Blackberry Animation Issue on App's Home Screen - blackberry

Question

I am trying to create an Application which has a Home Screen (MyScreen below) animation in Blackberry which makes an image float from the bottom to middle of the screen. Then after that, i want to push another Screen which brings a Login Screen or something (NewScreen below).
I am getting a blank Screen after the animation. On pressing back once, i am getting the Screen i pushed from the Animation Screen. Please guide me: where should i push to get the perfect result?
import net.rim.device.api.animation.AnimatedScalar;
import net.rim.device.api.animation.Animation;
import net.rim.device.api.animation.Animator;
import net.rim.device.api.animation.AnimatorListener;
import net.rim.device.api.system.Bitmap;
import net.rim.device.api.system.Display;
import net.rim.device.api.system.EncodedImage;
import net.rim.device.api.ui.Color;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.Screen;
import net.rim.device.api.ui.TransitionContext;
import net.rim.device.api.ui.Ui;
import net.rim.device.api.ui.UiApplication;
import net.rim.device.api.ui.UiEngineInstance;
import net.rim.device.api.ui.container.MainScreen;
import net.rim.device.api.ui.container.PopupScreen;
/**
* A class extending the MainScreen class, which provides default standard
* behavior for BlackBerry GUI applications.
*/
public final class MyScreen extends MainScreen implements AnimatorListener {
private RectangleToMove _rect;
private Animator _animator;
private Animation _xanimation;
private Animation _yanimation;
private boolean _bAnimating;
public static final int BALL_WIDTH = 50;
public Bitmap splashimg;
static TransitionContext transitionContextIn;
static TransitionContext transitionContextOut;
static UiEngineInstance engine = Ui.getUiEngineInstance();
/**
* Creates a new MyScreen object
*/
public MyScreen() {
EncodedImage img = EncodedImage.getEncodedImageResource("logo.png");
splashimg = img.getBitmap();
_bAnimating = false;
int midScreen = (Display.getWidth() / 2) - img.getWidth()/2;
int endScreen = Display.getHeight();
_rect = new RectangleToMove(midScreen, BALL_WIDTH);
_animator = new Animator(30);
_animator.setAnimatorListener(this);
_yanimation = _animator.addAnimationFromTo(_rect.getY(),
AnimatedScalar.ANIMATION_PROPERTY_SCALAR, endScreen
- BALL_WIDTH, Display.getHeight() / 2-30,
Animation.EASINGCURVE_LINEAR, 3000L);
_yanimation.setRepeatCount(1f);
_yanimation.begin(0);
UiApplication.getUiApplication().pushScreen(new NewScreen());
}
protected void paint(Graphics g) {
if (_bAnimating) {
_rect.draw(g, splashimg);
}
}
public void animatorUpdate() {
invalidate();
doPaint();
}
public void animatorProcessing(boolean processing) {
_bAnimating = processing;
}
}
class RectangleToMove {
private int xPos;
private AnimatedScalar yPos;
public void draw(Graphics g, Bitmap splashimg) {
g.setBackgroundColor(Color.BLACK);
g.clear();
g.setColor(Color.SLATEGRAY);
g.drawBitmap(xPos, yPos.getInt(), splashimg.getWidth(),
splashimg.getHeight(), splashimg, 0, 0);
/*
* g.fillEllipse(xPos,yPos.getInt(),
* xPos+MyScreen.BALL_WIDTH,yPos.getInt(),xPos,
* yPos.getInt()+MyScreen.BALL_WIDTH,0,360);
*/
}
public int getX() {
return xPos;
}
public AnimatedScalar getY() {
return yPos;
}
RectangleToMove(int x, int y) {
xPos = x;
yPos = new AnimatedScalar(y);
}
}

Answer 1

I'm not 100% sure I understand your problem, but I edited your question to describe what I think is the problem.
When your animation ends, you're seeing a blank white screen that you don't want. You have to press Back/ESC to make the white screen disappear, so that you can get back to your login screen (NewScreen). I assume you don't want to see the initial animation screen after it first shows (probably because it's a loading, or splash screen).
In order to do this, you need to wait until the animation completes before pushing your second screen. So, remove this call to pushScreen:
UiApplication.getUiApplication().pushScreen(new NewScreen());
that you have in the MyScreen constructor. At that point, the animation has not completed, so it's too soon to push the NewScreen.
Then, push the screen when the AnimatorListener is told that the animation has stopped. If you don't want the animation screen to be visible, when backing through your screens, then pop it after pushing the second screen:
public void animatorProcessing(boolean processing) {
_bAnimating = processing;
if (!processing) {
// the animation is complete
UiApplication.getUiApplication().pushScreen(new NewScreen());
// use this line if the instance of `MyScreen` should not be
// visible after the user presses Back/ESC:
UiApplication.getUiApplication().popScreen(this);
}
}