src/com/android/calendar/event/EventLocationAdapter.java - platform/packages/apps/Calendar - Git at Google

 /*
  * Copyright (C) 2012 The Android Open Source Project
  *
  * 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.
  */

 package com.android.calendar.event;

 import android.content.ContentResolver;
 import android.content.ContentUris;
 import android.content.Context;
 import android.database.Cursor;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.provider.CalendarContract.Events;
 import android.provider.ContactsContract.CommonDataKinds;
 import android.provider.ContactsContract.Contacts;
 import android.provider.ContactsContract.RawContacts;
 import android.text.TextUtils;
 import android.util.Log;
 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.ImageView;
 import android.widget.TextView;

 import com.android.calendar.R;

 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeSet;
 import java.util.concurrent.ExecutionException;

 // TODO: limit length of dropdown to stop at the soft keyboard
 // TODO: history icon resize asset

 /**
  * An adapter for autocomplete of the location field in edit-event view.
  */
 public class EventLocationAdapter extends ArrayAdapter<EventLocationAdapter.Result>
         implements Filterable {
     private static final String TAG = "EventLocationAdapter";

     /**
      * Internal class for containing info for an item in the auto-complete results.
      */
     public static class Result {
         private final String mName;
         private final String mAddress;

         // The default image resource for the icon.  This will be null if there should
         // be no icon (if multiple listings for a contact, only the first one should have the
         // photo icon).
         private final Integer mDefaultIcon;

         // The contact photo to use for the icon.  This will override the default icon.
         private final Uri mContactPhotoUri;

         public Result(String displayName, String address, Integer defaultIcon,
                 Uri contactPhotoUri) {
             this.mName = displayName;
             this.mAddress = address;
             this.mDefaultIcon = defaultIcon;
             this.mContactPhotoUri = contactPhotoUri;
         }

         /**
          * This is the autocompleted text.
          */
         @Override
         public String toString() {
             return mAddress;
         }
     }
     private static ArrayList<Result> EMPTY_LIST = new ArrayList<Result>();

     // Constants for contacts query:
     // SELECT ... FROM view_data data WHERE ((data1 LIKE 'input%' OR data1 LIKE '%input%' OR
     // display_name LIKE 'input%' OR display_name LIKE '%input%' )) ORDER BY display_name ASC
     private static final String[] CONTACTS_PROJECTION = new String[] {
         CommonDataKinds.StructuredPostal._ID,
         Contacts.DISPLAY_NAME,
         CommonDataKinds.StructuredPostal.FORMATTED_ADDRESS,
         RawContacts.CONTACT_ID,
         Contacts.PHOTO_ID,
     };
     private static final int CONTACTS_INDEX_ID = 0;
     private static final int CONTACTS_INDEX_DISPLAY_NAME = 1;
     private static final int CONTACTS_INDEX_ADDRESS = 2;
     private static final int CONTACTS_INDEX_CONTACT_ID = 3;
     private static final int CONTACTS_INDEX_PHOTO_ID = 4;
     // TODO: Only query visible contacts?
     private static final String CONTACTS_WHERE = new StringBuilder()
             .append("(")
             .append(CommonDataKinds.StructuredPostal.FORMATTED_ADDRESS)
             .append(" LIKE ? OR ")
             .append(CommonDataKinds.StructuredPostal.FORMATTED_ADDRESS)
             .append(" LIKE ? OR ")
             .append(Contacts.DISPLAY_NAME)
             .append(" LIKE ? OR ")
             .append(Contacts.DISPLAY_NAME)
             .append(" LIKE ? )")
             .toString();

     // Constants for recent locations query (in Events table):
     // SELECT ... FROM view_events WHERE (eventLocation LIKE 'input%') ORDER BY _id DESC
     private static final String[] EVENT_PROJECTION = new String[] {
         Events._ID,
         Events.EVENT_LOCATION,
         Events.VISIBLE,
     };
     private static final int EVENT_INDEX_ID = 0;
     private static final int EVENT_INDEX_LOCATION = 1;
     private static final int EVENT_INDEX_VISIBLE = 2;
     private static final String LOCATION_WHERE = Events.VISIBLE + "=? AND "
             + Events.EVENT_LOCATION + " LIKE ?";
     private static final int MAX_LOCATION_SUGGESTIONS = 4;

     private final ContentResolver mResolver;
     private final LayoutInflater mInflater;
     private final ArrayList<Result> mResultList = new ArrayList<Result>();

