diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/DataSource.java b/MyTracks/src/com/google/android/apps/mytracks/content/DataSource.java
new file mode 100644
index 000000000..5cda864d7
--- /dev/null
+++ b/MyTracks/src/com/google/android/apps/mytracks/content/DataSource.java
@@ -0,0 +1,192 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * 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.google.android.apps.mytracks.content;
+
+import static com.google.android.apps.mytracks.Constants.MAX_LOCATION_AGE_MS;
+
+import com.google.android.apps.mytracks.Constants;
+import com.google.android.maps.mytracks.R;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
+import android.database.ContentObserver;
+import android.hardware.Sensor;
+import android.hardware.SensorEventListener;
+import android.hardware.SensorManager;
+import android.location.Location;
+import android.location.LocationListener;
+import android.location.LocationManager;
+import android.net.Uri;
+import android.util.Log;
+import android.widget.Toast;
+
+/**
+ * Data source on the phone.
+ * 
+ * @author Rodrigo Damazio
+ */
+public class DataSource {
+
+  private static final int NETWORK_PROVIDER_MIN_TIME = 5 * 60 * 1000; // 5 minutes
+  private static final String TAG = DataSource.class.getSimpleName();
+
+  private final Context context;
+  private final ContentResolver contentResolver;
+  private final LocationManager locationManager;
+  private final SensorManager sensorManager;
+  private final SharedPreferences sharedPreferences;
+  
+  public DataSource(Context context) {
+    this.context = context;
+    contentResolver = context.getContentResolver();
+    locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
+    sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
+    sharedPreferences = context.getSharedPreferences(Constants.SETTINGS_NAME, Context.MODE_PRIVATE);
+  }
+
+  /**
+   * Registers a content observer.
+   * 
+   * @param uri the uri
+   * @param observer the observer
+   */
+  public void registerContentObserver(Uri uri, ContentObserver observer) {
+    contentResolver.registerContentObserver(uri, false, observer);
+  }
+
+  /**
+   * Unregisters a content observer.
+   * 
+   * @param observer the observer
+   */
+  public void unregisterContentObserver(ContentObserver observer) {
+    contentResolver.unregisterContentObserver(observer);
+  }
+
+  /**
+   * Registers a location listener.
+   * 
+   * @param listener the listener
+   */
+  public void registerLocationListener(LocationListener listener) {
+    // Check if the GPS provider exists
+    if (locationManager.getProvider(LocationManager.GPS_PROVIDER) == null) {
+      listener.onProviderDisabled(LocationManager.GPS_PROVIDER);
+      unregisterLocationListener(listener);
+      return;
+    }
+
+    // Listen for GPS location
+    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, listener);
+
+    // Update the listener with the current provider state
+    if (locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
+      listener.onProviderEnabled(LocationManager.GPS_PROVIDER);
+    } else {
+      listener.onProviderDisabled(LocationManager.GPS_PROVIDER);
+    }
+
+    // Listen for network location
+    try {
+      locationManager.requestLocationUpdates(
+          LocationManager.NETWORK_PROVIDER, NETWORK_PROVIDER_MIN_TIME, 0, listener);
+    } catch (RuntimeException e) {
+      // Network location is optional, so just log the exception
+      Log.w(TAG, "Could not register for network location.", e);
+    }
+  }
+
+  /**
+   * Unregisters a location listener.
+   * 
+   * @param listener the listener
+   */
+  public void unregisterLocationListener(LocationListener listener) {
+    locationManager.removeUpdates(listener);
+  }
+
+  /**
+   * Gets the last known location.
+   */
+  public Location getLastKnownLocation() {
+    Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
+    if (!isLocationRecent(location)) {
+      // Try network location
+      location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
+      int id = isLocationRecent(location) 
+          ? R.string.my_location_approximate_location : R.string.my_location_no_location;
+      Toast.makeText(context, id, Toast.LENGTH_LONG).show();
+    }
+    return location;
+  }
+
+  /**
+   * Returns true if the location is recent.
+   * 
+   * @param location the location
+   */
+  private boolean isLocationRecent(Location location) {
+    if (location == null) {
+      return false;
+    }
+    return location.getTime() > System.currentTimeMillis() - MAX_LOCATION_AGE_MS;
+  }
+
+  /**
+   * Registers a compass listener.
+   * 
+   * @param listener the listener
+   */
+  public void registerCompassListener(SensorEventListener listener) {
+    Sensor compass = sensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION);
+    if (compass == null) {
+      Log.d(TAG, "No compass sensor.");
+      return;
+    }
+    sensorManager.registerListener(listener, compass, SensorManager.SENSOR_DELAY_UI);
+  }
+
+  /**
+   * Unregisters a compass listener.
+   * 
+   * @param listener the listener
+   */
+  public void unregisterCompassListener(SensorEventListener listener) {
+    sensorManager.unregisterListener(listener);
+  }
+
+  /**
+   * Registers a shared preference change listener.
+   * 
+   * @param listener the listener
+   */
+  public void registerOnSharedPreferenceChangeListener(OnSharedPreferenceChangeListener listener) {
+    sharedPreferences.registerOnSharedPreferenceChangeListener(listener);
+  }
+
+  /**
+   * Unregisters a shared preference change listener.
+   * 
+   * @param listener the listener
+   */
+  public void unregisterOnSharedPreferenceChangeListener(
+      OnSharedPreferenceChangeListener listener) {
+    sharedPreferences.unregisterOnSharedPreferenceChangeListener(listener);
+  }
+}
\ No newline at end of file
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/DataSourceListener.java b/MyTracks/src/com/google/android/apps/mytracks/content/DataSourceListener.java
new file mode 100644
index 000000000..01cc1e7ef
--- /dev/null
+++ b/MyTracks/src/com/google/android/apps/mytracks/content/DataSourceListener.java
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * 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.google.android.apps.mytracks.content;
+
+import android.location.Location;
+
+/**
+ * Listener to be invoked when {@link DataSource} changes.
+ * 
+ * @author Jimmy Shih
+ */
+public interface DataSourceListener {
+
+  /**
+   * Notifies when the tracks table is updated.
+   */
+  public void notifyTracksTableUpdated();
+
+  /**
+   * Notifies when the waypoints table is updated.
+   */
+  public void notifyWaypointsTableUpdated();
+
+  /**
+   * Notifies when the track points table is updated.
+   */
+  public void notifyTrackPointsTableUpdated();
+
+  /**
+   * Notifies when the current location changes.
+   * 
+   * @param location the location
+   */
+  public void notifyLocationChanged(Location location);
+  
+  
+  /**
+   * Notifies when the location provider enabled status changes.
+   * 
+   * @param enabled true if enabled, false if not
+   */
+  public void notifyLocationProviderEnabled(boolean enabled);
+
+  /**
+   * Notifies when the location provider availability status changes.
+   * 
+   * @param available true if available, false if not
+   */
+  public void notifyLocationProviderAvailable(boolean available);
+
+  /**
+   * Notifies when the compass heading changes.
+   * 
+   * @param heading the new heading
+   */
+  public void notifyHeadingChanged(float heading);
+  
+  /**
+   * Notifies when a preference changes.
+   * 
+   * @param key the preference key
+   */
+  public void notifyPreferenceChanged(String key);
+}
\ No newline at end of file
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/DataSourceManager.java b/MyTracks/src/com/google/android/apps/mytracks/content/DataSourceManager.java
index 90c1e914d..8da7841a7 100644
--- a/MyTracks/src/com/google/android/apps/mytracks/content/DataSourceManager.java
+++ b/MyTracks/src/com/google/android/apps/mytracks/content/DataSourceManager.java
@@ -1,16 +1,29 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * 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.google.android.apps.mytracks.content;
 
