Ggtcf

I am trying to add headers to columns of RecyclerView list. All list items are not getting displayed when I add headers. Please find the relevant code below:

@Override
public int getItemCount() 

 return (myList == null)? 0 : myList.size();


@Override
public int getItemViewType(int position) 
 if (myList.get(position) == null) return -1;
 if (isPositionHeader(position))
 return ItemType.HEADER.getTypeCode();
 else
 return ItemType.ITEM.getTypeCode();


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

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

if (holder instanceof myListViewHolder) 
 ((myListViewHolder) 
holder).bindData(myList.get(position-1));

else if (holder instanceof myHeaderViewHolder)
 Log.d("RecyclerAdapter", "Setting Headers");

// Rest of the code


@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) 
 LayoutInflater inflater = LayoutInflater.from(parent.getContext());
 if (viewType == ItemType.ITEM.getTypeCode()) 
 return new 
myListViewHolder(inflater.inflate(R.layout.my_list_item, parent, false),
 callback);
 
 else if (viewType == ItemType.HEADER.getTypeCode()) 
 return new 
myHeaderViewHolder(inflater.inflate(R.layout.my_header_item, parent, false),
 callback);
 
 else 
 return new LoadViewHolder(inflater.inflate(R.layout.loading_view, 
parent, false));
 


protected Profile getItemByPosition(int position) 
 return myList.get(position);


@Override
public long getItemId(int position) 
 if (getItemByPosition(position) == null) return -1;
 return getItemByPosition(position).getId().hashCode();

With the above code, the headers are displayed at the zeroth position, next the list items are displayed leaving the last item i.e. if list has 5 elements, only 4 elements are getting displayed.
I have tried to return myList.size() +1 in getItemCount(), but this throws an IndexOutOfBounds exception.

Any help would be greatly appreciated.

Thanks

I've noticed you've not implemented createViewHolder as seen in https://developer.android.com/reference/android/support/v7/widget/RecyclerView.Adapter.html#createViewHolder(android.view.ViewGroup,%20int). That helps RecyclerView determine whether to use the header or list item view holder.

It would seem that the getItemCount method is implemented incorrectly - it needs to be the number of headers + number of items.

Then fix the method like this:

@Override
public int getItemViewType(int position) 
 if (isPositionHeader(position))
 return ItemType.HEADER.getTypeCode();
 else 
 if(myList.get(position - 1) == null)
 return -1;
 
 else 
 return ItemType.ITEM.getTypeCode();