Flash for a second

Question

Hello people,
Am trying to get a JLable to flash red for 1 second when the text changes. But am finding it very hard to figure out how to do it.
Here is an example of a JLabel that listens for a change and tries to flash red for 1 second, but its not working.
import java.beans.PropertyChangeListener;
import java.awt.*;
import java.awt.event.*;
public class TextListenerTester extends Frame implements ActionListener, PropertyChangeListener  { 
  TextField t;
  Label l;
    public TextListenerTester ( String s )   { 
       super ( s ) ;
       setLayout ( new FlowLayout() ) ;
       t = new TextField (  ) ;
       l = new Label("hello");
       t.setSize ( 100,100 ) ;
       t.setLocation ( 50,50 ) ;
       add ( t ) ;  
       add ( l ) ;
       t.addActionListener ( this ) ;
       l.addPropertyChangeListener(this);
    public void actionPerformed ( ActionEvent e )   { 
       l.setText(t.getText() ) ;
     public void propertyChange(java.beans.PropertyChangeEvent evt){
         //l.setBackground(Color.red);  // here to flash for 1 second
         //repaint();
         System.out.println("I have changed");
    public static void main ( String [  ]  args )   { 
       TextListenerTester textListenerTester = new TextListenerTester ( "Text Listener Tester" ) ;
       textListenerTester.setSize ( 400,400 ) ;
       textListenerTester.setVisible ( true ) ;
}Please help me out guys.
Thanks

Answer 1

How did you get it to work? Let's see your code. I had to try myself, and this is what I came up with. I created a subclass of JLabel and called a Thread.sleep method in a separate SwingWorker thread:
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class FlashingLabel extends JFrame
    private MyLabel fooLabel;
    private String[] fooLabelTexts = {"Foo Label 1", "Foo Label 2",
            "Foo Label 3", "What the heck?!?"};
    private MySwingWorker mySwingWorker;
    public FlashingLabel()
        super("My Swing App");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        getContentPane().add(myPanel());
        pack();
    private JPanel myPanel()
        JPanel fooPanel = new JPanel();
        GridLayout myGridLO = new GridLayout(0, 1);
        myGridLO.setHgap(5);
        myGridLO.setVgap(5);
        fooPanel.setLayout(myGridLO);
        fooPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
        JButton button = new JButton("Button");
        fooPanel.add(button);
        button.addActionListener(new ActionListener()
            public void actionPerformed(ActionEvent ae)
                btnAction(ae);
        fooLabel = new MyLabel(fooLabelTexts[0]);
        fooPanel.add(fooLabel);
        return fooPanel;
    private void btnAction(ActionEvent ae)
        String fooStr = fooLabel.getText();
        int indx = -1;
        for (int i = 0; i < fooLabelTexts.length; i++)
            if (fooStr.equals(fooLabelTexts))
indx = i;
indx++;
indx %= fooLabelTexts.length;
fooLabel.setText(fooLabelTexts[indx]);
private static void createAndShowGUI()
FlashingLabel myBriefSwing = new FlashingLabel();
myBriefSwing.setVisible(true);
public static void main(String[] args)
javax.swing.SwingUtilities.invokeLater(new Runnable()
public void run()
createAndShowGUI();
class MyLabel extends JLabel
private Color bkgdColor = null;
private boolean opaque;
public MyLabel()
super();
public MyLabel(String s)
super(s);
public void resetColor()
super.setOpaque(opaque);
super.setBackground(bkgdColor);
super.revalidate();
@Override
public void setText(String s)
// set only once, first time called
if (bkgdColor == null)
bkgdColor = super.getBackground();
opaque = super.isOpaque();
super.setBackground(Color.RED);
super.setOpaque(true);
super.setText(s);
super.revalidate();
mySwingWorker = new MySwingWorker();
mySwingWorker.execute();
class MySwingWorker extends SwingWorker<Void, Void>
@Override
protected Void doInBackground() throws Exception
Thread.sleep(1000);
return null;
@Override
public void done()
SwingUtilities.invokeLater(new Runnable()
public void run()
fooLabel.resetColor();
Message was edited by:
petes1234