How to create RecyclerView with multiple view type

Question

From https   developer android com preview material ui-widgets html  When we create RecyclerView Adapter we have to specify ViewHolder that will bind with the adapter   public class MyAdapter extends RecyclerView Adapter lt MyAdapter ViewHolder gt         private String   mDataset       public MyAdapter String   myDataset            mDataset   myDataset             public static class ViewHolder extends RecyclerView ViewHolder           public TextView mTextView          public ViewHolder TextView v                super v               mTextView   v                        Override     public MyAdapter ViewHolder onCreateViewHolder ViewGroup parent  int viewType            View v   LayoutInflater from parent getContext    inflate R layout some layout  parent  false              findViewById             ViewHolder vh   new ViewHolder v           return vh              Override     public void onBindViewHolder ViewHolder holder  int position            holder mTextView setText mDataset position                Override     public int getItemCount             return mDataset length            So  is it possible to create RecyclerView with multiple view types

User · Answer

You can use the library  https   github com vivchar RendererRecyclerViewAdapter  mRecyclerViewAdapter   new RendererRecyclerViewAdapter       included from library    mRecyclerViewAdapter registerRenderer new SomeViewRenderer SomeModel TYPE  this    mRecyclerViewAdapter registerRenderer          you can use several types of cells         For each item  you should to implement a ViewRenderer  ViewHolder  SomeModel   ViewHolder - it is a simple view holder of recycler view   SomeModel - it is your model with ItemModel interface  public class SomeViewRenderer extends ViewRenderer lt SomeModel  SomeViewHolder gt       public SomeViewRenderer final int type  final Context context        super type  context          Override  public void bindView  NonNull final SomeModel model   NonNull final SomeViewHolder holder        holder mTitle setText model getTitle          NonNull   Override  public SomeViewHolder createViewHolder  Nullable final ViewGroup parent        return new SomeViewHolder LayoutInflater from getContext    inflate R layout some item  parent  false           For more details you can look documentations

User · Answer

If the layouts for view types are only a few and binding logics are simple, follow Anton's solution.
But the code will be messy if you need to manage the complex layouts and binding logics.

I believe the following solution will be useful for someone who need to handle complex view types.

Base DataBinder class

abstract public class DataBinder<T extends RecyclerView.ViewHolder> {

    private DataBindAdapter mDataBindAdapter;

    public DataBinder(DataBindAdapter dataBindAdapter) {
        mDataBindAdapter = dataBindAdapter;
    }

    abstract public T newViewHolder(ViewGroup parent);

    abstract public void bindViewHolder(T holder, int position);

    abstract public int getItemCount();

......

}

The functions needed to define in this class are pretty much same as the adapter class when creating the single view type.
For each view type, create the class by extending this DataBinder.

Sample DataBinder class

public class Sample1Binder extends DataBinder<Sample1Binder.ViewHolder> {

    private List<String> mDataSet = new ArrayList();

    public Sample1Binder(DataBindAdapter dataBindAdapter) {
        super(dataBindAdapter);
    }

    @Override
    public ViewHolder newViewHolder(ViewGroup parent) {
        View view = LayoutInflater.from(parent.getContext()).inflate(
            R.layout.layout_sample1, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void bindViewHolder(ViewHolder holder, int position) {
        String title = mDataSet.get(position);
        holder.mTitleText.setText(title);
    }

    @Override
    public int getItemCount() {
        return mDataSet.size();
    }

    public void setDataSet(List<String> dataSet) {
        mDataSet.addAll(dataSet);
    }

    static class ViewHolder extends RecyclerView.ViewHolder {

        TextView mTitleText;

        public ViewHolder(View view) {
            super(view);
            mTitleText = (TextView) view.findViewById(R.id.title_type1);
        }
    }
}

In order to manage DataBinder classes, create adapter class.

Base DataBindAdapter class

abstract public class DataBindAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return getDataBinder(viewType).newViewHolder(parent);
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position) {
        int binderPosition = getBinderPosition(position);
        getDataBinder(viewHolder.getItemViewType()).bindViewHolder(viewHolder, binderPosition);
    }

    @Override
    public abstract int getItemCount();

    @Override
    public abstract int getItemViewType(int position);

    public abstract <T extends DataBinder> T getDataBinder(int viewType);

    public abstract int getPosition(DataBinder binder, int binderPosition);

    public abstract int getBinderPosition(int position);

......

}

Create the class by extending this base class, and then instantiate DataBinder classes and override abstract methods

getItemCount
Return the total item count of DataBinders
getItemViewType
Define the mapping logic between the adapter position and view type.
getDataBinder
Return the DataBinder instance based on the view type
getPosition
Define convert logic to the adapter position from the position in the specified DataBinder
getBinderPosition
Define convert logic to the position in the DataBinder from the adapter position

Hope this solution will be helpful.
I left more detail solution and samples in GitHub, so please refer the following link if you need.
https://github.com/yqritc/RecyclerView-MultipleViewTypesAdapter

User · Answer

Simpler than ever  forget about ViewTypes  Is not recommended to use multiple viewtypes inside one adapter  it will mess the code and break the single responsibility principle since now the adapter needs to handle logic to know which view to inflate  now imagine working in large teams where each team has to work in one of those viewtypes features  it will be a mess to touch the same adapter by all the teams that work in the different viewtypes  this is solved using ConcatAdapter where you isolate the adapters  code them one by one and then just merge them inside one view  From recyclerview 1 2 0-alpha04 you now can use ConcatAdapter If you need a view with different viewTypes   you can just write the Adapters for each section and just use ConcatAdapter to merge all of them inside one recyclerview ConcatAdapter This image shows 3 different viewtypes that one recyclerview has  header  content and footer   You only create one adapter for each section  and then just use ConcatAdapter to merge them inside one recyclerview val firstAdapter  FirstAdapter       val secondAdapter  SecondAdapter       val thirdAdapter  ThirdAdapter       val concatAdapter   ConcatAdapter firstAdapter  secondAdapter        thirdAdapter  recyclerView adapter   concatAdapter   Thats all you need to know  if you want to handle loading state  for example remove the last adapter after some loading happened  you can use LoadState

