我正在寻找一种方法，如何在列表中拖动fab，就像在todoist应用程序中一样：

对于drag-and-drop fab，我有一个继承的类：

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;

import com.google.android.material.floatingactionbutton.FloatingActionButton;

import org.jetbrains.annotations.NotNull;

public class MovableFloatingActionButton extends FloatingActionButton implements View.OnTouchListener {

    private final static float CLICK_DRAG_TOLERANCE = 10; // Often, there will be a slight, unintentional, drag when the user taps the FAB, so we need to account for this.

    private float downRawX, downRawY;
    private float dX, dY;
    private FabMoveListener moveListener;
    private OnTouchListener l;

    public void setMoveListener(FabMoveListener moveListener) {
        this.moveListener = moveListener;
    }

    public MovableFloatingActionButton(Context context) {
        super(context);
        init();
    }

    public MovableFloatingActionButton(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public MovableFloatingActionButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        setOnTouchListener(this);
    }

    @Override
    public boolean onTouch(@NotNull View view, @NotNull MotionEvent motionEvent) {
        l.onTouch(view, motionEvent);
        moveListener.onEvent(motionEvent);
        ViewGroup.MarginLayoutParams layoutParams = (ViewGroup.MarginLayoutParams) view.getLayoutParams();

        int action = motionEvent.getAction();
        if (action == MotionEvent.ACTION_DOWN) {

            downRawX = motionEvent.getRawX();
            downRawY = motionEvent.getRawY();
            dX = view.getX() - downRawX;
            dY = view.getY() - downRawY;

            return true; // Consumed

        } else if (action == MotionEvent.ACTION_MOVE) {

            int viewWidth = view.getWidth();
            int viewHeight = view.getHeight();

            View viewParent = (View) view.getParent();
            int parentWidth = viewParent.getWidth();
            int parentHeight = viewParent.getHeight();

            float newX = motionEvent.getRawX() + dX;
            newX = Math.max(layoutParams.leftMargin, newX); // Don't allow the FAB past the left hand side of the parent
            newX = Math.min(parentWidth - viewWidth - layoutParams.rightMargin, newX); // Don't allow the FAB past the right hand side of the parent

            float newY = motionEvent.getRawY() + dY;
            newY = Math.max(layoutParams.topMargin, newY); // Don't allow the FAB past the top of the parent
            newY = Math.min(parentHeight - viewHeight - layoutParams.bottomMargin, newY); // Don't allow the FAB past the bottom of the parent

            view.animate()
                    .x(newX)
                    .y(newY)
                    .setDuration(0)
                    .start();

            return true; // Consumed

        } else if (action == MotionEvent.ACTION_UP) {

            float upRawX = motionEvent.getRawX();
            float upRawY = motionEvent.getRawY();

            float upDX = upRawX - downRawX;
            float upDY = upRawY - downRawY;

            if (Math.abs(upDX) < CLICK_DRAG_TOLERANCE && Math.abs(upDY) < CLICK_DRAG_TOLERANCE) { // A click
                return performClick();
            } else { // A drag
                return true; // Consumed
            }

        } else {
            return super.onTouchEvent(motionEvent);
        }

    }

    public interface FabMoveListener {
        void onEvent(MotionEvent event);
    }
}

我假设itemtouchhelper也用于此，但是我仍然没有实现类似的行为。事实上，我需要在itemtouchhelper中开始拖动，同时拖动一个新的viewholder和一个按钮，但是如何才能做到这一点呢？