Generate Nearby list using Wikidata Query

Plus,
* remove duplicate location service manager
* add option to switch data sources of Nearby
* faster sorting of places
* minor coding style improvents

app/src/main/java/fr/free/nrw/commons/Utils.java

@@ -8,12 +8,7 @@ import com.nostra13.universalimageloader.core.DisplayImageOptions;
 import com.nostra13.universalimageloader.core.assist.ImageScaleType;
 import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer;
 
-import org.apache.commons.codec.binary.Hex;
+import fr.free.nrw.commons.settings.Prefs;
-import org.apache.commons.codec.digest.DigestUtils;
-import org.apache.commons.codec.net.URLCodec;
-import org.w3c.dom.Node;
-import org.xmlpull.v1.XmlPullParser;
-import org.xmlpull.v1.XmlPullParserException;
 
 import java.io.BufferedInputStream;
 import java.io.IOException;
@@ -28,6 +23,7 @@ import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Locale;
 import java.util.TimeZone;
+import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import javax.xml.transform.Transformer;
@@ -38,7 +34,13 @@ import javax.xml.transform.TransformerFactoryConfigurationError;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.stream.StreamResult;
 
-import fr.free.nrw.commons.settings.Prefs;
+import org.apache.commons.codec.binary.Hex;
+import org.apache.commons.codec.digest.DigestUtils;
+import org.apache.commons.codec.net.URLCodec;
+import org.w3c.dom.Node;
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+
 
 public class Utils {
 
@@ -81,6 +83,22 @@ public class Utils {
         }
     }
 
+    /**
+     * Strips localization symbols from a string.
+     * Removes the suffix after "@" and quotes.
+     *
+     * @param s string possibly containing localization symbols
+     * @return stripped string
+     */
+    public static String stripLocalizedString(String s) {
+        Matcher matcher = Pattern.compile("\\\"(.*)\\\"(@\\w+)?").matcher(s);
+        if (matcher.find()) {
+            return matcher.group(1);
+        } else {
+            return s;
+        }
+    }
+
     public static Date parseMWDate(String mwDate) {
         SimpleDateFormat isoFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.ENGLISH); // Assuming MW always gives me UTC
         try {
@@ -128,8 +146,9 @@ public class Utils {
     }
 
     private static DisplayImageOptions.Builder defaultImageOptionsBuilder;
+
     public static DisplayImageOptions.Builder getGenericDisplayOptions() {
-        if(defaultImageOptionsBuilder == null) {
+        if (defaultImageOptionsBuilder == null) {
             defaultImageOptionsBuilder = new DisplayImageOptions.Builder().cacheInMemory()
                     .imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2);
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
@@ -159,7 +178,7 @@ public class Utils {
     public static long countBytes(InputStream stream) throws IOException {
         long count = 0;
         BufferedInputStream bis = new BufferedInputStream(stream);
-        while(bis.read() != -1) {
+        while (bis.read() != -1) {
             count++;
         }
         return count;
@@ -168,11 +187,11 @@ public class Utils {
     public static String makeThumbUrl(String imageUrl, String filename, int width) {
         // Ugly Hack!
         // Update: OH DEAR GOD WHAT A HORRIBLE HACK I AM SO SORRY
-        if(imageUrl.endsWith("webm")) {
+        if (imageUrl.endsWith("webm")) {
             return imageUrl.replaceFirst("test/", "test/thumb/").replace("commons/", "commons/thumb/") + "/" + width + "px--" + filename.replaceAll("File:", "").replaceAll(" ", "_") + ".jpg";
         } else {
             String thumbUrl = imageUrl.replaceFirst("test/", "test/thumb/").replace("commons/", "commons/thumb/") + "/" + width + "px-" + filename.replaceAll("File:", "").replaceAll(" ", "_");
-            if(thumbUrl.endsWith("jpg") || thumbUrl.endsWith("png") || thumbUrl.endsWith("jpeg")) {
+            if (thumbUrl.endsWith("jpg") || thumbUrl.endsWith("png") || thumbUrl.endsWith("jpeg")) {
                 return thumbUrl;
             } else {
                 return thumbUrl + ".png";
@@ -181,50 +200,49 @@ public class Utils {
     }
 