User · Answer

Actually  I d like to improve on Anton s answer   Since getItemViewType int position  returns an integer value  you can return the layout resource ID you d need to inflate  That way you d save some logic in onCreateViewHolder ViewGroup parent  int viewType  method   Also  I wouldn t suggest doing intensive calculations in getItemCount   as that particular function is called at least 5 times while rendering the list  as well as while rendering each item beyond the visible items  Sadly since notifyDatasetChanged   method is final  you can t really override it  but you can call it from another function within the adapter

User · Answer

following Anton s solution  come up with this ViewHolder which holds handles delegates different type of layouts  But not sure if the replacing new layout would work when the recycling view s ViewHolder is not type of the data roll in   So basically   onCreateViewHolder ViewGroup parent  int viewType  is only called when new view layout is needed   getItemViewType int position  will be called for the viewType   onBindViewHolder ViewHolder holder  int position  is always called when recycling the view  new data is brought in and try to display with that ViewHolder    So when onBindViewHolder is called it needs to put in the right view layout and update the ViewHolder   Is the way correct to replacing the view layout for that ViewHolder to be brought in  or any problem   Appreciate any comment   public int getItemViewType int position        TypedData data   mDataSource get position       return data type     public ViewHolder onCreateViewHolder ViewGroup parent       int viewType        return ViewHolder makeViewHolder parent  viewType      public void onBindViewHolder ViewHolder holder       int position        TypedData data   mDataSource get position       holder updateData data          public static class ViewHolder extends      RecyclerView ViewHolder        ViewGroup mParentViewGroup      View mCurrentViewThisViewHolderIsFor      int mDataType       public TypeOneViewHolder mTypeOneViewHolder      public TypeTwoViewHolder mTypeTwoViewHolder       static ViewHolder makeViewHolder ViewGroup vwGrp           int dataType            View v   getLayoutView vwGrp  dataType           return new ViewHolder vwGrp  v  viewType              static View getLayoutView ViewGroup vwGrp           int dataType            int layoutId   getLayoutId dataType           return LayoutInflater from vwGrp getContext                                  inflate layoutId  null              static int getLayoutId int dataType            if  dataType    TYPE ONE                return R layout type one layout            else if  dataType    TYPE TWO                return R layout type two layout                       public ViewHolder ViewGroup vwGrp  View v           int dataType            super v           mDataType   dataType          mParentViewGroup   vwGrp          mCurrentViewThisViewHolderIsFor   v           if  data type    TYPE ONE                mTypeOneViewHolder   new TypeOneViewHolder v             else if  data type    TYPE TWO                mTypeTwoViewHolder   new TypeTwoViewHolder v                        public void updateData TypeData data            mDataType   data type          if  data type    TYPE ONE                mTypeTwoViewHolder   null              if  mTypeOneViewHolder    null                    View newView   getLayoutView mParentViewGroup                                 data type                                            how to replace new view with                      the view in the parent                      view container                                         replaceView mCurrentViewThisViewHolderIsFor                               newView                   mCurrentViewThisViewHolderIsFor   newView                   mTypeOneViewHolder                        new TypeOneViewHolder newView                             mTypeOneViewHolder updateDataTypeOne data              else if  data type    TYPE TWO               mTypeOneViewHolder   null              if  mTypeTwoViewHolder    null                    View newView   getLayoutView mParentViewGroup                                  data type                                            how to replace new view with                      the view in the parent view                      container                                         replaceView mCurrentViewThisViewHolderIsFor                               newView                   mCurrentViewThisViewHolderIsFor   newView                   mTypeTwoViewHolder                        new TypeTwoViewHolder newView                             mTypeTwoViewHolder updateDataTypeOne data                      public static void replaceView View currentView       View newView        ViewGroup parent    ViewGroup currentView getParent        if parent    null            return            final int index   parent indexOfChild currentView       parent removeView currentView       parent addView newView  index       Edit  ViewHolder has member mItemViewType to hold the view  Edit  looks like in onBindViewHolder ViewHolder holder  int position  the ViewHolder passed in has been picked up  or created  by looked at getItemViewType int position  to make sure it is a match  so may not need to worry there that ViewHolder s type does not match the data position  s type  Does anyone knows more how the ViewHolder in the onBindViewHolder   is picked up   Edit  Looks like The recycle ViewHolder is picked by type  so no warrior there   Edit  http   wiresareobsolete com 2014 09 building-a-recyclerview-layoutmanager-part-1  answers this question   It gets the recycle ViewHolder like   holder   getRecycledViewPool   getRecycledView mAdapter getItemViewType offsetPosition      or create new one if not find recycle ViewHolder of right type   public ViewHolder getRecycledView int viewType            final ArrayList lt ViewHolder gt  scrapHeap   mScrap get viewType           if  scrapHeap    null  amp  amp   scrapHeap isEmpty                  final int index   scrapHeap size   - 1              final ViewHolder scrap   scrapHeap get index               scrapHeap remove index               return scrap                    return null         View getViewForPosition int position  boolean dryRun                    if  holder    null                final int offsetPosition   mAdapterHelper findPositionOffset position               if  offsetPosition  lt  0    offsetPosition  gt   mAdapter getItemCount                      throw new IndexOutOfBoundsException  Inconsistency detected  Invalid item                              position     position     offset     offsetPosition                                   state     mState getItemCount                                final int type   mAdapter getItemViewType offsetPosition                  2  Find from scrap via stable ids  if exists             if  mAdapter hasStableIds                      holder   getScrapViewForId mAdapter getItemId offsetPosition   type  dryRun                   if  holder    null                           update position                     holder mPosition   offsetPosition                      fromScrap   true                                              if  holder    null  amp  amp  mViewCacheExtension    null                       We are NOT sending the offsetPosition because LayoutManager does not                    know it                  final View view   mViewCacheExtension                          getViewForPositionAndType this  position  type                   if  view    null                        holder   getChildViewHolder view                       if  holder    null                            throw new IllegalArgumentException  getViewForPositionAndType returned                                      a view which does not have a ViewHolder                          else if  holder shouldIgnore                              throw new IllegalArgumentException  getViewForPositionAndType returned                                      a view that is ignored  You must call stopIgnoring before                                      returning this view                                                                       if  holder    null       fallback to recycler                    try recycler                     Head to the shared pool                  if  DEBUG                        Log d TAG   getViewForPosition     position      fetching from shared                                  pool                                      holder   getRecycledViewPool                            getRecycledView mAdapter getItemViewType offsetPosition                    if  holder    null                        holder resetInternal                        if  FORCE INVALIDATE DISPLAY LIST                            invalidateDisplayListInt holder                                                                     if  holder    null                    holder   mAdapter createViewHolder RecyclerView this                          mAdapter getItemViewType offsetPosition                    if  DEBUG                        Log d TAG   getViewForPosition created new ViewHolder                                                      boolean bound   false          if  mState isPreLayout    amp  amp  holder isBound                     do not update unless we absolutely have to              holder mPreLayoutPosition   position            else if   holder isBound      holder needsUpdate      holder isInvalid                  if  DEBUG  amp  amp  holder isRemoved                      throw new IllegalStateException  Removed holder should be bound and it should                              come here only in pre-layout  Holder      holder                             final int offsetPosition   mAdapterHelper findPositionOffset position               mAdapter bindViewHolder holder  offsetPosition               attachAccessibilityDelegate holder itemView               bound   true              if  mState isPreLayout                      holder mPreLayoutPosition   position                                   final ViewGroup LayoutParams lp   holder itemView getLayoutParams            final LayoutParams rvLayoutParams          if  lp    null                rvLayoutParams    LayoutParams  generateDefaultLayoutParams                holder itemView setLayoutParams rvLayoutParams             else if   checkLayoutParams lp                 rvLayoutParams    LayoutParams  generateLayoutParams lp               holder itemView setLayoutParams rvLayoutParams             else               rvLayoutParams    LayoutParams  lp                    rvLayoutParams mViewHolder   holder          rvLayoutParams mPendingInvalidate   fromScrap  amp  amp  bound          return holder itemView

