return a value by firing a JButton event

[jhon max]

I have a class here that I want to act just like a JOptionPane..

 

import java.awt.Dimension;
import java.awt.Font;
import java.awt.Image;
import java.awt.Graphics;
import java.awt.Color;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;

import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.ImageIcon;
import javax.swing.JComponent;
import javax.swing.JDialog;
import javax.swing.JTextField;
import javax.swing.KeyStroke;

/**
 *
 * @author
 */

public class PopUp extends JDialog {
    
    private JPanel popUpPanel;

    private JLabel message;

    private JButton okButton;

    private JTextField textField;

    private Image icon;

    private ImageIcon background;

    private String frameTitle;
    private String messageLabel;
    private String buttonCommand;


    private PopUp(String title, String label) {

        frameTitle = title;
        messageLabel = label;
        initComponents();
    }

    private void initComponents() {

        icon = new ImageIcon("c:/pics/mercuryLogo.jpg").getImage().getScaledInstance(300, 300, 0);
        background = new ImageIcon("c:/pics/popupbck4.jpg");
        okButton = new JButton("Ok");
        message = new JLabel();
        textField = new JTextField();

        popUpPanel = new JPanel() {

            @Override
            public void paintComponent(Graphics g) {

                // Scale image to size of component
                Dimension d = getSize();

                g.drawImage(background.getImage(), 0, 0, d.width, d.height, null);

                super.paintComponent(g);
            }
        };
        popUpPanel.setOpaque(false);

        // set this panel's layout to null for absolute positioning of
        // components
        popUpPanel.setLayout(null);

        // set the properties and actions of this button
        okButton.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                // WHAT SHOULD I DO TO THIS COMMAND TO RETURN A VALUE?
            }
        });
        
        okButton.setBounds(130, 38, 75, 20);
        okButton.setFont(new Font("Monospaced", Font.BOLD, 11));
        okButton.setBackground(Color.LIGHT_GRAY);
        okButton.registerKeyboardAction(okButton.getActionForKeyStroke(
                                        KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0, false)),
                                        KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, false),
                                        JComponent.WHEN_IN_FOCUSED_WINDOW);
        okButton.registerKeyboardAction(okButton.getActionForKeyStroke(
                                        KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0, true)),
                                        KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, true),
                                        JComponent.WHEN_IN_FOCUSED_WINDOW);

        // set the properties of this label
        message.setText(messageLabel);
        message.setBounds(10, 3, 500, 30);
        message.setFont(new Font("Monospaced", Font.BOLD, 12));

        textField.setBounds(130, 10, 170, 20);

        
        popUpPanel.add(message);
        popUpPanel.add(okButton);
        popUpPanel.add(textField);

        // add the components to this container
        getContentPane().add(popUpPanel);

        // set the properties of this dialog
        setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        setIconImage(icon);
        setTitle(frameTitle);
        setSize(350, 100);
        setLocationRelativeTo(null);
        setResizable(false);
        setVisible(true);
    }

    public static void popTheInput(String title, String message) {

        new PopUp(title, message);
    }
    public static void main(String[] args) {

        PopUp.popTheInput("Frame", "Message");
    }
}
   

but Im stuck with returning a value.. anyway I left some of the method as void to be easily compiled, but lets assume that it returns a String value...
what I want is if I press the button it will return a value from another class that calls that method... please I need help ..

[Rob Spoor]

1) Give the Popup instance a value defaulting to null:

private String value = null;

2) Set this value when you press OK
3) Returns this value from the static method:

public static String popTheInput(String title, String message) {   
    Popup popup = new PopUp(title, message);   
    return popup.value;
}

Because you initialize it to null and only set it when OK is pressed the popTheInput method will return null if the user clicked Cancel or pressed the little X.

[jhon max]

       okButton.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                value = textField.getText();
            }
        });   

but I still get a null value

the whole changes I made

 public class PopUp extends JDialog {
    
    private JPanel popUpPanel;

    private JLabel message;

    private JButton okButton;

    private JTextField textField;

    private Image icon;

    private ImageIcon background;

    private String frameTitle;
    private String messageLabel;
    private String buttonCommand;

    private String value = null;

    private PopUp(String title, String label) {

        frameTitle = title;
        messageLabel = label;
        initComponents();
    }

    private void initComponents() {

        icon = new ImageIcon("c:/pics/mercuryLogo.jpg").getImage().getScaledInstance(300, 300, 0);
        background = new ImageIcon("c:/pics/popupbck4.jpg");
        okButton = new JButton("Ok");
        message = new JLabel();
        textField = new JTextField();

        popUpPanel = new JPanel() {

            @Override
            public void paintComponent(Graphics g) {

                // Scale image to size of component
                Dimension d = getSize();

                g.drawImage(background.getImage(), 0, 0, d.width, d.height, null);

                super.paintComponent(g);
            }
        };
        popUpPanel.setOpaque(false);

        // set this panel's layout to null for absolute positioning of
        // components
        popUpPanel.setLayout(null);

        // set the properties and actions of this button
        okButton.addActionListener(new ActionListener() {

            public void actionPerformed(ActionEvent e) {

                value = textField.getText();
            }
        });
        
        okButton.setBounds(130, 38, 75, 20);
        okButton.setFont(new Font("Monospaced", Font.BOLD, 11));
        okButton.setBackground(Color.LIGHT_GRAY);
        okButton.registerKeyboardAction(okButton.getActionForKeyStroke(
                                        KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0, false)),
                                        KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, false),
                                        JComponent.WHEN_IN_FOCUSED_WINDOW);
        okButton.registerKeyboardAction(okButton.getActionForKeyStroke(
                                        KeyStroke.getKeyStroke(KeyEvent.VK_SPACE, 0, true)),
                                        KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0, true),
                                        JComponent.WHEN_IN_FOCUSED_WINDOW);

        // set the properties of this label
        message.setText(messageLabel);
        message.setBounds(10, 3, 500, 30);
        message.setFont(new Font("Monospaced", Font.BOLD, 12));

        textField.setBounds(130, 10, 170, 20);
        
        popUpPanel.add(message);
        popUpPanel.add(okButton);
        popUpPanel.add(textField);

        // add the components to this container
        getContentPane().add(popUpPanel);

        // set the properties of this dialog
        setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        setIconImage(icon);
        setTitle(frameTitle);
        setSize(350, 100);
        setLocationRelativeTo(null);
        setResizable(false);
        setVisible(true);
    }

    public static String popTheInput(String title, String message) {

        PopUp popup = new PopUp(title, message);
        return popup.value;
    }
    
    public static void main(String[] args) {

        System.out.println(PopUp.popTheInput("Frame", "Message"));
    }
}
   

[Rob Spoor]

That's because your dialog is not a modal dialog, and it does not block the event dispatcher thread. Of course in your small example, it doesn't block the main thread either, which it never will because the main thread and the event dispatcher thread are always separate from the moment you realize your user interface.

[jhon max]

oh my... Is there any simple way to resolve this sir.??

[pete stein]

jhon max wrote:oh my... Is there any simple way to resolve this sir.??

um,... make it a modal dialog? The JDialog API will show you how.

[Rob Spoor]

And you should dispose or hide (setVisible(false)) your dialog when you press OK.