Generic-Adapter

One recycler view adapter for all your project

1.enable databinding in your app gradle

 dataBinding{
     enabled true
 }

Add dependency

  compile ('com.mohanmanu.genericadapter:genericadapter:1.0'){
         exclude group: 'com.android.support'
     }

Add attributes for your recycler view

 <data>

     <variable
         name="list"
         type="android.databinding.ObservableList" />
 </data>


 <LinearLayout
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical">

     <android.support.v7.widget.RecyclerView
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         app:genericLayout="@{@layout/adapter_single_view_type}"
         app:listItem="@{list}" />

 </LinearLayout>

provide observable list from your fragment or activity or viewmodel

say you are having fragment called SingleViewTypeFragment

  public class SingleViewTypeFragment extends Fragment {

       public ObservableList<String> observableList=new ObservableArrayList<>();


  @Nullable
  @Override
  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {

      FragmentSingleViewtypeBinding fragmentSingleViewtypeBinding=DataBindingUtil.inflate(inflater,R.layout.fragment_single_viewtype,container,false);
      fragmentSingleViewtypeBinding.setList(observableList);
      observableList.add("test string");
      return fragmentSingleViewtypeBinding.getRoot();
  }

 }

write adapter items layout

 <variable
     name="item"
     type="String" />

 <TextView
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:padding="@dimen/dimen_16"
     android:text="@{item}"
     tools:text="single view type" />

thats it you are done no need to write adapter everytime you create a new list

To handle Onclick events add one more attribute to recycler view

example

 <layout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   xmlns:app="http://schemas.android.com/apk/res-auto">

   <data>
       <variable
           name="list"
           type="android.databinding.ObservableList"/>
       <variable
           name="viewListener"
           type="com.mohang.genericadapter.ViewListener"/>
   </data>

   <LinearLayout
       android:orientation="vertical" android:layout_width="match_parent"
       android:layout_height="match_parent">
       <android.support.v7.widget.RecyclerView

           app:viewListener="@{viewListener}"
           app:genericLayout="@{@layout/adapter_single_view_type}"
           app:listItem="@{list}"
           android:layout_width="match_parent"
           android:layout_height="match_parent"
           />

   </LinearLayout>
 </layout>

in the above code snippet it is expecting a variable of type viewListener so provide the implementation for the viewListener in your activity or fragment or viewModel

public class ViewClickListenerFragment extends Fragment {

  public ObservableList observableList=new ObservableArrayList();

  @Nullable
  @Override
  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {

      FragmentViewListenerBinding fragmentSingleViewtypeBinding= DataBindingUtil.inflate(inflater,R.layout.fragment_view_listener,container,false);
      fragmentSingleViewtypeBinding.setList(observableList);
      observableList.addAll(DataSource.getListOfNUmbers());
      fragmentSingleViewtypeBinding.setViewListener(viewListener);
      return fragmentSingleViewtypeBinding.getRoot();
  }

  public ViewListener viewListener=new ViewListener() {
      @Override
      public void onClick(View v, int pos, Object object) {

          Toast.makeText(getActivity(), "item @ pos "+pos+" is "+((String)object), Toast.LENGTH_SHORT).show();
      }
  };
}

Thats how we can handle onClick event on an adapter

So next how to handle situation when I'm having multiple viewTypes? so that can also be handled by adding one more attribute called viewTypeListener

<variable
             name="viewTypeHandler"
             type="com.mohang.genericadapter.ViewTypeHandler"/>

provide variable of type ViewTypeHandler in your recyclerview

then write the ViewType handler in your view , based on the position or object that you are getting you can return different layout that you want to inflate

  ViewTypeHandler viewTypeHandler=new ViewTypeHandler() {
         @Override
         public int getViewType(int pos, Object item) {
             if(item instanceof Car){
                 return R.layout.adapter_car_view_type;
             }
             return R.layout.adapter_bus_view_type;
         }
     };

and add it onto recycler view

<android.support.v7.widget.RecyclerView
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          app:viewTypeHandler="@{viewTypeHandler}"
          app:listItem="@{list}" />

for more complex cases like gridlayout adapter ,and handling onclicks for different views on a same layout please refer to the examples given
Rules of adapter items

<data>
      
       <variable
               name="item"
               type="String" />
       <variable
               name="pos"
               type="Integer" />
       <variable
               name="actionHandler"
               type="your handler class which imlements ActionHandler" />
 </data>

your adapter item should always use the same variable to work

find the apk here https://play.google.com/store/apps/details?id=com.mohang.genericadapterexample

Generic Adapter

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Generic-Adapter