ClassNotFoundException: Didn't find class "com.orange.dgil.trail.app.android" about android-trail-drawing HOT 2 CLOSED

public class DrawingArea extends RelativeLayout implements IAnimListener {

    private ITrailDrawer drawer;

    public DrawingArea(Context context, AttributeSet attrs) {
        super(context, attrs);
        drawer = new TrailDrawer(this);
        drawer.getTrailOptions().setColor(Color.BLUE);
        drawer.setAnimationListener(this);
    }

    @Override
    public void draw(Canvas c) {
        super.draw(c);
        if (drawer != null) drawer.draw(c);
    }

    @Override
    public void animationFinished() {
        Log.w("animation", "finished");
        drawer.clear();
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        getParent().requestDisallowInterceptTouchEvent(true);
        switch (ev.getActionMasked()) {
            case MotionEvent.ACTION_DOWN:
                drawer.touchDown((int) ev.getX(), (int) ev.getY());
                break;
            case MotionEvent.ACTION_MOVE:
                for (int i = 0; i < ev.getHistorySize(); i++)
                    drawer.touchMove((int) ev.getHistoricalX(i), (int) ev.getHistoricalY(i));
                drawer.touchMove((int) ev.getX(), (int) ev.getY());
                break;
            case MotionEvent.ACTION_UP:
                drawer.touchUp();
                break;
            default:
                drawer.touchCancel();
                break;
        }
        return true;
    }

    public void trimMemory() {
        drawer.clear();
        drawer.trimMemory();
    }
}