     public static String capitalize(String string) {
-        return string.substring(0,1).toUpperCase(Locale.getDefault()) + string.substring(1);
+        return string.substring(0, 1).toUpperCase(Locale.getDefault()) + string.substring(1);
     }
 
     public static String licenseTemplateFor(String license) {
-        if(license.equals(Prefs.Licenses.CC_BY_3)) {
+        if (license.equals(Prefs.Licenses.CC_BY_3)) {
             return "{{self|cc-by-3.0}}";
-        } else if(license.equals(Prefs.Licenses.CC_BY_4)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_4)) {
             return "{{self|cc-by-4.0}}";
-        } else if(license.equals(Prefs.Licenses.CC_BY_SA_3)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_SA_3)) {
             return "{{self|cc-by-sa-3.0}}";
-        } else if(license.equals(Prefs.Licenses.CC_BY_SA_4)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_SA_4)) {
             return "{{self|cc-by-sa-4.0}}";
-        } else if(license.equals(Prefs.Licenses.CC0)) {
+        } else if (license.equals(Prefs.Licenses.CC0)) {
             return "{{self|cc-zero}}";
         }
         throw new RuntimeException("Unrecognized license value");
     }
 
     public static int licenseNameFor(String license) {
-        if(license.equals(Prefs.Licenses.CC_BY_3)) {
+        if (license.equals(Prefs.Licenses.CC_BY_3)) {
             return R.string.license_name_cc_by;
-        } else if(license.equals(Prefs.Licenses.CC_BY_4)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_4)) {
             return R.string.license_name_cc_by_four;
-        } else if(license.equals(Prefs.Licenses.CC_BY_SA_3)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_SA_3)) {
             return R.string.license_name_cc_by_sa;
-        } else if(license.equals(Prefs.Licenses.CC_BY_SA_4)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_SA_4)) {
             return R.string.license_name_cc_by_sa_four;
-        } else if(license.equals(Prefs.Licenses.CC0)) {
+        } else if (license.equals(Prefs.Licenses.CC0)) {
             return R.string.license_name_cc0;
         }
         throw new RuntimeException("Unrecognized license value");
     }
 
     public static String licenseUrlFor(String license) {
-        if(license.equals(Prefs.Licenses.CC_BY_3)) {
+        if (license.equals(Prefs.Licenses.CC_BY_3)) {
             return "https://creativecommons.org/licenses/by/3.0/";
-        } else if(license.equals(Prefs.Licenses.CC_BY_4)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_4)) {
             return "https://creativecommons.org/licenses/by/4.0/";
-        } else if(license.equals(Prefs.Licenses.CC_BY_SA_3)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_SA_3)) {
             return "https://creativecommons.org/licenses/by-sa/3.0/";
-        } else if(license.equals(Prefs.Licenses.CC_BY_SA_4)) {
+        } else if (license.equals(Prefs.Licenses.CC_BY_SA_4)) {
             return "https://creativecommons.org/licenses/by-sa/4.0/";
-        }
+        } else if (license.equals(Prefs.Licenses.CC0)) {
-        else if(license.equals(Prefs.Licenses.CC0)) {
             return "https://creativecommons.org/publicdomain/zero/1.0/";
         }
         throw new RuntimeException("Unrecognized license value");

app/src/main/java/fr/free/nrw/commons/nearby/NearbyActivity.java

@@ -32,12 +32,14 @@ public class NearbyActivity extends BaseActivity {
         ft.add(R.id.container, fragment);
         ft.commit();
     }
+
     @Override
-    public boolean onCreateOptionsMenu (Menu menu) {
+    public boolean onCreateOptionsMenu(Menu menu) {
         MenuInflater inflater = getMenuInflater();
         inflater.inflate(R.menu.menu_nearby, menu);
         return super.onCreateOptionsMenu(menu);
     }
+
     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         // Handle item selection
@@ -49,19 +51,23 @@ public class NearbyActivity extends BaseActivity {
                 return super.onOptionsItemSelected(item);
         }
     }
+
     @Override
-    protected void onResume(){
+    protected void onResume() {
         super.onResume();
     }
 