User · Answer

first you must create 2 layout xml   after that inside recyclerview adapter TYPE CALL and TYPE EMAIL are two static values with 1 and 2 respectively in adapter class   now Define two static values   at the Recycler view Adapter class level for example   private static int TYPE CALL   1  private static int TYPE EMAIL   2   Now create view holder with multiple views like this   class CallViewHolder extends RecyclerView ViewHolder        private TextView txtName      private TextView txtAddress       CallViewHolder  NonNull View itemView            super itemView           txtName   itemView findViewById R id txtName           txtAddress   itemView findViewById R id txtAddress           class EmailViewHolder extends RecyclerView ViewHolder        private TextView txtName      private TextView txtAddress       EmailViewHolder  NonNull View itemView            super itemView           txtName   itemView findViewById R id txtName           txtAddress   itemView findViewById R id txtAddress             Now code as below in onCreateViewHolder and onBindViewHolder method in recyclerview adapter    NonNull  Override public RecyclerView ViewHolder onCreateViewHolder  NonNull ViewGroup viewGroup  int viewType        View view      if  viewType    TYPE CALL       for call layout         view   LayoutInflater from context  inflate R layout item call  viewGroup  false           return new CallViewHolder view          else      for email layout         view   LayoutInflater from context  inflate R layout item email  viewGroup  false           return new EmailViewHolder view            Override public void onBindViewHolder  NonNull RecyclerView ViewHolder viewHolder  int position        if  getItemViewType position     TYPE CALL              CallViewHolder  viewHolder  setCallDetails employees get position          else             EmailViewHolder  viewHolder  setEmailDetails employees get position

User · Answer

Yes  it is possible  In your adapter getItemViewType Layout like this         public class MultiViewTypeAdapter extends RecyclerView Adapter            private ArrayList lt Model gt dataSet          Context mContext          int total types          MediaPlayer mPlayer          private boolean fabStateVolume   false           public static class TextTypeViewHolder extends RecyclerView ViewHolder                TextView txtType              CardView cardView               public TextTypeViewHolder View itemView                    super itemView                    this txtType    TextView  itemView findViewById R id type                   this cardView    CardView  itemView findViewById R id card view                                    public static class ImageTypeViewHolder extends RecyclerView ViewHolder                TextView txtType              ImageView image               public ImageTypeViewHolder View itemView                    super itemView                    this txtType    TextView  itemView findViewById R id type                   this image    ImageView  itemView findViewById R id background                                    public static class AudioTypeViewHolder extends RecyclerView ViewHolder                TextView txtType              FloatingActionButton fab               public AudioTypeViewHolder View itemView                    super itemView                    this txtType    TextView  itemView findViewById R id type                   this fab    FloatingActionButton  itemView findViewById R id fab                                    public MultiViewTypeAdapter ArrayList lt Model gt data  Context context                this dataSet   data              this mContext   context              total types   dataSet size                        Override         public RecyclerView ViewHolder onCreateViewHolder ViewGroup parent  int viewType                 View view              switch  viewType                    case Model TEXT TYPE                      view   LayoutInflater from parent getContext    inflate R layout text type  parent  false                       return new TextTypeViewHolder view                   case Model IMAGE TYPE                      view   LayoutInflater from parent getContext    inflate R layout image type  parent  false                       return new ImageTypeViewHolder view                   case Model AUDIO TYPE                      view   LayoutInflater from parent getContext    inflate R layout audio type  parent  false                       return new AudioTypeViewHolder view                             return null                      Override         public int getItemViewType int position                 switch  dataSet get position  type                    case 0                      return Model TEXT TYPE                  case 1                      return Model IMAGE TYPE                  case 2                      return Model AUDIO TYPE                  default                      return -1                                    Override         public void onBindViewHolder final RecyclerView ViewHolder holder  final int listPosition                 Model object   dataSet get listPosition               if  object    null                    switch  object type                        case Model TEXT TYPE                            TextTypeViewHolder  holder  txtType setText object text                            break                      case Model IMAGE TYPE                            ImageTypeViewHolder  holder  txtType setText object text                             ImageTypeViewHolder  holder  image setImageResource object data                           break                      case Model AUDIO TYPE                             AudioTypeViewHolder  holder  txtType setText object text                                                        Override         public int getItemCount                 return dataSet size                      for reference link   https   www journaldev com 12372 android-recyclerview-example

