The problem is this:
I've a swing application running, at a certain point a dialog requires to insert username and password and to press "ok".
I would like that when the user press "ok" the swing application does in this order:
This is the code that I wrote in the okButtonActionPerformed():
private void okButtonActionPerformed(java.awt.event.ActionEvent evt) {
//This class simply extends a JDialog and contains an image and a jlabel (Please wait)
final WaitDialog waitDialog = new WaitDialog(new javax.swing.JFrame(), false);
waitDialog.setVisible(true);
... //Do some operation (eventually show other JDialogs or JOptionPanes)
waitDialog.dispose()
}
This code obviously doesn't works because when I call the waitDialog in the same thread it blocks all till I don't close it.
So I tried to run it in a different thread:
private void okButtonActionPerformed(java.awt.event.ActionEvent evt) {
//This class simply extends a JDialog and contains an image and a jlabel (Please wait)
final WaitDialog waitDialog = new WaitDialog(new javax.swing.JFrame(), false);
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
waitDialog.setVisible(true);
}
});
... //Do some operation (eventually show other JDialogs or JOptionPanes)
waitDialog.dispose()
}
But also this doesn't work because the waitDialog is not displayed immediately but only after that the operation completed their work (when they show a joption pane "You are logged in as...")
I also tried to use invokeAndWait instead of invokeLater but in this case it throws an exception:
Exception in thread "AWT-EventQueue-0" java.lang.Error: Cannot call invokeAndWait from the event dispatcher thread
How can I do?
Consider using a SwingWorker to do your background work, and then closing the dialog either in the SwingWorker's done()
method or (my preference) in a PropertyChangeListener that is added to the SwingWorker.
e.g.,
import java.awt.BorderLayout;
import java.awt.Dialog.ModalityType;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
public class PleaseWaitEg {
public static void main(String[] args) {
JButton showWaitBtn = new JButton(new ShowWaitAction("Show Wait Dialog"));
JPanel panel = new JPanel();
panel.add(showWaitBtn);
JFrame frame = new JFrame("Frame");
frame.getContentPane().add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
class ShowWaitAction extends AbstractAction {
protected static final long SLEEP_TIME = 3 * 1000;
public ShowWaitAction(String name) {
super(name);
}
@Override
public void actionPerformed(ActionEvent evt) {
SwingWorker<Void, Void> mySwingWorker = new SwingWorker<Void, Void>(){
@Override
protected Void doInBackground() throws Exception {
// mimic some long-running process here...
Thread.sleep(SLEEP_TIME);
return null;
}
};
Window win = SwingUtilities.getWindowAncestor((AbstractButton)evt.getSource());
final JDialog dialog = new JDialog(win, "Dialog", ModalityType.APPLICATION_MODAL);
mySwingWorker.addPropertyChangeListener(new PropertyChangeListener() {
@Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getPropertyName().equals("state")) {
if (evt.getNewValue() == SwingWorker.StateValue.DONE) {
dialog.dispose();
}
}
}
});
mySwingWorker.execute();
JProgressBar progressBar = new JProgressBar();
progressBar.setIndeterminate(true);
JPanel panel = new JPanel(new BorderLayout());
panel.add(progressBar, BorderLayout.CENTER);
panel.add(new JLabel("Please wait......."), BorderLayout.PAGE_START);
dialog.add(panel);
dialog.pack();
dialog.setLocationRelativeTo(win);
dialog.setVisible(true);
}
}
Notes: