source: src/main/java/genius/gui/panels/DefaultOKCancelDialog.java@ 209

package genius.gui.panels;

import java.awt.BorderLayout;
import java.awt.Frame;
import java.awt.Panel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JDialog;

/**
 * open a modal OK/Cancel dialog. you must implement ok() and getPanel() to make
 * this working. Panel opens, gets result and returns result only when you call
 * getResult() Typical use: new YourOKCancelDialog(yourframe).getResult();
 * 
 * @author wouter 19aug08
 *
 */
public abstract class DefaultOKCancelDialog extends JDialog {

        private static final long serialVersionUID = 9106032262508127313L;
        JButton okbutton = new JButton("OK");
        JButton cancelbutton = new JButton("Cancel");
        Object the_result = null; // will be set after ok button is pressed. null in
                                                                // other cases (eg cancel)

        /**
         * 
         * @param owner
         *            is the parent frame, used only to center the dialog properly.
         *            Probably can be null
         * @param title
         *            the title of the dialog
         */
        public DefaultOKCancelDialog(Frame owner, String title) {
                super(owner, title, true); // modal dialog.
                getContentPane().setLayout(new BorderLayout());
        }

        /**
         * this function computes the result of the dialog. You may return null if
         * the user entered illegal choices or somehow cancelled the dialog. This
         * function will only be called when user presses OK button, which also
         * finishes the dialog and closes the dialog window.
         */
        public abstract Object ok();

        /**
         * this fucnction returns the actual contents for the dialog panel I
         * implemented this as a function, because we need it before opening the
         * window.
         * 
         * @return a Panel containing the actual dialog contents.
         * 
         */
        public abstract Panel getPanel();

        /** call this to get the result. Do not override, instead override ok(). */
        public Object getResult() {
                // actionlisteners MUST be added before putting buttons in panel!
                okbutton.addActionListener(new ActionListener() {
                        public void actionPerformed(ActionEvent e) {
                                // System.out.println("OK pressed");
                                the_result = ok();
                                setVisible(false);
                        }
                });

                cancelbutton.addActionListener(new ActionListener() {
                        public void actionPerformed(ActionEvent e) {
                                // System.out.println("cancel pressed");
                                setVisible(false);
                        }
                });

                Panel buttonrow = new Panel(new BorderLayout());
                buttonrow.add(okbutton, BorderLayout.WEST);
                buttonrow.add(cancelbutton, BorderLayout.EAST);

                add(buttonrow, BorderLayout.SOUTH);

                add(getPanel(), BorderLayout.CENTER);

                pack();
                setLocationRelativeTo(getOwner());
                setVisible(true); // block until closing window.
                return the_result;
        }
}