 import static com.google.android.apps.mytracks.Constants.TAG;
 
-import com.google.android.apps.mytracks.content.TrackDataHub.ListenerDataType;
-
 import android.content.SharedPreferences;
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
 import android.database.ContentObserver;
 import android.hardware.Sensor;
 import android.hardware.SensorEvent;
 import android.hardware.SensorEventListener;
-import android.hardware.SensorManager;
 import android.location.Location;
 import android.location.LocationListener;
 import android.location.LocationManager;
@@ -23,243 +36,281 @@ import java.util.EnumSet;
 import java.util.Set;
 
 /**
- * External data source manager, which converts system-level events into My Tracks data events.
- *
+ * Data source manager. Creates observers/listeners and manages their
+ * registration with {@link DataSource}. The observers/listeners calls
+ * {@link DataSourceListener} when data changes.
+ * 
  * @author Rodrigo Damazio
  */
-class DataSourceManager {
+public class DataSourceManager {
 
-  /** Single interface for receiving system events that were registered for. */
-  interface DataSourceListener {
-    void notifyTrackUpdated();
-    void notifyWaypointUpdated();
-    void notifyPointsUpdated();
-    void notifyPreferenceChanged(String key);
-    void notifyLocationProviderEnabled(boolean enabled);
-    void notifyLocationProviderAvailable(boolean available);
-    void notifyLocationChanged(Location loc);
-    void notifyHeadingChanged(float heading);
-  }
+  /**
+   * Observer when the tracks table is updated.
+   * 
+   * @author Jimmy Shih
+   */
+  private class TracksTableObserver extends ContentObserver {
 
-  private final DataSourceListener listener;
-
-  /** Observer for when the tracks table is updated. */
-  private class TrackObserver extends ContentObserver {
-    public TrackObserver() {
-      super(contentHandler);
+    public TracksTableObserver() {
+      super(handler);
     }
 
     @Override
     public void onChange(boolean selfChange) {
-      listener.notifyTrackUpdated();
+      dataSourceListener.notifyTracksTableUpdated();
     }
   }
 
-  /** Observer for when the waypoints table is updated. */
-  private class WaypointObserver extends ContentObserver {
-    public WaypointObserver() {
-      super(contentHandler);
+  /**
+   * Observer when the waypoints table is updated.
+   * 
+   * @author Jimmy Shih
+   */
+  private class WaypointsTableObserver extends ContentObserver {
+
+    public WaypointsTableObserver() {
+      super(handler);
     }
 
     @Override
     public void onChange(boolean selfChange) {
-      listener.notifyWaypointUpdated();
+      dataSourceListener.notifyWaypointsTableUpdated();
     }
   }
 
-  /** Observer for when the points table is updated. */
-  private class PointObserver extends ContentObserver {
-    public PointObserver() {
-      super(contentHandler);
+  /**
+   * Observer when the track points table is updated.
+   * 
+   * @author Jimmy Shih
+   */
+  private class TrackPointsTableObserver extends ContentObserver {
+
+    public TrackPointsTableObserver() {
+      super(handler);
     }
 
     @Override
     public void onChange(boolean selfChange) {
-      listener.notifyPointsUpdated();
+      dataSourceListener.notifyTrackPointsTableUpdated();
     }
   }
 
