java program flow on example of DynamicReports and progressbar

Question

i use DynamicReports library for make reports for my app. Createing report takes some time and i decided create custom progress bar while reports has not been created. Question after code examples.

progress bar class:

public class ProgressDialog implements DialogWrapper{

    private JFrame iFrame;
    private JDialog iDialog;
    private JPanel pane;
    private final JProgressBar aJProgressBar = new JProgressBar(0, 100);

    public ProgressDialog(){
        onCreate();
    }

    @Override
    public void onCreate() {
        iFrame = new JFrame("Создание отчета");
        iDialog = new JDialog(iFrame, true);
        pane = new JPanel();
        aJProgressBar.setIndeterminate(true);
        pane.add(aJProgressBar, BorderLayout.NORTH);
        iDialog.add(pane, BorderLayout.CENTER);
        iDialog.setTitle("Создание отчета");
        iDialog.setSize(300, 150);
        iDialog.setResizable(false);
        iDialog.setVisible(true);
        return;
    }

    @Override
    public void fillData() {}

    @Override
    public void onSubmit() {}

    protected void onCancel(){
        iDialog.setVisible(false);
        iDialog.dispose();
    }

    public void cancel(){
        onCancel();
    }
 }

Report abstract class

public abstract class AbstractReportMain<T extends ReportDesign<U>, U extends ReportData> {
private ProgressDialog pd;

public AbstractReportMain() {
    pd = new ProgressDialog();
    build();
}

protected void build() {
    try {
        JasperReportBuilder reportBuilder = DynamicReports.report();            
        U data = getReportData();
        if (data != null) {
            reportBuilder.setDataSource(data.createDataSource());
        }
        getReportDesign().configureReport(reportBuilder, data);

        pd.cancel();
        reportBuilder.show(false);
    } catch (DRException e) {
        e.printStackTrace();    
    }
}

protected U getReportData() {
    return null;
}

protected abstract T getReportDesign(); 
}

Question: when i create ProgressDialog, program flow stops while i do not close dialog. Why it's happen, how this behaviour called and where i can read about it? How it use and маке it work for me. Thanks.

Answer 1

I believe your problem is that you are not creating a new thread for your progress dialog. Here is an example that will help you. Modal Progress Dialog example