import javax.swing.*;
import java.awt.*; 
import javax.swing.border.*;

public class TryGridBagLayout
{
  // The window object
  static JFrame aWindow = new JFrame("This is a Gridbag Layout"); 

  public static void main(String[] args)
  {
    Toolkit theKit = aWindow.getToolkit();       // Get the window toolkit
    Dimension wndSize = theKit.getScreenSize();  // Get screen size

    // Set the position to screen center & size to half screen size
    aWindow.setBounds(wndSize.width/4, wndSize.height/4,   // Position
                      wndSize.width/2, wndSize.height/2);  // Size
    aWindow.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);

    GridBagLayout gridbag = new GridBagLayout();    // Create a layout manager
    GridBagConstraints constraints = new GridBagConstraints();
    aWindow.getContentPane().setLayout(gridbag);   // Set the container layout mgr

    // Set constraints and add first button
    constraints.weightx = constraints.weighty = 10.0;
    constraints.fill = constraints.BOTH;            // Fill the space
    addButton("Press", constraints, gridbag);       // Add the button
      
    // Set constraints and add second button 
    constraints.weightx = 5.0;                       // Weight half of first
    constraints.insets = new Insets(10, 30, 10, 20); // Left 30 & right 20
    constraints.gridwidth = constraints.RELATIVE;    // Rest of the row
    addButton("GO", constraints, gridbag);           // Create and add button

    // Set constraints and add third button 
    constraints.insets = new Insets(0,0,0,0);       // No insets
    constraints.gridx = 0;                          // Begin new row
    constraints.gridwidth = 1;                      // Width as "Press"
    addButton("Push", constraints, gridbag);        // Add button to content pane


    aWindow.setVisible(true);                              // Display the window
  }

  static void addButton(String label,
                     GridBagConstraints constraints, GridBagLayout layout)
  {
    // Create a Border object using a BorderFactory method
    Border edge = BorderFactory.createRaisedBevelBorder(); 

    JButton button = new JButton(label);           // Create a button
    button.setBorder(edge);                        // Add its border
    layout.setConstraints(button, constraints);    // Set the constraints
    aWindow.getContentPane().add(button);          // Add button to content pane
  }
}