov3rImage);
        }
        catch(Exception e) {
            System.out.println("Exception creating m0useov3rImageIcon: " + e.toString());
        }
        if (m0useov3rImageIcon == null) {
            System.out.println("m0useov3rImageIcon is null!");
        }
        else {
            System.out.println("m0useov3rImageIcon is not null");
        }
        
        this.setIcon(mouseAwayImageIcon);
        this.setFont(new Font("SansSerif", Font.BOLD, 12));
        this.setHorizontalAlignment(SwingConstants.CENTER);
        this.setVerticalAlignment(SwingConstants.CENTER);
        this.setHorizontalTextPosition(SwingConstants.CENTER);
        this.setVerticalTextPosition(SwingConstants.CENTER);
        this.setText(text);
        this.addMouseListener(this);
    }
    
    public void paintComponent(Graphics g) {
        //super.paintComponent(g);
        System.out.println("now in Button's paintComponent() method for '" + text + "' button");
        System.out.println("ism0useov3r: " + ism0useov3r);
        
    }
    
    public void mouseClicked(MouseEvent e) {
        
    }
    
    public void mouseEntered(MouseEvent e) {
        ism0useov3r = true;
        if (ism0useov3r) {
            this.setIcon(m0useov3rImageIcon);
            //int imageWidth = m0useov3rImage.getWidth(this);
            //int imageHeight = m0useov3rImage.getHeight(this);
            //g.drawImage(m0useov3rImage, 0, 0, imageWidth, imageHeight, this);
            //setPreferredSize(new Dimension(imageWidth, imageHeight));
        }
        else {
            this.setIcon(mouseAwayImageIcon);
            //int imageWidth = mouseAwayImage.getWidth(this);
            //int imageHeight = mouseAwayImage.getHeight(this);
            //g.drawImage(mouseAwayImage, 0, 0, imageWidth, imageHeight, this);
            //setPreferredSize(new Dimension(imageWidth, imageHeight));
        }
        this.setHorizontalAlignment(SwingConstants.CENTER);
        this.setVerticalAlignment(SwingConstants.CENTER);
        this.setHorizontalTextPosition(SwingConstants.CENTER);
        this.setVerticalTextPosition(SwingConstants.CENTER);
        this.setText(text);
    //    repaint();
    }
    
    public void mouseExited(MouseEvent e) {
        ism0useov3r = false;
        if (ism0useov3r) {
            this.setIcon(m0useov3rImageIcon);
            //int imageWidth = m0useov3rImage.getWidth(this);
            //int imageHeight = m0useov3rImage.getHeight(this);
            //g.drawImage(m0useov3rImage, 0, 0, imageWidth, imageHeight, this);
            //setPreferredSize(new Dimension(imageWidth, imageHeight));
        }
        else {
            this.setIcon(mouseAwayImageIcon);
            //int imageWidth = mouseAwayImage.getWidth(this);
            //int imageHeight = mouseAwayImage.getHeight(this);
            //g.drawImage(mouseAwayImage, 0, 0, imageWidth, imageHeight, this);
            //setPreferredSize(new Dimension(imageWidth, imageHeight));
        }
        this.setHorizontalAlignment(SwingConstants.CENTER);
        this.setVerticalAlignment(SwingConstants.CENTER);
        this.setHorizontalTextPosition(SwingConstants.CENTER);
        this.setVerticalTextPosition(SwingConstants.CENTER);
        this.setText(text);
      //  repaint();
    }
    
    public void mousePressed(MouseEvent e) {
        
    }
    
    public void mouseReleased(MouseEvent e) {
        
    }
    
}
 

[Michael Dunn]

you've overridden paintComponent() and commented out the super line
public void paintComponent(Graphics g) {
//super.paintComponent(g);

It worked OK for me (uncommenting above). I also changed the name from Button,
to avoid any conflicts with java.awt.Button.

only problem was the text displayed over the icon, so I passed "" as the text
in the constructor, and the icons toggled between #1 and #2, depending on mouse position

[James Hodgkiss]

Cheers Michael,

Meant to comment out the entire paintComponent method... late night.

I've found the source of the problem now. The filenames of the images I were using were 'yellowButton.jpg' and 'blueButton.JPG' . My code had used 'yellowButton.jpg' and 'blueButton.jpg' . The JPG / jpg difference was the reason it wasn't working when my applet was on the server, despite the image not coming up as null and despite the applet working when it was local on my machine...

Anyhow, thanks for checking the code out for me and your help. Much appreciated.

Cheers,
James