User · Answer

The below is not pseudocode and I have tested it and it has worked for me.

I wanted to create a headerview in my recyclerview and then display a list of pictures below the header which the user can click on.

I used a few switches in my code, don't know if that is the most efficient way to do this so feel free to give your comments:

   public class ViewHolder extends RecyclerView.ViewHolder{

        //These are the general elements in the RecyclerView
        public TextView place;
        public ImageView pics;

        //This is the Header on the Recycler (viewType = 0)
        public TextView name, description;

        //This constructor would switch what to findViewBy according to the type of viewType
        public ViewHolder(View v, int viewType) {
            super(v);
            if (viewType == 0) {
                name = (TextView) v.findViewById(R.id.name);
                decsription = (TextView) v.findViewById(R.id.description);
            } else if (viewType == 1) {
                place = (TextView) v.findViewById(R.id.place);
                pics = (ImageView) v.findViewById(R.id.pics);
            }
        }
    }


    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent,
                                         int viewType)
    {
        View v;
        ViewHolder vh;
        // create a new view
        switch (viewType) {
            case 0: //This would be the header view in my Recycler
                v = LayoutInflater.from(parent.getContext())
                    .inflate(R.layout.recyclerview_welcome, parent, false);
                vh = new ViewHolder(v,viewType);
                return  vh;
            default: //This would be the normal list with the pictures of the places in the world
                v = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.recyclerview_picture, parent, false);
                vh = new ViewHolder(v, viewType);
                v.setOnClickListener(new View.OnClickListener(){

                    @Override
                    public void onClick(View v) {
                        Intent intent = new Intent(mContext, nextActivity.class);
                        intent.putExtra("ListNo",mRecyclerView.getChildPosition(v));
                        mContext.startActivity(intent);
                    }
                });
                return vh;
        }
    }

    //Overriden so that I can display custom rows in the recyclerview
    @Override
    public int getItemViewType(int position) {
        int viewType = 1; //Default is 1
        if (position == 0) viewType = 0; //if zero, it will be a header view
        return viewType;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        //position == 0 means its the info header view on the Recycler
        if (position == 0) {
            holder.name.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(mContext,"name clicked", Toast.LENGTH_SHORT).show();
                }
            });
            holder.description.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Toast.makeText(mContext,"description clicked", Toast.LENGTH_SHORT).show();
                }
            });
            //this means it is beyond the headerview now as it is no longer 0. For testing purposes, I'm alternating between two pics for now
        } else if (position > 0) {
           holder.place.setText(mDataset[position]);
            if (position % 2 == 0) {
               holder.pics.setImageDrawable(mContext.getResources().getDrawable(R.drawable.pic1));
            }
            if (position % 2 == 1) {
                holder.pics.setImageDrawable(mContext.getResources().getDrawable(R.drawable.pic2));
            }

        }
    }

User · Answer

Yes  it is possible   Write a generic view holder       public abstract class GenericViewHolder extends RecyclerView ViewHolder       public GenericViewHolder View itemView            super itemView              public abstract  void setDataOnView int position       then create your view holders and make them extend the GenericViewHolder  For example  this one        public class SectionViewHolder extends GenericViewHolder      public final View mView      public final TextView dividerTxtV       public SectionViewHolder View itemView            super itemView           mView   itemView          dividerTxtV    TextView  mView findViewById R id dividerTxtV               Override     public void setDataOnView int position            try               String title  sections get position               if title   null                  this dividerTxtV setText title            catch  Exception e               new CustomError  Error   e getMessage    null  false  null  e                       then the RecyclerView Adapter class will look like this one   public class MyClassRecyclerViewAdapter extends RecyclerView Adapter lt MyClassRecyclerViewAdapter GenericViewHolder gt      Override public int getItemViewType int position            depends on your problem      switch  position             case   return VIEW TYPE1           case   return VIEW TYPE2                              Override    public GenericViewHolder onCreateViewHolder ViewGroup parent  int viewType         View view      if viewType    VIEW TYPE1           view   LayoutInflater from parent getContext    inflate R layout layout1  parent  false           return new SectionViewHolder view        else if  viewType    VIEW TYPE2           view   LayoutInflater from parent getContext    inflate R layout layout2  parent  false           return new OtherViewHolder view                Cont  other view holders         return null         Override public void onBindViewHolder GenericViewHolder holder  int position        holder setDataOnView position

User · Answer

Yes  it s possible  Just implement getItemViewType    and take care of the viewType parameter in onCreateViewHolder     So you do something like   public class MyAdapter extends RecyclerView Adapter lt RecyclerView ViewHolder gt        class ViewHolder0 extends RecyclerView ViewHolder                       public ViewHolder0 View itemView                                    class ViewHolder2 extends RecyclerView ViewHolder                       public ViewHolder2 View itemView                           Override     public int getItemViewType int position               Just as an example  return 0 or 2 depending on position            Note that unlike in ListView adapters  types don t have to be contiguous         return position   2   2              Override     public RecyclerView ViewHolder onCreateViewHolder ViewGroup parent  int viewType             switch  viewType                 case 0  return new ViewHolder0                    case 2  return new ViewHolder2                                               Override     public void onBindViewHolder final RecyclerView ViewHolder holder  final int position            switch  holder getItemViewType                  case 0                  ViewHolder0 viewHolder0    ViewHolder0 holder                                      break               case 2                  ViewHolder2 viewHolder2    ViewHolder2 holder                                      break

