Can a progress bar be used in a class outside main?

Question

Right now, my main just calls a gui with 10 rows. Based on how many of those rows have text, 1 of 9 classes is called (two rows must have text). The called class performs calculations that I'd like to have the progress bar tied to. Here is an example of one of the called classes (each class is similar, but different enough to warrant a new class.) I believe the problem is a violation of EDT rules, but all the examples I've seen on them involve a main argument. The frame appears when the code is run, but the progress bar doesn't update until all calculations are completed.

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class twoLoan extends JFrame {

    static JFrame progressFrame;
    static JProgressBar progressBar;
    static Container pane;
    double amountSaved = 0;
    int i = 0;

    public void runCalcs(Double MP, Double StepAmt,
        Double L1, Double L2, Double C1, Double C2,
        Double IM1, Double IM2, Double M1Start, Double M2Start) {

        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (Exception e) {
        }

        int iterations = (int) (MP - (M1Start * M2Start));

        //Create all components
        progressFrame = new JFrame("Calculation Progress");
        progressFrame.setSize(300, 100);
        pane = progressFrame.getContentPane();
        pane.setLayout(null);
        progressFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        progressBar = new JProgressBar(0, iterations);

        //Add components to pane
        pane.add(progressBar);

        //Position controls (X, Y, width, height)
        progressBar.setBounds(10, 10, 280, 20);

        //Make frame visible
        progressFrame.setResizable(false); //No resize
        progressFrame.setVisible(true);

        double M1 = M1Start;
        double M2 = M2Start;

        // Set MinLoop as maximum to start
        // Loan 1
        double N1 = (Math.log10(1 - IM1 * L1 / M1) * -1) / Math.log10(1 + IM1);
        double M1Sum = M1 * N1;
        // Loan 2
        double N2 = (Math.log10(1 - IM2 * L2 / M2) * -1) / Math.log10(1 + IM2);
        double M2Sum = M2 * N2;
        double minLoop = M1Sum + M2Sum;
        double MTotal = 0;


        // Define variables for mins
        double MP1 = 0;
        double MP2 = 0;
        double NP1 = 0;
        double NP2 = 0;
        double MP1Sum = 0;
        double MP2Sum = 0;

        while (M1 <= MP - M2Start && M2 >= M2Start) {
            N1 = (Math.log10(1 - IM1 * L1 / M1) * -1) / Math.log10(1 + IM1);
            M1Sum = N1 * M1;
            N2 = (Math.log10(1 - IM2 * L2 / M2) * -1) / Math.log10(1 + IM2);
            M2Sum = N2 * M2;
            MTotal = M1Sum + M2Sum;
            if (MTotal < minLoop) {
                minLoop = MTotal;
                MP1 = M1;
                MP2 = M2;
                NP1 = N1;
                NP2 = N2;
                MP1Sum = M1Sum;
                MP2Sum = M2Sum;
            } // end if
            M1 = M1 + StepAmt;
            M2 = MP - M1;
            // Reset monthly sums
            M1Sum = 0;
            M2Sum = 0;
            i++;
            progressBar.setValue(i);
            progressBar.repaint();
            if (i >= iterations) {
                progressFrame.dispose();
            }
        } // end while

        // if there's a value for current payments, calculate amount saved
        if (C1 > 0) {
            double CN1 = (Math.log10(1 - IM1 * L1 / C1) * -1) / Math.log10(1 + IM1);
            double CT1 = CN1 * C1;

            double CN2 = (Math.log10(1 - IM2 * L2 / C2) * -1) / Math.log10(1 + IM2);
            double CT2 = CN2 * C2;

            double CTotal = CT1 + CT2;
            amountSaved = CTotal - minLoop;
        }

    } // end method runCalcs

    //Workbook wb = new HSSFWorkbook();
    public double savedReturn() {
        return amountSaved;
    }
} // end class twoLoans  

Aiello

Answer 1

SwingWorker is ideal for this. The example below performs a simple iteration in the background, while reporting progress and intermediate results in a window. You can pass whatever parameters you need in a suitable SwingWorker constructor.

import java.awt.EventQueue;
import java.awt.GridLayout;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.text.DecimalFormat;
import java.util.List;
import javax.swing.*;

/** @see http://stackoverflow.com/questions/4637215 */
public class TwoRoot extends JFrame {

    private static final String s = "0.000000000000000";
    private JProgressBar progressBar = new JProgressBar(0, 100);
    private JLabel label = new JLabel(s, JLabel.CENTER);

    public TwoRoot() {
        this.setLayout(new GridLayout(0, 1));
        this.setTitle("√2");
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.add(progressBar);
        this.add(label);
        this.setSize(161, 100);
        this.setLocationRelativeTo(null);
        this.setVisible(true);
    }

    public void runCalc() {
        progressBar.setIndeterminate(true);
        TwoWorker task = new TwoWorker();
        task.addPropertyChangeListener(new PropertyChangeListener() {

