Canvas.getHeight() and getWidth()

Question

Hi all,
I'm completely stuck. I don't know what to do. I developed a complete MIDlet and now I'm running it to remove any kinks I put in while developing. And one kink I can not get out of my system. I'm running the code in the WIreless Toolkit from Sun (version 2.5).
I made (I think) a simple game, just to learn working with Bluetooth and Midp. My game isbased on the venerable Pong, which should be played between two mobiles. One of the mobiles will act as server, the other one as client. The server starts with waiting for a connection, the client starts with connecting to the server. Both server and client use the same code.
After connecting the Client starts with sending its width and height to the server, who will decide on the dimensions of the playing field. In theory a good approach, but what gets send over is nothing more that zero dimensions. I have been looking at this problem for the good part of a week, created several posts to the forums, and I still have no sollution for this problem. Who can help me finding the non-zero dimensions of the playing field.
Some code so you know what I'm doing:
First the MIDlet constructor:
    public MyMIDlet() {       
        // Retrieve the display for this MIDlet
        theDisplay = Display.getDisplay(this);
        // Set up the initial screen for the MIDlet
        createStartScreen(null);
        // Create the game object
        myGame = new MyGame (this);
    public void commandAction(Command command, Displayable displayable) {
         // Some code omitted
         else if (command == OKCOMMAND){
            // Start the game
            myGame.setSelection (gameType.isSelected(0));
            new Thread(myGame).start();
         else { /* do nothing, one of the other keys was pressed */ }
    }Next the MyGame object:
     public MyGame (MyMIDlet theParent) {     
          myMIDlet = theParent;
          myData   = new MyData ();
     public void run() {
          // Some code omitted
          if (!isGameStarted) {
               // Determine if this game should start as a server or
               // a client
               if (isServer) {
                    // Wait for other MyMIDlet to connect
                    connection = waitForConnection();
               else {
                    // Establish a connection to a MyMIDlet
                    connection = connectToServer();
                    if (connection == null) {
                         return;
               try {
                    ins  = connection.openInputStream();
                    dins  = new DataInputStream (ins);
                    outs  = connection.openOutputStream();
                    douts = new DataOutputStream (outs);
               catch (IOException ioException) {
                    displayMessage("IO Error",
                              "An error occurred while opening " +
                              "the input and output streams (IOException: " +
                              ioException.getMessage() + ")");
                    try {
                         connection.close();
                    catch (Exception exception) {
                         displayMessage("Exception",
                                   "An error occurred while closing the connection " +
                                   "(Exception: " + exception.getMessage() + ")" );
               // Create game canvas
               myCanvas = new MyCanvas(this, myData, FONT);
               myMIDlet.setCanvas(myCanvas);
               myCanvas.addCommand(LEFTCOMMAND);
               myCanvas.addCommand(RIGHTCOMMAND);
               myCanvas.setCommandListener(myMIDlet.getCommandListener() );
               // Negotiate game screen size
               myData = negotiateScreenSize(isServer);
                        // Rest code omitted
     private MyData negotiateScreenSize(boolean isServer){
          if (isServer) {
               try {
                    // Code to de-serialize data containing among others the dimensions
                                myData.resurrect(dins);
                    // Set field dimensions to smallest screen
                    setFieldDimension(myData);       
               catch (IOException ioException) {
                    displayMessage("IO Error",
                              "An error occurred while reading " +
                              "screen dimensions, (IOException: " +
                              ioException.getMessage() + ")");
          else {
               try {
                    myData.setFieldDimension(myCanvas.getWidth(), myCanvas.getHeight());
                                // Code to serialize data containing among others the dimensions
                    myData.transfer(douts);
               catch (IOException ioException) {
                    displayMessage("IO Error",
                              "An error occurred while writing " +
                              "screen dimensions, (IOException: " +
                              ioException.getMessage() + ")");
          return myData;
     }For good measures, I add code from the MyCanvas constructor. The first place you can ask the dimensions of the screen:
    public MyCanvas(MyGame theGame, MyData theData, Font theFont) {
         myGame = theGame;
        myData = theData;
        font   = theFont;
        // Let Server start the match
        isServerGame = true;
        // Get dimensions of the screen
        height = getHeight();      
        width  = getWidth();
        myData.setFieldDimension(width, height);
System.out.println ("myCanvas.constructor, set height=" + height + " and width = " + width + "."); 
}      The last line prints out the following information:
myCanvas.constructor, set height=0 and width=0.I have added more of these lines in my code to give me the values of the screen dimensions. I always get zero values.
Who knows what I need do to get the correct values?
Maik

Answer 1

can u please show the code of mycanvas classI found the problem. Its in the code you are asking for. To get access to the height and width from outside the MyCanvas object I added the following code:
    public int getHeight (){
         return height;
    public int getWidth() {
         return width;
    }And ofcourse this was bugging my code. So I changed the constructor of myCanvas to:
        myGame = theGame;
        myData = theData;
        font   = theFont;
        // Let Server start the match
        isServerGame = true;
        // Get dimensions of the screen
        height = super.getHeight();
        width  = super.getWidth();
        bpData.setFieldDimension(width, height);And the problem was solved. Thanks for pointing me to the code with the build in bug.
Regards,
Maik