Implementation of ArrayAdapter based on the CursorAdapter.

BaseArrayAdapter.java

/*
 * Copyright 2014 Evgeny Shishkin
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;

import java.util.List;

/**
 * Adapter that exposes data from an array of objects to a {@link android.widget.ListView ListView}
 * widget. Implementation is based on the {@link android.widget.CursorAdapter CursorAdapter}.
 *
 * @author Evgeny Shishkin
 */
public abstract class BaseArrayAdapter<T> extends BaseAdapter {

    private final Context mContext;
    private final LayoutInflater mLayoutInflater;

    private List<T> mItems;

    /**
     * Constructor.
     *
     * @param context The context
     */
    public BaseArrayAdapter(Context context) {
        mContext = context;
        mLayoutInflater = LayoutInflater.from(context);
    }

    /**
     * Constructor.
     *
     * @param context The context
     * @param items   The objects to represent in the ListView
     */
    public BaseArrayAdapter(Context context, List<T> items) {
        this(context);
        mItems = items;
    }

    /**
     * Set items to display.
     *
     * @param items The items
     */
    public void setItems(List<T> items) {
        if (items != mItems) {
            mItems = items;
            notifyDataSetChanged();
        }
    }

    /**
     * Return the items.
     *
     * @return The items
     */
    public List<T> getItems() {
        return mItems;
    }

    /**
     * Returns the context associated with this array adapter.
     *
     * @return The context
     */
    public Context getContext() {
        return mContext;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int getCount() {
        return mItems != null ? mItems.size() : 0;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public T getItem(int position) {
        return mItems != null ? mItems.get(position) : null;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public long getItemId(int position) {
        return position;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        final T item = getItem(position);

        View view;
        if (convertView == null) {
            view = newView(mLayoutInflater, item, parent);
        } else {
            view = convertView;
        }

        bindView(view, mContext, item);

        return view;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public View getDropDownView(int position, View convertView, ViewGroup parent) {
        final T item = getItem(position);

        View view;
        if (convertView == null) {
            view = newDropDownView(mLayoutInflater, item, parent);
        } else {
            view = convertView;
        }

        bindView(view, mContext, item);

        return view;
    }

    /**
     * Makes a new view to hold the item's data.
     *
     * @param inflater The LayoutInflater object that can be used to inflate item view
     * @param item     The item
     * @param parent   The parent to which the new view is attached to
     * @return the newly created view.
     */
    public abstract View newView(LayoutInflater inflater, T item, ViewGroup parent);

    /**
     * Makes a new drop down view to hold the item's data.
     *
     * @param inflater The LayoutInflater object that can be used to inflate item view
     * @param item     The item
     * @param parent   The parent to which the new view is attached to
     * @return the newly created view.
     */
    public View newDropDownView(LayoutInflater inflater, T item, ViewGroup parent) {
        return newView(inflater, item, parent);
    }

    /**
     * Bind an existing view to the item's data.
     *
     * @param view    Existing view, returned earlier by newView
     * @param context Interface to application's global information
     * @param item    The item
     */
    public abstract void bindView(View view, Context context, T item);

}