如何在运行android 4.1的android emulator上模拟蓝牙鼠标滚轮事件

现在我没有任何安卓4.1设备，但老板要求在我的安卓应用程序中处理蓝牙鼠标滚轮事件

public boolean onTrackballEvent(MotionEvent event)
{
    if(event.getButtonState() == MotionEvent.BUTTON_TERTIARY)
    {
      //This is the wheel event case,
      //but I don't know what the other things about wheel rolling forward or rolling back,
      //who can tell me how to process the wheel rolling forward and back status
    }
}

请帮帮我，谢谢