Circular Progress Bar for Java Swing not working

Deviling Master picture Deviling Master · Aug 7, 2012 · Viewed 11.1k times · Source

i've discovered this test project from Oracle site because i want to add a circular progress bar in my project.

I'm developing the application with Netbeans, and when i start the application, the JPanel where the circle should be.... disappaer.

I've removed all the code that is not useful to solve this problem and i've got this code:

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import javax.swing.*;
import javax.swing.plaf.LayerUI;


public class Loading_Test extends javax.swing.JFrame
{
    static final WaitLayerUI layerUI = new WaitLayerUI();
    public Loading_Test()
    {

        JPanel panel = new JPanel();
        JLayer<JPanel> jlayer = new JLayer<>(panel, layerUI);
        add(jlayer);

        initComponents();
    }

    @SuppressWarnings("unchecked")
    private void initComponents() {

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 300, Short.MAX_VALUE)
        );

        pack();
    }

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

            @Override
            public void run()
            {                
                JFrame frame = new Loading_Test();
                frame.setVisible(true);
                layerUI.start();
            }
        });
    }
}
class WaitLayerUI extends LayerUI<JPanel> implements ActionListener
{

    private boolean mIsRunning;
    private boolean mIsFadingOut;
    private Timer mTimer;
    private int mAngle;
    private int mFadeCount;
    private int mFadeLimit = 15;

    @Override
    public void paint(Graphics g, JComponent c)
    {
        int w = c.getWidth();
        int h = c.getHeight();

        // Paint the view.
        super.paint(g, c);

        if (!mIsRunning)
        {
            return;
        }

        Graphics2D g2 = (Graphics2D) g.create();

        float fade = (float) mFadeCount / (float) mFadeLimit;
        // Gray it out.
        Composite urComposite = g2.getComposite();
        g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .5f * fade));
        g2.fillRect(0, 0, w, h);
        g2.setComposite(urComposite);

        // Paint the wait indicator.
        int s = Math.min(w, h) / 5;
        int cx = w / 2;
        int cy = h / 2;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setStroke(new BasicStroke(s / 4, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
        g2.setPaint(Color.white);
        g2.rotate(Math.PI * mAngle / 180, cx, cy);
        for (int i = 0; i < 12; i++)
        {
            float scale = (11.0f - (float) i) / 11.0f;
            g2.drawLine(cx + s, cy, cx + s * 2, cy);
            g2.rotate(-Math.PI / 6, cx, cy);
            g2.setComposite(AlphaComposite.getInstance(
                    AlphaComposite.SRC_OVER, scale * fade));
        }

        g2.dispose();
    }

    @Override
    public void actionPerformed(ActionEvent e)
    {
        if (mIsRunning)
        {
            firePropertyChange("tick", 0, 1);
            mAngle += 3;
            if (mAngle >= 360)
            {
                mAngle = 0;
            }
            if (mIsFadingOut)
            {
                if (--mFadeCount == 0)
                {
                    mIsRunning = false;
                    mTimer.stop();
                }
            }
            else if (mFadeCount < mFadeLimit)
            {
                mFadeCount++;
            }
        }
    }

    public void start()
    {
        if (mIsRunning)
        {
            return;
        }

        // Run a thread for animation.
        mIsRunning = true;
        mIsFadingOut = false;
        mFadeCount = 0;
        int fps = 24;
        int tick = 1000 / fps;
        mTimer = new Timer(tick, this);
        mTimer.start();
    }

    public void stop()
    {
        mIsFadingOut = true;
    }

    @Override
    public void applyPropertyChange(PropertyChangeEvent pce, JLayer l)
    {
        if ("tick".equals(pce.getPropertyName()))
        {
            l.repaint();
        }
    }
}

If you run this code "as is", you should have the same my problem, the JPanel is not shown.

But i've discovered that if i remove the layout-related lines (27~36) the progress bar starts to work.

