Flash for a second
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.*;
publicclass TextListenerTesterextends Frameimplements 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);
}
publicvoid actionPerformed ( ActionEvent e ){
l.setText(t.getText() ) ;
}
publicvoid propertyChange(java.beans.PropertyChangeEvent evt){
//l.setBackground(Color.red); // here to flash for 1 second
//repaint();
System.out.println("I have changed");
}
publicstaticvoid main ( String [ ] args ){
TextListenerTester textListenerTester =new TextListenerTester ("Text Listener Tester" ) ;
textListenerTester.setSize ( 400,400 ) ;
textListenerTester.setVisible (true ) ;
}
}
Please help me out guys.
Thanks
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[i]))
{
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
