how to pause program until a button press?

Question

i use from a class that extended from jframe and it has a button(i use from it in my program)

i want when run jframe in my program the whole of my program pause

until i press the button.

how can i do it

in c++ getch() do this.

i want a function like that.

Answer 1

Pausing Execution with Sleep, although I doubt that is the mechanism that you'll want to use. So, as others have suggested, I believe you'll need to implement wait-notify logic. Here's an extremely contrived example:

import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.concurrent.atomic.AtomicBoolean;
import javax.swing.JButton;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

@SuppressWarnings("serial")
public class PanelWithButton extends JPanel
{
    // Field members
    private AtomicBoolean paused;
    private JTextArea textArea;
    private JButton button;
    private Thread threadObject;

    /**
     * Constructor
     */
    public PanelWithButton()
    {
        paused = new AtomicBoolean(false);
        textArea = new JTextArea(5, 30);
        button = new JButton();

        initComponents();
    }

    /**
     * Initializes components
     */
    public void initComponents()
    {
        // Construct components
        textArea.setLineWrap(true);
        textArea.setWrapStyleWord(true);
        add( new JScrollPane(textArea));
        button.setPreferredSize(new Dimension(100, 100));
        button.setText("Pause");
        button.addActionListener(new ButtonListener());
        add(button);

        // Runnable that continually writes to text area
        Runnable runnable = new Runnable()
        {
            @Override
            public void run() 
            {
                while(true)
                {
                    for(int i = 0; i < Integer.MAX_VALUE; i++)
                    {
                        if(paused.get())
                        {
                            synchronized(threadObject)
                            {
                                // Pause
                                try 
                                {
                                    threadObject.wait();
                                } 
                                catch (InterruptedException e) 
                                {
                                }
                            }
                        }

                        // Write to text area
                        textArea.append(Integer.toString(i) + ", ");


                        // Sleep
                        try 
                        {
                            Thread.sleep(500);
                        } 
                        catch (InterruptedException e) 
                        {
                        }
                    }
                }
            }
        };
        threadObject = new Thread(runnable);
        threadObject.start();
    }

    @Override
    public Dimension getPreferredSize()
    {
        return new Dimension(400, 200);
    }

    /**
     * Button action listener
     * @author meherts
     *
     */
    class ButtonListener implements ActionListener
    {
        @Override
        public void actionPerformed(ActionEvent evt) 
        {
            if(!paused.get())
            {
                button.setText("Start");
                paused.set(true);
            }
            else
            {
                button.setText("Pause");
                paused.set(false);

                // Resume
                synchronized(threadObject)
                {
                    threadObject.notify();
                }
            }
        }
    }
}

And here's your main class:

 import javax.swing.JFrame;
    import javax.swing.SwingUtilities;


    public class MainClass 
    {
        /**
         * Main method of this application
         */
        public static void main(final String[] arg)
        {
            SwingUtilities.invokeLater(new Runnable()
            {
                public void run()
                {
                    JFrame frame = new JFrame();
                    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                    frame.add(new PanelWithButton());
                    frame.pack();
                    frame.setVisible(true);
                    frame.setLocationRelativeTo(null);
                }
            });
        }
    }

As you can see, this example application will continually write to the text area until you click the button that reads 'Pause', whereupon to resume you'll need to click that same button which will now read 'Start'.