package com.example.recyclerplayground;

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                .add(android.R.id.content, new MyFragment())
                .commit();
        }
    }

    public static class MyFragment extends Fragment {
        private RecyclerView mRecyclerView;
        private final ArrayList<String> mItems = new ArrayList<>();
        private int mItemCount = 0;
        private int itemsToAdd = 100;
        private MySimpleAdapter mAdapter;

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View v = inflater.inflate(R.layout.activity_main, container, false);
            mRecyclerView = (RecyclerView) v.findViewById(R.id.recyclerView);
            RecyclerView.LayoutManager layoutManager =
                new GridLayoutManager(getContext(), 2, LinearLayoutManager.VERTICAL, false);
            for (mItemCount = 0; mItemCount < itemsToAdd; mItemCount++) {
                mItems.add(mItemCount, "Item # " + mItemCount);
            }
            mAdapter = new MySimpleAdapter(mItems);
            mRecyclerView.setLayoutManager(layoutManager);
            mRecyclerView.setHasFixedSize(true);
            mRecyclerView.setAdapter(mAdapter);
            return v;
        }

        private class MySimpleAdapter extends RecyclerView.Adapter<MySimpleAdapter.ItemHolder> {
            private ArrayList<String> mData;

            MySimpleAdapter(ArrayList<String> data) {
                mData = data;
            }

            @Override
            public ItemHolder onCreateViewHolder(ViewGroup parent, int viewType) {
                return new ItemHolder(
                    LayoutInflater.from(parent.getContext())
                        .inflate(android.R.layout.simple_list_item_1, parent, false));
            }

            @Override
            public void onBindViewHolder(final ItemHolder holder, int position) {
                holder.mTextView.setText(mData.get(position));
            }

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

            class ItemHolder extends RecyclerView.ViewHolder {
                private TextView mTextView;

                ItemHolder(View itemView) {
                    super(itemView);
                    mTextView = (TextView) itemView.findViewById(android.R.id.text1);
                }
            }
        }
    }

}