Expandable Recycler Adapter

ExpandableRecyclerAdapter.java

package com.autoportal.adapter;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.text.TextUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.autoportal.R;
import com.autoportal.model.VariantDescriptionItem;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import butterknife.ButterKnife;
import butterknife.InjectView;

/**
 * Created by Kirill-Penzykov on 18.05.2015.
 */
public abstract class ExpandableRecyclerAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    //    TODO: update logic to real data types and replace fake data
    public static final int HEADER_VIEW = 0;
    public static final int GROUP_VIEW = 1;
    public static final int ITEM_VIEW = 2;

    private List<VariantDescriptionItem> headers;
    private Context context;
    private Map<Integer, VariantDescriptionItem> openItems = new LinkedHashMap<>();

    public ExpandableRecyclerAdapter(Context context, List<VariantDescriptionItem> details) {
        this.headers = details;
        this.context = context;

    }

    @Override
    public int getItemViewType(int position) {
        if (position == 0) {
            return HEADER_VIEW;
        }
        if (TextUtils.isEmpty(headers.get(position).getValue())) {
            return GROUP_VIEW;
        } else {
            return ITEM_VIEW;
        }
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
        switch (viewType) {
            case GROUP_VIEW:
                View groupView = LayoutInflater.from(viewGroup.getContext())
                        .inflate(R.layout.item_group_model_variant_detail, viewGroup, false);
                GroupViewHolder groupViewHolder = new GroupViewHolder(groupView);
                setGroupItemClickListener(groupViewHolder);
                return groupViewHolder;
            case ITEM_VIEW:
                View itemView = LayoutInflater.from(viewGroup.getContext())
                        .inflate(R.layout.item_model_variant_detail, viewGroup, false);
                return new ItemViewHolder(itemView);
            case HEADER_VIEW:
            default:
                View headerView = LayoutInflater.from(viewGroup.getContext())
                        .inflate(getHeaderLayoutResource(), viewGroup, false);
                return getHeaderViewHolder(headerView);

        }
    }

    public abstract int getHeaderLayoutResource();
    public abstract RecyclerView.ViewHolder getHeaderViewHolder(View headerView);


    @Override
    public void onBindViewHolder(final RecyclerView.ViewHolder viewHolder, int viewType) {

    }

    private void setGroupItemClickListener(final GroupViewHolder viewHolder) {
        viewHolder.groupHeaderTextView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int position = viewHolder.getLayoutPosition();
                int nextPosition = position + 1;
                if (!openItems.containsKey(headers.get(position).getId())) {
                    List<VariantDescriptionItem> subHeaders = new ArrayList<>();
                    subHeaders.add(new VariantDescriptionItem(99, "Safety", "Yes"));
                    subHeaders.add(new VariantDescriptionItem(100, "Safety", "Yes"));
                    subHeaders.add(new VariantDescriptionItem(101, "Safety", "Yes"));
                    headers.addAll(nextPosition, subHeaders);
                    notifyItemRangeInserted(nextPosition, subHeaders.size());
                    openItems.put(headers.get(position).getId(), headers.get(position));
                    viewHolder.dropDownImageView.setImageResource(R.drawable.ic_arrow_dropdown_common_up);
                    viewHolder.bottomDividerView.setVisibility(View.VISIBLE);
                } else {
                    int removedCounter = 0;
                    while (nextPosition < headers.size() && !TextUtils.isEmpty(headers.get(nextPosition).getValue())) {
                        headers.remove(nextPosition);
                        removedCounter++;
                    }
                    notifyItemRangeRemoved(nextPosition, removedCounter);
                    openItems.remove(headers.get(position).getId());
                    viewHolder.dropDownImageView.setImageResource(R.drawable.ic_arrow_dropdown_common);
                    viewHolder.bottomDividerView.setVisibility(View.GONE);

                }
            }
        });
    }

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


    static class GroupViewHolder extends RecyclerView.ViewHolder {
        @InjectView(R.id.text_view_group_header)
        TextView groupHeaderTextView;
        @InjectView(R.id.image_view_dropdown)
        ImageView dropDownImageView;
        @InjectView(R.id.view_bottom_divider)
        View bottomDividerView;

        public GroupViewHolder(View view) {
            super(view);
            ButterKnife.inject(this, view);
        }
    }

    static class ItemViewHolder extends RecyclerView.ViewHolder {
        @InjectView(R.id.text_view_item_header)
        TextView itemHeaderTextView;

        public ItemViewHolder(View view) {
            super(view);
            ButterKnife.inject(this, view);
        }
    }

}