se.chalmers.watchme.activity.AutoCompleteAdapter.java Source code

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Here is the source code for se.chalmers.watchme.activity.AutoCompleteAdapter.java

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/**
*   AutoCompleteAdapter.java
*
*   Custom Array adapter for auto complete dropdowns.
*
*   Includes custom view drawing with objects of the type Movie instead
*   of plain Strings.   
*
*   @author Johan Brook
*   @copyright (c) 2012 Johan Brook, Robin Andersson, Lisa Stenberg, Mattias Henriksson
*   @license MIT
*/

package se.chalmers.watchme.activity;

import org.json.JSONArray;
import org.json.JSONObject;

import se.chalmers.watchme.R;
import se.chalmers.watchme.model.Movie;
import se.chalmers.watchme.net.MovieSource;
import se.chalmers.watchme.utils.DateTimeUtils;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.TextView;

public class AutoCompleteAdapter extends ArrayAdapter<JSONObject> implements Filterable {

    private LayoutInflater inflater;
    private MovieSource source;
    private JSONArray movies;

    /**
     * Create a new AutoCompleteAdapter.
     * 
     * <p>Custom filtering of movie suggestions from IMDb.</p>
     * 
     * @param context The context
     * @param textViewResourceId The view ID
     * @param source The data source to fetch movies from
     */
    public AutoCompleteAdapter(Context context, int textViewResourceId, MovieSource source) {
        super(context, textViewResourceId);

        this.source = source;
        this.inflater = LayoutInflater.from(getContext());
    }

    @Override
    public int getCount() {
        return this.movies.length();
    }

    @Override
    public JSONObject getItem(int position) {
        return this.movies.optJSONObject(position);
    }

    @Override
    public Filter getFilter() {

        return new Filter() {

            /*
             * Override this method in order to populate the auto complete field
             * with the actual movie name when selecting a suggestion from the list,
             * instead of the default toString implementation.
             * 
             * @see android.widget.Filter#convertResultToString(java.lang.Object)
             */
            @Override
            public CharSequence convertResultToString(Object result) {
                if (result instanceof JSONObject) {
                    return ((JSONObject) result).optString(Movie.JSON_KEY_NAME);
                }

                return super.convertResultToString(result);
            }

            /*
             * The actual filtering, where the call to the API is made. The method
             * is called in a worker thread apart from the UI thread, so we're okay.
             * 
             * @see android.widget.Filter#performFiltering(java.lang.CharSequence)
             */
            @Override
            protected FilterResults performFiltering(CharSequence constraint) {

                FilterResults results = new FilterResults();
                if (constraint != null) {
                    JSONArray json = source.getMoviesByTitle(constraint.toString());

                    results.values = json;
                    results.count = json.length();
                }

                return results;
            }

            /*
             * Update the list.
             * 
             * @see android.widget.Filter#publishResults(java.lang.CharSequence, android.widget.Filter.FilterResults)
             */
            @Override
            protected void publishResults(CharSequence constraint, FilterResults results) {
                if (results != null && results.count > 0) {
                    movies = (JSONArray) results.values;
                    notifyDataSetChanged();
                } else {
                    notifyDataSetInvalidated();
                }
            }

        };
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        /**
         * Performance tweaks in overriden getView:
         * 
         * Re-use the "trash view" convertView instead of always inflating
         * a new view from XML. Only inflate if convertView is null.
         * 
         * Also make use of a ViewHolder to cache references to subviews. A 
         * reference to a ViewHolder is created if a new view is inflated,
         * otherwise we just use the attached ViewHolder of the old view.
         */

        ViewHolder holder;
        JSONObject suggestion = this.getItem(position);

        if (convertView == null) {
            convertView = this.inflater.inflate(R.layout.auto_complete_item, null);
            holder = new ViewHolder();
            holder.title = (TextView) convertView.findViewById(R.id.autocomplete_title);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        if (suggestion != null) {
            String releaseDate = suggestion.optString("released");
            releaseDate = (releaseDate.isEmpty()) ? null : releaseDate;
            String year = DateTimeUtils.parseYearFromDate(releaseDate);

            holder.title
                    .setText(suggestion.optString(Movie.JSON_KEY_NAME) + ((year != null) ? " (" + year + ")" : ""));
        }

        return convertView;
    }

    /**
     * A ViewHolder with a title, year and position fields. 
     * 
     * @author Johan
     */
    static class ViewHolder {
        public TextView title;
        public int position;
    }

}