-    protected void refreshView()
+    protected void refreshView() {
-    {
         getSupportFragmentManager().beginTransaction()
                 .replace(R.id.container, new NearbyListFragment()).commit();
     }
 
+    public LocationServiceManager getLocationManager() {
+        return locationManager;
+    }
+
     @Override
-    protected void onDestroy(){
+    protected void onDestroy() {
         super.onDestroy();
         locationManager.unregisterLocationManager();
     }

app/src/main/java/fr/free/nrw/commons/nearby/NearbyAdapter.java

@@ -33,7 +33,7 @@ public class NearbyAdapter extends ArrayAdapter<Place> {
     public View getView(int position, View convertView, ViewGroup parent) {
         // Get the data item for this position
         Place place = getItem(position);
-        Log.d("NearbyAdapter", "Place " + place.name);
+        Log.v("NearbyAdapter", "" + place);
 
         // Check if an existing view is being reused, otherwise inflate the view
         if (convertView == null) {

app/src/main/java/fr/free/nrw/commons/nearby/NearbyListFragment.java

@@ -4,9 +4,11 @@ import static fr.free.nrw.commons.utils.LengthUtils.computeDistanceBetween;
 import static fr.free.nrw.commons.utils.LengthUtils.formatDistanceBetween;
 
 import android.content.Intent;
+import android.content.SharedPreferences;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Bundle;
+import android.preference.PreferenceManager;
 import android.support.v4.app.ListFragment;
 import android.util.Log;
 import android.view.LayoutInflater;
@@ -20,16 +22,18 @@ import butterknife.ButterKnife;
 import butterknife.OnItemClick;
 import fr.free.nrw.commons.R;
 import fr.free.nrw.commons.location.LatLng;
-import fr.free.nrw.commons.location.LocationServiceManager;
 
 import java.util.Collections;
 import java.util.Comparator;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
+import java.util.Map;
 
 public class NearbyListFragment extends ListFragment implements TaskListener {
 
+    private static final int MAX_RESULTS = 1000;
     private NearbyAsyncTask nearbyAsyncTask;
-    private NearbyAdapter mAdapter;
 
     @BindView(R.id.listview) ListView listview;
     @BindView(R.id.progressBar) ProgressBar progressBar;
@@ -37,7 +41,6 @@ public class NearbyListFragment extends ListFragment implements TaskListener {
     private boolean isTaskRunning = false;
 
     private List<Place> places;
-    private LatLng mLatestLocation;
 
     private static final String TAG = NearbyListFragment.class.getName();
 
@@ -64,8 +67,7 @@ public class NearbyListFragment extends ListFragment implements TaskListener {
     public void onViewCreated(View view, Bundle savedInstanceState) {
 
         //Check that this is the first time view is created, to avoid double list when screen orientation changed
-        if(savedInstanceState == null) {
+        if (savedInstanceState == null) {
-            mLatestLocation = new LocationServiceManager(getActivity()).getLatestLocation();
             nearbyAsyncTask = new NearbyAsyncTask(this);
             nearbyAsyncTask.execute();
             progressBar.setVisibility(View.VISIBLE);
@@ -116,7 +118,7 @@ public class NearbyListFragment extends ListFragment implements TaskListener {
         super.onDestroy();
 
         // See http://stackoverflow.com/questions/18264408/incomplete-asynctask-crashes-my-app
-        if(nearbyAsyncTask != null && nearbyAsyncTask.getStatus() != AsyncTask.Status.FINISHED) {
+        if (nearbyAsyncTask != null && nearbyAsyncTask.getStatus() != AsyncTask.Status.FINISHED) {
             nearbyAsyncTask.cancel(true);
         }
     }
@@ -125,7 +127,7 @@ public class NearbyListFragment extends ListFragment implements TaskListener {
 
         private final TaskListener listener;
 
-        public NearbyAsyncTask (TaskListener listener) {
+        public NearbyAsyncTask(TaskListener listener) {
             this.listener = listener;
         }
 