-  /** Listener for when preferences change. */
-  private class HubSharedPreferenceListener implements OnSharedPreferenceChangeListener {
-    @Override
-    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
-      listener.notifyPreferenceChanged(key);
-    }
-  }
-
-  /** Listener for the current location (independent from track data). */
-  private class CurrentLocationListener implements
-      LocationListener {
-    @Override
-    public void onStatusChanged(String provider, int status, Bundle extras) {
-      if (!LocationManager.GPS_PROVIDER.equals(provider)) return;
-
-      listener.notifyLocationProviderAvailable(status == LocationProvider.AVAILABLE);
-    }
+  /**
+   * Listener for location changes.
+   * 
+   * @author Jimmy Shih
+   */
+  private class CurrentLocationListener implements LocationListener {
 
     @Override
-    public void onProviderEnabled(String provider) {
-      if (!LocationManager.GPS_PROVIDER.equals(provider)) return;
-
-      listener.notifyLocationProviderEnabled(true);
+    public void onLocationChanged(Location location) {
+      dataSourceListener.notifyLocationChanged(location);
     }
 
     @Override
     public void onProviderDisabled(String provider) {
-      if (!LocationManager.GPS_PROVIDER.equals(provider)) return;
-
-      listener.notifyLocationProviderEnabled(false);
+      if (!LocationManager.GPS_PROVIDER.equals(provider)) {
+        return;
+      }
+      dataSourceListener.notifyLocationProviderEnabled(false);
     }
 
     @Override
-    public void onLocationChanged(Location location) {
-      listener.notifyLocationChanged(location);
+    public void onProviderEnabled(String provider) {
+      if (!LocationManager.GPS_PROVIDER.equals(provider)) {
+        return;
+      }
+      dataSourceListener.notifyLocationProviderEnabled(true);
+    }
+
+    @Override
+    public void onStatusChanged(String provider, int status, Bundle extras) {
+      if (!LocationManager.GPS_PROVIDER.equals(provider)) {
+        return;
+      }
+      dataSourceListener.notifyLocationProviderAvailable(status == LocationProvider.AVAILABLE);
     }
   }
 
-  /** Listener for compass readings. */
-  private class CompassListener implements
-      SensorEventListener {
-    @Override
-    public void onSensorChanged(SensorEvent event) {
-      listener.notifyHeadingChanged(event.values[0]);
-    }
+  /**
+   * Listener for compass changes.
+   * 
+   * @author Jimmy Shih
+   */
+  private class CompassListener implements SensorEventListener {
 
     @Override
     public void onAccuracyChanged(Sensor sensor, int accuracy) {
       // Do nothing
     }
+
+    @Override
+    public void onSensorChanged(SensorEvent event) {
+      dataSourceListener.notifyHeadingChanged(event.values[0]);
+    }
   }
 
-  /** Wrapper for registering internal listeners. */
-  private final DataSourcesWrapper dataSources;
+  /**
+   * Listener for preference changes.
+   * 
+   * @author Jimmy Shih
+   */
+  private class PreferenceListener implements OnSharedPreferenceChangeListener {
 
-  // Internal listeners (to receive data from the system)
-  private final Set<ListenerDataType> registeredListeners =
-      EnumSet.noneOf(ListenerDataType.class);
-  private final Handler contentHandler;
-  private final ContentObserver pointObserver;
-  private final ContentObserver waypointObserver;
-  private final ContentObserver trackObserver;
-  private final LocationListener locationListener;
-  private final OnSharedPreferenceChangeListener preferenceListener;
-  private final SensorEventListener compassListener;
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+      dataSourceListener.notifyPreferenceChanged(key);
+    }
+  }
 
-  DataSourceManager(DataSourceListener listener, DataSourcesWrapper dataSources) {
-    this.listener = listener;
-    this.dataSources = dataSources;
+  private final DataSource dataSource;
+  private final DataSourceListener dataSourceListener;
 
-    contentHandler = new Handler();
-    pointObserver = new PointObserver();
-    waypointObserver = new WaypointObserver();
-    trackObserver = new TrackObserver();
+  // Registered listeners
+  private final Set<TrackDataType> registeredListeners = EnumSet.noneOf(TrackDataType.class);
+  
+  private final Handler handler;
+  private final TracksTableObserver tracksTableObserver;
+  private final WaypointsTableObserver waypointsTableObserver;
+  private final TrackPointsTableObserver trackPointsTableObserver;
+  private final CurrentLocationListener currentLocationListener;
+  private final CompassListener compassListener;
+  private final PreferenceListener preferenceListener;
 
+  public DataSourceManager(DataSource dataSource, DataSourceListener dataSourceListener) {
+    this.dataSource = dataSource;
+    this.dataSourceListener = dataSourceListener;
+
+    handler = new Handler();
+    tracksTableObserver = new TracksTableObserver();
+    waypointsTableObserver = new WaypointsTableObserver();
+    trackPointsTableObserver = new TrackPointsTableObserver();
+    currentLocationListener = new CurrentLocationListener();
     compassListener = new CompassListener();
-    locationListener = new CurrentLocationListener();
-    preferenceListener = new HubSharedPreferenceListener();
+    preferenceListener = new PreferenceListener();
   }
 
-  /** Updates the internal (sensor, position, etc) listeners. */
-  void updateAllListeners(EnumSet<ListenerDataType> externallyNeededListeners) {
-    EnumSet<ListenerDataType> neededListeners = EnumSet.copyOf(externallyNeededListeners);
+  /**
+   * Updates listeners with data source.
+   * 
+   * @param listeners the listeners
+   */
+  public void updateListeners(EnumSet<TrackDataType> listeners) {
+    EnumSet<TrackDataType> neededListeners = EnumSet.copyOf(listeners);
 
