Expandable recyclerview adapter with different layouts

Question

I am trying to make an expandable RecyclerView adapter that will have different layouts for the parent and the child view. I have never done an expanable RecyclerView adapter before, so I don't know if this is even possible. Here is my code:

public class GroupsAdapter extends ExpandableRecyclerViewAdapter<GroupsAdapter.ParentVehicleViewHolder, GroupsAdapter.ChildItemViewHolder> {

    //region final Fields
    private final GroupsClickListener mOnItemClickListener;
    private final Repository mRepository;
    private boolean mIsClicked;
    private int mFilterField;
    private int mFilterType;
    private int viewType;
    //endregion

    //region Fields
    private List<ParentVehicle> mGroups = new ArrayList<>();
    //endregion

    //region Constructors
    public GroupsAdapter(List<ParentVehicle> groups, Repository repository,
                         GroupsClickListener listener, boolean isClicked, int Layout) {
        super(groups);
        this.mOnItemClickListener = listener;
        this.mRepository = repository;
        this.mGroups = groups;
        this.mIsClicked = isClicked;
        this.viewType = Layout;
    }
    //endregion


    @Override
    public int getItemViewType(int position) {
        if (position == 0){
            viewType = 0;
        }else {
            viewType=1;
        }
        return viewType;
    }

    public int getViewTypeCount() {
        return 2;
    }


    public void setData(List<ParentVehicle> groups, boolean isClicked) {
        mGroups.clear();
        mGroups.addAll(groups);
        mIsClicked = isClicked;
        notifyDataSetChanged();
    }

    public void setGroup(ParentVehicle group) {
        mGroups.clear();
        mGroups.add(group);
        notifyDataSetChanged();
    }

    public void sortByName() {
        if (mFilterField == Constants.FIELD_NAME) {
            if (mFilterType == Constants.DECREASING) {
                mFilterType = Constants.INCREASING;
                Collections.sort(mGroups, new ParentVehicle.NameComparator());
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.NameComparator());
                }
            } else {
                mFilterType = Constants.DECREASING;
                Collections.sort(mGroups, Collections.reverseOrder(new ParentVehicle.NameComparator()));
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), Collections.reverseOrder(new Vehicle.NameComparator()));
                }
            }
        } else {
            mFilterType = Constants.INCREASING;
            mFilterField = Constants.FIELD_NAME;
            Collections.sort(mGroups, new ParentVehicle.NameComparator());
            if (mIsClicked) {
                Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.NameComparator());
            }
        }
        notifyDataSetChanged();
    }

    public void sortByNumber() {
        if (mFilterField == Constants.FIELD_ID) {
            if (mFilterType == Constants.DECREASING) {
                mFilterType = Constants.INCREASING;
                Collections.sort(mGroups, new ParentVehicle.IdComparator());
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.IdComparator());
                }
            } else {
                mFilterType = Constants.DECREASING;
                Collections.sort(mGroups, Collections.reverseOrder(new ParentVehicle.IdComparator()));
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), Collections.reverseOrder(new Vehicle.IdComparator()));
                }
            }
        } else {
            mFilterType = Constants.INCREASING;
            mFilterField = Constants.FIELD_ID;
            Collections.sort(mGroups, new ParentVehicle.IdComparator());
            if (mIsClicked) {
                Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.IdComparator());
            }
        }
        notifyDataSetChanged();
    }


    public void sortByDays() {
        if (mFilterField == Constants.FIELD_DAYS) {
            if (mFilterType == Constants.DECREASING) {
                mFilterType = Constants.INCREASING;
                Collections.sort(mGroups, new ParentVehicle.DaysComparator());
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.DaysComparator());
                }
            } else {
                mFilterType = Constants.DECREASING;
                Collections.sort(mGroups, Collections.reverseOrder(new ParentVehicle.DaysComparator()));
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), Collections.reverseOrder(new Vehicle.DaysComparator()));
                }
            }
        } else {
            mFilterType = Constants.INCREASING;
            mFilterField = Constants.FIELD_DAYS;
            Collections.sort(mGroups, new ParentVehicle.DaysComparator());
            if (mIsClicked) {
                Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.DaysComparator());
            }
        }
        notifyDataSetChanged();
    }