            @Override
            public void propertyChange(PropertyChangeEvent e) {
                if ("progress".equals(e.getPropertyName())) {
                    progressBar.setIndeterminate(false);
                    progressBar.setValue((Integer) e.getNewValue());
                }
            }
        });
        task.execute();
    }

    private class TwoWorker extends SwingWorker<Double, Double> {

        private static final int N = 5;
        private final DecimalFormat df = new DecimalFormat(s);
        double x = 1;

        @Override
        protected Double doInBackground() throws Exception {
            for (int i = 1; i <= N; i++) {
                x = x - (((x * x - 2) / (2 * x)));
                setProgress(i * (100 / N));
                publish(Double.valueOf(x));
                Thread.sleep(1000); // simulate latency
            }
            return Double.valueOf(x);
        }

        @Override
        protected void process(List<Double> chunks) {
            for (double d : chunks) {
                label.setText(df.format(d));
            }
        }
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                TwoRoot t = new TwoRoot();
                t.runCalc();
            }
        });
    }
}

Pikeperch

How could I run this if in an actionPerformed? Would an invokeLater still be necessary or could I just instantiate the SwingWorker and execute it directly? – Deadline

The latter, as shown here. – Pikeperch

See also this related JFreeChart example. – Pikeperch

Answer 2

I think you premonition is right, you need to adhere to Swing threading rules.

So what to do?

First, I am not sure how your app is designed exactly. You say that you have a main frame with a bunch of rows, and potentially each could potentially call one of 9 classes, and they all look like the one above. It seems that these classes will generate their own JFrame. I guess that this new frame is solely used for the progress bar. I will assume that this is the design and will suggest accordingly.

I suggest that you perform a couple actions in instances of Runnable, and you drop those Runnable instances into SwingUtilities.invokeLater to have them run on the EDT. At the same time, I would take the time to reorganize your code for ease if reading.

1. move the creation of your GUI bits into a method:

public void createComponents () {
      SwingUtilities.invokeLater(new Runnable() {
        public void run() {
          //Create all components
          progressFrame = new JFrame("Calculation Progress");
          progressFrame.setSize(300, 100);
          pane = progressFrame.getContentPane();
          pane.setLayout(null);
          progressFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          progressBar = new JProgressBar(0, iterations);
          //Add components to pane
          pane.add(progressBar);

          //Position controls (X, Y, width, height)
          progressBar.setBounds(10, 10, 280, 20);

          //Make frame visible
          progressFrame.setResizable(false); //No resize
          progressFrame.setVisible(true);
       }
      });

    }

1. Then I would methodize the two GUI actions that you have in your calc:

     private void updateProgressBar(final int i) {
           SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                   progressBar.setValue(i);
                   //no need for the following
                   //progressBar.repaint(); 

                }
           });
    }

    private void killDialog() {
           SwingUtilities.invokeLater(new Runnable() {
                public void run() {
                    progressFrame.setVisible(false);
                }
            });
    } 

1. Finally, replace where the code contained in these new methods with calls to the methods.

Blairblaire

Thanks a lot for your help, I've been stuck on this one for a while. I've been working on it, but I can't figure out how to call the new methods in real time. With my updated code, the GUI is created, and the progress bar is updated after the calculations are performed. Would you mind helping me out with calling the methods? I have everything called similarly within "runCalcs" as follows: SwingUtilities.invokeLater(new Runnable() { public void run() { createComponents(iterations); } }); – Aiello

Answer 3

Thanks for the help. I started with trying to use the first response, but I couldn't get the bar to run concurrently, and it ran when the program finished. I'm sure it would work, but I wasn't able to figure it out. Using trashgod's response and some other examples, I was able to get it to work using SwingWorker. Unfortunately, I don't totally understand how it works, but I'll take it for now.

The gui and method to run the calculations are called in another class first:

iterations = (int) (MPay - (M1Start + M2Start));
        twoLoan myLoan = new twoLoan();
        myLoan.createGui(iterations);
        myLoan.runCalcs(MPay, Step, L1, L2, C1, C2, IM1, IM2, M1Start, M2Start);

