How to pass the KeyEvent from one component to other

Question

I am able to get a key event for a scroll bar from that scroll bars key listener. Now i want to pass this key event to another components key listener. How can i do this.

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class KeyCommunication
    public static void main(String[] args)
        final JScrollBar
            left  = new JScrollBar(JScrollBar.VERTICAL),
            right = new JScrollBar(JScrollBar.VERTICAL);
         * if KeyEvent originates with left, forwards KeyEvent to right
        left.addKeyListener(new KeyAdapter()
            public void keyPressed(KeyEvent e)
                int keyCode = e.getKeyCode();
                int direction = 0;
                if(keyCode == KeyEvent.VK_UP)
                    direction = -1;
                if(keyCode == KeyEvent.VK_DOWN)
                    direction = 1;
                left.setValue(left.getValue() +
                              left.getBlockIncrement(direction) * direction);
                if(e.getSource() == left)
                    right.dispatchEvent(e);
         * forwards KeyEvent to left scrollbar if KeyEvent originates here
        right.addKeyListener(new KeyAdapter()
            public void keyPressed(KeyEvent e)
                int keyCode = e.getKeyCode();
                int direction = 0;
                if(keyCode == KeyEvent.VK_UP)
                    direction = -1;
                if(keyCode == KeyEvent.VK_DOWN)
                    direction = 1;
                right.setValue(right.getValue() +
                               right.getBlockIncrement(direction) * direction);
                if(e.getSource() == right)
                    left.dispatchEvent(e);
         * paints track of focused scrollbar blue
         * use tab key for navigation between scrollbars
        FocusListener l = new FocusListener()
            Color bgColor = UIManager.getColor("ScrollBar.background");
            public void focusLost(FocusEvent e)
                JScrollBar scrollBar = (JScrollBar)e.getSource();
                scrollBar.setBackground(bgColor);
                scrollBar.repaint();
            public void focusGained(FocusEvent e)
                JScrollBar scrollBar = (JScrollBar)e.getSource();
                scrollBar.setBackground(Color.blue);
                scrollBar.repaint();
        left.addFocusListener(l);
        right.addFocusListener(l);
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(10,0,10,0);
        gbc.weightx = 1.0;
        gbc.weighty = 1.0;
        gbc.fill = gbc.VERTICAL;
        panel.add(left, gbc);
        panel.add(right, gbc);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(panel);
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
}