User · Answer

View types implementation becomes easier with kotlin  here is a sample with this light library https   github com Link184 KidAdapter  recyclerView setUp       withViewType           withLayoutResId R layout item int          withItems mutableListOf 1  2  3  4  5  6           bind lt Int gt       this - is adapter view hoder itemView  it - current item             intName text   it toString                         withViewType  SECOND STRING TAG             withLayoutResId R layout item text          withItems mutableListOf  eight    nine    ten    eleven    twelve            bind lt String gt                stringName text   it

User · Answer

I see there are a lot of great answers  incredibly detailed and extensive  In my case  I always understand things better if I follow along the reasoning from almost scratch  step by step  I would recommend you check this link out and whenever you have similar doubts  search for any codelabs that address the issue  https   developer android com codelabs kotlin-android-training-headers 0

User · Answer

If you want to use it in conjunction with Android Data Binding look into the https://github.com/evant/binding-collection-adapter - it is by far the best solution for the multiple view types RecyclerView I have even seen.

you may use it like

var items: AsyncDiffPagedObservableList<BaseListItem> =
        AsyncDiffPagedObservableList(GenericDiff)

    val onItemBind: OnItemBind<BaseListItem> =
        OnItemBind { itemBinding, _, item -> itemBinding.set(BR.item, item.layoutRes) }

and then in the layout where list is

 <androidx.recyclerview.widget.RecyclerView
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"
                app:enableAnimations="@{false}"
                app:scrollToPosition="@{viewModel.scrollPosition}"

                app:itemBinding="@{viewModel.onItemBind}"
                app:items="@{viewModel.items}"

                app:reverseLayoutManager="@{true}"/>

your list items must implement BaseListItem interface that looks like this

interface BaseListItem {
    val layoutRes: Int
}

and item view should look something like this

<layout xmlns:android="http://schemas.android.com/apk/res/android">

    <data>

        <variable
                name="item"
                type="...presentation.somescreen.list.YourListItem"/>
    </data>

   ...

</layout>

Where YourListItem implements BaseListItem

Hope it will help someone.

User · Answer

You can deal multipleViewTypes RecyclerAdapter by making getItemViewType   return the expected viewType value for that position  I prepared an MultipleViewTypeAdapter for constructing MCQ list for examinations which may throw a question that may have 2 or more valid answers  checkbox options  and a single answer questions  radiobutton options    For this i get the type of Question from API response and i used that for deciding which view i have to show for that question    public class MultiViewTypeAdapter extends RecyclerView Adapter        Context mContext      ArrayList lt Question gt  dataSet      ArrayList lt String gt  questions      private Object radiobuttontype1           Viewholder to display Questions with checkboxes     public static class Checkboxtype2 extends RecyclerView ViewHolder           ImageView imgclockcheck          CheckBox checkbox           public Checkboxtype2  NonNull View itemView                super itemView               imgclockcheck    ImageView  itemView findViewById R id clockout cbox image               checkbox    CheckBox  itemView findViewById R id clockout cbox                                Viewholder to display Questions with radiobuttons      public static class Radiobuttontype1 extends RecyclerView ViewHolder           ImageView clockout imageradiobutton          RadioButton clockout radiobutton          TextView sample           public radiobuttontype1 View itemView                super itemView               clockout imageradiobutton    ImageView  itemView findViewById R id clockout imageradiobutton               clockout radiobutton    RadioButton  itemView findViewById R id clockout radiobutton               sample    TextView  itemView findViewById R id sample                        public MultiViewTypeAdapter ArrayList lt QueDatum gt  data  Context context            this dataSet   data          this mContext   context               NonNull      Override     public RecyclerView ViewHolder onCreateViewHolder  NonNull ViewGroup viewGroup  int viewType             if  viewType equalsIgnoreCase  1                  View view   LayoutInflater from viewGroup getContext    inflate R layout clockout radio list row  viewGroup  false               return new radiobuttontype1 view              else if  viewType equalsIgnoreCase  2                  View view   LayoutInflater from viewGroup getContext    inflate R layout clockout cbox list row  viewGroup  false               view setHorizontalFadingEdgeEnabled true               return new Checkboxtype2 view              else if  viewType equalsIgnoreCase  3                  View view   LayoutInflater from viewGroup getContext    inflate R layout clockout radio list row  viewGroup  false               return new Radiobuttontype1 view              else if  viewType equalsIgnoreCase  4                  View view   LayoutInflater from viewGroup getContext    inflate R layout clockout radio list row  viewGroup  false               return new Radiobuttontype1 view              else if  viewType equalsIgnoreCase  5                  View view   LayoutInflater from viewGroup getContext    inflate R layout clockout radio list row  viewGroup  false               return new Radiobuttontype1 view                       return null              Override     public void onBindViewHolder  NonNull RecyclerView ViewHolder viewHolder  int viewType            if  viewType equalsIgnoreCase  1                  options    dataSet get i  getOptions                question   dataSet get i  getQuestion                image   options get i  getValue                  radiobuttontype1  viewHolder  clockout radiobutton setChecked false                 radiobuttontype1  viewHolder  sample setText question                 loading image bitmap in the ViewHolder s View             Picasso with mContext                       load image                       into   radiobuttontype1  viewHolder  clockout imageradiobutton              else if  viewType equalsIgnoreCase  2                  options    ArrayList lt Clockout questions Option gt   dataSet get i  getOptions                question   dataSet get i  getQuestion                image   options get i  getValue                  loading image bitmap in the ViewHolder s View             Picasso with mContext                       load image                       into   Checkboxtype2  viewHolder  imgclockcheck              else if  viewType equalsIgnoreCase  3                        fit data to viewHolder for ViewType 3           else if  viewType equalsIgnoreCase  4        fit data to viewHolder for ViewType 4              else if  viewType equalsIgnoreCase  5        fit data to viewHolder for ViewType 5                            Override     public int getItemCount             return dataSet size                          returns viewType for that position by picking the viewType value from the             dataset              Override     public int getItemViewType int position            return dataSet get position  getViewType                 You can avoid multiple conditional based viewHolder data fillings in onBindViewHolder   by assigning same ids for the similar views across viewHolders which differ in their positioning

