android控件实现单击拖动效果

//绑定拖动事件
floatView.floatMenuIcon.setOnTouchListener(touchListener);
//绑定单击事件，此处为lambda表达式
floatView.floatMenuIcon.setOnClickListener(view -> {
 EventBus.getDefault().post(AccessibilityService.GLOBAL_ACTION_BACK);
});

private final View.OnTouchListener touchListener = new View.OnTouchListener() {
 //记录初使按下时的坐标，会因为拖动而改变
 private float dX;
 private float dY;
 //记录初使按下时的坐标，不因拖动而改变
 private float sX;
 private float sY;

 @SuppressLint("ClickableViewAccessibility")
 @Override
 public boolean onTouch(View view, MotionEvent motionEvent) {
  switch (motionEvent.getAction()) {
   case MotionEvent.ACTION_DOWN:
    dX = motionEvent.getRawX();
    dY = motionEvent.getRawY();
    sX = motionEvent.getRawX();
    sY = motionEvent.getRawY();
    break;
   case MotionEvent.ACTION_MOVE:
    //拖动事件，为了能够实时拖动，而非抬起后再移动，所以处理代码放到ACTION_MOVE中
    float nX = (int) motionEvent.getRawX();
    float nY = (int) motionEvent.getRawY();
    float cW = nX - dX;
    float cH = nY - dY;
    dX = nX;
    dY = nY;
    layoutParams.x = (int) (layoutParams.x + cW);
    layoutParams.y = (int) (layoutParams.y + cH);
    windowManager.updateViewLayout(mView, layoutParams);
    break;
   case MotionEvent.ACTION_UP:
    //如果抬起时的位置和按下时的位置大致相同视作单击事件
    //间隔值可能为负值，所以要取绝对值进行比较
    if (Math.abs(motionEvent.getRawX() - sX) > 6 && Math.abs(motionEvent.getRawY() - sY) > 6) {
     return true;
    }
    break;
  }
  return false;
 }
};