Creating the main MIDlet

AMMSMIDlet class

The main MIDlet class.

1. Create the AMMSMIDlet class file.

2. Import the required classes.

   
   package com.nokia.mid.mansion;
   
   import javax.microedition.midlet.*;
   import javax.microedition.lcdui.*;
   
   

3. Set the AMMSMIDlet to extend MIDlet and implement CommandListener. Define the Commands and objects used by the application.

   /**
    * AMMSMIDlet class.
    *
    */
   public class AMMSMIDlet extends MIDlet implements CommandListener {
   
       Display display;
       MansionCanvas canvas;		// The main screen
       private Command exitCommand = new Command("Exit", Command.EXIT, 1);
       private Command toggleCommand = new Command("Start", Command.SCREEN, 1);
       private Command helpCommand = new Command("Help", Command.HELP, 1);
       private Command aboutCommand = new Command("About", Command.HELP, 2);
       private Form helpScreen, aboutScreen;
   
   

4. Create the constructor for the AMMDMIDlet class.

       /*
        * Create the canvas
        */
       public AMMSMIDlet() {
   	display = Display.getDisplay(this);
   	canvas = new MansionCanvas(display);
   	canvas.addCommand(exitCommand);
   	canvas.addCommand(toggleCommand);
   	canvas.addCommand(helpCommand);
   	canvas.addCommand(aboutCommand);
   	canvas.setCommandListener(this);
       }
   
   

5. Create the three required MIDlet methods.

       public void startApp() throws MIDletStateChangeException {
       	canvas.start();
       }
   
       public void pauseApp() {
       	canvas.pause();
       }
   
       public void destroyApp(boolean unconditional) throws MIDletStateChangeException {
       	canvas.destroy();
       }
   
   

6. Create a method for monitoring command use.

       /*
        * Respond to a command issued on the Canvas.
        */
       public void commandAction(Command c, Displayable s) {
   		if (c == toggleCommand) {
   		    if (canvas.isPaused()) canvas.start();
   		    else canvas.pause();
   		} 
   		else if (c == helpCommand) {
   		    canvas.pause();
   		    showHelp();
   		} 
   		else if (c == exitCommand) {
   		    try {
   				destroyApp(false);
   				notifyDestroyed();
   			} catch (MIDletStateChangeException ex) {
   		    }
   		} 
   		else if (c == aboutCommand) {
   		    canvas.pause();
   		    showAbout();
   		}
       }
   
   

7. Create a method for showing the help screen.

       /*
        * Put up the help screen. Create it if necessary.
        * Add only the Resume command.
        */
       void showHelp() {
   		if (helpScreen == null) {
   		    helpScreen = new Form("Walking Help");
   		    helpScreen.append("^ = walk forward\n");
   		    helpScreen.append("v = walk backwards\n");
   		    helpScreen.append("< = turn left\n");
   		    helpScreen.append("> = turn right\n");
   		    helpScreen.append("fire = change reverb manually\n");
   		}
   		helpScreen.addCommand(toggleCommand);
   		helpScreen.setCommandListener(this);
   		display.setCurrent(helpScreen);
       }
   
   

8. Create the method for showing the about screen.

       /*
        * Put up the about screen. Create it if necessary.
        * Add only the Resume command.
        */
       void showAbout() {
   		if (aboutScreen == null) {
   		    aboutScreen = new Form("About AMMS Mansion demo");
   		    aboutScreen.append("This MIDlet demonstrates the 3D audio capabilities of AMMS API.\n");
   		    aboutScreen.append("\n");
   		    aboutScreen.append("Copyright (c) 2006 Nokia. All rights reserved.\n");
   		    aboutScreen.append("\n");
   		    aboutScreen.append("\n");
   		}
   		aboutScreen.addCommand(toggleCommand);
   		aboutScreen.setCommandListener(this);
   		display.setCurrent(aboutScreen);
       }
   }