JProgressBar Changing Bar Color dynamically

Question

I am using JProgressBar component along with the Nimbus UI Defaults. The problem is that When I want to manually change each progressbar's Bar color, I use BasicProgressBarUI by setting JProgressBar.setUI() function. This makes more trouble because I would like to just change the bar color and it seems that I loose the default look of the jprogressbar (Border, backgroundcolor dissappears).

So I can set UIDefaults of Nimbus ProgressBar when the code initializes. It works.

But I want to change each progressbar's bar color dynamically.

Is there any other way of changing Bar color of JProgressBar?

public class ProgressGenerator extends JFrame {

    protected int minValue = 0;
    protected int maxValue = 100;
    protected int counter = 0;
    protected JProgressBar progressBar;

    public ProgressGenerator() {
        super("JProgressBar Demo");
        setSize(300, 100);

        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
        } catch (ClassNotFoundException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (InstantiationException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (IllegalAccessException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        } catch (UnsupportedLookAndFeelException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }

        progressBar = new JProgressBar();
        progressBar.setMinimum(minValue);
        progressBar.setMaximum(maxValue);
        progressBar.setStringPainted(true);

        progressBar.setForeground(Color.GREEN);

        JButton start = new JButton("Start");
        start.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                Thread runner = new Thread() {
                    public void run() {
                        counter = minValue;
                        while (counter <= maxValue) {
                            Runnable runme = new Runnable() {
                                public void run() {
                                    progressBar.setValue(counter);
                                }
                            };
                            SwingUtilities.invokeLater(runme);
                            counter++;
                            try {
                                Thread.sleep(100);
                            } catch (Exception ex) {
                            }
                        }
                    }
                };
                runner.start();
            }
        });
        getContentPane().add(progressBar, BorderLayout.CENTER);
        getContentPane().add(start, BorderLayout.WEST);
        WindowListener wndCloser = new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        };
        addWindowListener(wndCloser);
        setVisible(true);
    }

    public static void main(String[] args) {
        new ProgressGenerator();
    }
}

Belindabelisarius

for better help sooner post an SSCCE, short, runnable, compilable, otherwise have to search, google can returns that – Crabb

See this similar question/answer, which shows how to use UIDefaults and putClientProperty to change a single JProgressBar colour – Weems

The current problem is When I change the Bar color by using setForeground(Color.GREEN); it changes the SelectionBackground Color. And It seems that setBackgroundColor(Color.RED); command does not do anything. – Belindabelisarius

As answer linked by @DavidKroukamp shows, your sscce should include your custom Painter. – Devoirs

I set the UI as Nimbus and I wanted to change bar color by progressBar.setForeground(Color.GREEN) and it doesnt work. – Belindabelisarius

I wanted to change bar color by progressBar.setForeground - and I want to get money by snipping fingers :-) Or in other words: if we apply the incorrect approach, we won't get the expected result. Repeating trashgod - see the QA already referenced by @DavidKroukamp – Anxiety

@Belindabelisarius as Kleo has said that wont work, though I must ask what is wrong with creating your own ProgressBarUI and calling the method on the progressbars UI instance to change color there? – Weems

@DavidKroukamp a custom ui is mostly the wrong approach (and much more work than you'd expect to get it right) - only advisable if you need functionality that's not provided by the core uis. As I understand the question, here it's only a config issue solveable as outlined in the other thread. – Anxiety

@Anxiety +1 Thank you for that verification, (before I posted wrong code as answer) I was not sure if the custom UI approach is better, but if you wrap it in your own custom JProgressBar class and forwarding the setBackground and setForeground call of JProgressBar to the UI which changes the color... I guess still UIDefaults are better? – Weems

@DavidKroukamp not sure I entirely understand what you meant - so saying none of both :-) Nimbus supports per-class and per-instance skinning, so that's the way the go - though it's typically tougher than expected, Nimbus being ... not quite grown-up. – Anxiety

Answer 1

+1 to Kelopatra for being first.

Here is an example I made:

The JProgressBar color is initaily set via:

UIDefaults defaults = new UIDefaults();
defaults.put("ProgressBar[Enabled].foregroundPainter", new MyPainter(Color.GREEN));
defaults.put("ProgressBar[Enabled+Finished].foregroundPainter", new MyPainter(Color.GREEN));

progressBar.putClientProperty("Nimbus.Overrides.InheritDefaults", Boolean.TRUE);
progressBar.putClientProperty("Nimbus.Overrides", defaults);

On 50% progress the color will be changed to RED:

if (progressBar.getValue() == 50) {//change color on 50%
   UIDefaults defaults = new UIDefaults();
   defaults.put("ProgressBar[Enabled].foregroundPainter", new MyPainter(Color.RED));
   defaults.put("ProgressBar[Enabled+Finished].foregroundPainter", new MyPainter(Color.RED));
   progressBar.putClientProperty("Nimbus.Overrides.InheritDefaults", Boolean.TRUE);
   progressBar.putClientProperty("Nimbus.Overrides", defaults);                          
}

