Step 9.7: Add a new class, Prompt

This will create a class Prompt in the default package (because you left package blank) in project SWT, as shown in Figure 9.53.

Figure 9.53: The result of the addition of the new class Prompt.

Step 9.8: Modify the new Prompt class

As usual, you can do this one of two ways: write the code or import the code. Option 1 is to modify the source manually. If you'd rather skip this step, go on to Option 2 to import the code.

Option 1: Source Entry

Enter the new code.

q 9.8(a) Enter the following source code after the comments.

import java.util.Hashtable;

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

public class Prompt {

      // Resources
      Display display;
      Shell shell;
      Color red, white;

      // Fields
      Text f1;
      Label f2;

      public Prompt() {
      }
      public void run() {
          init();
          setLayout();
          createWidgets();
          show() ;
          cleanup();
      }
  private void init() {
         // Create a standard window
         display = new Display();
         shell = new Shell(display);
         shell.setText("Prompt3");

         // Create some colors
         red = new Color(display, 255, 0, 0);
         white = new Color(display, 255, 255, 255);
  }

  private void setLayout() {
         // Create the layout for the widgets
         GridLayout grid = new GridLayout();
         grid.numColumns = 2;
         grid.makeColumnsEqualWidth = true;
         shell.setLayout(grid);
  }

  private void createWidgets () {
         // Create my widgets
         Label l1 = new Label(shell, SWT.NONE);
         l1.setText("Item Number:");

         f1 = new Text(shell, SWT.BORDER  SWT.SINGLE);
         f1.setTextLimit(20);

         Label l2 = new Label(shell, SWT.NONE);
         l2.setText("Description:");

         f2 = new Label(shell, SWT.NONE);
         f2.setText(" ");

         Button bl = new Button(shell, SWT.PUSH);
         b1.setText("Find");
         b1.addListener(SWT.Selection, new Listener() {
                public void handleEvent(Event event) {
                doFind();
                }
         });

         Button b2 = new Button(shell, SWT.PUSH);
         b2.setText("Exit");
         b2.addListener(SWT.Selection, new Listener() {
                public void handleEvent(Event event) {
                      doExit() ;
                }
         });
  }
  private void doFind() {
        String desc = getDescription(f1.getText());

        if (desc == null)
        {
              f1.setForeground(white);
              f1.setBackground(red);
              f2.setText("Not Found");
              f2.setForeground(red);
        }
        else
        {
              f1.setForeground(null);
              f1.setBackground(null);
              f2.setText(desc);
              f2.setForeground(null);
        }
  }

  private void doExit() {
         shell.close() ;
  }

  private static final Hashtable items;
  static {
         items = new Hashtable();
         items.put("DOG", "My Puppy");
         items.put("CAT", "My Kitty");
         items.put("OCTOPUS", "Calamari Kid");
  }

  private String getDescription(String item)
  {
         return (String) items.get(item);
  }

  private void show() {
         // Final setup - size the display show it
         shell.setSize(200, 100);
         shell.open();
         while (!shell.isDisposed()) {
               if (!display.readAndDispatch())
                     display.sleep();
         }
  }
  private void cleanup() {
         // When done, clean up resources
         display.dispose();
         red.dispose();
         white.dispose();
  }

  public static void main(String[] args) {
        new Prompt().run();
        System.exit(0);
  }
}