AndroidTextView跑马灯效果实现方法

public class MyTextView extends TextView{
  public MyTextView(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub
  }
  public MyTextView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    // TODO Auto-generated constructor stub
  }
  public MyTextView(Context context) {
    super(context);
    // TODO Auto-generated constructor stub
  }
  @Override
  public boolean isFocused() {
    // TODO Auto-generated method stub
    return true;   //must be return true;
  }
}