Main.java Source code

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Here is the source code for Main.java

Source

import java.awt.BorderLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import java.awt.image.FilteredImageSource;
import java.awt.image.RGBImageFilter;

import javax.swing.AbstractAction;
import javax.swing.BoundedRangeModel;
import javax.swing.DefaultBoundedRangeModel;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLayer;
import javax.swing.JPanel;
import javax.swing.JProgressBar;
import javax.swing.WindowConstants;
import javax.swing.plaf.LayerUI;

public class Main {
    public static void main(String[] args) {
        BoundedRangeModel model = new DefaultBoundedRangeModel();
        BlockedColorLayerUI layerUI = new BlockedColorLayerUI();
        JPanel p = new JPanel(new GridLayout(2, 1, 12, 12));

        p.add(new JLayer<JProgressBar>(new JProgressBar(model), layerUI));

        JPanel box = new JPanel();
        box.add(new JButton(new AbstractAction("+10") {
            private int i = 0;

            @Override
            public void actionPerformed(ActionEvent e) {
                model.setValue(i = (i >= 100) ? 0 : i + 10);
            }
        }));

        p.repaint();

        JPanel panel = new JPanel(new BorderLayout());
        panel.add(p, BorderLayout.NORTH);
        panel.add(box, BorderLayout.SOUTH);

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

class BlockedColorLayerUI extends LayerUI<JProgressBar> {
    BufferedImage bi;
    int prevw, prevh;

    @Override
    public void paint(Graphics g, JComponent c) {
        JLayer jlayer = (JLayer) c;
        JProgressBar progress = (JProgressBar) jlayer.getView();
        int w = progress.getSize().width;
        int h = progress.getSize().height;

        if (bi == null || w != prevw || h != prevh) {
            bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
        }
        prevw = w;
        prevh = h;

        Graphics2D g2 = bi.createGraphics();
        super.paint(g2, c);
        g2.dispose();

        Image image = c.createImage(new FilteredImageSource(bi.getSource(), new RedGreenChannelSwapFilter()));
        g.drawImage(image, 0, 0, c);
    }
}

class RedGreenChannelSwapFilter extends RGBImageFilter {
    @Override
    public int filterRGB(int x, int y, int argb) {
        int r = (int) ((argb >> 16) & 0xff);
        int g = (int) ((argb >> 8) & 0xff);
        int b = (int) ((argb) & 0xff);
        return (argb & 0xff000000) | (g << 16) | (r << 8) | (b);
    }
}