You also have to set manually the windows size adding

setSize(300, 300);

after

pack();

Because the layout-lines are automatically generated by Netbeans, i'm trying to understand how to solve this problem, because this particular lines of code are blocked for editing by Netbeans Editor.

Answer

mKorbel picture mKorbel · Aug 7, 2012

I've lost one day and it still not working.... I'll use an animated gif on JLabel.... End of story!

@Robin has important info, and seems like as you limited by usage of GuiBulder..., then I'm don't want to comment something, result is

enter image description here

from little bit modified code

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import javax.swing.*;
import javax.swing.plaf.LayerUI;

public class Loading_Test {

    static final WaitLayerUI layerUI = new WaitLayerUI();
    JFrame frame = new JFrame("JLayer With Animated Gif");

    public Loading_Test() {
        JPanel panel = new JPanel() {

            @Override
            public Dimension getPreferredSize() {
                return new Dimension(400, 300);
            }
        };
        JLayer<JPanel> jlayer = new JLayer<>(panel, layerUI);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(jlayer);
        frame.pack();
        frame.setVisible(true);
        layerUI.start();
    }

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

            @Override
            public void run() {
                Loading_Test loading_Test = new Loading_Test();

            }
        });
    }
}

class WaitLayerUI extends LayerUI<JPanel> implements ActionListener {

    private boolean mIsRunning;
    private boolean mIsFadingOut;
    private Timer mTimer;
    private int mAngle;
    private int mFadeCount;
    private int mFadeLimit = 15;

    @Override
    public void paint(Graphics g, JComponent c) {
        int w = c.getWidth();
        int h = c.getHeight();
        super.paint(g, c); // Paint the view.
        if (!mIsRunning) {
            return;
        }
        Graphics2D g2 = (Graphics2D) g.create();
        float fade = (float) mFadeCount / (float) mFadeLimit;
        Composite urComposite = g2.getComposite(); // Gray it out.
        g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .5f * fade));
        g2.fillRect(0, 0, w, h);
        g2.setComposite(urComposite);
        int s = Math.min(w, h) / 5;// Paint the wait indicator.
        int cx = w / 2;
        int cy = h / 2;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setStroke(new BasicStroke(s / 4, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
        g2.setPaint(Color.white);
        g2.rotate(Math.PI * mAngle / 180, cx, cy);
        for (int i = 0; i < 12; i++) {
            float scale = (11.0f - (float) i) / 11.0f;
            g2.drawLine(cx + s, cy, cx + s * 2, cy);
            g2.rotate(-Math.PI / 6, cx, cy);
            g2.setComposite(AlphaComposite.getInstance(
                    AlphaComposite.SRC_OVER, scale * fade));
        }
        g2.dispose();
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (mIsRunning) {
            firePropertyChange("tick", 0, 1);
            mAngle += 3;
            if (mAngle >= 360) {
                mAngle = 0;
            }
            if (mIsFadingOut) {
                if (--mFadeCount == 0) {
                    mIsRunning = false;
                    mTimer.stop();
                }
            } else if (mFadeCount < mFadeLimit) {
                mFadeCount++;
            }
        }
    }

    public void start() {
        if (mIsRunning) {
            return;
        }
        mIsRunning = true;// Run a thread for animation.
        mIsFadingOut = false;
        mFadeCount = 0;
        int fps = 24;
        int tick = 1000 / fps;
        mTimer = new Timer(tick, this);
        mTimer.start();
    }

    public void stop() {
        mIsFadingOut = true;
    }

    @Override
    public void applyPropertyChange(PropertyChangeEvent pce, JLayer l) {
        if ("tick".equals(pce.getPropertyName())) {
            l.repaint();
        }
    }
}
  • have to add two JButtons, one for start and second for stop (show and hide animated Gig)

  • don't forger that JPanel has implemented FlowLayout, that pretty accepting PreferredSize came from its childs,