Adding 1 JComponent to 2 different JPanels: good idea?

Question

Is there any general rule which says it is a bad idea to add 1 JComponent to 2 different JPanels?
It would make my life a lot easier if it's no problem. In that case I only have to update one.

Answer 1

Good point about models. With text components you can share the Document. With other components you can share the model. Here is a simple example:
import java.awt.*;
import javax.swing.*;
public class MirrorTextField extends JFrame
     public MirrorTextField()
          JTextField textField1 = new JTextField( 20 );
          getContentPane().add( textField1, BorderLayout.NORTH );
          JTextField textField2 = new JTextField( 20 );
          textField2.setDocument( textField1.getDocument() );
          getContentPane().add( textField2, BorderLayout.SOUTH );
          String[] items = { "one", "two", "three", "four", };
          DefaultComboBoxModel model = new DefaultComboBoxModel( items );
          JComboBox comboBox1 = new JComboBox( model );
          getContentPane().add( comboBox1, BorderLayout.WEST );
          JComboBox comboBox2 = new JComboBox( model );
          getContentPane().add( comboBox2, BorderLayout.EAST );
     public static void main(String[] args)
          MirrorTextField frame = new MirrorTextField();
          frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
          frame.pack();
          frame.setVisible(true);
}Other components like JButton, JCheckBox, JRadioButton extend AbstractButton which has getModel(), setModel() methods you should be able to use.