/**
 * Created by Jlanglang on 2016/12/7.
*
 */
public abstract class TreeAdapterItem<D> {
 /**
 * 當前item的數據
 */
 protected D data;
 /**
 * 持有的子數據
 */
 protected List<TreeAdapterItem> childs;
 /**
 * 是否展開
 */
 protected boolean isExpand;
 /**
 * 布局資源id
 */
 protected int layoutId;
 /**
 * 在每行中所占的比例
 */
 protected int spanSize;

 ····
 get/set方法省略。。。。
 ····
 public TreeAdapterItem(D data) {
 this.data = data;
 childs = initChildsList(data);
 layoutId = initLayoutId();
 spanSize = initSpansize();
 }
 /**
 * 展開
 */
 public void onExpand() {
 isExpand = true;
 }

 /**
 * 折疊
 */
 public void onCollapse() {
 isExpand = false;
 }

 /**
 * 遞歸遍歷所有的子數據，包括子數據的子數據
 *
 * @return List<TreeAdapterItem>
 */
 public List<TreeAdapterItem> getAllChilds() {

  ArrayList<TreeAdapterItem> treeAdapterItems = new ArrayList<>();

  for (int i = 0; i < childs.size(); i++) {

  TreeAdapterItem treeAdapterItem = childs.get(i);

  treeAdapterItems.add(treeAdapterItem);

  if (treeAdapterItem.isParent()) {

   List list = treeAdapterItem.getAllChilds();

   if (list != null && list.size() > 0) {

   treeAdapterItems.addAll(list);
   }
  }
  }
  return treeAdapterItems;
 }

 /**
 * 是否持有子數據
 *
 * @return
 */
 public boolean isParent() {
  return childs != null && childs.size() > 0;
 }
 /**
 * item在每行中的spansize
 * 默認為0,如果為0則占滿一行
 * 不建議連續的兩級,都設置該數值
 *
 * @return 所占值
 */
 public int initSpansize() {
  return spanSize;
 }
 /**
 * 初始化子數據
 *
 * @param data
 * @return
 */
 protected abstract List<TreeAdapterItem> initChildsList(D data);
 /**
 * 該條目的布局id
 *
 * @return 布局id
 */
 protected abstract int initLayoutId();

 /**
 * 抽象holder的綁定
 *
 * @param holder ViewHolder
 */
 public abstract void onBindViewHolder(ViewHolder holder);
}

public class TreeRecyclerViewAdapter<T extends TreeAdapterItem> extends RecyclerView.Adapter<ViewHolder> {

 protected Context mContext;
 /**
 * 存儲所有可見的Node
 */
 protected List<T> mDatas;//處理后的展示數據

 /**
 * 點擊item的回調接口
 */
 private OnTreeItemClickListener onTreeItemClickListener;

 public void setOnTreeItemClickListener(OnTreeItemClickListener onTreeItemClickListener) {
 this.onTreeItemClickListener = onTreeItemClickListener;
 }

 /**
 *
 * @param context 上下文
 * @param datas 條目數據
 */
 public TreeRecyclerViewAdapter(Context context, List<T> datas) {
 mContext = context;
 mDatas = datas;
 }

 /**
 * 相應RecyclerView的點擊事件 展開或關閉
 * 重要
 * @param position 觸發的條目
 */
 public void expandOrCollapse(int position) {
 //獲取當前點擊的條目
 TreeAdapterItem treeAdapterItem = mDatas.get(position);
 //判斷點擊的條目有沒有下一級
 if (!treeAdapterItem.isParent()) {
  return;
 }
 //判斷是否展開
 boolean expand = treeAdapterItem.isExpand();
 if (expand) {
  //獲取所有的子數據.
  List allChilds = treeAdapterItem.getAllChilds();
  mDatas.removeAll(allChilds);
  //告訴item,折疊
  treeAdapterItem.onCollapse();
 } else {
  //獲取下一級的數據
  mDatas.addAll(position + 1, treeAdapterItem.getChilds());
  //告訴item,展開
  treeAdapterItem.onExpand();
 }
 notifyDataSetChanged();
 }
 //adapter綁定Recycleview后.
 @Override
 public void onAttachedToRecyclerView(RecyclerView recyclerView) {
 super.onAttachedToRecyclerView(recyclerView);
 //拿到布局管理器
 RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
 //判斷是否是GridLayoutManager,因為GridLayoutManager才能設置每個條目的行占比.
 if (layoutManager instanceof GridLayoutManager) {
  final GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
  gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
  @Override
  public int getSpanSize(int position) {

