BaseListAdapter.java

package com.dgorod.tourbag.presentation.adapter.base;

import android.content.Context;
import android.support.annotation.CallSuper;
import android.support.annotation.LayoutRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

import com.dgorod.tourbag.commons.Preconditions;
import com.dgorod.tourbag.presentation.adapter.holder.base.BaseHolder;

import java.util.List;

/**
 * Wrapper above {@link BaseAdapter} to hide ConvertView approach boilerplate code.
 * Adapter's generics must be specified.
 * DataType - class that will be used in adapter data.
 * ViewHolder - class to be instantiated as view holder.
 *
 * Created by Dmytro Gorodnytskyi on 01-Apr-16.
 */
public abstract class BaseListAdapter<DataType, ViewHolder extends BaseHolder> extends BaseAdapter {

    private final int itemLayout;

    private LayoutInflater inflater;

    protected List<DataType> data;

    public BaseListAdapter(@LayoutRes int itemLayout, @NonNull Context context) {
        Preconditions.checkNotNull(context);

        this.itemLayout = itemLayout;
        this.inflater = LayoutInflater.from(context);
    }

    @NonNull
    public abstract ViewHolder onCreateViewHolder(@NonNull View itemView);

    public abstract void onBindViewHolder(@NonNull ViewHolder holder, int position);

    @Nullable
    public List<DataType> getData() {
        return data;
    }

    public void setData(@Nullable List<DataType> data) {
        this.data = data;
        notifyDataSetChanged();
    }

    @CallSuper
    @Override
    public int getCount() {
        return data == null ? 0 : data.size();
    }

    @CallSuper
    @Override
    public DataType getItem(int position) {
        return data.get(position);
    }

    @SuppressWarnings("unchecked cast")
    @Override
    public final View getView(int position, View convertView, ViewGroup parent) {
        View resultView = convertView;
        ViewHolder holder;
        if (convertView == null) {
            resultView = inflater.inflate(itemLayout, parent, false);
            holder = this.onCreateViewHolder(resultView);
            resultView.setTag(holder);
        }
        else {
            holder = (ViewHolder) resultView.getTag();
        }

        this.onBindViewHolder(holder, position);

        return resultView;
    }

    public int getItemPosition(long itemId)
    {
        for (int i = 0; i < getCount(); i++) {
            if (getItemId(i) == itemId) {
                return i;
            }
        }
        return -1;
    }
}