     // The cache for contacts photos.  We don't have to worry about clearing this, as a
     // new adapter is created for every edit event.
     private final Map<Uri, Bitmap> mPhotoCache = new HashMap<Uri, Bitmap>();

     /**
      * Constructor.
      */
     public EventLocationAdapter(Context context) {
         super(context, R.layout.location_dropdown_item, EMPTY_LIST);

         mResolver = context.getContentResolver();
         mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
     }

     @Override
     public int getCount() {
         return mResultList.size();
     }

     @Override
     public Result getItem(int index) {
         if (index < mResultList.size()) {
             return mResultList.get(index);
         } else {
             return null;
         }
     }

     @Override
     public View getView(final int position, final View convertView, final ViewGroup parent) {
         View view = convertView;
         if (view == null) {
             view = mInflater.inflate(R.layout.location_dropdown_item, parent, false);
         }
         final Result result = getItem(position);
         if (result == null) {
             return view;
         }

         // Update the display name in the item in auto-complete list.
         TextView nameView = (TextView) view.findViewById(R.id.location_name);
         if (nameView != null) {
             if (result.mName == null) {
                 nameView.setVisibility(View.GONE);
             } else {
                 nameView.setVisibility(View.VISIBLE);
                 nameView.setText(result.mName);
             }
         }

         // Update the address line.
         TextView addressView = (TextView) view.findViewById(R.id.location_address);
         if (addressView != null) {
             addressView.setText(result.mAddress);
         }

         // Update the icon.
         final ImageView imageView = (ImageView) view.findViewById(R.id.icon);
         if (imageView != null) {
             if (result.mDefaultIcon == null) {
                 imageView.setVisibility(View.INVISIBLE);
             } else {
                 imageView.setVisibility(View.VISIBLE);
                 imageView.setImageResource(result.mDefaultIcon);

                 // Save the URI on the view, so we can check against it later when updating
                 // the image.  Otherwise the async image update with using 'convertView' above
                 // resulted in the wrong list items being updated.
                 imageView.setTag(result.mContactPhotoUri);
                 if (result.mContactPhotoUri != null) {
                     Bitmap cachedPhoto = mPhotoCache.get(result.mContactPhotoUri);
                     if (cachedPhoto != null) {
                         // Use photo in cache.
                         imageView.setImageBitmap(cachedPhoto);
                     } else {
                         // Asynchronously load photo and update.
                         asyncLoadPhotoAndUpdateView(result.mContactPhotoUri, imageView);
                     }
                 }
             }
         }
         return view;
     }

     // TODO: Refactor to share code with ContactsAsyncHelper.
     private void asyncLoadPhotoAndUpdateView(final Uri contactPhotoUri,
             final ImageView imageView) {
         AsyncTask<Void, Void, Bitmap> photoUpdaterTask =
                 new AsyncTask<Void, Void, Bitmap>() {
             @Override
             protected Bitmap doInBackground(Void... params) {
                 Bitmap photo = null;
                 InputStream imageStream = Contacts.openContactPhotoInputStream(
                         mResolver, contactPhotoUri);
                 if (imageStream != null) {
                     photo = BitmapFactory.decodeStream(imageStream);
                     mPhotoCache.put(contactPhotoUri, photo);
                 }
                 return photo;
             }

             @Override
             public void onPostExecute(Bitmap photo) {
                 // The View may have already been reused (because using 'convertView' above), so
                 // we must check the URI is as expected before setting the icon, or we may be
                 // setting the icon in other items.
                 if (photo != null && imageView.getTag() == contactPhotoUri) {
                     imageView.setImageBitmap(photo);
                 }
             }
         }.execute();
     }

     /**
      * Return filter for matching against contacts info and recent locations.
      */
     @Override
     public Filter getFilter() {
         return new LocationFilter();
     }

     /**
      * Filter implementation for matching the input string against contacts info and
      * recent locations.
      */
     public class LocationFilter extends Filter {

         @Override
         protected FilterResults performFiltering(CharSequence constraint) {
             long startTime = System.currentTimeMillis();
             final String filter = constraint == null ? "" : constraint.toString();
             if (filter.isEmpty()) {
                 return null;
             }

             // Start the recent locations query (async).
             AsyncTask<Void, Void, List<Result>> locationsQueryTask =
                     new AsyncTask<Void, Void, List<Result>>() {
                 @Override
                 protected List<Result> doInBackground(Void... params) {
                     return queryRecentLocations(mResolver, filter);
                 }
             }.execute();