    public void sortByGeo() {
        if (mFilterField == Constants.FIELD_GEO) {
            if (mFilterType == Constants.DECREASING) {
                mFilterType = Constants.INCREASING;
                Collections.sort(mGroups, new ParentVehicle.GeoComparator());
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.GeoComparator());
                }
            } else {
                mFilterType = Constants.DECREASING;
                Collections.sort(mGroups, Collections.reverseOrder(new ParentVehicle.GeoComparator()));
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), Collections.reverseOrder(new Vehicle.GeoComparator()));
                }
            }
        } else {
            mFilterType = Constants.INCREASING;
            mFilterField = Constants.FIELD_GEO;
            Collections.sort(mGroups, new ParentVehicle.GeoComparator());
            if (mIsClicked) {
                Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.GeoComparator());
            }
        }
        notifyDataSetChanged();
    }

    public void sortByWarning() {
        if (mFilterField == Constants.FIELD_WARNING) {
            if (mFilterType == Constants.DECREASING) {
                mFilterType = Constants.INCREASING;
                Collections.sort(mGroups, new ParentVehicle.WarningComparator());
                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.WarningComparator());
                }
            } else {
                mFilterType = Constants.DECREASING;
                Collections.sort(mGroups, Collections.reverseOrder(new ParentVehicle.WarningComparator()));

                if (mIsClicked) {
                    Collections.sort(mGroups.get(0).getVehicles(), Collections.reverseOrder(new Vehicle.WarningComparator()));
                }
            }
        } else {
            mFilterType = Constants.INCREASING;
            mFilterField = Constants.FIELD_WARNING;
            Collections.sort(mGroups, new ParentVehicle.WarningComparator());

            if (mIsClicked) {
                Collections.sort(mGroups.get(0).getVehicles(), new Vehicle.WarningComparator());
            }
        }
        notifyDataSetChanged();
    }


    void filter(String text) {
        List<Group> temp = new ArrayList();
        for (Group group : getAllGroups()) {
            if (group.getName().toLowerCase().contains(text)) {
                temp.add(group);
            }
        }
        if (TextUtils.isEmpty(text)) {
            temp = getAllGroups();
        }
        //update recyclerview
        //setData(temp);
    }

    private List<Group> getAllGroups() {
        final List<Group> tempGroupList = new ArrayList<>();
        if (!mRepository.getCompanies().isEmpty()) {
            for (Company company : mRepository.getCompanies()) {
                tempGroupList.addAll(Arrays.asList(company.getGroups()));
            }
        }
        return tempGroupList;
    }

    //region expandableAdapterMethods
    @Override
    public ParentVehicleViewHolder onCreateGroupViewHolder(ViewGroup parent, int viewType) {
         View view;
       if (viewType==0){
              view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_table, parent, false);
            return new ParentVehicleViewHolder(view,viewType);
        } else if (viewType==1) {
           view = LayoutInflater.from(parent.getContext()).inflate(R.layout.delete_row, parent, false);
           return new ParentVehicleViewHolder(view,viewType);
       } return null;
    }

    @Override
    public ChildItemViewHolder onCreateChildViewHolder(ViewGroup child, int viewType) {
        View view;
        if (viewType == 0) {
            view = LayoutInflater.from(child.getContext()).inflate(R.layout.item_table, child, false);
            return new ChildItemViewHolder(view, viewType);
        } else if (viewType == 1) {
            view = LayoutInflater.from(child.getContext()).inflate(R.layout.delete_row, child, false);
            return new ChildItemViewHolder(view, viewType);
        }return null;
    }

    @Override
    public void onBindChildViewHolder(ChildItemViewHolder holder, int position, ExpandableGroup group, int childIndex) {
       int viewType = getItemViewType(position);
        if (viewType==0){
            final Vehicle vehicle = ((ParentVehicle) group).getItems().get(childIndex);
            holder.bind(vehicle, mOnItemClickListener);
        } else if (viewType==1){
            final Vehicle vehicle = ((ParentVehicle) group).getItems().get(childIndex);
            holder.bind2(vehicle, mOnItemClickListener);
        }
    }

    @Override
    public void onBindGroupViewHolder(ParentVehicleViewHolder holder, int position, ExpandableGroup group) {
       int viewType = getItemViewType(position);
        if (viewType==0){
            holder.bind(((ParentVehicle) group), mOnItemClickListener, mIsClicked);
        } else if (viewType==1){
            holder.bind2(((ParentVehicle) group), mIsClicked);
        }