@@ -143,7 +145,9 @@ public class NearbyListFragment extends ListFragment implements TaskListener {
 
         @Override
         protected List<Place> doInBackground(Void... params) {
-            places = loadAttractionsFromLocation(mLatestLocation);
+            places = loadAttractionsFromLocation(
+                    ((NearbyActivity)getActivity()).getLocationManager().getLatestLocation()
+            );
             return places;
         }
 
@@ -151,18 +155,17 @@ public class NearbyListFragment extends ListFragment implements TaskListener {
         protected void onPostExecute(List<Place> result) {
             super.onPostExecute(result);
 
-            if(isCancelled()) {
+            if (isCancelled()) {
                 return;
             }
 
             progressBar.setVisibility(View.GONE);
+            NearbyAdapter adapter = new NearbyAdapter(getActivity(), places);
 
-            mAdapter = new NearbyAdapter(getActivity(), places);
+            listview.setAdapter(adapter);
-
-            listview.setAdapter(mAdapter);
 
             listener.onTaskFinished(result);
-            mAdapter.notifyDataSetChanged();
+            adapter.notifyDataSetChanged();
         }
     }
 
@@ -188,32 +191,39 @@ public class NearbyListFragment extends ListFragment implements TaskListener {
         }
     }
 
-    private List<Place> loadAttractionsFromLocation(final LatLng curLatLng) {
+    private List<Place> loadAttractionsFromLocation(LatLng curLatLng) {
-
+        Log.d(TAG, "Loading attractions near " + curLatLng);
-        List<Place> places = NearbyPlaces.get();
+        if (curLatLng == null) {
+            return Collections.emptyList();
+        }
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(getActivity());
+        List<Place> places = prefs.getBoolean("useWikidata", true)
+                ? NearbyPlaces.getInstance().getFromWikidataQuery(
+                        curLatLng, Locale.getDefault().getLanguage())
+                : NearbyPlaces.getInstance().getFromWikiNeedsPictures();
         if (curLatLng != null) {
             Log.d(TAG, "Sorting places by distance...");
+            final Map<Place, Double> distances = new HashMap<>();
+            for (Place place: places) {
+                distances.put(place, computeDistanceBetween(place.location, curLatLng));
+            }
             Collections.sort(places,
                     new Comparator<Place>() {
                         @Override
                         public int compare(Place lhs, Place rhs) {
-                            double lhsDistance = computeDistanceBetween(
+                            double lhsDistance = distances.get(lhs);
-                                    lhs.location, curLatLng);
+                            double rhsDistance = distances.get(rhs);
-                            double rhsDistance = computeDistanceBetween(
-                                    rhs.location, curLatLng);
                             return (int) (lhsDistance - rhsDistance);
                         }
                     }
             );
         }
 
-        if (places.size() > 0) {
+        places = places.subList(0, Math.min(places.size(), MAX_RESULTS));
-            for (int i = 0; i < 100; i++) {
+        for (Place place: places) {
-                Place place = places.get(i);
+            String distance = formatDistanceBetween(curLatLng, place.location);
-                String distance = formatDistanceBetween(mLatestLocation, place.location);
             place.setDistance(distance);
         }
-        }
         return places;
     }
 }

app/src/main/java/fr/free/nrw/commons/nearby/NearbyPlaces.java

@@ -1,31 +1,166 @@
 package fr.free.nrw.commons.nearby;
 
+import android.net.Uri;
 import android.os.StrictMode;
 import android.util.Log;
 
+import fr.free.nrw.commons.Utils;
 import fr.free.nrw.commons.location.LatLng;
 
