Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.SwingWorker;
import javax.swing.WindowConstants;
import javax.swing.plaf.basic.BasicProgressBarUI;

public class Main {
    public static void main(String[] args) {
        JProgressBar progressBar = new JProgressBar();
        progressBar.setOpaque(false);
        progressBar.setUI(new GradientPalletProgressBarUI());

        JPanel p = new JPanel();
        p.add(progressBar);
        p.add(new JButton(new AbstractAction("Start") {
            @Override
            public void actionPerformed(ActionEvent e) {
                SwingWorker<Void, Void> worker = new SwingWorker<Void, Void>() {
                    @Override
                    public Void doInBackground() {
                        int current = 0, lengthOfTask = 100;
                        while (current <= lengthOfTask && !isCancelled()) {
                            try {
                                Thread.sleep(50);
                            } catch (Exception ie) {
                                return null;
                            }
                            setProgress(100 * current / lengthOfTask);
                            current++;
                        }
                        return null;
                    }
                };
                worker.addPropertyChangeListener(new ProgressListener(progressBar));
                worker.execute();
            }
        }));

        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.getContentPane().add(p);
        frame.setSize(320, 240);
        frame.setVisible(true);
    }
}

class ProgressListener implements PropertyChangeListener {
    private final JProgressBar progressBar;

    ProgressListener(JProgressBar progressBar) {
        this.progressBar = progressBar;
        this.progressBar.setValue(0);
    }

    @Override
    public void propertyChange(PropertyChangeEvent evt) {
        String strPropertyName = evt.getPropertyName();
        if ("progress".equals(strPropertyName)) {
            progressBar.setIndeterminate(false);
            int progress = (Integer) evt.getNewValue();
            progressBar.setValue(progress);
        }
    }
}

class GradientPalletProgressBarUI extends BasicProgressBarUI {

    public GradientPalletProgressBarUI() {
        super();
    }

    @Override
    public void paintDeterminate(Graphics g, JComponent c) {
        if (!(g instanceof Graphics2D)) {
            return;
        }
        Insets b = progressBar.getInsets(); // area for border
        int barRectWidth = progressBar.getWidth() - (b.right + b.left);
        int barRectHeight = progressBar.getHeight() - (b.top + b.bottom);
        if (barRectWidth <= 0 || barRectHeight <= 0) {
            return;
        }
        int cellLength = getCellLength();
        int cellSpacing = getCellSpacing();

        int amountFull = getAmountFull(b, barRectWidth, barRectHeight);

        if (progressBar.getOrientation() == JProgressBar.HORIZONTAL) {

            float x = amountFull / (float) barRectWidth;
            g.setColor(Color.BLUE);
            g.fillRect(b.left, b.top, amountFull, barRectHeight);

        } else { // VERTICAL

        }
        if (progressBar.isStringPainted()) {
            paintString(g, b.left, b.top, barRectWidth, barRectHeight, amountFull, b);
        }
    }
}