             // Perform the contacts query (sync).
             HashSet<String> contactsAddresses = new HashSet<String>();
             List<Result> contacts = queryContacts(mResolver, filter, contactsAddresses);

             ArrayList<Result> resultList = new ArrayList<Result>();
             try {
                 // Wait for the locations query.
                 List<Result> recentLocations = locationsQueryTask.get();

                 // Add the matched recent locations to returned results.  If a match exists in
                 // both the recent locations query and the contacts addresses, only display it
                 // as a contacts match.
                 for (Result recentLocation : recentLocations) {
                     if (recentLocation.mAddress != null &&
                             !contactsAddresses.contains(recentLocation.mAddress)) {
                         resultList.add(recentLocation);
                     }
                 }
             } catch (ExecutionException e) {
                 Log.e(TAG, "Failed waiting for locations query results.", e);
             } catch (InterruptedException e) {
                 Log.e(TAG, "Failed waiting for locations query results.", e);
             }

             // Add all the contacts matches to returned results.
             if (contacts != null) {
                 resultList.addAll(contacts);
             }

             // Log the processing duration.
             if (Log.isLoggable(TAG, Log.DEBUG)) {
                 long duration = System.currentTimeMillis() - startTime;
                 StringBuilder msg = new StringBuilder();
                 msg.append("Autocomplete of ").append(constraint);
                 msg.append(": location query match took ").append(duration).append("ms ");
                 msg.append("(").append(resultList.size()).append(" results)");
                 Log.d(TAG, msg.toString());
             }

             final FilterResults filterResults = new FilterResults();
             filterResults.values = resultList;
             filterResults.count = resultList.size();
             return filterResults;
         }

         @Override
         protected void publishResults(CharSequence constraint, FilterResults results) {
             mResultList.clear();
             if (results != null && results.count > 0) {
                 mResultList.addAll((ArrayList<Result>) results.values);
                 notifyDataSetChanged();
             } else {
                 notifyDataSetInvalidated();
             }
         }
     }

     /**
      * Matches the input string against contacts names and addresses.
      *
      * @param resolver The content resolver.
      * @param input The user-typed input string.
      * @param addressesRetVal The addresses in the returned result are also returned here
      *     for faster lookup.  Pass in an empty set.
      * @return Ordered list of all the matched results.  If there are multiple address matches
      *     for the same contact, they will be listed together in individual items, with only
      *     the first item containing a name/icon.
      */
     private static List<Result> queryContacts(ContentResolver resolver, String input,
             HashSet<String> addressesRetVal) {
         String where = null;
         String[] whereArgs = null;

         // Match any word in contact name or address.
         if (!TextUtils.isEmpty(input)) {
             where = CONTACTS_WHERE;
             String param1 = input + "%";
             String param2 = "% " + input + "%";
             whereArgs = new String[] {param1, param2, param1, param2};
         }

         // Perform the query.
         Cursor c = resolver.query(CommonDataKinds.StructuredPostal.CONTENT_URI,
                 CONTACTS_PROJECTION, where, whereArgs, Contacts.DISPLAY_NAME + " ASC");

         // Process results.  Group together addresses for the same contact.
         try {
             Map<String, List<Result>> nameToAddresses = new HashMap<String, List<Result>>();
             c.moveToPosition(-1);
             while (c.moveToNext()) {
                 String name = c.getString(CONTACTS_INDEX_DISPLAY_NAME);
                 String address = c.getString(CONTACTS_INDEX_ADDRESS);
                 if (name != null) {

                     List<Result> addressesForName = nameToAddresses.get(name);
                     Result result;
                     if (addressesForName == null) {
                         // Determine if there is a photo for the icon.
                         Uri contactPhotoUri = null;
                         if (c.getLong(CONTACTS_INDEX_PHOTO_ID) > 0) {
                             contactPhotoUri = ContentUris.withAppendedId(Contacts.CONTENT_URI,
                                     c.getLong(CONTACTS_INDEX_CONTACT_ID));
                         }

                         // First listing for a distinct contact should have the name/icon.
                         addressesForName = new ArrayList<Result>();
                         nameToAddresses.put(name, addressesForName);
                         result = new Result(name, address, R.drawable.ic_contact_picture,
                                 contactPhotoUri);
                     } else {
                         // Do not include name/icon in subsequent listings for the same contact.
                         result = new Result(null, address, null, null);
                     }

                     addressesForName.add(result);
                     addressesRetVal.add(address);
                 }
             }

