using threads or there's another way?

[miguel lisboa]

in a swing standalone app i want a message to appear for a few seconds confirming user did deleted something
i'm using this code:

Thread t = new Thread() {
    public void run() {
    int i = 200;
    while( i > 0) {
        jLabelEpocaEliminada.setVisible(true);
        try {
            sleep(10);
            i--;
            jLabelEpocaEliminada.setVisible(false);
        }
        catch(InterruptedException e) {
            throw new RuntimeException(e);
        }
    }
}};
t.start();
 
    

is there a better/smoother way of doing this?

TiA

[Henry Wong]

Actually, once your swing application has been displayed, you are not allowed to access any of the components from anything that is not the event dispatching thread. With the exception of a few methods, like repaint(), it is not thread safe to do so.

Having a separate thread to handle the timing for changing the visibility is fine, but it is not allowed to directly manipulate the component. Take a look at the invokeLater() method of the SwingUtilities to dispatch that task back to the event dispatching thread.

Henry

[miguel lisboa]

i'm not sure if i got it right:
my main:

public static void main(String[] args) {
 
SwingUtilities.invokeLater(new Runnable() {

public void run() {
 
Aplicacao application = new Aplicacao();

application.getJFrame().setVisible(true);

}

});

}
    

my refactored code:

 
    botaoEliminarEpoca.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {
 
eliminaEpoca();
 
    }

});
//...
 
    mostraMensagemEliminacaoEpoca();
 
//...
 
private void mostraMensagemEliminacaoEpoca() {

 Runnable mostraMensagem = new Runnable() {
 
     public void run() {
     
    Thread t = new Thread() {
    
    public void run() {
    
    int i = 200;
    
    while( i > 0) {
    
    getEpoca();
    
    jLabelEpocaEliminada.setText("�poca " + getEpoca().toString() + " eliminada");
    
    jLabelEpocaEliminada.setVisible(true);
    
try {
    
    sleep(10);
    
    i--; 
    jLabelEpocaEliminada.setVisible(false);
    
}
catch(InterruptedException e) {
    
throw new RuntimeException(e);
    
}
    
}
    
}};
    
t.start();
}
};
SwingUtilities.invokeLater(mostraMensagem);

}   

[Justin Fox]

create a JFrame as private member data, create an inner class to display
the message

ex:

private class A{

public A()
{

public void paintComponent(Graphics g){}
}
}


and in your program create new instance of the private frame
and do:
.getContentPane().add(new A());
.pack();
.setVisible(true);

now you have a JFrame you can call
.setVisible(true/false);
or
.dispose();

so say you want that frame to popup when they click a certain button
you would say.

myFrame.setVisible(true);
myFrame.setAlwaysOnTop(true);

you can also set the location of the frame by

Point p = MainFrame.getLocation(); // your main clients window.
myFrame.setLocation(new Point(p.getX()+MainFrame.getLength()/2,p.getY()+MainFrame.getWidth()/2));

that would set the top left corner of your popup display message to approx.
the middle of the "MainFrame".


Justin

[Justin Fox]

well you would call the timer, then in the timer, once the
message box is visible, you would just count everytime the
timer is called, then you would .dispose() the message box
when you are out of the counter loop, and stop the current timer.


Justin