BlackBerry Splash Screen

By Radu Motisan Posted on January 12th, 2012 , 687 Views (Rate 1.39)

A splash screen is an application window, that appears at startup, usually showing some logo. It lasts for only a few seconds, then the application workflow continues (eg. next screen pops up).

But how to do this for BlackBerry, programmatically?

First you create a new project. The entry point should be:

 
 /**
     * Entry point for application
     * 
     * @param args
     *            Command line arguments (not used)
     */
    public static void main( String[] args ) {
        // Create a new instance of the application and make the currently
        // running thread the application's event dispatch thread.
        MainApp theApp = new MainApp();
        theApp.enterEventDispatcher();
    }
 
    /**
     * Creates a new MainApp object
     */
    public MainApp() {
    	// init app globals
    	g_nScreenWidth =  Display.getHeight();
        g_nScreenHeight = Display.getWidth();
 
        // Push a screen onto the UI stack for rendering.
        splashScreen = new SplashScreen();
        pushScreen( splashScreen );
    }

When the SplashScreen class loads, we use an image in resources as the splash image to display:

 
 BitmapField bmp = new BitmapField( 
        		Utils.getFitBitmapImage("splash1.png",MainApp.g_nScreenWidth, MainApp.g_nScreenHeight),
        		BitmapField.FIELD_HCENTER | BitmapField.FIELD_VCENTER);  
 
        HorizontalFieldManager rowHolder = new HorizontalFieldManager(NO_HORIZONTAL_SCROLL | NO_VERTICAL_SCROLL|
                Field.FIELD_HCENTER | USE_ALL_HEIGHT );
        rowHolder.add(bmp);
        add(rowHolder);

This helper function is used to resize a given resource bitmap to match a rectangular area. This can be used to shrink or enlarge the image, it can also be used to make the image cover to whole screen.

 
    // Resize a bitmap proportionally  (shrink or enlarge) to make it fit a maxX x maxY rectangle
    static public Bitmap getFitBitmapImage(String imagename, int maxX, int maxY)
    {
 
        EncodedImage image = EncodedImage.getEncodedImageResource(imagename); 
 
        int currentWidthFixed32 = Fixed32.toFP(image.getWidth());
        int currentHeightFixed32 = Fixed32.toFP(image.getHeight());
 
		//double ratio = (double)ratioX / (double) ratioY;
		double rx = (double) image.getWidth() / (double)maxX; 
		double ry = (double) image.getHeight() / (double)maxY;
		double r = 0;
		if (rx > ry) r = rx; else r= ry;
		double w = (double) image.getWidth() / r; 
		double h = (double) image.getHeight() / r;
 
		int width = (int) w;
		int height = (int) h;
 
		int requiredWidthFixed32 = Fixed32.toFP(width);
		int requiredHeightFixed32 = Fixed32.toFP(height);
 
		int scaleXFixed32 = Fixed32.div(currentWidthFixed32, requiredWidthFixed32);
		int scaleYFixed32 = Fixed32.div(currentHeightFixed32, requiredHeightFixed32);
 
		image = image.scaleImage32(scaleXFixed32, scaleYFixed32);
 
		return image.getBitmap();
    }

To make the program load the next class automatically and skip the splash screen use:

 
MainApp.homeScreen = new HomeScreen();
        UiApplication.getUiApplication().invokeLater(new Runnable() {
            public void run() {
                UiApplication.getUiApplication().pushScreen(MainApp.homeScreen);
                UiApplication.getUiApplication().popScreen(MainApp.splashScreen);
            }
        }, 2000, false);