-    // Special case - map sampled-out points type to points type since they
-    // correspond to the same internal listener.
-    if (neededListeners.contains(ListenerDataType.SAMPLED_OUT_POINT_UPDATES)) {
-      neededListeners.remove(ListenerDataType.SAMPLED_OUT_POINT_UPDATES);
-      neededListeners.add(ListenerDataType.POINT_UPDATES);
+    /*
+     * Map SAMPLED_OUT_POINT_UPDATES to POINT_UPDATES since they correspond to
+     * the same internal listener
+     */
+    if (neededListeners.contains(TrackDataType.SAMPLED_OUT_TRACK_POINTS)) {
+      neededListeners.remove(TrackDataType.SAMPLED_OUT_TRACK_POINTS);
+      neededListeners.add(TrackDataType.TRACK_POINTS_TABLE);
     }
 
-    Log.d(TAG, "Updating internal listeners to types " + neededListeners);
+    Log.d(TAG, "Updating listeners " + neededListeners);
 
     // Unnecessary = registered - needed
-    Set<ListenerDataType> unnecessaryListeners = EnumSet.copyOf(registeredListeners);
+    Set<TrackDataType> unnecessaryListeners = EnumSet.copyOf(registeredListeners);
     unnecessaryListeners.removeAll(neededListeners);
 
     // Missing = needed - registered
-    Set<ListenerDataType> missingListeners = EnumSet.copyOf(neededListeners);
+    Set<TrackDataType> missingListeners = EnumSet.copyOf(neededListeners);
     missingListeners.removeAll(registeredListeners);
 
-    // Remove all unnecessary listeners.
-    for (ListenerDataType type : unnecessaryListeners) {
-      unregisterListener(type);
+    // Remove unnecessary listeners
+    for (TrackDataType trackDataType : unnecessaryListeners) {
+      unregisterListener(trackDataType);
     }
 
-    // Add all missing listeners.
-    for (ListenerDataType type : missingListeners) {
-      registerListener(type);
+    // Add missing listeners
+    for (TrackDataType trackDataType : missingListeners) {
+      registerListener(trackDataType);
     }
 
-    // Now all needed types are registered.
+    // Update registered listeners
     registeredListeners.clear();
     registeredListeners.addAll(neededListeners);
   }
 
-  private void registerListener(ListenerDataType type) {
-    switch (type) {
-      case COMPASS_UPDATES: {
-        // Listen to compass
-        Sensor compass = dataSources.getSensor(Sensor.TYPE_ORIENTATION);
-        if (compass != null) {
-          Log.d(TAG, "TrackDataHub: Now registering sensor listener.");
-          dataSources.registerSensorListener(compassListener, compass, SensorManager.SENSOR_DELAY_UI);
-        }
+  /**
+   * Registers a listener with data source.
+   * 
+   * @param trackDataType the listener data type
+   */
+  private void registerListener(TrackDataType trackDataType) {
+    switch (trackDataType) {
+      case SELECTED_TRACK:
+        // Do nothing
         break;
-      }
-      case LOCATION_UPDATES:
-        dataSources.requestLocationUpdates(locationListener);
+      case TRACKS_TABLE:
+        dataSource.registerContentObserver(TracksColumns.CONTENT_URI, tracksTableObserver);
         break;
-      case POINT_UPDATES:
-        dataSources.registerContentObserver(
-            TrackPointsColumns.CONTENT_URI, false, pointObserver);
+      case WAYPOINTS_TABLE:
+        dataSource.registerContentObserver(WaypointsColumns.CONTENT_URI, waypointsTableObserver);
         break;
-      case TRACK_UPDATES:
-        dataSources.registerContentObserver(TracksColumns.CONTENT_URI, false, trackObserver);
+      case TRACK_POINTS_TABLE:
+        dataSource.registerContentObserver(
+            TrackPointsColumns.CONTENT_URI, trackPointsTableObserver);
         break;
-      case WAYPOINT_UPDATES:
-        dataSources.registerContentObserver(
-            WaypointsColumns.CONTENT_URI, false, waypointObserver);
+      case SAMPLED_OUT_TRACK_POINTS:
+        // Do nothing. SAMPLED_OUT_POINT_UPDATES is mapped to POINT_UPDATES.
         break;
-      case DISPLAY_PREFERENCES:
-        dataSources.registerOnSharedPreferenceChangeListener(preferenceListener);
+      case LOCATION:
+        dataSource.registerLocationListener(currentLocationListener);
+        break;
+      case COMPASS:
+        dataSource.registerCompassListener(compassListener);
+        break;
+      case PREFERENCE:
+        dataSource.registerOnSharedPreferenceChangeListener(preferenceListener);
+        break;
+      default:
         break;
-      case SAMPLED_OUT_POINT_UPDATES:
-        throw new IllegalArgumentException("Should have been mapped to point updates");
     }
   }
 
