Two ArrayList one RecyclerView Adapter

Question

I have a chat screen where i can chat with other user, i am sending chat data (message,time and sender via List) to RecyclerAdapter which populate chat views with data.Now i have one more List which has data with different layout. Like this

Here is my method from where i am calling second arraylist into RecyclerAdapter

public void TransferResultTo_Activity(List<Image_data_Wrapper> list) {
        Log.d(TAG,"Here is data Result From AsyncTask "+list.size());
        getResult=list;
        Image_data_Wrapper Image=getResult.get(0);
        Log.d(TAG,"Result from Image data "+Image.getPage_Title());
        adapter=new Chat_Adapter(this,message,getResult);
        adapter.notifyDataSetChanged();
    }

As in above method when i try to call adapter by recyclerView.setAdapter(adapter); it remove all messages from screen and shows my image data. but i want to keep all messages and show image with data via new list

Here is my Chat Adapter

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

    private String UserID;
    private Context context;
    //TAG FOR TRACKING SELF MESSAGE
    private int Self_Msg=0;
    //ARRAYLIST OF MESSAGES OBJECT CONTAINING ALL THE MESSAGES IN THE THREAD
    private List<Chat_Wrapper> arrayList_message;
    public static final String TAG="###CHAT_ADAPTER###";
    private List<Image_data_Wrapper> data_Result;
    boolean valtype;


    public Chat_Adapter(Context context, List<Chat_Wrapper> message) {
        //UserID = userID;
        this.context = context;
        this.arrayList_message = message;
        Log.d(TAG,"Chat Adapter Calling");
    }
    public Chat_Adapter(Context context, List<Image_data_Wrapper> result,boolean val) {
        this.context = context;
        this.data_Result = result;
        this.valtype=val;
        Log.d(TAG,"Image data Chat Adapter Calling");
    }

    public Chat_Adapter() {
    }


    @Override
    public Chat_Adapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView;
        Log.d(TAG,"On Create View Holder Calling ");
        if (viewType==Self_Msg){
            itemView= LayoutInflater.from(parent.getContext()).inflate(R.layout.chat_screen_message_item,parent,false);
            Log.d(TAG,"On Create View Holder Calling View Type is "+itemView);
        }

        else if (valtype==true){
            itemView= LayoutInflater.from(parent.getContext()).inflate(R.layout.Image_data_layout,parent,false);
            Log.d(TAG,"ON CREATE VIEW HOLDER RUNNING AND data RESULT VIEW TYPE IS RUNNING "+viewType);
        }

        else {
            itemView= LayoutInflater.from(parent.getContext()).inflate(R.layout.chat_screen_message_item,parent,false);
            Log.d(TAG,"On Create View Holder Calling View Type is "+itemView);
        }
        return new ViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(Chat_Adapter.ViewHolder holder, int position) {
        if (valtype==true){
            Image_data_Wrapper wrapper=data_Result.get(position);
            holder.data_title.setText(wrapper.getPage_Title());
            holder.data_link.setText(wrapper.getPage_Link());
            holder.data_snippet.setText(wrapper.getPage_Desc());
            Picasso.with(context).load(wrapper.getPage_ImageThumb()).into(holder.Image_Image);
            valtype=false;

        }
        else {

            Log.d(TAG,"On Bind VIew Holder Context "+context);
            Chat_Wrapper wrapper=arrayList_message.get(position);
            Log.d(TAG,"On Bind VIew Holder Chat Wrapper "+wrapper);
            holder.Message.setText(wrapper.getMessage());
            holder.TimeStamp.setText(wrapper.getTimestamp());

        }



    }

    @Override
    public int getItemCount() {
        Log.d(TAG,"Get Item Count Running");
        int items;
        if (valtype==true){
            Log.d(TAG,"data Result Array is not empty");
            items=data_Result.size();
            Log.d(TAG,"Total Number Of Item "+items);
            return items;
        }
        else {
            Log.d(TAG,"ARRAY SIZE AT GETITEM COUNT "+arrayList_message.size());
            return arrayList_message.size();
        }





    }


    @Override
    public int getItemViewType(int position) {
        Log.d(TAG,"Get Item View Type Running");
        return position;
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView Message,TimeStamp,data_title,data_link,data_snippet;
        ImageView User_image,Image_Image;
        ImageButton data_SendButton;


         public ViewHolder(View itemView) {
             super(itemView);
             Message= (TextView) itemView.findViewById(R.id.Single_Item_Chat_Message);
             TimeStamp= (TextView) itemView.findViewById(R.id.Single_Item_Chat_TimeStamp);
             User_image= (ImageView) itemView.findViewById(R.id.Single_Item_Chat_ImageView);

             if (valtype==true){
                 Log.d(TAG,"Setting View For Image data ");
                 data_title= (TextView) itemView.findViewById(R.id.Image_data_Title);
                 data_link= (TextView) itemView.findViewById(R.id.Image_data_Link);
                 data_snippet= (TextView) itemView.findViewById(R.id.Image_data_Snippet);

                 Image_Image= (ImageView) itemView.findViewById(R.id.Image_data_Image);
                 data_SendButton= (ImageButton) itemView.findViewById(R.id.Image_data_SendButton);
             }




        }
    }

    public void updateDataWithdataResult(List<Image_data_Wrapper> list,boolean setValue){
        Log.d(TAG,"Update Data Method Calling");
        this.data_Result=list;
        this.valtype=setValue;
    }
}

The issues i am facing with this code

• With notifiydatasetchanged only Adapter constructor is calling(Correct one) but never getItemCount()
• Is sending boolean value with data is right way to check, If calls from ImageArrayList only then enter in its related data or views?
• What is the best way to get both List into single RecyclerView with their own layout

UPDATE : When i call adapter by recyclerView.setAdapter(adapter) it worked as i want but adapter.notifyDataSetChanged make call stuck at adapter constructor (Thanks to DanielLaneDC). So can i leave it like that or adapter.notifyDataSetChanged should work?

