JFrame Problem

[Eoin Mac Aoidh]

Hi...
I am running a mapping application that accepts info from the user in a JFrame, and then loads a map according to his preferences in a second JFrame. I wish to load the layers of the map visually layer by layer. This works fine if I dont use two separate JFrames (if I hard code the user info) However... my problem occurs when I try to take the user info in the first frame, then load the map layers in the second... nothing displays until all the layers have loaded - then they all show togather!
The First frame appears to block the second one from rendering properly.
Any suggestions as to what the problem might be or a way around it?

Thanks,

Eoin.

[Stuart Gray]

Possibly this is a 'doing something time consuming on the Swing thread' problem? There was a nice little TechTips article about this recently.

[Craig Wood]

My first idea about this was that it might be a focus problem (j2se 1.4+) as pointed to in the isFocusableWindow method of the Window api. So I tried a couple of tests to see, one with loading components and the other with drawing images. Both worked just fine in j2se 1.5.

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.*;
import javax.imageio.ImageIO;
import javax.swing.*;
 
public class FocusTest
{
    JFrame iconFrame, imageFrame;
    BufferedImage[] images;
    Thread thread;
    boolean loading;
    IPanel ip;
 
    public FocusTest()
    {
        loadImages();
    }
 
    private void showIconFrame()
    {
        if(iconFrame == null)
        {
            iconFrame = new JFrame("icons");
            iconFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            iconFrame.getContentPane().setLayout(new GridLayout(0,2));
            iconFrame.setSize(300,300);
            iconFrame.setLocation(465,50);
            iconFrame.setVisible(true);
        }
        else if(!iconFrame.isVisible())
            iconFrame.setVisible(true);
        else
            iconFrame.toFront();
        if(iconFrame.isVisible() && !loading)
            (thread = new Thread(runner)).start();
    }
 
    private void showImageFrame()
    {
        if(imageFrame == null)
        {
            ip = new IPanel(images);
            imageFrame = new JFrame("graphic");
            imageFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
            imageFrame.getContentPane().add(ip);
            imageFrame.setSize(300,300);
            imageFrame.setLocation(465,375);
            imageFrame.setVisible(true);
        }
        else if(!imageFrame.isVisible())
            imageFrame.setVisible(true);
        else
            imageFrame.toFront();
        if(imageFrame.isVisible() && !ip.stillPainting)
            ip.start();
    }
 
    private Runnable runner = new Runnable()
    {
        public void run()
        {
            int count = 0;
            loading = true;
            while(loading)
            {
                try
                {
                    Thread.sleep(1000);
                }
                catch(InterruptedException ie)
                {
                    System.err.println("interrupt: " + ie.getMessage());
                }
                JLabel label = new JLabel(new ImageIcon(images[count++]));
                iconFrame.getContentPane().add(label);
                iconFrame.validate();
                if(count == images.length)
                {
                    try      // pause
                    {
                        Thread.sleep(4000);
                    }
                        catch(InterruptedException ie)
                    {
                        System.err.println("interrupt: " + ie.getMessage());
                    }
                    // clear components from content pane
                    iconFrame.getContentPane().removeAll();
                    iconFrame.repaint();
                    loading = false;
                }
            }
        }
    };
 
    private void loadImages()
    {
        String[] fileNames = {
            "-----", "-c---", "-cg--", "-c-h-"  // size: (83, 67)
        };
        images = new BufferedImage[fileNames.length];
        for(int j = 0; j < images.length; j++)
            try
            {
                String s = "images/geek" + fileNames[j] + ".gif";
                URL url = getClass().getResource(s);
                images[j] = ImageIO.read(url);
            }
            catch(MalformedURLException mue)
            {
                System.err.println("url: " + mue.getMessage());
            }
            catch(IOException ioe)
            {
                System.err.println("read: " + ioe.getMessage());
            }
    }
 
    private JPanel getUIPanel()
    {
        final JButton
            openIconFrame  = new JButton("show icon frame"),
            openImageFrame = new JButton("show image frame");
        ActionListener l = new ActionListener()
        {
            public void actionPerformed(ActionEvent e)
            {
                JButton button = (JButton)e.getSource();
                if(button == openIconFrame)
                    showIconFrame();
                if(button == openImageFrame)
                    showImageFrame();
            }
        };
        openIconFrame.addActionListener(l);
        openImageFrame.addActionListener(l);
        JPanel panel = new JPanel(new BorderLayout());
        panel.add(openIconFrame, "North");
        panel.add(openImageFrame, "South");
        return panel;
    }
 
    public static void main(String[] args)
    {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(new FocusTest().getUIPanel());
        f.setSize(240,120);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}
 
class IPanel extends JPanel
{
    BufferedImage[] images;
    Thread thread;
    boolean stillPainting;
    int count;
 
    public IPanel(BufferedImage[] images)
    {
        this.images = images;
    }
 
    protected void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        int w = getWidth();
        int h = getHeight();
        int xInc = (w - 2*images[0].getWidth())/3;
        int yInc = (h - 2*images[0].getHeight())/3;
        for(int j = 0; j < count; j++)
        {
            int x = j % 2 == 0 ? xInc : 2*xInc + images[0].getWidth();
            int y = j < 2      ? yInc : 2*yInc + images[0].getHeight();
            g.drawImage(images[j], x, y, this);
        }
    }
 
    protected void start()
    {
        if(thread == null)
        {
            stillPainting = true;
            thread = new Thread(painter);
            thread.start();
        }
    }
 
    protected void stop()
    {
        if(stillPainting)
        {
            stillPainting = false;
            thread = null;
        }
    }
 
    private Runnable painter = new Runnable()
    {    
        public void run()
        {
            count = 0;
            while(stillPainting)
            {
                try
                {
                    Thread.sleep(1000);
                }
                catch(InterruptedException ie)
                {
                    System.err.println("interrupt: " + ie.getMessage());
                }
                count++;
                repaint();
                if(count == images.length)
                {
                    stop();    // stop thread
                    try        // pause action
                    {
                        Thread.sleep(4000);
                    }
                        catch(InterruptedException ie)
                    {
                        System.err.println("interrupt: " + ie.getMessage());
                    }
                    // clear all images from panel
                    count = -1;
                    repaint();
                }
            }
        }
    };
}

[Eoin Mac Aoidh]

Thanks Stuart and Craig, I found a simple way around the problem: By using a coustom dialog for the user to enter his details, when the details are entered the dialog disposes and the main frame loads.

Thanks again,

Eoin.