Example almost straight out of book doesn't display image

[apchar boiir]

This little bit of code is almost straight out of "Core Java2" except it's Netbeanified. I know it gets the image because it prints the right width. But the frame is blank. Where did I go wrong?

package my.stuff;

import java.awt.*;
import javax.imageio.*;
import javax.swing.*;
import java.net.*;

public class jarredImages extends JFrame
{
	Image image = null;
	
	public jarredImages()
	{
		initComponents();
		ImagePanel imagePanel = new ImagePanel();
		add(imagePanel);
	}

	private class ImagePanel extends JPanel
	{
		private Image image;

		public ImagePanel()
		{
			URL url = jarredImages.class.getResource("/s2000.jpg");
			try { image = ImageIO.read(url); }
			catch (Exception ee) { ee.printStackTrace(); }
			System.out.println("width = " + image.getWidth(this));
		}

		public void paintComponent(Graphics g)
		{
			super.paintComponent(g);
			if (image == null) return;

			int width = image.getWidth(this);
			int height = image.getHeight(this);

			g.drawImage(image, 1, 1, this);
		}
	}

    /** 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.
     */
    @SuppressWarnings("unchecked")
        // <editor-fold defaultstate="collapsed" desc="Generated Code">
        private void initComponents() {

                setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

                javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
                getContentPane().setLayout(layout);
                layout.setHorizontalGroup(
                        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addGap(0, 400, Short.MAX_VALUE)
                );
                layout.setVerticalGroup(
                        layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                        .addGap(0, 300, Short.MAX_VALUE)
                );

                pack();
        }// </editor-fold>

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new jarredImages().setVisible(true);
            }
        });
    }

        // Variables declaration - do not modify
        // End of variables declaration
}

[Rob Spoor]

The problem appears to be in the layout manager. If I uncomment the call to "getContentPane().setLayout(layout);" I get the image.

I haven't used GroupLayout myself but its Javadoc page seems to require you to add the components through the layout manager, not directly through the content pane.

[apchar boiir]

Rob Spoor wrote:The problem appears to be in the layout manager. If I uncomment the call to "getContentPane().setLayout(layout);" I get the image.

I haven't used GroupLayout myself but its Javadoc page seems to require you to add the components through the layout manager, not directly through the content pane.

Yikes! But netbeans doesn't give us access to the layout manager! It's in the protected code block. You can unlock the code block but that breaks the GUI builder. Surely I'm not the only person to run into this. Gadzillions of people use Netbeans day & night (or at least a few hundred for a few hours a day).

[apchar boiir]

Turns out it was a panel size issue. I just assumed imagePanel would automatically fill the frame. It doesn't. When I set it to the size of the image it works fine.

[Rob Spoor]

apchar boiir wrote:But netbeans doesn't give us access to the layout manager! It's in the protected code block. You can unlock the code block but that breaks the GUI builder.

Which is exactly why many people prefer to write GUI code by hand instead of using a GUI designer.

[Darryl Burke]

netbeans doesn't give us access to the layout manager

Not so. Check the context menu in the Visual Designer.