             // Return the list of results.
             List<Result> allResults = new ArrayList<Result>();
             for (List<Result> result : nameToAddresses.values()) {
                 allResults.addAll(result);
             }
             return allResults;

         } finally {
             if (c != null) {
                 c.close();
             }
         }
     }

     /**
      * Matches the input string against recent locations.
      */
     private static List<Result> queryRecentLocations(ContentResolver resolver, String input) {
         // TODO: also match each word in the address?
         String filter = input == null ? "" : input + "%";
         if (filter.isEmpty()) {
             return null;
         }

         // Query all locations prefixed with the constraint.  There is no way to insert
         // 'DISTINCT' or 'GROUP BY' to get rid of dupes, so use post-processing to
         // remove dupes.  We will order query results by descending event ID to show
         // results that were most recently inputed.
         Cursor c = resolver.query(Events.CONTENT_URI, EVENT_PROJECTION, LOCATION_WHERE,
                 new String[] { "1", filter }, Events._ID + " DESC");
         try {
             List<Result> recentLocations = null;
             if (c != null) {
                 // Post process query results.
                 recentLocations = processLocationsQueryResults(c);
             }
             return recentLocations;
         } finally {
             if (c != null) {
                 c.close();
             }
         }
     }

     /**
      * Post-process the query results to return the first MAX_LOCATION_SUGGESTIONS
      * unique locations in alphabetical order.
      *
      * TODO: Refactor to share code with the recent titles auto-complete.
      */
     private static List<Result> processLocationsQueryResults(Cursor cursor) {
         TreeSet<String> locations = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
         cursor.moveToPosition(-1);

         // Remove dupes.
         while ((locations.size() < MAX_LOCATION_SUGGESTIONS) && cursor.moveToNext()) {
             String location = cursor.getString(EVENT_INDEX_LOCATION).trim();
             locations.add(location);
         }

         // Copy the sorted results.
         List<Result> results = new ArrayList<Result>();
         for (String location : locations) {
             results.add(new Result(null, location, R.drawable.ic_history_holo_light, null));
         }
         return results;
     }
 }
	/*
	* Copyright (C) 2012 The Android Open Source Project
	*
	* 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.
	*/

	package com.android.calendar.event;

	import android.content.ContentResolver;
	import android.content.ContentUris;
	import android.content.Context;
	import android.database.Cursor;
	import android.graphics.Bitmap;
	import android.graphics.BitmapFactory;
	import android.net.Uri;
	import android.os.AsyncTask;
	import android.provider.CalendarContract.Events;
	import android.provider.ContactsContract.CommonDataKinds;
	import android.provider.ContactsContract.Contacts;
	import android.provider.ContactsContract.RawContacts;
	import android.text.TextUtils;
	import android.util.Log;
	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.ImageView;
	import android.widget.TextView;

	import com.android.calendar.R;

	import java.io.InputStream;
	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.TreeSet;
	import java.util.concurrent.ExecutionException;

	// TODO: limit length of dropdown to stop at the soft keyboard
	// TODO: history icon resize asset

	/**
	* An adapter for autocomplete of the location field in edit-event view.
	*/
	public class EventLocationAdapter extends ArrayAdapter<EventLocationAdapter.Result>
	implements Filterable {
	private static final String TAG = "EventLocationAdapter";

	/**
	* Internal class for containing info for an item in the auto-complete results.
	*/
	public static class Result {
	private final String mName;
	private final String mAddress;

	// The default image resource for the icon. This will be null if there should
	// be no icon (if multiple listings for a contact, only the first one should have the
	// photo icon).
	private final Integer mDefaultIcon;

	// The contact photo to use for the icon. This will override the default icon.
	private final Uri mContactPhotoUri;

	public Result(String displayName, String address, Integer defaultIcon,
	Uri contactPhotoUri) {
	this.mName = displayName;
	this.mAddress = address;
	this.mDefaultIcon = defaultIcon;
	this.mContactPhotoUri = contactPhotoUri;
	}

	/**
	* This is the autocompleted text.
	*/
	@Override
	public String toString() {
	return mAddress;
	}
	}
	private static ArrayList<Result> EMPTY_LIST = new ArrayList<Result>();

