package com.netease.nim.uikit.common.ui.recyclerview.entity; import java.util.List; /** * implement the interface if the item is expandable */ public interface IExpandable<T> { boolean isExpanded(); void setExpanded(boolean expanded); List<T> getSubItems(); /** * Get the level of this item. The level start from 0. * If you don't care about the level, just return a negative. */ int getLevel(); }