User · Answer

Here is a complete sample to show RecyclerView with 2 types, the view type decide by the object

Class model

open class RecyclerViewItem
class SectionItem(val title: String) : RecyclerViewItem()
class ContentItem(val name: String, val number: Int) : RecyclerViewItem()

Adapter code

const val VIEW_TYPE_SECTION = 1
const val VIEW_TYPE_ITEM = 2

class UserAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {

    var data = listOf<RecyclerViewItem>()

    override fun getItemViewType(position: Int): Int {
        if (data[position] is SectionItem) {
            return VIEW_TYPE_SECTION
        }
        return VIEW_TYPE_ITEM
    }

    override fun getItemCount(): Int {
        return data.size
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        if (viewType == VIEW_TYPE_SECTION) {
            return SectionViewHolder(
                LayoutInflater.from(parent.context).inflate(R.layout.item_user_section, parent, false)
            )
        }
        return ContentViewHolder(
            LayoutInflater.from(parent.context).inflate(R.layout.item_user_content, parent, false)
        )
    }

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        val item = data[position]
        if (holder is SectionViewHolder && item is SectionItem) {
            holder.bind(item)
        }
        if (holder is ContentViewHolder && item is ContentItem) {
            holder.bind(item)
        }
    }

    internal inner class SectionViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(item: SectionItem) {
            itemView.text_section.text = item.title
        }
    }

    internal inner class ContentViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(item: ContentItem) {
            itemView.text_name.text = item.name
            itemView.text_number.text = item.number.toString()
        }
    }
}

item_user_section.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/text_section"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#eee"
    android:padding="16dp" />

item_user_content.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="32dp">

    <TextView
        android:id="@+id/text_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        tools:text="Name" />

    <TextView
        android:id="@+id/text_number"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

Example using

val dataSet = arrayListOf<RecyclerViewItem>(
    SectionItem("A1"),
    ContentItem("11", 11),
    ContentItem("12", 12),
    ContentItem("13", 13),

    SectionItem("A2"),
    ContentItem("21", 21),
    ContentItem("22", 22),

    SectionItem("A3"),
    ContentItem("31", 31),
    ContentItem("32", 32),
    ContentItem("33", 33),
    ContentItem("33", 34),
)

recyclerAdapter.data = dataSet
recyclerAdapter.notifyDataSetChanged()

User · Answer

I recommend this library from Hannes Dorfmann  It encapsulates all the logic related to particular view type in a separate object called  AdapterDelegate   https   github com sockeqwe AdapterDelegates   public class CatAdapterDelegate extends AdapterDelegate lt List lt Animal gt  gt       private LayoutInflater inflater     public CatAdapterDelegate Activity activity        inflater   activity getLayoutInflater            Override public boolean isForViewType  NonNull List lt Animal gt  items  int position        return items get position  instanceof Cat          NonNull  Override public RecyclerView ViewHolder onCreateViewHolder ViewGroup parent        return new CatViewHolder inflater inflate R layout item cat  parent  false            Override public void onBindViewHolder  NonNull List lt Animal gt  items  int position         NonNull RecyclerView ViewHolder holder   Nullable List lt Object gt  payloads         CatViewHolder vh    CatViewHolder  holder      Cat cat    Cat  items get position        vh name setText cat getName            static class CatViewHolder extends RecyclerView ViewHolder        public TextView name       public CatViewHolder View itemView          super itemView         name    TextView  itemView findViewById R id name                public class AnimalAdapter extends ListDelegationAdapter lt List lt Animal gt  gt       public AnimalAdapter Activity activity  List lt Animal gt  items            DelegatesManager is a protected Field in ListDelegationAdapter     delegatesManager addDelegate new CatAdapterDelegate activity                        addDelegate new DogAdapterDelegate activity                        addDelegate new GeckoAdapterDelegate activity                        addDelegate 23  new SnakeAdapterDelegate activity            Set the items from super class      setItems items

User · Answer

I have a better solution which allows to create multiple view types in a declarative and type safe way. It’s written in Kotlin which btw is really nice.

Simple view holders for all required view types

class ViewHolderMedium(itemView: View) : RecyclerView.ViewHolder(itemView) {
    val icon: ImageView = itemView.findViewById(R.id.icon) as ImageView
    val label: TextView = itemView.findViewById(R.id.label) as TextView
}

There is an abstraction of adapter data item. Note that a view type is represented by a hashCode of particular view holder class (KClass in Kotlin)

trait AdapterItem {
   val viewType: Int
   fun bindViewHolder(viewHolder: RecyclerView.ViewHolder)
}

abstract class AdapterItemBase<T>(val viewHolderClass: KClass<T>) : AdapterItem {
   override val viewType: Int = viewHolderClass.hashCode()  
   abstract fun bindViewHolder(viewHolder: T)
   override fun bindViewHolder(viewHolder: RecyclerView.ViewHolder) {
       bindViewHolder(viewHolder as T)
   }
}

Only bindViewHolder needs to be overriden in concrete adapter item classes (type safe way)

class AdapterItemMedium(val icon: Drawable, val label: String, val onClick: () -> Unit) : AdapterItemBase<ViewHolderMedium>(ViewHolderMedium::class) {
    override fun bindViewHolder(viewHolder: ViewHolderMedium) {
        viewHolder.icon.setImageDrawable(icon)
        viewHolder.label.setText(label)
        viewHolder.itemView.setOnClickListener { onClick() }
    }
}

List of such AdapterItemMedium objects is a data source for the adapter which actually accepts List<AdapterItem> see below.

