GridBagDemo2.java

// Fig. 14.20: GridBagDemo2.java
// Demonstrating GridBagLayout constants.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Main extends JFrame {
  private GridBagLayout layout;
  private GridBagConstraints constraints;
  private Container container;

  // set up GUI
  public Main(){
    super( "GridBagLayout");

    container = getContentPane();
    layout = new GridBagLayout();
    container.setLayout( layout );

    // instantiate gridbag constraint
    constraints = new GridBagConstraints();

    // create GUI components
    String metals[] = { "Copper", "Aluminum", "Silver"};
    JComboBox comboBox = new JComboBox( metals );

    JTextField textField = new JTextField( "TextField");

    String fonts[] = { "Serif", "Monospaced"};  
    JList list = new JList( fonts );

    String names[] = { "zero", "one", "two", "three", "four"};
    JButton buttons[] = new JButton[ names.length ];

    for( int count = 0; count < buttons.length; count++ )
      buttons[ count ] = new JButton( names[ count ] );

    // define GUI component constraints for textField
    constraints.weightx = 1;
    constraints.weighty = 1;
    constraints.fill = GridBagConstraints.BOTH;
    constraints.gridwidth = GridBagConstraints.REMAINDER;
    addComponent( textField );

    // buttons[0] --weightx and weighty are 1: fill is BOTH
    constraints.gridwidth = 1;
    addComponent( buttons[ 0] );

    // buttons[1] --weightx and weighty are 1: fill is BOTH
    constraints.gridwidth = GridBagConstraints.RELATIVE;
    addComponent( buttons[ 1] );

    // buttons[2] --weightx and weighty are 1: fill is BOTH
    constraints.gridwidth = GridBagConstraints.REMAINDER;
    addComponent( buttons[ 2] );

    // comboBox --weightx is 1: fill is BOTH
    constraints.weighty = 0;
    constraints.gridwidth = GridBagConstraints.REMAINDER;
    addComponent( comboBox );

    // buttons[3] --weightx is 1: fill is BOTH
    constraints.weighty = 1;
    constraints.gridwidth = GridBagConstraints.REMAINDER;
    addComponent( buttons[ 3] );

    // buttons[4] --weightx and weighty are 1: fill is BOTH
    constraints.gridwidth = GridBagConstraints.RELATIVE;
    addComponent( buttons[ 4] );

    // list --weightx and weighty are 1: fill is BOTH
    constraints.gridwidth = GridBagConstraints.REMAINDER;
    addComponent( list );

    setSize( 300, 200);
    setVisible( true);
    
  }  // end constructor
  // add a Component to the container
  private void addComponent( Component component ){
    layout.setConstraints( component, constraints );
    container.add( component );      // add component
  }
  public static void main( String args[] ) {
    Main application = new Main();
    application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE);
  }
}  // end class GridBagDemo2