	// Constants for contacts query:
	// SELECT ... FROM view_data data WHERE ((data1 LIKE 'input%' OR data1 LIKE '%input%' OR
	// display_name LIKE 'input%' OR display_name LIKE '%input%' )) ORDER BY display_name ASC
	private static final String[] CONTACTS_PROJECTION = new String[] {
	CommonDataKinds.StructuredPostal._ID,
	Contacts.DISPLAY_NAME,
	CommonDataKinds.StructuredPostal.FORMATTED_ADDRESS,
	RawContacts.CONTACT_ID,
	Contacts.PHOTO_ID,
	};
	private static final int CONTACTS_INDEX_ID = 0;
	private static final int CONTACTS_INDEX_DISPLAY_NAME = 1;
	private static final int CONTACTS_INDEX_ADDRESS = 2;
	private static final int CONTACTS_INDEX_CONTACT_ID = 3;
	private static final int CONTACTS_INDEX_PHOTO_ID = 4;
	// TODO: Only query visible contacts?
	private static final String CONTACTS_WHERE = new StringBuilder()
	.append("(")
	.append(CommonDataKinds.StructuredPostal.FORMATTED_ADDRESS)
	.append(" LIKE ? OR ")
	.append(CommonDataKinds.StructuredPostal.FORMATTED_ADDRESS)
	.append(" LIKE ? OR ")
	.append(Contacts.DISPLAY_NAME)
	.append(" LIKE ? OR ")
	.append(Contacts.DISPLAY_NAME)
	.append(" LIKE ? )")
	.toString();

	// Constants for recent locations query (in Events table):
	// SELECT ... FROM view_events WHERE (eventLocation LIKE 'input%') ORDER BY _id DESC
	private static final String[] EVENT_PROJECTION = new String[] {
	Events._ID,
	Events.EVENT_LOCATION,
	Events.VISIBLE,
	};
	private static final int EVENT_INDEX_ID = 0;
	private static final int EVENT_INDEX_LOCATION = 1;
	private static final int EVENT_INDEX_VISIBLE = 2;
	private static final String LOCATION_WHERE = Events.VISIBLE + "=? AND "
	+ Events.EVENT_LOCATION + " LIKE ?";
	private static final int MAX_LOCATION_SUGGESTIONS = 4;

	private final ContentResolver mResolver;
	private final LayoutInflater mInflater;
	private final ArrayList<Result> mResultList = new ArrayList<Result>();

	// The cache for contacts photos. We don't have to worry about clearing this, as a
	// new adapter is created for every edit event.
	private final Map<Uri, Bitmap> mPhotoCache = new HashMap<Uri, Bitmap>();

	/**
	* Constructor.
	*/
	public EventLocationAdapter(Context context) {
	super(context, R.layout.location_dropdown_item, EMPTY_LIST);

	mResolver = context.getContentResolver();
	mInflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
	}

	@Override
	public int getCount() {
	return mResultList.size();
	}

	@Override
	public Result getItem(int index) {
	if (index < mResultList.size()) {
	return mResultList.get(index);
	} else {
	return null;
	}
	}

	@Override
	public View getView(final int position, final View convertView, final ViewGroup parent) {
	View view = convertView;
	if (view == null) {
	view = mInflater.inflate(R.layout.location_dropdown_item, parent, false);
	}
	final Result result = getItem(position);
	if (result == null) {
	return view;
	}

	// Update the display name in the item in auto-complete list.
	TextView nameView = (TextView) view.findViewById(R.id.location_name);
	if (nameView != null) {
	if (result.mName == null) {
	nameView.setVisibility(View.GONE);
	} else {
	nameView.setVisibility(View.VISIBLE);
	nameView.setText(result.mName);
	}
	}

	// Update the address line.
	TextView addressView = (TextView) view.findViewById(R.id.location_address);
	if (addressView != null) {
	addressView.setText(result.mAddress);
	}

	// Update the icon.
	final ImageView imageView = (ImageView) view.findViewById(R.id.icon);
	if (imageView != null) {
	if (result.mDefaultIcon == null) {
	imageView.setVisibility(View.INVISIBLE);
	} else {
	imageView.setVisibility(View.VISIBLE);
	imageView.setImageResource(result.mDefaultIcon);