Important part of this solution is a view holder factory which will provide fresh instances of a specific ViewHolder

class ViewHolderProvider {
    private val viewHolderFactories = hashMapOf<Int, Pair<Int, Any>>()

    fun provideViewHolder(viewGroup: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        val (layoutId: Int, f: Any) = viewHolderFactories.get(viewType)
        val viewHolderFactory = f as (View) -> RecyclerView.ViewHolder
        val view = LayoutInflater.from(viewGroup.getContext()).inflate(layoutId, viewGroup, false)
        return viewHolderFactory(view)
    }

    fun registerViewHolderFactory<T>(key: KClass<T>, layoutId: Int, viewHolderFactory: (View) -> T) {
        viewHolderFactories.put(key.hashCode(), Pair(layoutId, viewHolderFactory))
    }
}

And the simple adapter class looks like this

public class MultitypeAdapter(val items: List<AdapterItem>) : RecyclerView.Adapter<RecyclerView.ViewHolder>() {

   val viewHolderProvider = ViewHolderProvider() // inject ex Dagger2

   init {
        viewHolderProvider!!.registerViewHolderFactory(ViewHolderMedium::class, R.layout.item_medium, { itemView ->
            ViewHolderMedium(itemView)
        })
   }

   override fun getItemViewType(position: Int): Int {
        return items[position].viewType
    }

    override fun getItemCount(): Int {
        return items.size()
    }

    override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): RecyclerView.ViewHolder? {
        return viewHolderProvider!!.provideViewHolder(viewGroup, viewType)
    }

    override fun onBindViewHolder(viewHolder: RecyclerView.ViewHolder, position: Int) {
        items[position].bindViewHolder(viewHolder)     
    }
}

Only 3 steps to create a new view type:

create a view holder class
create an adapter item class (extending from AdapterItemBase)
register view holder class in ViewHolderProvider

Here is an example of this concept : android-drawer-template It goes even further - view type which act as a spinner component, selectable adapter items.

User · Answer

It is very simple and straight forward   Just Override getItemViewType   method in your adapter  On the basis of data return different itemViewType values  e g Consider an object of type Person with a member isMale  if isMale is true  return 1 and isMale is false  return 2 in getItemViewType   method   Now comes to the createViewHolder  ViewGroup parent  int viewType   on the basis of different viewType yon can inflate the different layout file  like the following   if  viewType   1       View view   LayoutInflater from parent getContext    inflate R layout male parent false       return new AdapterMaleViewHolder view     else      View view   LayoutInflater from parent getContext    inflate R layout female parent false       return new AdapterFemaleViewHolder view       in onBindViewHolder  VH holder int position  check where holder is instance of AdapterFemaleViewHolder or AdapterMaleViewHolder by instanceof and accordingly assign the values   ViewHolder May be like this      class AdapterMaleViewHolder extends RecyclerView ViewHolder                               public AdapterMaleViewHolder View itemView                                                class AdapterFemaleViewHolder extends RecyclerView ViewHolder                         public AdapterFemaleViewHolder View itemView

User · Answer

Although the selected answer is correct  I just want to further elaborate it  I found here a useful Custom Adapter for multiple View Types in RecyclerView  Its Kotlin version is here   Custom Adapter is following  public class CustomAdapter extends RecyclerView Adapter lt RecyclerView ViewHolder gt    private final Context context  ArrayList lt String gt  list     ArrayList of your Data Model final int VIEW TYPE ONE   1  final int VIEW TYPE TWO   2   public CustomAdapter Context context  ArrayList lt String gt  list       you can pass other parameters in constructor     this context   context      this list   list     private class ViewHolder1 extends RecyclerView ViewHolder        TextView yourView      ViewHolder1 final View itemView            super itemView           yourView   itemView findViewById R id yourView      Initialize your All views prensent in list items           void bind int position               This method will be called anytime a list item is created or update its data           Do your stuff here         yourView setText list get position             private class ViewHolder2 extends RecyclerView ViewHolder        TextView yourView      ViewHolder2 final View itemView            super itemView           yourView   itemView findViewById R id yourView      Initialize your All views prensent in list items           void bind int position               This method will be called anytime a list item is created or update its data           Do your stuff here         yourView setText list get position              Override public RecyclerView ViewHolder onCreateViewHolder ViewGroup parent  int viewType       if  viewType    VIEW TYPE ONE           return new ViewHolder1 LayoutInflater from context  inflate R layout your list item 1  parent  false              if its not VIEW TYPE ONE then its VIEW TYPE TWO    return new ViewHolder2 LayoutInflater from context  inflate R layout your list item 2  parent  false         Override public void onBindViewHolder RecyclerView ViewHolder holder  int position        if  list get position  type    Something       put your condition  according to your requirements           ViewHolder1  holder  bind position         else             ViewHolder2  holder  bind position              Override public int getItemCount         return list size        Override public int getItemViewType int position           here you can get decide from your model s ArrayList  which type of view you need to load  Like     if  list get position  type    Something       put your condition  according to your requirements         return VIEW TYPE ONE            return VIEW TYPE TWO

