IntroScrollView

public class IntroScrollView extends ScrollView{

// private Context mContext;
private ScrollViewListener scrollViewListener = null;
public interface ScrollViewListener {

   void onScrollChanged(IntroScrollView scrollView, int x, int y, int oldx, int oldy);

}
public IntroScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
// mContext = context;
}

public IntroScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
// mContext = context;
}

public IntroScrollView(Context context) {
super(context);
// TODO Auto-generated constructor stub
// mContext = context;
}

@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
// TODO Auto-generated method stub
super.onScrollChanged(l, t, oldl, oldt);
if(scrollViewListener != null) {
            scrollViewListener.onScrollChanged(this, l, t, oldl, oldt);
        }
}
public void setScrollViewListener(ScrollViewListener scrollViewListener) {
        this.scrollViewListener = scrollViewListener;
    }
}