Start animation with AndEngine Live Wallpaper extansion

Question

I have code like this:

public class SnowFallService extends BaseLiveWallpaperService implements IOnAreaTouchListener{

    // ===========================================================
    // Constants
    // ===========================================================

    private static final int CAMERA_WIDTH = 480;
    private static final int CAMERA_HEIGHT = 800;

    private ArrayList<Sprite> allSnow = new ArrayList<Sprite>();
    // ===========================================================
    // Fields
    // ===========================================================

    private ScreenOrientation screenOrientation;

    private static TextureRegion snowTexture;
    private static TextureRegion backgroundTexture;
    private static Textures texture = null;

    private Scene mScene;

    public org.anddev.andengine.engine.Engine onLoadEngine() {
        return new org.anddev.andengine.engine.Engine(new EngineOptions(true, this.screenOrientation, new FillResolutionPolicy(), new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT)));
    }

    public void onLoadResources() {
        texture = new Textures(this, getEngine());
    }

    public void onUnloadResources() {

    }

    public Scene onLoadScene() {

        final Scene mScene = new Scene();
        backgroundTexture = texture.getBackground();
        mScene.attachChild(new Sprite(0, 0, backgroundTexture));
        snowTexture = texture.getSnowTextureRegion();

        mScene.registerUpdateHandler(new IUpdateHandler() {
            private long lastRaindropAdd = 0;

            @Override
            public void onUpdate(final float pSecondsElapsed) {
                int size = allSnow.size();
                int tmpInt = 0;
                Random randGen = new Random();
                for (int i = 0; i < size; i++) {
                    if (allSnow.get(i) != null){
                        Sprite snow = allSnow.get(i);

                        tmpInt = randGen.nextInt(4);
                        snow.setPosition(snow.getX() + (randGen.nextInt(5) - randGen.nextInt(5)) * randGen.nextInt(3), snow.getY() + tmpInt);

                        if (snow.getY() > CAMERA_HEIGHT || snow.getX() > CAMERA_WIDTH) {
                            synchronized(snow) {
                                size--;
                                allSnow.remove(i);
                                mScene.detachChild(snow);
                            }
                        }
                    }
                }

                tmpInt = randGen.nextInt(5000);

                if (System.currentTimeMillis() - lastRaindropAdd  > tmpInt) {
                    lastRaindropAdd = System.currentTimeMillis();

                    tmpInt = randGen.nextInt(CAMERA_WIDTH);

                    Sprite snow = getRaindrop(tmpInt, 0);
                    allSnow.add(snow);
                    mScene.attachChild(snow);
                }
            }

            @Override
            public void reset() {
            }
        });
        return mScene;
    }

    public void onLoadComplete() {
        // TODO Auto-generated method stub

    }

    public void onPauseGame() {
        // TODO Auto-generated method stub

    }

    public void onResumeGame() {
        // TODO Auto-generated method stub

    }

    public Sprite getRaindrop(float x, float y) {
        return (new Sprite(x, y, snowTexture.deepCopy()));
    }

    @Override
    public boolean onAreaTouched(TouchEvent pSceneTouchEvent,ITouchArea pTouchArea, float pTouchAreaLocalX, float pTouchAreaLocalY) {
        if(pSceneTouchEvent.isActionDown()) {
            // HERE I WANT PLACE CODE, THAT WILL START ANIMATION.
            return true;
        }
        return false;
    }
}

So how to start animation on click? I want to make something like small cartoon.

Answer 1

In your onLoadScene method after registering update handler disable it.

mUpdateHandler.setEnabled(false);

And in onAreaTouched method enable it.

mUpdateHandler.setEnabled(true);

Btw I think it's not good practice to create Random instance every time in onUpdate method.

Answer 2

Here Josh describes how to override onTouch method (andEngine does not handle touch events for livewallpaper correctly, so you have to do it on your own). In few words, all you have to do is to override following function in BaseWallpaperGLEngine class (class is a part of andEngine live wallpaper extension:

@Override
        public void onTouchEvent (MotionEvent event)
        {
        }