    }
    //endregion

    static class ParentVehicleViewHolder extends GroupViewHolder {
        TextView novText;
        ImageView strelka;
        TextView day7;
        TextView day6;
        TextView day5;
        TextView day4;
        TextView day3;
        TextView day2;
        TextView day1;
        TextView mId;
        TextView mNumber;
        ImageView mBattery;
        ImageView mGsimbol;
        ImageView mWarning;
        ImageView mGroupArrow;
        private View mView;

        public ParentVehicleViewHolder(View itemView, int viewType) {
            super(itemView);
            this.mView = itemView;
            ButterKnife.bind(this, itemView);
            if (viewType == 0) {
                day7 = itemView.findViewById(R.id.number_7);
                day6 = itemView.findViewById(R.id.number_6);
                day5=itemView.findViewById(R.id.number_5);
                day4=itemView.findViewById(R.id.number_4);
                day3=itemView.findViewById(R.id.number_3);
                day2=itemView.findViewById(R.id.number_2);
                day1=itemView.findViewById(R.id.number_1);
                mId=itemView.findViewById(R.id.item_unit_id);
                mNumber=itemView.findViewById(R.id.item_number);
                mBattery=itemView.findViewById(R.id.item_battery);
                mGsimbol=itemView.findViewById(R.id.item_gsimbol);
                mWarning=itemView.findViewById(R.id.icon_warning);
                mGroupArrow=itemView.findViewById(R.id.group_arrow);


            } else if (viewType==1){
                novText=itemView.findViewById(R.id.item_numberEden);
                strelka=itemView.findViewById(R.id.group_arrowEden);
            }
        }

        public void bind(ParentVehicle parentVehicle, GroupsClickListener groupsClickListener, boolean showArrow) {
            mNumber.setText(parentVehicle.getId());
            mId.setText(parentVehicle.getName());
            mId.setTextColor(mView.getContext().getResources().getColor(R.color.light_blue));

            mView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (parentVehicle.isCompany()) {
                        groupsClickListener.onCompanyItemClick(parentVehicle.getId());
                    } else {
                        groupsClickListener.onGroupItemClick(parentVehicle.getId());
                    }
                }
            });

            mGroupArrow.setVisibility(showArrow ? View.VISIBLE : View.GONE);

            if (parentVehicle.getVehicles() != null && !parentVehicle.getVehicles().isEmpty()) {
                if (isGeo(parentVehicle.getVehicles())) {
                    mGsimbol.setVisibility(View.INVISIBLE);
                } else {
                    mGsimbol.setVisibility(View.VISIBLE);
                }

                if (isWarning(parentVehicle.getVehicles())) {
                    mWarning.setVisibility(View.VISIBLE);
                } else {
                    mWarning.setVisibility(View.INVISIBLE);
                }
            }
            day1.setBackgroundResource(isActiveDay(parentVehicle.getVehicles(), 0) ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day2.setBackgroundResource(isActiveDay(parentVehicle.getVehicles(), 1) ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day3.setBackgroundResource(isActiveDay(parentVehicle.getVehicles(), 2) ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day4.setBackgroundResource(isActiveDay(parentVehicle.getVehicles(), 3) ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day5.setBackgroundResource(isActiveDay(parentVehicle.getVehicles(), 4) ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day6.setBackgroundResource(isActiveDay(parentVehicle.getVehicles(), 5) ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day7.setBackgroundResource(isActiveDay(parentVehicle.getVehicles(), 6) ? R.drawable.green_rectangle : R.drawable.red_rectangle);
        }

        private boolean isGeo(List<Vehicle> vehicles) {
            if (vehicles == null || vehicles.isEmpty()) {
                return true;
            }
            for (Vehicle vehicle : vehicles) {
                if (!vehicle.hasGeofenceAlarm()) {
                    return false;
                }
            }
            return true;
        }

        private boolean isWarning(List<Vehicle> vehicles) {
            if (vehicles == null || vehicles.isEmpty()) {
                return false;
            }
            for (Vehicle vehicle : vehicles) {
                if (vehicle.isWarning()) {
                    return true;
                }
            }
            return false;
        }

        private boolean isActiveDay(List<Vehicle> vehicles, int day) {
            if (vehicles == null || vehicles.isEmpty()) {
                return true;
            }
            for (Vehicle vehicle : vehicles) {
                if (vehicle.getDays() == null || vehicle.getDays().length == 0 || !vehicle.getDays()[day]) {
                    return false;
                }
            }
            return true;
        }

        public void bind2(ParentVehicle parentVehicle,  boolean showArrow) {
            novText.setText(parentVehicle.getName());
            strelka.setVisibility(showArrow ? View.VISIBLE : View.GONE);
        }
    }


