ViewHolderPassData

Sample Demonstrates how to pass Data between two different ViewHolder which results in either cases.

• Notify from one adapter to another that something has changed.
• Pass result from second adapter to first adapter.
  

This sample code contains 4 files :

• MyCustomParentAdapter
• ChildAdapter
• MainActivity
• CustomModel

MainActivity

Responsible for loading dummy data from data.json present inside assets folder.
Source can be REST API also depending on requirement. Contains 2 RecyclerView

MyCustomParentAdapter

Responsible for loading parent views.

private OnClickParentHeader mListener;

public interface OnClickParentHeader {
    void changeChildItems(List<CustomModel> items);
}

 public MyCustomParentAdapter(Context ctx,
                             HashMap<String, String> hMapHeaderAndCount,
                             LinkedHashMap<String, List<CustomModel>> lstData,
                             OnClickParentHeader listener) {
    this.mListener = listener;
    this.ctx = ctx;
    this.lstData = lstData;
    this.hMapHeaderAndCount = hMapHeaderAndCount;
    this.lstKey = getKeys();
}

• OnClickParentHeader
  CallBack Interface between Adapter & MainActivity.

• HashMap<String, String> hMapHeaderAndCount
  HashMap <K,V> where K is Key (Title) displayed in 1st list on left side ,V is the value which will maintain the count of items selected in 2nd list.
  

• LinkedHashMap<String, List> lstData
  LinkedHashMap<K,V> where K is Key (Title) displayed in 1st list on left side, V is the value in this case List

ChildAdapter

Responsible for loading child views.

public interface ListenerCountCallback {
    void notifyParentAdapter(int count);
}

public ChildAdapter(Context ctx,List<CustomModel> lstChild,ListenerCountCallback adapter) {
    this.mListener = adapter;
    this.lstChild = lstChild;
    this.ctx = ctx;
}