Then it runs as follows:

public class twoLoan extends JFrame {

    JFrame progressFrame;
    JProgressBar progressBar;
    JLabel label = new JLabel("Calculating...");;
    Container pane;

    double amountSaved = 0;
    int i = 0;
    int iterations;

    public void createGui(int iterations) {
           //Create all components
          progressFrame = new JFrame("Calculation Progress");
          progressFrame.setSize(300, 100);
          pane = progressFrame.getContentPane();
          pane.setLayout(null);
          label = new JLabel("Calculating...");
          label.setBounds(115, 35, 200, 25);
          progressBar = new JProgressBar(0, iterations);
          progressBar.setBounds(10, 10, 280, 20);
          progressBar.setStringPainted(true);
          //Add components to pane
          pane.add(progressBar);
          pane.add(label);
          //Make frame visible
          progressFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          progressFrame.setResizable(false); //No resize
          progressFrame.setLocationRelativeTo(null);
          progressFrame.setVisible(true);
    }

    public void runCalcs (double MP, double StepAmt, double L1, double L2,
            double C1, double C2, double IM1, double IM2, double M1Start, double M2Start) {

        progressBar.setIndeterminate(false);
        TwoWorker task = new TwoWorker(MP, StepAmt, L1, L2, C1, C2, IM1, IM2, M1Start, M2Start);
        task.addPropertyChangeListener(new PropertyChangeListener() {

            @Override
            public void propertyChange(PropertyChangeEvent e) {
                if ("progress".equals(e.getPropertyName())) {
                    progressBar.setIndeterminate(false);
                    progressBar.setValue((Integer) e.getNewValue());
                }
            }
        });
        task.execute();
    } //end method runCalcs

    public class TwoWorker extends SwingWorker<Double, Double> {

        private final double MP, StepAmt,L1, L2,
            C1, C2, IM1, IM2, M1Start, M2Start;

        public TwoWorker(double MPa, double StepAmta, double L1a, double L2a,
            double C1a, double C2a, double IM1a, double IM2a, double M1Starta, double M2Starta) {

            MP = MPa;
            StepAmt = StepAmta;
            L1 = L1a;
            L2 = L2a;
            C1 = C1a;
            C2 = C2a;
            IM1 = IM1a;
            IM2 = IM2a;
            M1Start = M1Starta;
            M2Start = M2Starta;
           }
        @Override
        protected Double doInBackground() {

            double M1 = M1Start;
            double M2 = M2Start;

        // Set MinLoop as maximum to start
        // Loan 1
        double N1 = (Math.log10(1 - IM1 * L1 / M1) * -1)/Math.log10(1 + IM1);
    double M1Sum = M1 * N1;
    // Loan 2
    double N2 = (Math.log10(1 - IM2 * L2 / M2) * -1)/Math.log10(1 + IM2);
    double M2Sum = M2 * N2;
    double minLoop = M1Sum + M2Sum;
    double MTotal = 0;

        // Define variables for mins
    double MP1 = 0;
    double MP2 = 0;
    double NP1 = 0;
    double NP2 = 0;
    double MP1Sum = 0;
    double MP2Sum = 0;

        while ( M1 <= MP - M2Start && M2 >= M2Start ) {
            N1 = (Math.log10(1 - IM1 * L1 / M1) * -1)/Math.log10(1 + IM1);
            M1Sum = N1 * M1;
            N2 = (Math.log10(1 - IM2 * L2 / M2) * -1)/Math.log10(1 + IM2);
            M2Sum = N2 * M2;
            MTotal = M1Sum + M2Sum;
            if (MTotal < minLoop) {
                minLoop = MTotal;
                MP1 = M1;
                MP2 = M2;
                NP1 = N1;
                NP2 = N2;
                MP1Sum = M1Sum;
                MP2Sum = M2Sum;
            } // end if
                        i++;
                        progressBar.setValue(i);
                    M1 = M1 + StepAmt;
            M2 = MP - M1;
            // Reset monthly sums
            M1Sum = 0;
            M2Sum = 0;
        } // end while

        System.out.printf("MP1 = %.2f\n", MP1);
        System.out.printf("MP2 = %.2f\n", MP2);
        System.out.printf("NP1 = %.2f\n", NP1);
        System.out.printf("NP2 = %.2f\n", NP2);
        System.out.printf("MP1Sum = %.2f\n", MP1Sum);
        System.out.printf("MP2Sum = %.2f\n", MP2Sum);
                System.out.printf("MTotal = %.2f\n", minLoop);
                System.out.printf("i = %d\n",i);
                System.out.printf("M1Start = %.2f\n", M1Start);
        System.out.printf("M2Start = %.2f\n", M2Start);
                System.out.printf("MP= %.2f\n",MP);

    // if there's a value for current payments, calculate amount saved
    if( C1 > 0 ) {
        double CN1 = (Math.log10(1 - IM1 * L1 / C1) * -1)/Math.log10(1 + IM1);
        double CT1 = CN1 * C1;

        double CN2 = (Math.log10(1 - IM2 * L2 / C2) * -1)/Math.log10(1 + IM2);
        double CT2 = CN2 * C2;

        double CTotal = CT1 + CT2;
        amountSaved = CTotal - minLoop;
        } // end if

        return null;

    } // end doInBackGround

        @Override
        protected void done() {
            label.setBounds(133, 35, 200, 25);
            label.setText("Done!");
        }
    } // end TwoWorker


    public double savedReturn() {
        return amountSaved;
    }

} // end class twoLoans

Aiello