Background

To establish a context for this discussion, we begin by reviewing the code developed in the Java User Interface I lessonfor in which we built the visual protion of a basic application window:

import java.applet.Applet;
import java.awt.*;

public class step3 extends Applet{

// application window that includes menus and scrollbars 

Frame outerBox = new Frame ( );

Panel topPanel = new Panel ( );
Panel centerPanel = new Panel ( );
Panel bottomPanel = new Panel ( );

MenuBar menuBar = new MenuBar ( );
Menu fileMenu = new Menu ("File");
Menu editMenu = new Menu ("Edit");
Menu helpMenu = new Menu ("Help");

Scrollbar scrollbarV;
Scrollbar scrollbarH;

TextField message;


  public void init ( ){

    centerPanel . setBackground (Color.white);

// *** Build Menus

    fileMenu.add ( new MenuItem ( "New" ) );
    fileMenu.add ( new MenuItem ( "Open" ) );
    fileMenu.add ( new MenuItem ( "Close" ) );
    fileMenu.add ( new MenuItem ( "Save" ) );
    fileMenu.add ( new MenuItem ( "Quit" ) );

    editMenu.add ( new MenuItem ( "Cut" ) );
    editMenu.add ( new MenuItem ( "Copy" ) );
    editMenu.add ( new MenuItem ( "Paste" ) );
    editMenu.add ( new MenuItem ( "Delete" ) );

    helpMenu.add ( new MenuItem ( "Help" ) );

    menuBar .add ( fileMenu );
    menuBar .add ( editMenu );
    menuBar .add ( helpMenu );
    menuBar .setHelpMenu ( helpMenu );

    outerBox.setMenuBar ( menuBar );

// *** Build Scrollbars and Message area

    scrollbarV = new Scrollbar (Scrollbar.VERTICAL, 0, 100, 0, 1000 );
    scrollbarH = new Scrollbar (Scrollbar.HORIZONTAL, 0, 100, 0, 1000 );

    message = new TextField ( "Messages Displayed Here", 80 );
    message.setEditable ( false );


// *** Build display

    bottomPanel.setLayout ( new BorderLayout ( ) );
    bottomPanel.add ( "North", scrollbarH );
    bottomPanel.add ( "South", message );

    outerBox. setLayout (new BorderLayout ( ) );
    outerBox.add ("Center", centerPanel);
    outerBox.add ("South", bottomPanel);
    outerBox.add ("East", scrollbarV);
    outerBox.resize (600, 500);
    outerBox. setBackground (Color.white);
    outerBox.show( );

  } // end init

}// end step3 

Run the applet

The discussion continues with Step 4.