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLEncoder;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 
 public class NearbyPlaces {
 
     private static final String TAG = NearbyPlaces.class.getName();
-    static List<Place> places = null;
+    private static final int MIN_RESULTS = 40;
+    private static final double INITIAL_RADIUS = 1.0;
+    private static final double MAX_RADIUS = 300.0;
+    private static final double RADIUS_MULTIPLIER = 1.618;
+    private static final String WIKIDATA_QUERY_URL = "https://query.wikidata.org/sparql?query=${QUERY}";
+    private static final String WIKIDATA_QUERY_TEMPLATE = "SELECT\n" +
+                    "  (SAMPLE(?location) as ?location)\n" +
+                    "  ?item\n" +
+                    "  (SAMPLE(COALESCE(?item_label_preferred_language, ?item_label_any_language)) as ?label)\n" +
+                    "  (SAMPLE(?classId) as ?class)\n" +
+                    "  (SAMPLE(COALESCE(?class_label_preferred_language, ?class_label_any_language, \"?\")) as ?class_label)\n" +
+                    "  (SAMPLE(COALESCE(?icon0, ?icon1)) as ?icon)\n" +
+                    "  (SAMPLE(COALESCE(?emoji0, ?emoji1)) as ?emoji)\n" +
+                    "WHERE {\n" +
+                    "  # Around given location...\n" +
+                    "  SERVICE wikibase:around {\n" +
+                    "    ?item wdt:P625 ?location.\n" +
+                    "    bd:serviceParam wikibase:center \"Point(${LONG} ${LAT})\"^^geo:wktLiteral. \n" +
+                    "    bd:serviceParam wikibase:radius \"${RADIUS}\" . # Radius in kilometers.\n" +
+                    "  }\n" +
+                    "  \n" +
+                    "  # ... and without an image.\n" +
+                    "  MINUS {?item wdt:P18 []}\n" +
+                    "  \n" +
+                    "  # Get the label in the preferred language of the user, or any other language if no label is available in that language.\n" +
+                    "  OPTIONAL {?item rdfs:label ?item_label_preferred_language. FILTER (lang(?item_label_preferred_language) = \"${LANG}\")}\n" +
+                    "  OPTIONAL {?item rdfs:label ?item_label_any_language}\n" +
+                    "  \n" +
+                    "  # Get the class label in the preferred language of the user, or any other language if no label is available in that language.\n" +
+                    "  OPTIONAL {\n" +
+                    "    ?item p:P31/ps:P31 ?classId.\n" +
+                    "    OPTIONAL {?classId rdfs:label ?class_label_preferred_language. FILTER (lang(?class_label_preferred_language) = \"${LANG}\")}\n" +
+                    "    OPTIONAL {?classId rdfs:label ?class_label_any_language}\n" +
+                    "\n" +
+                    "    # Get icon\n" +
+                    "    OPTIONAL { ?classId wdt:P2910 ?icon0. }\n" +
+                    "    OPTIONAL { ?classId wdt:P279*/wdt:P2910 ?icon1. }\n" +
+                    "    # Get emoji\n" +
+                    "    OPTIONAL { ?classId wdt:P487 ?emoji0. }\n" +
+                    "    OPTIONAL { ?classId wdt:P279*/wdt:P487 ?emoji1. }\n" +
+                    "  }\n" +
+                    "}\n" +
+                    "GROUP BY ?item\n";
+    private static NearbyPlaces singleton;
+    private double radius = INITIAL_RADIUS;
+    private List<Place> places;
 