-  private void unregisterListener(ListenerDataType type) {
-    switch (type) {
-      case COMPASS_UPDATES:
-        dataSources.unregisterSensorListener(compassListener);
+  /**
+   * Unregisters a listener with data source.
+   * 
+   * @param trackDataType listener data type
+   */
+  private void unregisterListener(TrackDataType trackDataType) {
+    switch (trackDataType) {
+      case SELECTED_TRACK:
+        // Do nothing
         break;
-      case LOCATION_UPDATES:
-        dataSources.removeLocationUpdates(locationListener);
+      case TRACKS_TABLE:
+        dataSource.unregisterContentObserver(tracksTableObserver);
         break;
-      case POINT_UPDATES:
-        dataSources.unregisterContentObserver(pointObserver);
+      case WAYPOINTS_TABLE:
+        dataSource.unregisterContentObserver(waypointsTableObserver);
         break;
-      case TRACK_UPDATES:
-        dataSources.unregisterContentObserver(trackObserver);
+      case TRACK_POINTS_TABLE:
+        dataSource.unregisterContentObserver(trackPointsTableObserver);
         break;
-      case WAYPOINT_UPDATES:
-        dataSources.unregisterContentObserver(waypointObserver);
+      case SAMPLED_OUT_TRACK_POINTS:
+        // Do nothing. SAMPLED_OUT_POINT_UPDATES is mapped to POINT_UPDATES.
         break;
-      case DISPLAY_PREFERENCES:
-        dataSources.unregisterOnSharedPreferenceChangeListener(preferenceListener);
+      case LOCATION:
+        dataSource.unregisterLocationListener(currentLocationListener);
+        break;
+      case COMPASS:
+        dataSource.unregisterCompassListener(compassListener);
+        break;
+      case PREFERENCE:
+        dataSource.unregisterOnSharedPreferenceChangeListener(preferenceListener);
+        break;
+      default:
         break;
-      case SAMPLED_OUT_POINT_UPDATES:
-        throw new IllegalArgumentException("Should have been mapped to point updates");
     }
   }
 