User · Answer

I did something like this  I passed  quot fragmentType quot  and created two ViewHolders and on basis of this  i classified my Layouts accordingly in a single adapter that can have different Layouts and LayoutManagers private Context mContext  protected IOnLoyaltyCardCategoriesItemClicked mListener  private String fragmentType  private View view   public LoyaltyCardsCategoriesRecyclerViewAdapter Context context  IOnLoyaltyCardCategoriesItemClicked itemListener  String fragmentType        this mContext   context      this mListener   itemListener      this fragmentType   fragmentType     public class LoyaltyCardCategoriesFragmentViewHolder extends RecyclerView ViewHolder implements View OnClickListener        private ImageView lc categories iv      private TextView lc categories name tv      private int pos       public LoyaltyCardCategoriesFragmentViewHolder View v            super v           view setOnClickListener this           lc categories iv    ImageView  v findViewById R id lc categories iv           lc categories name tv    TextView  v findViewById R id lc categories name tv               public void setData int pos            this pos   pos          lc categories iv setImageResource R mipmap ic launcher           lc categories name tv setText  quot Loyalty Card Categories quot                Override     public void onClick View view            if  mListener    null                mListener onLoyaltyCardCategoriesItemClicked pos                      public class MyLoyaltyCardsFragmentTagViewHolder extends RecyclerView ViewHolder implements View OnClickListener        public ImageButton lc categories btn      private int pos       public MyLoyaltyCardsFragmentTagViewHolder View v            super v           lc categories btn    ImageButton  v findViewById R id lc categories btn           lc categories btn setOnClickListener this              public void setData int pos            this pos   pos          lc categories btn setImageResource R mipmap ic launcher               Override     public void onClick View view            if  mListener    null                mListener onLoyaltyCardCategoriesItemClicked pos                       NonNull  Override public RecyclerView ViewHolder onCreateViewHolder ViewGroup parent  int viewType        if  fragmentType equalsIgnoreCase Constants LoyaltyCardCategoriesFragmentTag             view   LayoutInflater from mContext  inflate R layout loyalty cards categories frag item  parent  false           return new LoyaltyCardCategoriesFragmentViewHolder view         else if  fragmentType equalsIgnoreCase Constants MyLoyaltyCardsFragmentTag             view   LayoutInflater from mContext  inflate R layout my loyalty cards categories frag item  parent  false           return new MyLoyaltyCardsFragmentTagViewHolder view         else           return null            Override public void onBindViewHolder  NonNull RecyclerView ViewHolder holder  int position        if  fragmentType equalsIgnoreCase Constants LoyaltyCardCategoriesFragmentTag               LoyaltyCardCategoriesFragmentViewHolder  holder  setData position         else if  fragmentType equalsIgnoreCase Constants MyLoyaltyCardsFragmentTag               MyLoyaltyCardsFragmentTagViewHolder  holder  setData position              Override public int getItemCount         return 7

User · Answer

Create different ViewHolder for different layout

RecyclerView can have any number of viewholders you want but for better readability lets see how to create one with two ViewHolders.

It can be done in three simple steps

Override public int getItemViewType(int position)
Return different ViewHolders based on the ViewType in onCreateViewHolder() method
Populate View based on the itemViewType in onBindViewHolder() method

Here is a small code snippet

public class YourListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

   private static final int LAYOUT_ONE= 0;
   private static final int LAYOUT_TWO= 1;

   @Override
   public int getItemViewType(int position)
   {
      if(position==0)
        return LAYOUT_ONE;
      else
        return LAYOUT_TWO;
   }

   @Override
   public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

      View view =null;
      RecyclerView.ViewHolder viewHolder = null;

      if(viewType==LAYOUT_ONE)
      {
          view = LayoutInflater.from(parent.getContext()).inflate(R.layout.one,parent,false);
          viewHolder = new ViewHolderOne(view);
      }
      else
      {
          view = LayoutInflater.from(parent.getContext()).inflate(R.layout.two,parent,false);
          viewHolder= new ViewHolderTwo(view);
      }

      return viewHolder;
   }

   @Override
   public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {

      if(holder.getItemViewType()== LAYOUT_ONE)
      {
            // Typecast Viewholder 
            // Set Viewholder properties 
            // Add any click listener if any 
      }
      else {

        ViewHolderOne vaultItemHolder = (ViewHolderOne) holder;
        vaultItemHolder.name.setText(displayText);
        vaultItemHolder.name.setOnClickListener(new View.OnClickListener() {
           @Override
           public void onClick(View v) {
            .......
           }
         });

       }

   }

  //****************  VIEW HOLDER 1 ******************//

   public class ViewHolderOne extends RecyclerView.ViewHolder {

      public TextView name;

      public ViewHolderOne(View itemView) {
         super(itemView);
         name = (TextView)itemView.findViewById(R.id.displayName);
     }
   }


   //****************  VIEW HOLDER 2 ******************//

   public class ViewHolderTwo extends RecyclerView.ViewHolder{

      public ViewHolderTwo(View itemView) {
         super(itemView);

        ..... Do something
      }
   }
}

getItemViewType(int position) is the key

In my opinion,the starting point to create this kind of recyclerView is the knowledge of this method. Since this method is optional to override therefore it is not visible in RecylerView class by default which in turn makes many developers(including me) wonder where to begin. Once you know that this method exists, creating such RecyclerView would be a cakewalk.

Lets see one example to prove my point. If you want to show two layout at alternate positions do this

@Override
public int getItemViewType(int position)
{
   if(position%2==0)       // Even position 
     return LAYOUT_ONE;
   else                   // Odd position 
     return LAYOUT_TWO;
}

Relevant Links:

Check out the project where I have implemented this

User · Answer

if anyone is interested to see the super simple solution written in Kotlin, check the blogpost I just created. The example in the blogpost is based on creating Sectioned RecyclerView:

https://brona.blog/2020/06/sectioned-recyclerview-in-three-steps/

User · Answer

I firstly recommend you to read Hannes Dorfmann's great article about this topic.

When new view type comes, you have to edit your adapter and you have to handle so many mess things. Your adapter should be Open for extension but Closed for modification.

You may check this two project, they can give the idea about how to handle different ViewTypes in Adapter:

[java] How to create RecyclerView with multiple view type?

The answer is

ConcatAdapter

Create different ViewHolder for different layout

getItemViewType(int position) is the key

Relevant Links:

Examples related to java

Examples related to android

Examples related to user-interface

Examples related to android-recyclerview

Tags