Handling exit button which is create automatically?

Question

I am building a text editor and I don't know how to handle a listener on Swing exit button, which is create automatically. I want to use dialogs when user doesn't save file, for example press exit button.

Welcome to SO. What does it mean created automatically ? By GUI builder ? So use the GUI builder to add a listener. If it has a listeners - edit it. If it doesn't and you can't add one - you can't use it. — c0der, May 13 '17 at 08:25
Maybe he means the window decorations provided by Windows, Mac OS, or whatever operating system? — Kevin Anderson, May 13 '17 at 09:03
It is not clear what kind of exit-button you mean. You should add a screen-shot showing it. — Thomas Fritsch, May 13 '17 at 10:23

score 1 · Answer 1 · edited May 23 '17 at 12:03

final JFrame f = new JFrame("Good Location & Size");
// make sure the exit operation is correct.
f.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE); 
f.addWindowListener( new WindowAdapter() {
    public void windowClosing(WindowEvent we) {
        // pop the dialog here, and if the user agrees..
        System.exit(0);
    }
});

As seen in this answer to Best practice for setting JFrame locations, which serializes the frame location & size before exiting.

Deepesh Choudhary · Answer 2 · 2017-05-13T08:03:57.947

0

Go stepwise:

Declare a boolean variable saved and set its default value to false.
When user saves the file, change it to true
When exit button is pressed, check the variable.
If true, exit, else, prompt user for saving file.

So, finally this code snippet looks like:

public boolean saved = false;

saveButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        saved = true;
        //Code to save file
    }
});

exitButton.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        if(saved)
            System.exit(0);
        else {
            //Code to prompt user to save file
        }
    }
});

edited May 13 '17 at 08:03

answered May 13 '17 at 07:57

Deepesh Choudhary

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i cant add listener to exit button because this button is creating automatically – sadasdaaaa May 13 '17 at 08:16
1

@thenewproblem add all important info to the question. Not in comments. What does it mean created automatically ? If it has a listeners - edit it. If it doesn't and you can't add one - you can't use it. – c0der May 13 '17 at 08:24

score 0 · Accepted Answer · answered May 13 '17 at 10:08

Assuming you have a handle on your window, assuming it's a Window object (e.g. a JFrame or other kind of window), you can listen to WindowEvent events. Here is an example with windowClosed, you can replace it with windowClosing if you need to intercept it before.

    frame.addWindowListener(new WindowAdapter() {
        @Override
        public void windowClosed(WindowEvent e) {
            // do something here
        }
    });

Handling exit button which is create automatically?

3 Answers3