   TreeAdapterItem treeAdapterItem = mDatas.get(position);
   if (treeAdapterItem.getSpanSize() == 0) {
   //如果是默認的大小,則占一行
   return gridLayoutManager.getSpanCount();
   }
   //根據item的SpanSize來決定所占大小
   return treeAdapterItem.getSpanSize();
  }
  });
 }
 }


 @Override
 public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
 //這里,直接通過item設置的id來創建Viewholder
 return ViewHolder.createViewHolder(mContext, parent, viewType);
 }

 @Override
 public void onBindViewHolder(ViewHolder holder, final int position) {
 final TreeAdapterItem treeAdapterItem = mDatas.get(position);
 holder.itemView.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View v) {
  //折疊或展開
  expandOrCollapse(position);
  if (onTreeItemClickListener != null) {
   //點擊監聽的回調.一般不是最后一級,不需要處理吧.
   onTreeItemClickListener.onClick(treeAdapterItem, position);
  }
  }
 });
 treeAdapterItem.onBindViewHolder(holder);
 }

 @Override
 public int getItemViewType(int position) {
 //返回item的layoutId
 return mDatas.get(position).getLayoutId();
 }

 @Override
 public int getItemCount() {
 return mDatas == null ? 0 : mDatas.size();
 }

 public interface OnTreeItemClickListener {
 void onClick(TreeAdapterItem node, int position);
 }
}

/**
 * Created by baozi on 2016/12/8.
 */
public class OneItem extends TreeAdapterItem<CityBean> {

 public OneItem(CityBean data) {
 super(data);
 }
 //這里數據用的是,一個三級城市列表數據。
 @Override
 protected List<TreeAdapterItem> initChildsList(CityBean data) {//這個CityBean 是一級數據
 ArrayList<TreeAdapterItem> oneChilds= new ArrayList<>();
 List<CityBean.CitysBean> citys = data.getCitys();
 if (citys == null) {//如果沒有二級數據就直接返回.
  return null;
 }
 for (int i = 0; i < citys.size(); i++) {//遍歷二級數據.
  TwoItem twoItem = new TwoItem(citys.get(i));//創建二級條目。
  oneChilds.add(twoItem);
 }
 return oneChilds;
 }

 @Override
 protected int initLayoutId() {//當前級數的布局
 return R.layout.itme_one;
 }

 @Override
 public void onExpand() {
 super.onExpand();

 }


 @Override
 public void onBindViewHolder(ViewHolder holder) {
 //設置當前級數的viewhodler.
 //如果需要某個view展開關閉時的動畫，可以在這里保存view到成員變量。
 //然后在onExpand()方法里面操作。
 holder.setText(R.id.tv_content, data.getProvinceName());
 }
}

/**
 * Created by baozi on 2016/12/8.
 */
public class FourItem extends TreeAdapterItem<String> {
....

 @Override
 protected List<TreeAdapterItem> initChildsList(String data) {
 ArrayList<TreeAdapterItem> treeAdapterItems = new ArrayList<>();
 for (int i = 0; i < 10; i++) {
  FiveItem threeItem = new FiveItem("我是五級");
  //在遍歷的時候,通過條件,重設孩子的布局id.和所占比
  if (i % 4 == 0) {//偷個懶,不多寫布局了.
  threeItem.setLayoutId(R.layout.itme_one);
  threeItem.setSpanSize(0);
  } else if (i % 3 == 0) {
  threeItem.setLayoutId(R.layout.item_two);
  threeItem.setSpanSize(2);
  }
  treeAdapterItems.add(threeItem);
 }
 return treeAdapterItems;
 }
....
}

/**
 * Created by baozi on 2016/12/8.
 */
public class FiveItem extends TreeAdapterItem<String> {
 .......
//設置默認的布局
 @Override
 protected int initLayoutId() {
 return R.layout.item_five;
 }
//設置默認的占比
 @Override
 public int initSpansize() {
 return 2;
 }
 //根據layoutId來判斷viewhodler并設置
 @Override
 public void onBindViewHolder(ViewHolder holder) {
 if (layoutId == R.layout.itme_one) {
  holder.setText(R.id.tv_content, "我是第一種五級");
 } else if (layoutId == R.layout.item_five) {
  holder.setText(R.id.tv_content, "我是第二種五級");
 }else if (layoutId == R.layout.item_two) {
  holder.setText(R.id.tv_content, "我是第三種五級");
 }
 }
}