	// Save the URI on the view, so we can check against it later when updating
	// the image. Otherwise the async image update with using 'convertView' above
	// resulted in the wrong list items being updated.
	imageView.setTag(result.mContactPhotoUri);
	if (result.mContactPhotoUri != null) {
	Bitmap cachedPhoto = mPhotoCache.get(result.mContactPhotoUri);
	if (cachedPhoto != null) {
	// Use photo in cache.
	imageView.setImageBitmap(cachedPhoto);
	} else {
	// Asynchronously load photo and update.
	asyncLoadPhotoAndUpdateView(result.mContactPhotoUri, imageView);
	}
	}
	}
	}
	return view;
	}

	// TODO: Refactor to share code with ContactsAsyncHelper.
	private void asyncLoadPhotoAndUpdateView(final Uri contactPhotoUri,
	final ImageView imageView) {
	AsyncTask<Void, Void, Bitmap> photoUpdaterTask =
	new AsyncTask<Void, Void, Bitmap>() {
	@Override
	protected Bitmap doInBackground(Void... params) {
	Bitmap photo = null;
	InputStream imageStream = Contacts.openContactPhotoInputStream(
	mResolver, contactPhotoUri);
	if (imageStream != null) {
	photo = BitmapFactory.decodeStream(imageStream);
	mPhotoCache.put(contactPhotoUri, photo);
	}
	return photo;
	}

	@Override
	public void onPostExecute(Bitmap photo) {
	// The View may have already been reused (because using 'convertView' above), so
	// we must check the URI is as expected before setting the icon, or we may be
	// setting the icon in other items.
	if (photo != null && imageView.getTag() == contactPhotoUri) {
	imageView.setImageBitmap(photo);
	}
	}
	}.execute();
	}

	/**
	* Return filter for matching against contacts info and recent locations.
	*/
	@Override
	public Filter getFilter() {
	return new LocationFilter();
	}

	/**
	* Filter implementation for matching the input string against contacts info and
	* recent locations.
	*/
	public class LocationFilter extends Filter {

	@Override
	protected FilterResults performFiltering(CharSequence constraint) {
	long startTime = System.currentTimeMillis();
	final String filter = constraint == null ? "" : constraint.toString();
	if (filter.isEmpty()) {
	return null;
	}

	// Start the recent locations query (async).
	AsyncTask<Void, Void, List<Result>> locationsQueryTask =
	new AsyncTask<Void, Void, List<Result>>() {
	@Override
	protected List<Result> doInBackground(Void... params) {
	return queryRecentLocations(mResolver, filter);
	}
	}.execute();

	// Perform the contacts query (sync).
	HashSet<String> contactsAddresses = new HashSet<String>();
	List<Result> contacts = queryContacts(mResolver, filter, contactsAddresses);

	ArrayList<Result> resultList = new ArrayList<Result>();
	try {
	// Wait for the locations query.
	List<Result> recentLocations = locationsQueryTask.get();

	// Add the matched recent locations to returned results. If a match exists in
	// both the recent locations query and the contacts addresses, only display it
	// as a contacts match.
	for (Result recentLocation : recentLocations) {
	if (recentLocation.mAddress != null &&
	!contactsAddresses.contains(recentLocation.mAddress)) {
	resultList.add(recentLocation);
	}
	}
	} catch (ExecutionException e) {
	Log.e(TAG, "Failed waiting for locations query results.", e);
	} catch (InterruptedException e) {
	Log.e(TAG, "Failed waiting for locations query results.", e);
	}

	// Add all the contacts matches to returned results.
	if (contacts != null) {
	resultList.addAll(contacts);
	}

	// Log the processing duration.
	if (Log.isLoggable(TAG, Log.DEBUG)) {
	long duration = System.currentTimeMillis() - startTime;
	StringBuilder msg = new StringBuilder();
	msg.append("Autocomplete of ").append(constraint);
	msg.append(": location query match took ").append(duration).append("ms ");
	msg.append("(").append(resultList.size()).append(" results)");
	Log.d(TAG, msg.toString());
	}

	final FilterResults filterResults = new FilterResults();
	filterResults.values = resultList;
	filterResults.count = resultList.size();
	return filterResults;
	}

	@Override
	protected void publishResults(CharSequence constraint, FilterResults results) {
	mResultList.clear();
	if (results != null && results.count > 0) {
	mResultList.addAll((ArrayList<Result>) results.values);
	notifyDataSetChanged();
	} else {
	notifyDataSetInvalidated();
	}
	}
	}

