Source of ListFrame.java


  1: // Fig. 11.23: ListFrame.java
  2: // Selecting colors from a JList.
  3: import java.awt.FlowLayout;
  4: import java.awt.Color;
  5: import javax.swing.JFrame;
  6: import javax.swing.JList;
  7: import javax.swing.JScrollPane;
  8: import javax.swing.event.ListSelectionListener;
  9: import javax.swing.event.ListSelectionEvent;
 10: import javax.swing.ListSelectionModel;
 11: 
 12: public class ListFrame extends JFrame 
 13: {
 14:    private JList colorJList; // list to display colors
 15:    private final String colorNames[] = { "Black", "Blue", "Cyan", 
 16:       "Dark Gray", "Gray", "Green", "Light Gray", "Magenta",
 17:       "Orange", "Pink", "Red", "White", "Yellow" };
 18:    private final Color colors[] = { Color.BLACK, Color.BLUE, Color.CYAN, 
 19:       Color.DARK_GRAY, Color.GRAY, Color.GREEN, Color.LIGHT_GRAY, 
 20:       Color.MAGENTA, Color.ORANGE, Color.PINK, Color.RED, Color.WHITE, 
 21:       Color.YELLOW };
 22: 
 23:    // ListFrame constructor add JScrollPane containing JList to JFrame
 24:    public ListFrame()
 25:    {
 26:       super( "List Test" );
 27:       setLayout( new FlowLayout() ); // set frame layout
 28: 
 29:       colorJList = new JList( colorNames ); // create with colorNames
 30:       colorJList.setVisibleRowCount( 5 ); // display five rows at once
 31:       
 32:       // do not allow multiple selections
 33:       colorJList.setSelectionMode( ListSelectionModel.SINGLE_SELECTION );
 34: 
 35:       // add a JScrollPane containing JList to frame
 36:       add( new JScrollPane( colorJList ) );
 37: 
 38:       colorJList.addListSelectionListener(
 39:          new ListSelectionListener() // anonymous inner class
 40:          {   
 41:             // handle list selection events
 42:             public void valueChanged( ListSelectionEvent event )
 43:             {
 44:                getContentPane().setBackground( 
 45:                   colors[ colorJList.getSelectedIndex() ] );
 46:             } // end method valueChanged
 47:          } // end anonymous inner class
 48:       ); // end call to addListSelectionListener
 49:    } // end ListFrame constructor
 50: } // end class ListFrame
 51: 
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 53:  * (C) Copyright 1992-2005 by Deitel & Associates, Inc. and               *
 54:  * Pearson Education, Inc. All Rights Reserved.                           *
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