Physics Simulation       Lecture 8A   Standalone Java   Simple Application   Window App   Applet to App 1   Applet to App 2   Applet Viewer   Inner Classes   AnnonymousClass   AdapterClass   Lectures 1A: Introduction 1B: Java Intro 2A: BuildingBlocks 2B: Objects 3A: More Objects 3B: Exceptions        & Threads 4A: Waves 4B: Nuclear &        Particle 5A: AWT 5B: More AWT       & Graphics 6A:Detectors &       Simulation 6B: LHC/Atlas &      RandomSims     7A: Swing 7B: Java2D 8A: Java Apps 8B: Dialogs &     MoreClasses 9A: Java I/O 9B: Utilities,         Unicode 10A: More     Threading 10B: File     Handling 11A: Array,Print,     Images 11B: SimplePhysics     Simulation 12A: Tips &     Techniques 12B: More Tips &     Techniques 13A: Satellite     Simulations 13B: Intro to Java     Networking 14A: Java Servers 14B: HTTP Server 15A: ServerClient 15B: ServerClient    Expt.Simulation 16A: Course           Review 16B: ExerciseTest         Discussion     Contacts     Description     Exercises     Index     Outline     Q&A     Resources     StudentInfoForm     Student Pages     What's New

Home : Lectures : Lecture 8A : Converting Applet to Application Converting an Applet into an Application An applet can be converted with minimal changes into an application. (Short of recreating a full scale browser type environment with the AppletStub interface.) The recipe goes as follows: Create a Frame subclass to hold the applet. In main() create an instance of the Frame. Add the applet to the Frame. Let main() call the init(), stop(), and start(). getParameter() will not work. Other techniques for passing the values must be used such as using an init() method with arguments that pass the parameters of interest. getImage() also does not work. Use  Toolkit.getDefaultToolkit.getImage(String img) The example of double buffering that we discussed in Lecture 5B will be converted to an application. We first create a "holder" application that will create a frame with a menubar for containing the applet. We will modify the applet to add an initImg() to pass the image filename. We also modify the applet's init() to remove any non-compatible methods such as getImage(). DBAppletHolder.java /*  * An application to run the double buffer  * applet example.  */ import java.awt.*; import java.awt.event.*; public class DBAppletHolder extends Frame   implements ActionListener{   public static void main(String [] args){     // Pass the image name as a command line argument     if( args.length != 1) {       System.out.println(           "Usage: java DBAppletHolder imageFilename");       System.exit(0);     }     // Create an instance of this frame class     // for holding the applet     DBAppletHolder h= new DBAppletHolder();     // Create an instance of the applet     DoubleBufferedClipped DBApplet = new        DoubleBufferedClipped();     // Call init() to do whatever initialization can be     // done outside of a browser environment.     DBApplet.init();     // Pass the applet the image name     DBApplet.initImg(args[0]);     h.add("Center", DBApplet);       // Use an adapter to close the window     WindowListener listener = new WindowAdapter() {         public void windowClosing(WindowEvent e){         System.exit(0);       }     };     h.addWindowListener(listener);     h.pack();     h.show();   }   // Add a menubar with only the Quit item.   DBAppletHolder() {     setTitle("Hello World");     Menu m = new Menu("File");     MenuItem mi = new MenuItem( "Quit" );     mi.addActionListener( this );     m.add(mi);     MenuBar mb = new MenuBar();     mb.add(m);     setMenuBar(mb);   }   // Catch the Quit menuItem event to close the window.   public void actionPerformed( ActionEvent e ) {   if ( e.getActionCommand().equals("Quit") )     dispose();     System.exit(0);   } }

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