    static class ChildItemViewHolder extends ChildViewHolder {

        TextView novText2;
        TextView day7;
        TextView day6;
        TextView day5;
        TextView day4;
        TextView day3;
        TextView day2;
        TextView day1;
        TextView mId;
        ImageView mBattery;
        ImageView mGsimbol;
        ImageView mWarning;
        private View mView;

        public ChildItemViewHolder(View itemView, int viewType) {
            super(itemView);
            this.mView = itemView;
            ButterKnife.bind(this, itemView);
            if (viewType==0){
                day7 = itemView.findViewById(R.id.number_7);
                day6 = itemView.findViewById(R.id.number_6);
                day5=itemView.findViewById(R.id.number_5);
                day4=itemView.findViewById(R.id.number_4);
                day3=itemView.findViewById(R.id.number_3);
                day2=itemView.findViewById(R.id.number_2);
                day1=itemView.findViewById(R.id.number_1);
                mId=itemView.findViewById(R.id.item_unit_id);
               mBattery=itemView.findViewById(R.id.item_battery);
                mGsimbol=itemView.findViewById(R.id.item_gsimbol);
                mWarning=itemView.findViewById(R.id.icon_warning);
            } else if (viewType==1){
                novText2=itemView.findViewById(R.id.item_numberEden);
            }



        }

        public void bind(Vehicle vehicle, GroupsClickListener onItemClickListener) {
            mId.setText(vehicle.getName());

            if (vehicle.hasGeofenceAlarm()) {
                mGsimbol.setVisibility(View.INVISIBLE);
            } else {
                mGsimbol.setVisibility(View.VISIBLE);
            }

            if (vehicle.isWarning()) {
                mWarning.setVisibility(View.VISIBLE);
            } else {
                mWarning.setVisibility(View.INVISIBLE);
            }

            mView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    onItemClickListener.onGroupChildItemClick(vehicle.getId());
                }
            });

            day1.setBackgroundResource(vehicle.getDays()[0] ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day2.setBackgroundResource(vehicle.getDays()[1] ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day3.setBackgroundResource(vehicle.getDays()[2] ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day4.setBackgroundResource(vehicle.getDays()[3] ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day5.setBackgroundResource(vehicle.getDays()[4] ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day6.setBackgroundResource(vehicle.getDays()[5] ? R.drawable.green_rectangle : R.drawable.red_rectangle);
            day7.setBackgroundResource(vehicle.getDays()[6] ? R.drawable.green_rectangle : R.drawable.red_rectangle);
        }
        public void bind2(Vehicle vehicle, GroupsClickListener onItemClickListener) {
            novText2.setText(vehicle.getName());}
    }
}

and I am getting this error:

java.lang.IllegalArgumentException: viewType is not valid at com.thoughtbot.expandablerecyclerview.ExpandableRecyclerViewAdapter.onCreateViewHolder(ExpandableRecyclerViewAdapter.java:57) at android.support.v7.widget.RecyclerView$Adapter.createViewHolder(RecyclerView.java:6493) at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5680) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5563) at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5559) at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2229) at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1556) at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1516) at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:608) at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3693) at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:3109) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1486) at android.widget.LinearLayout.measureVertical(LinearLayout.java:765) at android.widget.LinearLayout.onMeasure(LinearLayout.java:647) at android.view.View.measure(View.java:18930) at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:1109) at android.widget.LinearLayout.onMeasure(LinearLayout.java:649) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1486) at android.widget.LinearLayout.measureVertical(LinearLayout.java:765) at android.widget.LinearLayout.onMeasure(LinearLayout.java:647) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1486) at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:1129) at android.widget.LinearLayout.onMeasure(LinearLayout.java:649) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1486) at android.widget.LinearLayout.measureVertical(LinearLayout.java:765) at android.widget.LinearLayout.onMeasure(LinearLayout.java:647) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1486) at android.widget.LinearLayout.measureVertical(LinearLayout.java:765) at android.widget.LinearLayout.onMeasure(LinearLayout.java:647) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1486) at android.widget.LinearLayout.measureVertical(LinearLayout.java:765) at android.widget.LinearLayout.onMeasure(LinearLayout.java:647) at android.view.View.measure(View.java:18930) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5976) at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) at com.android.internal.poli

Blockquote

What am I doing wrong? Why am I getting viewType is not valid?

Answer 1

I tried using the same ExpandableRecyclerViewAdapter and I would like to point out on few things.