	/**
	* Matches the input string against contacts names and addresses.
	*
	* @param resolver The content resolver.
	* @param input The user-typed input string.
	* @param addressesRetVal The addresses in the returned result are also returned here
	* for faster lookup. Pass in an empty set.
	* @return Ordered list of all the matched results. If there are multiple address matches
	* for the same contact, they will be listed together in individual items, with only
	* the first item containing a name/icon.
	*/
	private static List<Result> queryContacts(ContentResolver resolver, String input,
	HashSet<String> addressesRetVal) {
	String where = null;
	String[] whereArgs = null;

	// Match any word in contact name or address.
	if (!TextUtils.isEmpty(input)) {
	where = CONTACTS_WHERE;
	String param1 = input + "%";
	String param2 = "% " + input + "%";
	whereArgs = new String[] {param1, param2, param1, param2};
	}

	// Perform the query.
	Cursor c = resolver.query(CommonDataKinds.StructuredPostal.CONTENT_URI,
	CONTACTS_PROJECTION, where, whereArgs, Contacts.DISPLAY_NAME + " ASC");

	// Process results. Group together addresses for the same contact.
	try {
	Map<String, List<Result>> nameToAddresses = new HashMap<String, List<Result>>();
	c.moveToPosition(-1);
	while (c.moveToNext()) {
	String name = c.getString(CONTACTS_INDEX_DISPLAY_NAME);
	String address = c.getString(CONTACTS_INDEX_ADDRESS);
	if (name != null) {

	List<Result> addressesForName = nameToAddresses.get(name);
	Result result;
	if (addressesForName == null) {
	// Determine if there is a photo for the icon.
	Uri contactPhotoUri = null;
	if (c.getLong(CONTACTS_INDEX_PHOTO_ID) > 0) {
	contactPhotoUri = ContentUris.withAppendedId(Contacts.CONTENT_URI,
	c.getLong(CONTACTS_INDEX_CONTACT_ID));
	}

	// First listing for a distinct contact should have the name/icon.
	addressesForName = new ArrayList<Result>();
	nameToAddresses.put(name, addressesForName);
	result = new Result(name, address, R.drawable.ic_contact_picture,
	contactPhotoUri);
	} else {
	// Do not include name/icon in subsequent listings for the same contact.
	result = new Result(null, address, null, null);
	}

	addressesForName.add(result);
	addressesRetVal.add(address);
	}
	}

	// Return the list of results.
	List<Result> allResults = new ArrayList<Result>();
	for (List<Result> result : nameToAddresses.values()) {
	allResults.addAll(result);
	}
	return allResults;

	} finally {
	if (c != null) {
	c.close();
	}
	}
	}

	/**
	* Matches the input string against recent locations.
	*/
	private static List<Result> queryRecentLocations(ContentResolver resolver, String input) {
	// TODO: also match each word in the address?
	String filter = input == null ? "" : input + "%";
	if (filter.isEmpty()) {
	return null;
	}

	// Query all locations prefixed with the constraint. There is no way to insert
	// 'DISTINCT' or 'GROUP BY' to get rid of dupes, so use post-processing to
	// remove dupes. We will order query results by descending event ID to show
	// results that were most recently inputed.
	Cursor c = resolver.query(Events.CONTENT_URI, EVENT_PROJECTION, LOCATION_WHERE,
	new String[] { "1", filter }, Events._ID + " DESC");
	try {
	List<Result> recentLocations = null;
	if (c != null) {
	// Post process query results.
	recentLocations = processLocationsQueryResults(c);
	}
	return recentLocations;
	} finally {
	if (c != null) {
	c.close();
	}
	}
	}

	/**
	* Post-process the query results to return the first MAX_LOCATION_SUGGESTIONS
	* unique locations in alphabetical order.
	*
	* TODO: Refactor to share code with the recent titles auto-complete.
	*/
	private static List<Result> processLocationsQueryResults(Cursor cursor) {
	TreeSet<String> locations = new TreeSet<String>(String.CASE_INSENSITIVE_ORDER);
	cursor.moveToPosition(-1);

	// Remove dupes.
	while ((locations.size() < MAX_LOCATION_SUGGESTIONS) && cursor.moveToNext()) {
	String location = cursor.getString(EVENT_INDEX_LOCATION).trim();
	locations.add(location);
	}

	// Copy the sorted results.
	List<Result> results = new ArrayList<Result>();
	for (String location : locations) {
	results.add(new Result(null, location, R.drawable.ic_history_holo_light, null));
	}
	return results;
	}
	}