Question

I am trying to implement a progress JDialog in Java. I am parsing files, and I want the JDialog to refresh after I started to parse a new File. My problem is that the JDialog is not refreshing. I have tried to repaint it, or resize it, so it would repaint. I have also tried to remove the label, and add a new one.

The ProgressDialog class:

public class ProgressDialog extends javax.swing.JDialog {
    private JLabel jLabel1;

    public ProgressDialog(Window frame) {
        super(frame);
        this.setResizable(false);
        this.setLocationRelativeTo(frame);
        initGUI();
        //this.setVisible(true);

    }

    private void initGUI() {
        try {
            {
                setDefaultCloseOperation(DO_NOTHING_ON_CLOSE);
                getContentPane().setLayout(null);
                {
                    jLabel1 = new JLabel();
                    getContentPane().add(jLabel1);
                    jLabel1.setText("In Progress..");
                    jLabel1.setBounds(12, 12, 215, 52);
                    jLabel1.setHorizontalAlignment(SwingConstants.CENTER);
                }
            }
            this.setSize(255, 114);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void setText(String s){
        this.setVisible(true);
        jLabel1.setText(s);
        this.resize(this.getSize());
        this.repaint();
    }
}

How I use it:

ProgressDialog pd = new ProgressDialog(frame);
for(File file:files){
    pd.setText("Parsing " + file + ".");

    ...

}

Answer 1

You should perform the parsing of the file on a worker thread, and update your progress dialog on the Event Dispath Thread. A few links worth reading:

• Concurrency in Swing
• How to use progress bars tutorial: although it shows progress with a progress bar, the mechanism you need to use is the same. It contains an example of the SwingWorker class
• The SwingWorker javadoc
• A small piece of sample code I wrote for a related question illustrating the use of the SwingWorker class and showing progress to the user