Answer 1

It sounds like you want to show two different lists of items in the same RecyclerView using the same RecyclerView.Adapter. Thankfully, this is the kind of thing RecyclerView.Adapter can handle really nicely.

Here's how your RecyclerView.Adapter should look:

public class ChatAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    final int VIEW_TYPE_MESSAGE = 0;
    final int VIEW_TYPE_IMAGE = 1;

    Context context;
    List<ChatWrapper> messages;
    List<ImageDataWrapper> images;

    public ChatAdapter(Context context, List<ChatWrapper> messages, List<ImageDataWrapper> images){
        this.context = context;
        this.messages = messages;
        this.images = images;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType){
        if(viewType == VIEW_TYPE_MESSAGE){
            return new MessageViewHolder(itemView);
        }

        if(viewType == VIEW_TYPE_IMAGE){
            return new ImageViewHolder(itemView);
        }

        return null;
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder viewHolder, int position){
        if(viewHolder instanceof MessageViewHolder){
            ((MessageViewHolder) viewHolder).populate(messages.get(position));
        }

        if(viewHolder instanceof ImageViewHolder){
            ((ImageViewHolder) viewHolder).populate(images.get(position - messages.size()));
        }
    }

    @Override
    public int getItemCount(){
        return messages.size() + images.size();
    }

    @Override
    public int getItemViewType(int position){
        if(position < messages.size()){
            return VIEW_TYPE_MESSAGE;
        }

        if(position - messages.size() < images.size()){
            return VIEW_TYPE_IMAGE;
        }

        return -1;
    }

    public class MessageViewHolder extends RecyclerView.ViewHolder {
        TextView message;
        TextView timeStamp;
        ImageView userImage;

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

            message = (TextView) itemView.findViewById(R.id.Single_Item_Chat_Message);
            timeStamp = (TextView) itemView.findViewById(R.id.Single_Item_Chat_TimeStamp);
            userImage = (ImageView) itemView.findViewById(R.id.Single_Item_Chat_ImageView);
        }

        public void populate(ChatWrapper chatWrapper){
            message.setText(chatWrapper.getMessage());
            userImage.setText(chatWrapper.getTimestamp());
        }
    }

    public class ImageViewHolder extends RecyclerView.ViewHolder {
        TextView dataTitle;
        TextView dataLink;
        TextView dataSnippet;
        ImageView image;
        ImageButton dataSendButton;

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

            dataTitle = (TextView) itemView.findViewById(R.id.Image_data_Title);
            dataLink = (TextView) itemView.findViewById(R.id.Image_data_Link);
            dataSnippet = (TextView) itemView.findViewById(R.id.Image_data_Snippet);
            image = (ImageView) itemView.findViewById(R.id.Image_data_Image);
            dataSendButton = (ImageButton) itemView.findViewById(R.id.Image_data_SendButton);
        }

        public void populate(ImageDataWrapper imageDataWrapper){
            dataTitle.setText(imageDataWrapper.getPage_Title());
            dataLink.setText(imageDataWrapper.getPage_Link());
            dataSnippet.setText(imageDataWrapper.getPage_Desc());
            Picasso.with(context).load(imageDataWrapper.getPage_ImageThumb()).into(image);
        }
    }
}

Here's what your Activity is going to need:

List<ChatWrapper> messages;
List<ImageDataWrapper> images;
ChatAdapter adapter;

@Override
public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);

    messages = new ArrayList<>();
    images = new ArrayList<>();
    ChatAdapter adapter = new ChatAdapter(this, messages, images);

    RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    recyclerView.setLayoutManager(new LinearLayoutManager(this));
    recyclerView.setAdapter(adapter);
}

public void addMessage(ChatWrapper message){
    messages.add(message);
    adapter.notifyDataSetChanged();
}

public void removeMessage(ChatWrapper message){
    if(messages.remove(message)){
        adapter.notifyDataSetChanged();
    }
}

public void addImage(ImageDataWrapper image){
    images.add(image);
    adapter.notifyDataSetChanged();
}

public void removeImage(ImageDataWrapper image){
    if(images.remove(image)){
        adapter.notifyDataSetChanged();
    }
}

When you want to update the data, just call addMessage(ChatWrapper) or removeMessage(ChatWrapper) for messages and addImage(ImageDataWrapper) or removeImage(ImageDataWrapper) for images.

Some key points:

• You don't want to create any new Adapters or Lists, you simply want to call methods on our existing objects.
• Your Adapter should behave as if it always has to deal with messages and images, but just that it can handle 0 messages or 0 images (no valType variable, getItemCount() should always return the size of both lists combined, etc.)