-  /** Unregisters all internal (sensor, position, etc.) listeners. */
-  void unregisterAllListeners() {
-    dataSources.removeLocationUpdates(locationListener);
-    dataSources.unregisterSensorListener(compassListener);
-    dataSources.unregisterContentObserver(trackObserver);
-    dataSources.unregisterContentObserver(waypointObserver);
-    dataSources.unregisterContentObserver(pointObserver);
-    dataSources.unregisterOnSharedPreferenceChangeListener(preferenceListener);
+  /**
+   * Unregisters all listeners with data source.
+   */
+  public void unregisterAllListeners() {
+    for (TrackDataType trackDataType : TrackDataType.values()) {
+      unregisterListener(trackDataType);
+    }
   }
 }
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/DataSourcesWrapper.java b/MyTracks/src/com/google/android/apps/mytracks/content/DataSourcesWrapper.java
deleted file mode 100644
index a4dbf3544..000000000
--- a/MyTracks/src/com/google/android/apps/mytracks/content/DataSourcesWrapper.java
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright 2011 Google Inc.
- * 
- * 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.google.android.apps.mytracks.content;
-
-import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
-import android.database.ContentObserver;
-import android.hardware.Sensor;
-import android.hardware.SensorEventListener;
-import android.location.Location;
-import android.location.LocationListener;
-import android.net.Uri;
-
-/**
- * Interface for abstracting registration of external data source listeners.
- *
- * @author Rodrigo Damazio
- */
-interface DataSourcesWrapper {
-  // Preferences
-  void registerOnSharedPreferenceChangeListener(
-      OnSharedPreferenceChangeListener listener);
-  void unregisterOnSharedPreferenceChangeListener(
-      OnSharedPreferenceChangeListener listener);
-
-  // Content provider
-  void registerContentObserver(Uri contentUri, boolean descendents,
-      ContentObserver observer);
-  void unregisterContentObserver(ContentObserver observer);
-
-  // Sensors
-  Sensor getSensor(int type);
-  void registerSensorListener(SensorEventListener listener,
-      Sensor sensor, int sensorDelay);
-  void unregisterSensorListener(SensorEventListener listener);
-
-  // Location
-  boolean isLocationProviderEnabled(String provider);
-  void requestLocationUpdates(LocationListener listener);
-  void removeLocationUpdates(LocationListener listener);
-  Location getLastKnownLocation();
-} 
\ No newline at end of file
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/DataSourcesWrapperImpl.java b/MyTracks/src/com/google/android/apps/mytracks/content/DataSourcesWrapperImpl.java
deleted file mode 100644
index 9bc57f08c..000000000
--- a/MyTracks/src/com/google/android/apps/mytracks/content/DataSourcesWrapperImpl.java
+++ /dev/null
@@ -1,166 +0,0 @@
-/*
- * Copyright 2011 Google Inc.
- * 
- * 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.google.android.apps.mytracks.content;
-
-import static com.google.android.apps.mytracks.Constants.MAX_LOCATION_AGE_MS;
-import static com.google.android.apps.mytracks.Constants.MAX_NETWORK_AGE_MS;
-
-import com.google.android.apps.mytracks.Constants;
-import com.google.android.maps.mytracks.R;
-
-import android.content.ContentResolver;
-import android.content.Context;
-import android.content.SharedPreferences;
-import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
-import android.database.ContentObserver;
-import android.hardware.Sensor;
-import android.hardware.SensorEventListener;
-import android.hardware.SensorManager;
-import android.location.Location;
-import android.location.LocationListener;
-import android.location.LocationManager;
-import android.location.LocationProvider;
-import android.net.Uri;
-import android.util.Log;
-import android.widget.Toast;
-
-/**
- * Real implementation of the data sources, which talks to system services.
- *
- * @author Rodrigo Damazio
- */
-class DataSourcesWrapperImpl implements DataSourcesWrapper {
-  // System services
-  private final SensorManager sensorManager;
-  private final LocationManager locationManager;
-  private final ContentResolver contentResolver;
-  private final SharedPreferences sharedPreferences;
-  private final Context context;
-
-  DataSourcesWrapperImpl(Context context, SharedPreferences sharedPreferences) {
-    this.context = context;
-    this.sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
-    this.locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
-    this.contentResolver = context.getContentResolver();
-    this.sharedPreferences = sharedPreferences;
-  }
-
-  @Override
-  public void registerOnSharedPreferenceChangeListener(
-      OnSharedPreferenceChangeListener listener) {
-    sharedPreferences.registerOnSharedPreferenceChangeListener(listener);
-  }
-
-  @Override
-  public void unregisterOnSharedPreferenceChangeListener(
-      OnSharedPreferenceChangeListener listener) {
-    sharedPreferences.unregisterOnSharedPreferenceChangeListener(listener);
-  }
-
-  @Override
-  public void registerContentObserver(Uri contentUri, boolean descendents,
-      ContentObserver observer) {
-    contentResolver.registerContentObserver(contentUri, descendents, observer);
-  }
-
-  @Override
-  public void unregisterContentObserver(ContentObserver observer) {
-    contentResolver.unregisterContentObserver(observer);
-  }
-
-  @Override
-  public Sensor getSensor(int type) {
-    return sensorManager.getDefaultSensor(type);
-  }
-
-  @Override
-  public void registerSensorListener(SensorEventListener listener,
-      Sensor sensor, int sensorDelay) {
-    sensorManager.registerListener(listener, sensor, sensorDelay);
-  }
-
-  @Override
-  public void unregisterSensorListener(SensorEventListener listener) {
-    sensorManager.unregisterListener(listener);
-  }
-
-  @Override
-  public boolean isLocationProviderEnabled(String provider) {
-    return locationManager.isProviderEnabled(provider);
-  }
-
-  @Override
-  public void requestLocationUpdates(LocationListener listener) {
-    // Check if the provider exists.
-    LocationProvider gpsProvider = locationManager.getProvider(LocationManager.GPS_PROVIDER);
-    if (gpsProvider == null) {
-      listener.onProviderDisabled(LocationManager.GPS_PROVIDER);
-      locationManager.removeUpdates(listener);
-      return;
-    }
-
-    // Listen to GPS location.
-    String providerName = gpsProvider.getName();
-    Log.d(Constants.TAG, "TrackDataHub: Using location provider " + providerName);
-    locationManager.requestLocationUpdates(providerName,
-        0 /*minTime*/, 0 /*minDist*/, listener);
-
-    // Give an initial update on provider state.
-    if (locationManager.isProviderEnabled(providerName)) {
-      listener.onProviderEnabled(providerName);
-    } else {
-      listener.onProviderDisabled(providerName);
-    }
-
-    // Listen to network location
-    try {
-      locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER,
-          1000 * 60 * 5 /*minTime*/, 0 /*minDist*/, listener);
-    } catch (RuntimeException e) {
-      // If anything at all goes wrong with getting a cell location do not
-      // abort. Cell location is not essential to this app.
-      Log.w(Constants.TAG, "Could not register network location listener.", e);
-    }
-  }
-
-  @Override
-  public Location getLastKnownLocation() {
-    // TODO: Let's look at more advanced algorithms to determine the best
-    // current location.
-
-    Location loc = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
-    final long now = System.currentTimeMillis();
-    if (loc == null || loc.getTime() < now - MAX_LOCATION_AGE_MS) {
-      // We don't have a recent GPS fix, just use cell towers if available
-      loc = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
-
-      int toastResId = R.string.my_location_approximate_location;
-      if (loc == null || loc.getTime() < now - MAX_NETWORK_AGE_MS) {
-        // We don't have a recent cell tower location, let the user know:
-        toastResId = R.string.my_location_no_location;
-      }
-
-      // Let the user know we have only an approximate location:
-     Toast.makeText(context, toastResId, Toast.LENGTH_LONG).show();
-    }
-    return loc;
-  }
-
-  @Override
-  public void removeLocationUpdates(LocationListener listener) {
-    locationManager.removeUpdates(listener);
-  }
-}
\ No newline at end of file
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/ListenerState.java b/MyTracks/src/com/google/android/apps/mytracks/content/ListenerState.java
new file mode 100644
index 000000000..e1e3598a7
--- /dev/null
+++ b/MyTracks/src/com/google/android/apps/mytracks/content/ListenerState.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * 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.google.android.apps.mytracks.content;
+
+import java.util.EnumSet;
+
+/**
+ * State for a registered {@link TrackDataListener}.
+ * 
+ * @author Jimmy Shih
+ */
+public class ListenerState {
+  
+  private TrackDataListener trackDataListener;
+  private EnumSet<TrackDataType> trackDataTypes;
+
+  private long lastTrackId;
+  private long lastPointId;
+  private int lastSamplingFrequency;
+  private int numberOfLoadedPoints;
+
+  public ListenerState(
+      TrackDataListener trackDataListener, EnumSet<TrackDataType> trackDataTypes) {
+    this.trackDataListener = trackDataListener;
+    this.trackDataTypes = trackDataTypes;
+  }
+
+  /**
+   * Gets the {@link TrackDataListener}.
+   */
+  public TrackDataListener getTrackDataListener() {
+    return trackDataListener;
+  }
+
+  /**
+   * Gets the track data types.
+   */
+  public EnumSet<TrackDataType> getTrackDataTypes() {
+    return trackDataTypes;
+  }
+
+  /**
+   * Gets the last track id.
+   */
+  public long getLastTrackId() {
+    return lastTrackId;
+  }
+
+  /**
+   * Gets the last point id.
+   */
+  public long getLastPointId() {
+    return lastPointId;
+  }
+
+  /**
+   * Gets the last sampling frequency.
+   */
+  public int getLastSamplingFrequency() {
+    return lastSamplingFrequency;
+  }
+
+  /**
+   * Get the number of loaded points.
+   */
+  public int getNumberOfLoadedPoints() {
+    return numberOfLoadedPoints;
+  }
+
+  /**
+   * Sets the listener state.
+   * 
+   * @param trackId track id
+   * @param pointId point id
+   * @param samplingFrequency sampling frequency
+   * @param loadedPoints number of loaded points
+   */
+  public void setState(long trackId, long pointId, int samplingFrequency, int loadedPoints) {
+    lastTrackId = trackId;
+    lastPointId = pointId;
+    lastSamplingFrequency = samplingFrequency;
+    numberOfLoadedPoints = loadedPoints;
+  }
+
+  /**
+   * Resets state.
+   */
+  public void resetState() {
+    setState(0L, 0L, 0, 0);
+  }
+}
\ No newline at end of file
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataHub.java b/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataHub.java
index fc5b8b7cd..52c8c3c4a 100644
--- a/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataHub.java
+++ b/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataHub.java
@@ -21,18 +21,14 @@ import static com.google.android.apps.mytracks.Constants.MAX_NETWORK_AGE_MS;
 import static com.google.android.apps.mytracks.Constants.TAG;
 import static com.google.android.apps.mytracks.Constants.TARGET_DISPLAYED_TRACK_POINTS;
 
