Apps Add data to RecyclerView .

[Chaitanya Yanamala]

I am developing app for my collage project. I started building app for online food ordering app . So I created a layout with the recyclerview that shows the items. Now I stuck to add that Items to the cart layout . So can anybody help me how to add those items and which methods should use in the both the layouts. And the use case is when ever the quantity(increment) button is pressed in the ItemsfFragment class that layout should add to the cart.

I have attached the image of itemsFragments class layout below .

public class ItemsFragment extends Fragment {


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        RecyclerView recyclerView = (RecyclerView) inflater.inflate(
                R.layout.recycler_view, container, false);
        ContentAdapter adapter = new ContentAdapter(recyclerView.getContext());
        recyclerView.setAdapter(adapter);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        return recyclerView;
    }

    public static class ViewHolder extends RecyclerView.ViewHolder {
        public ImageView picture ;
        public TextView name;
        public TextView price;
        public TextView quantity;
        public int mQuantity = 0;

        public ViewHolder(View itemView,  TextView name, TextView price, int mQuantity) {
            super(itemView);

            this.name = name;
            this.price = price;

            this.mQuantity = mQuantity;
        }



        public TextView getName() {
            return name;
        }

        public TextView getPrice() {
            return price;
        }



        public int getmQuantity() {
            return mQuantity;
        }



        public void setName(TextView name) {
            this.name = name;
        }

        public void setPrice(TextView price) {
            this.price = price;
        }


        public void setmQuantity(int mQuantity) {
            this.mQuantity = mQuantity;
        }

        public ViewHolder(LayoutInflater inflater, ViewGroup parent) {
            super(inflater.inflate(R.layout.list_item, parent, false));
            picture = (ImageView) itemView.findViewById(R.id.item_image);
           name= (TextView) itemView.findViewById(R.id.item_name);
            price = (TextView) itemView.findViewById(R.id.item_price);
            quantity =(TextView)itemView.findViewById(R.id.quantity);




            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Context context = v.getContext();
                    Intent intent = new Intent(context, DetailActivity.class);
                    intent.putExtra(DetailActivity.EXTRA_POSITION, getAdapterPosition());
                    context.startActivity(intent);
                }
            });

            ImageButton addImageButton =
                    (ImageButton) itemView.findViewById(R.id.add_button);
            addImageButton.setOnClickListener(new View.OnClickListener(){
                @Override
                public void onClick(View v) {

                    if (mQuantity == 5) {
                        return;
                    }

                    quantity.setText(String.valueOf(++mQuantity));

                }
            });

            ImageButton minusImageButton = (ImageButton) itemView.findViewById(R.id.minus_button);
            minusImageButton.setOnClickListener(new View.OnClickListener(){
                @Override
                public void onClick(View v) {

                    if (mQuantity == 0) {
                        return;
                    }
                    quantity.setText(String.valueOf(--mQuantity));

                }
            });
        }
    }

    /**
     * Adapter to display recycler view.
     */
    public static class ContentAdapter extends RecyclerView.Adapter<ViewHolder> {
        // Set numbers of Card in RecyclerView.
        private static final int LENGTH = 11;

        private final String[] mNames;
        private final String[] mPrice;
        private final Drawable[] mItemPics;



        public ContentAdapter(Context context) {
            Resources resources = context.getResources();
            mNames = resources.getStringArray(R.array.ItemNames);
            mPrice = resources.getStringArray(R.array.ItemPrice);
            TypedArray a = resources.obtainTypedArray(R.array.item_picture);
            mItemPics = new Drawable[a.length()];
            for (int i = 0; i < mItemPics.length; i++) {
                mItemPics[i] = a.getDrawable(i);
            }
            a.recycle();

        }



        @Override
        public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            return new ViewHolder(LayoutInflater.from(parent.getContext()), parent);
        }


        @Override
        public void onBindViewHolder(ViewHolder holder, int position) {
            holder.picture.setImageDrawable(mItemPics[position % mItemPics.length]);
            holder.name.setText(mNames[position % mNames.length]);
            holder.price.setText(mPrice[position % mPrice.length]);
        }

        @Override
        public int getItemCount() {
            return LENGTH;
        }
    }
}

 

[Deleted User]

You've done most of the work. You have click listeners for the '+' and '-' buttons.
So all you need to do is define a data structure for your 'cart'. This could be a class something like this

public class Cart {
  private HashMap<String name, ViewHolder item> items;
  ...
}

So every time you click '+', an entry is added to the HashMap. If you click '-' and the quantity is 0, then remove that item from the HashMap.
It's just a suggestion, there are other ways of doing this.

 

[arnavp]

As user adds quantity, you need to capture the data as suggested above and show it in the action bar with item quantity in cart.