A simple cusstom linearlayout manager

MyLinearLayoutManager.java

import android.view.View;

import androidx.recyclerview.widget.RecyclerView;

public class MyLinearLayoutManager extends RecyclerView.LayoutManager {

    private int mOffsetY = 0;

    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return new RecyclerView.LayoutParams(RecyclerView.LayoutParams.WRAP_CONTENT,
                RecyclerView.LayoutParams.WRAP_CONTENT);
    }

    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        super.onLayoutChildren(recycler, state);
        int offsetY = 0;
        for (int i = 0; i < getItemCount(); i++) {
            View view = recycler.getViewForPosition(i);
            addView(view);
            measureChildWithMargins(view, 0, 0);
            int width = getDecoratedMeasuredWidth(view);
            int height = getDecoratedMeasuredHeight(view);
            int middleWidth = (getWidth() - width) / 2;
            layoutDecorated(view, middleWidth, offsetY, middleWidth + width, offsetY + height);
            offsetY += height;
        }
    }

    @Override
    public boolean canScrollVertically() {
        return true;
    }

    @Override
    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler,
            RecyclerView.State state) {
        int offset = dy;
        if (mOffsetY + dy < 0) {
            offset = -mOffsetY;
        }
        mOffsetY += offset;
        offsetChildrenVertical(-offset);
        return offset;
    }
}