First of all in regards to your error, you are getting this because if you look into the onCreateViewHolder method of ExpandableRecyclerViewAdapter class, it is expecting either of the two - ExpandableListPosition.GROUP or ExpandableListPosition.CHILD with values 2 and 1 respectively.

Now the first mistake you did was you override getItemViewType with viewtype values to 0 and 1 where in 1 is already used in library so it is throwing you the illegal exception as per the library class, which is correct.

Now in order to get multiple child views as in my case,

First of all extend your adapter class with MultiTypeExpandableRecyclerViewAdapter and create 2 clases that extends ChildViewHolder and then if you see the class extension declaration it will now be as follows:

public class ScoreCardDataAdapter extends MultiTypeExpandableRecyclerViewAdapter<TeamScoreCardViewHolder, ChildViewHolder> {

Also, I used 2 variables for viewtype as TYPE_HEADER and TYPE_ITEM with values 3 and 4. you can use anything but make sure it is greater than 2.

and then override following methods:

  @Override
  public boolean isChild(int viewType) {
    return viewType == TYPE_HEADER || viewType == TYPE_ITEM;
  }

In this method I implemented a method to say the first position is the header and return TYPE_HEADER for that case.

 @Override
        public int getChildViewType(int position, ExpandableGroup group, int childIndex) {
            if(isPositionHeader(childIndex))
                return TYPE_HEADER;
            else
                return TYPE_ITEM;
        }

private boolean isPositionHeader(int position) {
    return position == 0;
}

then in your onCreateChildViewHolder,

you can check for view types and return the expected VIEWHOLDER.

and bind the viewholder too by calling the following method:

  @Override
  public void onBindChildViewHolder(ChildViewHolder holder, int flatPosition, ExpandableGroup group,
      int childIndex) {
    int viewType = getItemViewType(flatPosition);
//here based on the view type pass the appropriate data.
}

Kindly see below my complete adapter class implementation for your reference.

public class ScoreCardDataAdapter extends MultiTypeExpandableRecyclerViewAdapter<TeamScoreCardViewHolder, ChildViewHolder> {

private static final int TYPE_HEADER = 3;
private static final int TYPE_ITEM = 4;

public ScoreCardDataAdapter(Fragment fragment, List<? extends ExpandableGroup> groups) {
    super(groups);
}

@Override
public TeamScoreCardViewHolder onCreateGroupViewHolder(ViewGroup parent, int viewType) {
    final View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.team_score_card_parent_view_holder, parent, false);
    return new TeamScoreCardViewHolder(view);
}

@Override
public ChildViewHolder onCreateChildViewHolder(ViewGroup parent, final int viewType) {
    if(viewType == TYPE_ITEM) {
        final View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.team_score_card_data_child_view_holder, parent, false);
        return new ScoreCardDataViewHolder(view, TYPE_ITEM);
    } else if(viewType == TYPE_HEADER) {
        final View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.header_item, parent, false);
        return new ScoreCardHeaderViewHolder(view, TYPE_HEADER);
    }
    throw new RuntimeException("there is no type that matches the type " + viewType + " + make sure your using types correctly");
}

@Override
public void onBindChildViewHolder(ChildViewHolder holder, int flatPosition, ExpandableGroup group, int childIndex) {
    int viewType = getItemViewType(flatPosition);
    if(viewType == TYPE_HEADER) {
        //Currently I am passing string and binding it to ScoreCardHeaderViewHolder
        // but we can pass any data.
        ((ScoreCardHeaderViewHolder) holder).onBind("batsman");
    } else if(viewType == TYPE_ITEM) {
        //here I am getting my data from api passed to adapter and binding it to the ScoreCardDataViewHolder
        final BattingData battingData = ((BattingDataExpandable) group).getItems().get(childIndex);
        ((ScoreCardDataViewHolder) holder).onBind(battingData, group, childIndex);
    }
}

@Override
public void onBindGroupViewHolder(TeamScoreCardViewHolder holder, int flatPosition, ExpandableGroup group) {
    holder.setTeamName(group);
}

@Override
public boolean isChild(int viewType) {
    return viewType == TYPE_HEADER || viewType == TYPE_ITEM;
}

@Override
public int getChildViewType(int position, ExpandableGroup group, int childIndex) {
    if(isPositionHeader(position))
        return TYPE_HEADER;
    else
        return TYPE_ITEM;
}

private boolean isPositionHeader(int position) {
    return position == 0;
}
}