-import com.google.android.apps.mytracks.Constants;
-import com.google.android.apps.mytracks.content.DataSourceManager.DataSourceListener;
 import com.google.android.apps.mytracks.content.MyTracksProviderUtils.DoubleBufferedLocationFactory;
 import com.google.android.apps.mytracks.content.MyTracksProviderUtils.LocationIterator;
 import com.google.android.apps.mytracks.content.TrackDataListener.ProviderState;
-import com.google.android.apps.mytracks.content.TrackDataListeners.ListenerRegistration;
 import com.google.android.apps.mytracks.util.LocationUtils;
 import com.google.android.apps.mytracks.util.PreferencesUtils;
 import com.google.android.maps.mytracks.R;
 
 import android.content.Context;
-import android.content.SharedPreferences;
 import android.database.Cursor;
 import android.hardware.GeomagneticField;
 import android.location.Location;
@@ -60,54 +56,23 @@ public class TrackDataHub {
   // Overridable constants
   private final int targetNumPoints;
 
-  /** Types of data that we can expose. */
-  public static enum ListenerDataType {
-    /** Listen to when the selected track changes. */
-    SELECTED_TRACK_CHANGED,
-
-    /** Listen to when the tracks change. */
-    TRACK_UPDATES,
-
-    /** Listen to when the waypoints change. */
-    WAYPOINT_UPDATES,
-
-    /** Listen to when the current track points change. */
-    POINT_UPDATES,
-
-    /**
-     * Listen to sampled-out points.
-     * Listening to this without listening to {@link #POINT_UPDATES}
-     * makes no sense and may yield unexpected results.
-     */
-    SAMPLED_OUT_POINT_UPDATES,
-
-    /** Listen to updates to the current location. */
-    LOCATION_UPDATES,
-
-    /** Listen to updates to the current heading. */
-    COMPASS_UPDATES,
-
-    /** Listens to changes in display preferences. */
-    DISPLAY_PREFERENCES;
-  }
-
   /** Listener which receives events from the system. */
   private class HubDataSourceListener implements DataSourceListener {
     @Override
-    public void notifyTrackUpdated() {
-      TrackDataHub.this.notifyTrackUpdated(getListenersFor(ListenerDataType.TRACK_UPDATES));
+    public void notifyTracksTableUpdated() {
+      TrackDataHub.this.notifyTrackUpdated(getListenersFor(TrackDataType.TRACKS_TABLE));
     }
 
     @Override
-    public void notifyWaypointUpdated() {
-      TrackDataHub.this.notifyWaypointUpdated(getListenersFor(ListenerDataType.WAYPOINT_UPDATES));
+    public void notifyWaypointsTableUpdated() {
+      TrackDataHub.this.notifyWaypointUpdated(getListenersFor(TrackDataType.WAYPOINTS_TABLE));
     }
 
     @Override
-    public void notifyPointsUpdated() {
+    public void notifyTrackPointsTableUpdated() {
       TrackDataHub.this.notifyPointsUpdated(true, 0, 0,
-          getListenersFor(ListenerDataType.POINT_UPDATES),
-          getListenersFor(ListenerDataType.SAMPLED_OUT_POINT_UPDATES));
+          getListenersFor(TrackDataType.TRACK_POINTS_TABLE),
+          getListenersFor(TrackDataType.SAMPLED_OUT_TRACK_POINTS));
     }
 
     @Override
@@ -130,21 +95,20 @@ public class TrackDataHub {
     @Override
     public void notifyLocationChanged(Location loc) {
       TrackDataHub.this.notifyLocationChanged(loc,
-          getListenersFor(ListenerDataType.LOCATION_UPDATES));
+          getListenersFor(TrackDataType.LOCATION));
     }
 
     @Override
     public void notifyHeadingChanged(float heading) {
       lastSeenMagneticHeading = heading;
       maybeUpdateDeclination();
-      TrackDataHub.this.notifyHeadingChanged(getListenersFor(ListenerDataType.COMPASS_UPDATES));
+      TrackDataHub.this.notifyHeadingChanged(getListenersFor(TrackDataType.COMPASS));
     }
   }
 
   // Application services
   private final Context context;
   private final MyTracksProviderUtils providerUtils;
-  private final SharedPreferences preferences;
 
