[rubicita]

Hi,
I tested some applications that extends the GameCanvas, when I tested on simulator J2ME Wireless Toolkit it hasn't problem when I download the application on phone (Nokia 6260) the program show screen and it work ok but when i try go out the application send the two errors

"Buffer closed java.lang.RunTimeException
0 java.lang.NullPointerException"

It's possible that phone not support the class javax.microedition.lcdui.game.GameCanvas? or what's the problem?
Help me please,
Thanks
P.S Below put the code, maybe this way is easer.

// A simple example of a game canvas that displays
// a scrolling star field. The UP and DOWN keys
// speed up or slow down the rate of scrolling.

public class StarField extends GameCanvas implements Runnable{

private static final int SLEEP_INCREMENT = 10;
private static final int SLEEP_INITIAL = 150;
private static final int SLEEP_MAX = 300;

private Graphics graphics;
private Random random;
private int sleepTime = SLEEP_INITIAL;
private volatile Thread thread;
private Command salir = null;

public StarField(){
super( true );

graphics = getGraphics();
graphics.setColor( 0, 0, 0 );
graphics.fillRect( 0, 0, getWidth(), getHeight() );
}

// When the game canvas is hidden, stop the thread.
protected void hideNotify(){
thread = null;
}

// The game loop.
public void run(){
int w = getWidth();
int h = getHeight() - 1;
while( thread == Thread.currentThread() ){
// Increment or decrement the scrolling interval
// based on key presses
int state = getKeyStates();
if( ( state & DOWN_PRESSED ) != 0 ){
sleepTime += SLEEP_INCREMENT;
if( sleepTime > SLEEP_MAX )
sleepTime = SLEEP_MAX;
} else if( ( state & UP_PRESSED ) != 0 ){
sleepTime -= SLEEP_INCREMENT;
if( sleepTime < 0 ) sleepTime = 0;
}
// Repaint the screen by first scrolling the
// existing starfield down one and painting in
// new stars...
graphics.copyArea( 0, 0, w, h, 0, 1,
Graphics.TOP | Graphics.LEFT );
graphics.setColor( 0, 0, 0 );
graphics.drawLine( 0, 0, w, 1 );
graphics.setColor( 255, 255, 255 );
for( int i = 0; i < w; ++i ){
int test = Math.abs( random.nextInt() ) % 10;
if( test < 4 ){
graphics.drawLine( i, 0, i, 0 );
}
}

flushGraphics();
// Now wait...
try {
Thread.currentThread().sleep( sleepTime );
}
catch( InterruptedException e ){
}
}
}

// When the canvas is shown, start a thread to
// run the game loop.
protected void showNotify(){
random = new Random();
thread = new Thread( this );
thread.start();
}
}

Thanks, see you