Test.java:

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.event.*;
import java.beans.*;
import javax.swing.*;

public class Test {

    public static void createAndShowGUI() {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        final JProgressBar progressBar = new JProgressBar();
        progressBar.setStringPainted(true);
        progressBar.setValue(0);
        progressBar.setBorderPainted(false);

        JButton startButton = new JButton("Start");

        startButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent ae) {
                UIDefaults defaults = new UIDefaults();
                defaults.put("ProgressBar[Enabled].foregroundPainter", new MyPainter(Color.GREEN));
                defaults.put("ProgressBar[Enabled+Finished].foregroundPainter", new MyPainter(Color.GREEN));

                progressBar.putClientProperty("Nimbus.Overrides.InheritDefaults", Boolean.TRUE);
                progressBar.putClientProperty("Nimbus.Overrides", defaults);

                SwingWorker worker = new SwingWorker() {
                    int current = 0, lengthOfTask = 100;

                    @Override
                    public Void doInBackground() {
                        while (current <= lengthOfTask && !isCancelled()) {

                            try { // dummy task
                                Thread.sleep(50);
                            } catch (InterruptedException ie) {
                            }

                            setProgress(100 * current / lengthOfTask);
                            current++;
                        }
                        return null;
                    }
                };
                worker.addPropertyChangeListener(new PropertyChangeListener() {
                    @Override
                    public void propertyChange(PropertyChangeEvent pce) {

                        String strPropertyName = pce.getPropertyName();
                        if ("progress".equals(strPropertyName)) {
                            int progress = (Integer) pce.getNewValue();
                            progressBar.setValue(progress);

                            if (progressBar.getValue() == 50) {//change color on 50%
                                UIDefaults defaults = new UIDefaults();
                                defaults.put("ProgressBar[Enabled].foregroundPainter", new MyPainter(Color.RED));
                                defaults.put("ProgressBar[Enabled+Finished].foregroundPainter", new MyPainter(Color.RED));

                                progressBar.putClientProperty("Nimbus.Overrides.InheritDefaults", Boolean.TRUE);
                                progressBar.putClientProperty("Nimbus.Overrides", defaults);
                            }

                        }
                    }
                });
                worker.execute();
            }
        });

        JPanel holder = new JPanel();
        holder.add(progressBar);
        holder.add(startButton);

        frame.add(holder);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }
                createAndShowGUI();
            }
        });
    }
}

class MyPainter implements Painter<JProgressBar> {

    private final Color color;

    public MyPainter(Color c1) {
        this.color = c1;
    }
    @Override
    public void paint(Graphics2D gd, JProgressBar t, int width, int height) {
        gd.setColor(color);
        gd.fillRect(0, 0, width, height);
    }
}

Weems

+1 for dynamically changing the color depending on value, nice touch :-) – Anxiety

@David Kroukamp Does it mean I can override setBackground and setForeground methods of JProgressBar and applying UI Defaults right? – Belindabelisarius

@DavidKroukamp I have question relating with Painter class. The bar in the progressbar I want it to not exceed the border area. I tried changing g.fillRect(0,0, width, height -4 ); it does change bottom however the top still exceeds the border. Any Solution? – Belindabelisarius

Answer 2

Nimbus supports per-component skinning, such as already answered in the other QA. Applied to a JProgressBar "bar" that means configuring the instance with a custom foregroundPainter like:

progressBar = new JProgressBar();

UIDefaults defaults = new UIDefaults();
Painter painter = new MyPainter(Color.GREEN);
defaults.put("ProgressBar[Enabled].foregroundPainter", painter);
defaults.put("ProgressBar[Enabled+Finished].foregroundPainter", painter);

progressBar.putClientProperty("Nimbus.Overrides.InheritDefaults", Boolean.TRUE);
progressBar.putClientProperty("Nimbus.Overrides", defaults);

The mimimal (ugly looking) painter would be something like:

public static class MyPainter extends AbstractRegionPainter {

    private Color fillColor;
    public MyPainter(Color color) {
        // as a slight visual improvement, make the color transparent
        // to at least see the background gradient
        // the default progressBarPainter does it as well (plus a bit more)
        fillColor = new Color(
                color.getRed(), color.getGreen(), color.getBlue(), 156);
    }

    @Override
    protected void doPaint(Graphics2D g, JComponent c, int width,
            int height, Object[] extendedCacheKeys) {
        g.setColor(Color.GREEN);
        g.fillRect(0, 0, width, height);
    }

    @Override
    protected PaintContext getPaintContext() {
        return null;
    }

}

To make it visually pleasing, have a look into ProgressBarPainter: it's package private so you can't do much other than understand how it achieves its gradients/path painting and do the same in a custom implementation.

Anxiety

+1 dont forget "ProgressBar[Enabled+Finished].foregroundPainter" or it will revert to orginal on 100% compeletion – Weems