[cristisor]

Hi. I'm working on a game for the BB and I have a problem. The game was designed to work first on other mobile devices, so it extends the usual MIDlet and GameCanvas classes. Now I'm trying to port my app on BlackBerry and I'm trying to find a way to extend also the UiApplication and Screen classes, because I need to register keyListeners, trackBallListeners, to override the navigationMovement(...) method, etc. I'm sorry if I'm asking for too much or what I want can't happen, but I'm new to J2ME and RIM. Thank you!

public class game extends GameCanvas implements Runnable {...}
public class midlet extends MIDlet {...}

[andreybutov]

I'm afraid that you can't do that.

The BlackBerry documentation clearly states that you cannot mix two user interface types in one application on a BlackBerry device. You will need to either stick with a pure J2ME implementation (UI wise), or switch over to the RIM UI classes and drop the J2ME GameCanvas stuff.

[cristisor]

Originally Posted by andreybutov

I'm afraid that you can't do that.

The BlackBerry documentation clearly states that you cannot mix two user interface types in one application on a BlackBerry device. You will need to either stick with a pure J2ME implementation (UI wise), or switch over to the RIM UI classes and drop the J2ME GameCanvas stuff.

But do you think that the RIM UI classes will do a good job in developing games, like the GameCanvas did? Thank you for your help.

[andreybutov]

Certainly. It requires a bit of a different mentality, as you have to play nice with the RIM UI classes, but we've had no trouble created games for the BlackBerry without using any of the J2ME things.

As an example, Asteroid Jane ( http://www.antairgames.com/asteroidjane.html ) was made entirely with native RIM UI classes.