-    public static List<Place> get() {
+    private NearbyPlaces(){
-        if(places != null) {
+    }
+
+    List<Place> getFromWikidataQuery(LatLng curLatLng, String lang) {
+        List<Place> places = Collections.emptyList();
+
+        try {
+            // increase the radius gradually to find a satisfactory number of nearby places
+            while (radius < MAX_RADIUS) {
+                places = getFromWikidataQuery(curLatLng, lang, radius);
+                Log.d(TAG, places.size() + " results at radius: " + radius);
+                if (places.size() >= MIN_RESULTS) {
+                    break;
+                } else {
+                    radius *= RADIUS_MULTIPLIER;
+                }
+            }
+        } catch (IOException e) {
+            Log.d(TAG, "" + e.toString());
+            // errors tend to be caused by too many results (and time out)
+            // try a small radius next time
+            Log.d(TAG, "back to initial radius: " + radius);
+            radius = INITIAL_RADIUS;
+        }
         return places;
     }
-        else {
+
+    private List<Place> getFromWikidataQuery(LatLng cur, String lang, double radius)
+            throws IOException {
+        List<Place> places = new ArrayList<>();
+        String query = WIKIDATA_QUERY_TEMPLATE.replace("${RADIUS}", "" + radius)
+                .replace("${LAT}", "" + String.format("%.3f", cur.latitude))
+                .replace("${LONG}", "" + String.format("%.3f", cur.longitude))
+                .replace("${LANG}", "" + lang);
+        query = URLEncoder.encode(query, "utf-8").replace("+", "%20");
+        String url = WIKIDATA_QUERY_URL.replace("${QUERY}", query);
+        Log.d(TAG, url.toString());
+        URLConnection conn = new URL(url).openConnection();
+        conn.setRequestProperty("Accept", "text/tab-separated-values");
+        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
+
+        String line;
+        Log.d(TAG, "Reading from query result...");
+        while ((line = in.readLine()) != null) {
+            Log.v(TAG, line);
+            line = line + "\n"; // to pad columns and make fields a fixed size
+            if (!line.startsWith("\"Point")) {
+                continue;
+            }
+
+            String[] fields = line.split("\t");
+            String point = fields[0];
+            String name = Utils.stripLocalizedString(fields[2]);
+            String type = Utils.stripLocalizedString(fields[4]);
+            String icon = fields[5];
+
+            double latitude = 0;
+            double longitude = 0;
+            Matcher matcher =
+                    Pattern.compile("Point\\(([^ ]+) ([^ ]+)\\)").matcher(point);
+            if (!matcher.find()) {
+                continue;
+            }
+            try {
+                longitude = Double.parseDouble(matcher.group(1));
+                latitude = Double.parseDouble(matcher.group(2));
+            } catch (NumberFormatException e) {
+                throw new RuntimeException("LatLng parse error: " + point);
+            }
+
+            places.add(new Place(
+                    name,
+                    type, // list
+                    type, // details
+                    Uri.parse(icon),
+                    new LatLng(latitude, longitude)
+            ));
+        }
+        in.close();
+
+        return places;
+    }
+
+    List<Place> getFromWikiNeedsPictures() {
+        if (places != null) {
+            return places;
+        } else {
             try {
                 places = new ArrayList<>();
-                StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
+                StrictMode.ThreadPolicy policy
+                        = new StrictMode.ThreadPolicy.Builder().permitAll().build();
                 StrictMode.setThreadPolicy(policy);
 
                 URL file = new URL("https://tools.wmflabs.org/wiki-needs-pictures/data/data.csv");
@@ -45,7 +180,7 @@ public class NearbyPlaces {
                     }
 
                     String[] fields = line.split(",");
-                    String name = fields[0];
+                    String name = Utils.stripLocalizedString(fields[0]);
 
                     double latitude;
                     double longitude;
@@ -73,10 +208,22 @@ public class NearbyPlaces {
                 in.close();
 
             } catch (IOException e) {
-                e.printStackTrace();
+                Log.d(TAG, e.toString());
             }
         }
         return places;
     }
 
+    /**
+     * Get the singleton instance of this class.
+     * The instance is created upon the first invocation of this method, and then reused.
+     *
+     * @return The singleton instance
+     */
+    public static synchronized NearbyPlaces getInstance() {
+        if (singleton == null) {
+            singleton = new NearbyPlaces();
+        }
+        return singleton;
+    }
 }

app/src/main/java/fr/free/nrw/commons/nearby/NearbyViewHolder.java

@@ -23,10 +23,8 @@ public class NearbyViewHolder implements ViewHolder<Place> {
 
     @Override
     public void bindModel(Context context, Place place) {
-        String quotelessName = place.name.replaceAll("^\"|\"$", "");
-
         // Populate the data into the template view using the data object
-        tvName.setText(quotelessName);
+        tvName.setText(place.name);
         tvDesc.setText(place.description);
         distance.setText(place.distance);
 

app/src/main/java/fr/free/nrw/commons/nearby/Place.java

@@ -7,18 +7,16 @@ import fr.free.nrw.commons.location.LatLng;
 
 public class Place {
 
-    public String name;
+    public final String name;
-    public String description;
+    public final String description;
-    public String longDescription;
+    public final String longDescription;
-    public Uri secondaryImageUrl;
+    public final Uri secondaryImageUrl;
-    public LatLng location;
+    public final LatLng location;
 
     public Bitmap image;
     public Bitmap secondaryImage;
     public String distance;
 
