ListTest.java

Dynamic application


ListTest.java

// Fig. 12.24: ListTest.java
// JList that displays a list of colors.
import java.awt.FlowLayout;
import java.awt.Color;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.event.ListSelectionListener;
import javax.swing.event.ListSelectionEvent;
import javax.swing.ListSelectionModel;

class ListFrame extends JFrame 
{
   private final JList<String> colorJList; // list to display colors
   private static final String[] colorNames = {"Black", "Blue", "Cyan",
      "Dark Gray", "Gray", "Green", "Light Gray", "Magenta",
      "Orange", "Pink", "Red", "White", "Yellow"};
   private static final Color[] colors = {Color.BLACK, Color.BLUE,
      Color.CYAN, Color.DARK_GRAY, Color.GRAY, Color.GREEN, 
      Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE, Color.PINK, 
      Color.RED, Color.WHITE, Color.YELLOW};

   // ListFrame constructor add JScrollPane containing JList to JFrame
   public ListFrame()
   {
      super("List Test");
      setLayout(new FlowLayout()); 

      colorJList = new JList<String>(colorNames); // list of colorNames
      colorJList.setVisibleRowCount(5); // display five rows at once
      
      // do not allow multiple selections
      colorJList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

      // add a JScrollPane containing JList to frame
      add(new JScrollPane(colorJList));

      colorJList.addListSelectionListener(
         new ListSelectionListener() // anonymous inner class
         {   
            // handle list selection events
            @Override
            public void valueChanged(ListSelectionEvent event)
            {
               getContentPane().setBackground(
                  colors[colorJList.getSelectedIndex()]);
            } 
         } 
      ); 
   } 
} // end class ListFrame
public class ListTest 
{
   public static void main(String[] args)
   { 
      ListFrame listFrame = new ListFrame(); // create ListFrame
      listFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      listFrame.setSize(350, 150); 
      listFrame.setVisible(true); 
   } 
} // end class ListTest


Maintained by John Loomis, updated Sat Feb 11 17:07:19 2017