Question

I’m creating an about JFrame for my program. I have an icon which I used for the program and I have that show up as the first thing on the about JFrame, but I’m having issues trying to center the image. If I do some kind of centering it screws up the whole alignment of everything else.

I’m trying to have all the JLabels, other than the icon, to be left aligned. Then have the icon aligned to the center.

I had to remove some personal information, whatever I did remove I put them between “[]”.

import java.awt.Dimension;
import java.awt.Font;

import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class About extends JFrame {

    public About() {
        super("About [PROGRAM]");
        setIconImage([PROGRAM].getInstance().setIcon());

        JPanel main = new JPanel();

        main.setLayout(new BoxLayout(main, BoxLayout.Y_AXIS));
        main.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));

        JLabel icon = new JLabel("", new ImageIcon(getClass().getResource(Constants.ICON_FULL)), JLabel.CENTER);        
        JLabel name = new JLabel("[PROGRAM]");
        JLabel expandedName = new JLabel("[PROGRAM DESCRIPTION]");
        JLabel copyright = new JLabel("[COPYRIGHT JUNK]");
        JLabel credits = new JLabel("[CREDITS]");

        name.setFont(new Font(name.getFont().getFamily(), Font.BOLD, 18));

        copyright.setBorder(BorderFactory.createEmptyBorder(0,0,10,0));

        main.add(icon);
        main.add(Box.createRigidArea(new Dimension(0, 10)));
        main.add(name);
        main.add(expandedName);
        main.add(copyright);
        main.add(credits);

        add(main);

        pack();
        setLocationRelativeTo(null);
        setVisible(true);
    }

}

Answer 1

Consider using some layouts to help you out. Ones that come to mind include BorderLayout with the icon in the BorderLayout.CENTER position. You can stack stuff on one side using a BoxLayout using JPanel that is added to the main BorderLayout-using JPanel.

e.g.,

import java.awt.BorderLayout;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;

import javax.imageio.ImageIO;
import javax.swing.*;

@SuppressWarnings("serial")
public class About extends JDialog {
   public static final String IMAGE_PATH = "http://upload.wikimedia.org/wikipedia/"
         + "commons/thumb/3/39/European_Common_Frog_Rana_temporaria.jpg/"
         + "800px-European_Common_Frog_Rana_temporaria.jpg";

   public About(JFrame frame) {
      super(frame, "About [PROGRAM]", true);

      ImageIcon myIcon = null;
      try {
         URL imgUrl = new URL(IMAGE_PATH);
         BufferedImage img = ImageIO.read(imgUrl);
         myIcon = new ImageIcon(img);
      } catch (MalformedURLException e) {
         e.printStackTrace();
         System.exit(-1);
      } catch (IOException e) {
         e.printStackTrace();
         System.exit(-1);
      }

      JPanel main = new JPanel(new BorderLayout());

      main.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));

      JLabel centerLabel = new JLabel(myIcon);
      JLabel name = new JLabel("[PROGRAM]");
      JLabel expandedName = new JLabel("[PROGRAM DESCRIPTION]");
      JLabel copyright = new JLabel("[COPYRIGHT JUNK]");
      JLabel credits = new JLabel("[CREDITS]");

      name.setFont(new Font(name.getFont().getFamily(), Font.BOLD, 18));

      copyright.setBorder(BorderFactory.createEmptyBorder(0, 0, 10, 0));

      int eb = 20;
      centerLabel.setBorder(BorderFactory.createEmptyBorder(eb, eb, eb, eb));

      JPanel leftPanel = new JPanel();
      leftPanel.setLayout(new BoxLayout(leftPanel, BoxLayout.PAGE_AXIS));
      leftPanel.add(name);
      leftPanel.add(Box.createVerticalGlue());
      leftPanel.add(expandedName);
      leftPanel.add(copyright);
      leftPanel.add(credits);
      leftPanel.add(Box.createVerticalGlue());

      main.add(centerLabel, BorderLayout.CENTER);
      main.add(leftPanel, BorderLayout.LINE_START);

      add(main);

      pack();
   }

   public static void main(String[] args) {
      final JFrame frame = new JFrame("GUI");
      JPanel panel = new JPanel();
      panel.add(new JButton(new AbstractAction("About") {

         @Override
         public void actionPerformed(ActionEvent e) {
            About about = new About(frame);
            about.setLocationRelativeTo(frame);
            about.setVisible(true);
         }
      }));
      frame.add(panel);
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setVisible(true);
   }
}