Android scrollview如何监听滑动状态

nestedScrollView.setOnScrollChangeListener(new View.OnScrollChangeListener() {
      @Override
      public void onScrollChange(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
 
      }
    });

public class MyScrollView extends NestedScrollView {
   private OnScrollChanged mOnScrollChanged;
  public MyScrollView(Context context) {
    this(context, null);
  }
  public MyScrollView(Context context, AttributeSet attributeSet) {
    this(context, attributeSet, 0);
  }
  public MyScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
  }
  @Override
  protected void onScrollChanged(int l, int t, int oldl, int oldt) {
    super.onScrollChanged(l, t, oldl, oldt);
    if (mOnScrollChanged != null) {
      mOnScrollChanged.onScroll(l, t, oldl, oldt);
    }
  }
  public void setOnScrollChanged(OnScrollChanged onScrollChanged) {
    this.mOnScrollChanged = onScrollChanged;
  }
  public interface OnScrollChanged {
    void onScroll(int l, int t, int oldl, int oldt);
  }
}

public interface OnScrollChanged {
    void onScroll(int l, int t, int oldl, int oldt);
 
    void onTouch(boolean isDown);
  }

@Override
  public boolean onTouchEvent(MotionEvent ev) {
      switch (ev.getAction()) {
      case MotionEvent.ACTION_UP:
      case MotionEvent.ACTION_CANCEL:
        if (mOnScrollChanged != null) {
          mOnScrollChanged.onTouch(false);
        }
        break;
      case MotionEvent.ACTION_DOWN:
      case MotionEvent.ACTION_MOVE:
        if (mOnScrollChanged != null) {
          mOnScrollChanged.onTouch(true);
        }
        break;
    }
    return super.onTouchEvent(ev);
  }

//静止状态
private final static int SCROLL_STATE_IDLE = 1;
//拖动或者惯性滑动状态
private final static int SCROLL_STATE_SCROLL = 2;
 
//判断是否是拖动状态
boolean isDragState = false;
 
int currentState = SCROLL_STATE_IDLE;
 
//这里采用100ms来判断是否已经是静止状态，100ms结束后证明是静止状态
private CountDownTimer scrollCountTimer = new CountDownTimer(100, 1) {
    @Override
    public void onTick(long millisUntilFinished) {
 
    }
 
    @Override
    public void onFinish() {
      setScrollState(SCROLL_STATE_IDLE);
    }
};
 
private void initScrollView() {
    scrollView.setOnScrollChanged(new MyScrollView.OnScrollChanged() {
      @Override
      public void onScroll(int l, int t, int oldl, int oldt) {
        if (isDragState) {//拖动状态单独处理不再进行滚动状态监测
          return;
        }
        //滑动时先取消倒计时，设置滑动状态
        scrollCountTimer.cancel();
        if(currentState != SCROLL_STATE_SCROLL) {
          setScrollState(SCROLL_STATE_SCROLL);
        }
        scrollCountTimer.start();
      }
 
      @Override
      public void onTouch(boolean isDown) {
        isDragState = isDown;
        //我这里把按下的状态默认为了滚动的状态，当然你也可以分开定义
        if (isDown) {
          scrollCountTimer.cancel();
          setScrollState(SCROLL_STATE_SCROLL);
        } else {
          scrollCountTimer.start();
        }
      }
});
//最后记得页面销毁时，cancel掉timer