Source of GridBagFrame2.java


  1: // Fig. 22.31: GridBagFrame2.java
  2: // Demonstrating GridBagLayout constants.
  3: import java.awt.GridBagLayout;
  4: import java.awt.GridBagConstraints;
  5: import java.awt.Component;
  6: import javax.swing.JFrame;
  7: import javax.swing.JComboBox;
  8: import javax.swing.JTextField;
  9: import javax.swing.JList;
 10: import javax.swing.JButton;
 11: 
 12: public class GridBagFrame2 extends JFrame 
 13: { 
 14:    private GridBagLayout layout; // layout of this frame
 15:    private GridBagConstraints constraints; // constraints of this layout
 16:     
 17:    // set up GUI
 18:    public GridBagFrame2()
 19:    {
 20:       super( "GridBagLayout" );
 21:       layout = new GridBagLayout();
 22:       setLayout( layout ); // set frame layout 
 23:       constraints = new GridBagConstraints(); // instantiate constraints
 24: 
 25:       // create GUI components
 26:       String metals[] = { "Copper", "Aluminum", "Silver" };
 27:       JComboBox comboBox = new JComboBox( metals );
 28: 
 29:       JTextField textField = new JTextField( "TextField" );
 30: 
 31:       String fonts[] = { "Serif", "Monospaced" };
 32:       JList list = new JList( fonts );
 33: 
 34:       String names[] = { "zero", "one", "two", "three", "four" };
 35:       JButton buttons[] = new JButton[ names.length ];
 36: 
 37:       for ( int count = 0; count < buttons.length; count++ )
 38:          buttons[ count ] = new JButton( names[ count ] );
 39: 
 40:       // define GUI component constraints for textField
 41:       constraints.weightx = 1;
 42:       constraints.weighty = 1;  
 43:       constraints.fill = GridBagConstraints.BOTH;
 44:       constraints.gridwidth = GridBagConstraints.REMAINDER;
 45:       addComponent( textField );
 46: 
 47:       // buttons[0] -- weightx and weighty are 1: fill is BOTH
 48:       constraints.gridwidth = 1;
 49:       addComponent( buttons[ 0 ] );
 50: 
 51:       // buttons[1] -- weightx and weighty are 1: fill is BOTH
 52:       constraints.gridwidth = GridBagConstraints.RELATIVE;
 53:       addComponent( buttons[ 1 ] );
 54: 
 55:       // buttons[2] -- weightx and weighty are 1: fill is BOTH
 56:       constraints.gridwidth = GridBagConstraints.REMAINDER;
 57:       addComponent( buttons[ 2 ] );
 58: 
 59:       // comboBox -- weightx is 1: fill is BOTH
 60:       constraints.weighty = 0;
 61:       constraints.gridwidth = GridBagConstraints.REMAINDER;
 62:       addComponent( comboBox );
 63:       
 64:       // buttons[3] -- weightx is 1: fill is BOTH
 65:       constraints.weighty = 1;
 66:       constraints.gridwidth = GridBagConstraints.REMAINDER;
 67:       addComponent( buttons[ 3 ] ); 
 68: 
 69:       // buttons[4] -- weightx and weighty are 1: fill is BOTH
 70:       constraints.gridwidth = GridBagConstraints.RELATIVE;
 71:       addComponent( buttons[ 4 ] );
 72: 
 73:       // list -- weightx and weighty are 1: fill is BOTH
 74:       constraints.gridwidth = GridBagConstraints.REMAINDER;
 75:       addComponent( list );
 76:    } // end GridBagFrame2 constructor
 77: 
 78:    // add a component to the container
 79:    private void addComponent( Component component ) 
 80:    {
 81:       layout.setConstraints( component, constraints );
 82:       add( component ); // add component
 83:    } // end method addComponent
 84: } // end class GridBagFrame2
 85: 
 86: /**************************************************************************
 87:  * (C) Copyright 1992-2005 by Deitel & Associates, Inc. and               *
 88:  * Pearson Education, Inc. All Rights Reserved.                           *
 89:  *                                                                        *
 90:  * DISCLAIMER: The authors and publisher of this book have used their     *
 91:  * best efforts in preparing the book. These efforts include the          *
 92:  * development, research, and testing of the theories and programs        *
 93:  * to determine their effectiveness. The authors and publisher make       *
 94:  * no warranty of any kind, expressed or implied, with regard to these    *
 95:  * programs or to the documentation contained in these books. The authors *
 96:  * and publisher shall not be liable in any event for incidental or       *
 97:  * consequential damages in connection with, or arising out of, the       *
 98:  * furnishing, performance, or use of these programs.                     *
 99:  *************************************************************************/