JFrame one instance

[Andraz Poje]

How can I get just one instance of JFrame when I click on JButton?
Every time I click on the button I got a new JFrame over the old one.
I want to use one instance of the frame(and should be the first instance I created it when I click on the button) every time I click on the button
please help me.

[Rob Spoor]

Check out the singleton design pattern. You can use lazy initialization since you should only create frames from the Event Dispatcher Thread.

[Andraz Poje]

Rob Prime wrote:Check out the singleton design pattern. You can use lazy initialization since you should only create frames from the Event Dispatcher Thread.

I checked it out, too complicated code examples for newbie like me... Can anyone provide simpler code?

something like that

if (someFrame isvisible==true) put it on top
else someframe.setVisible(true);

[Paul Clapham]

Yes, just like that. Only simpler.

First, create the JFrame when you create all the other components of your GUI. Don't make it visible just yet.

Then, when the controller button is clicked, just make it visible. You don't need to test whether it is visible; if it were visible you wouldn't be able to see the button and click it.

[Christiaan Lombard]

Hi

Can't really help you if I can't see your code, but maybe this will help:

  import javax.swing.*;
import java.awt.event.*;

public class TestFrame{
	
	JFrame frame;
	JFrame frame2;
	JButton button;
	
	public TestFrame(){
		frame = new JFrame("Main Frame");
		frame2 = new JFrame("Second Frame");
		button = new JButton("Open Frame");
		
		frame.add(button);
		frame.setSize(300,300);
		frame2.setBounds(300,0,300,300);
		frame.setVisible(true);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		button.addActionListener(new ActionListener(){
		
			public void actionPerformed(ActionEvent e){
				wakeFrame();
			}
		
		});
		
	}
	
	public void wakeFrame(){
	
		if(frame2.isVisible()){
			button.setText("Open Frame");
			frame2.setVisible(false);
		}else{
			button.setText("Close Frame");
			frame2.setVisible(true);
		}
	
	}
	
	public static void main(String[] args){
		new TestFrame();
	}

}  

[Maneesh Godbole]

Moving to the UI forum.

[Michael Dunn]

oyu already have a JButton showing, so you must already have a JFrame (JWindow etc) showing,
and when you click the button you only want a single 'other' JFrame to appear.

if this is correct, change the 2nd JFrame to a modal JDialog, which will prevent the JButton from being clicked
whilst the JDialog is showing