-    public Place() {}
-
     public Place(String name, String description, String longDescription,
                  Uri secondaryImageUrl, LatLng location) {
         this.name = name;
@@ -32,4 +30,24 @@ public class Place {
         this.distance = distance;
     }
 
+    @Override
+    public boolean equals(Object o) {
+        if (o instanceof Place) {
+            Place that = (Place)o;
+            return this.name.equals(that.name) && this.location.equals(that.location);
+        } else {
+            return false;
+        }
+    }
+
+    @Override
+    public int hashCode() {
+        return this.name.hashCode() * 31 + this.location.hashCode();
+    }
+
+    @Override
+    public String toString() {
+        return String.format("Place(%s@%s)", name, location);
+    }
+
 }

app/src/main/java/fr/free/nrw/commons/utils/LengthUtils.java

@@ -27,8 +27,14 @@ public class LengthUtils {
         return numberFormat.format(distance) + "m";
     }
 
+    /**
+     * Computes the distance between two points.
+     * @param from one of the two end points
+     * @param to one of the two end points
+     * @return distance between the points in meter
+     */
     public static double computeDistanceBetween(LatLng from, LatLng to) {
-        return computeAngleBetween(from, to) * 6371009.0D;
+        return computeAngleBetween(from, to) * 6371009.0D; // Earth's radius in meter
     }
 
     private static double computeAngleBetween(LatLng from, LatLng to) {

app/src/main/res/values/strings.xml

@@ -165,4 +165,6 @@ Tap this message (or hit back) to skip this step.</string>
   <string name="become_a_tester_title">Become a Beta Tester</string>
   <string name="become_a_tester_description">Opt-in to our beta channel on Google Play and get early access to new features and bug fixes</string>
   <string name="beta_opt_in_link">https://play.google.com/apps/testing/fr.free.nrw.commons</string>
+  <string name="use_wikidata">Use Wikidata</string>
+  <string name="use_wikidata_summary">(Warning: disabling this may cause large mobile data consumption)</string>
 </resources>

app/src/main/res/xml/preferences.xml

@@ -31,4 +31,11 @@
         android:key="theme"
         />
 
+    <CheckBoxPreference
+        android:key="useWikidata"
+        android:title="@string/use_wikidata"
+        android:defaultValue="true"
+        android:summary="@string/use_wikidata_summary"
+        />
+
 </PreferenceScreen>

app/src/test/java/fr/free/nrw/commons/UtilsTest.java

@@ -1,8 +1,8 @@
 package fr.free.nrw.commons;
 import org.junit.Test;
 
-import static org.junit.Assert.*;
 import static org.hamcrest.CoreMatchers.is;
+import static org.junit.Assert.*;
 
 
 public class UtilsTest {
@@ -11,7 +11,7 @@ public class UtilsTest {
         assertThat(Utils.fixExtension("SampleFile.jpeg", "jpeg"), is("SampleFile.jpg"));
     }
 
-    @Test public void fixExtensionJPEGToJpg() {
+    @Test public void fixExtensionJpegToJpg() {
         assertThat(Utils.fixExtension("SampleFile.JPEG", null), is("SampleFile.jpg"));
     }
 
@@ -46,4 +46,12 @@ public class UtilsTest {
     @Test public void fixExtensionJpegNotExtension() {
         assertThat(Utils.fixExtension("SAMPLE.jpeg.SAMPLE", "jpg"), is("SAMPLE.jpeg.SAMPLE.jpg"));
     }
+
+    @Test public void stripLocalizedStringPass() {
+        assertThat(Utils.stripLocalizedString("Hello"), is("Hello"));
+    }
+
+    @Test public void stripLocalizedStringJa() {
+        assertThat(Utils.stripLocalizedString("\"こんにちは\"@ja"), is("こんにちは"));
+    }
 }