   // Get content notifications on the main thread, send listener callbacks in another.
   // This ensures listener calls are serialized.
@@ -152,12 +116,9 @@ public class TrackDataHub {
   private Handler listenerHandler;
 
   /** Manager for external listeners (those from activities). */
-  private final TrackDataListeners dataListeners;
+  private final TrackDataManager trackDataManager;
 
-  /** Wrapper for interacting with system data managers. */
-  private DataSourcesWrapper dataSources;
-
-  /** Manager for system data listener registrations. */
+  private DataSource dataSource;
   private DataSourceManager dataSourceManager;
 
   /** Condensed listener for system data listener events. */
@@ -193,24 +154,19 @@ public class TrackDataHub {
    * Builds a new {@link TrackDataHub} instance.
    */
   public synchronized static TrackDataHub newInstance(Context context) {
-    SharedPreferences preferences = context.getSharedPreferences(
-        Constants.SETTINGS_NAME, Context.MODE_PRIVATE);
     MyTracksProviderUtils providerUtils = MyTracksProviderUtils.Factory.get(context);
-    return new TrackDataHub(context,
-        new TrackDataListeners(),
-        preferences, providerUtils,
-        TARGET_DISPLAYED_TRACK_POINTS);
+    return new TrackDataHub(
+        context, new TrackDataManager(), providerUtils, TARGET_DISPLAYED_TRACK_POINTS);
   }
 
   /**
    * Injection constructor.
    */
   // @VisibleForTesting
-  TrackDataHub(Context ctx, TrackDataListeners listeners, SharedPreferences preferences,
-      MyTracksProviderUtils providerUtils, int targetNumPoints) {
+  TrackDataHub(Context ctx, TrackDataManager trackDataManager, MyTracksProviderUtils providerUtils,
+      int targetNumPoints) {
     this.context = ctx;
-    this.dataListeners = listeners;
-    this.preferences = preferences;
+    this.trackDataManager = trackDataManager;
     this.providerUtils = providerUtils;
     this.targetNumPoints = targetNumPoints;
     this.locationFactory = new DoubleBufferedLocationFactory();
@@ -233,12 +189,12 @@ public class TrackDataHub {
     listenerHandlerThread = new HandlerThread("trackDataContentThread");
     listenerHandlerThread.start();
     listenerHandler = new Handler(listenerHandlerThread.getLooper());
-    dataSources = newDataSources();
-    dataSourceManager = new DataSourceManager(dataSourceListener, dataSources);
+    dataSource = newDataSource();
+    dataSourceManager = new DataSourceManager(dataSource, dataSourceListener);
 
     // This may or may not register internal listeners, depending on whether
     // we already had external listeners.
-    dataSourceManager.updateAllListeners(getNeededListenerTypes());
+    dataSourceManager.updateListeners(getNeededListenerTypes());
     loadSharedPreferences();
 
     // If there were listeners already registered, make sure they become up-to-date.
@@ -246,8 +202,8 @@ public class TrackDataHub {
   }
 
   // @VisibleForTesting
-  protected DataSourcesWrapper newDataSources() {
-    return new DataSourcesWrapperImpl(context, preferences);
+  protected DataSource newDataSource() {
+    return new DataSource(context);
   }
 
   /**
@@ -267,7 +223,7 @@ public class TrackDataHub {
 
     started = false;
 
-    dataSources = null;
+    dataSource = null;
     dataSourceManager = null;
     listenerHandlerThread = null;
     listenerHandler = null;
@@ -343,9 +299,9 @@ public class TrackDataHub {
     }
     Log.i(TAG, "Forcing location update");
 
-    Location loc = dataSources.getLastKnownLocation();
+    Location loc = dataSource.getLastKnownLocation();
     if (loc != null) {
-      notifyLocationChanged(loc, getListenersFor(ListenerDataType.LOCATION_UPDATES));
+      notifyLocationChanged(loc, getListenersFor(TrackDataType.LOCATION));
     }
   }
 
@@ -415,30 +371,31 @@ public class TrackDataHub {
   }
 
   public void registerTrackDataListener(
-      TrackDataListener listener, EnumSet<ListenerDataType> dataTypes) {
-    synchronized (dataListeners) {
-      ListenerRegistration registration =
-          dataListeners.registerTrackDataListener(listener, dataTypes);
+      TrackDataListener listener, EnumSet<TrackDataType> dataTypes) {
+    synchronized (trackDataManager) {
+      ListenerState listenerState = trackDataManager.registerListener(listener, dataTypes);
 
       // Don't load any data or start internal listeners if start() hasn't been
       // called. When it is called, we'll do both things.
-      if (!isStarted()) return;
+      if (!isStarted()) {
+        return;
+      }
 
-      loadNewDataForListener(registration);
+      loadNewDataForListener(listenerState);
 
-      dataSourceManager.updateAllListeners(getNeededListenerTypes());
+      dataSourceManager.updateListeners(getNeededListenerTypes());
     }
   }
 
   public void unregisterTrackDataListener(TrackDataListener listener) {
-    synchronized (dataListeners) {
-      dataListeners.unregisterTrackDataListener(listener);
+    synchronized (trackDataManager) {
+      trackDataManager.unregisterListener(listener);
 
       // Don't load any data or start internal listeners if start() hasn't been
       // called. When it is called, we'll do both things.
       if (!isStarted()) return;
 
-      dataSourceManager.updateAllListeners(getNeededListenerTypes());
+      dataSourceManager.updateListeners(getNeededListenerTypes());
     }
   }
 
@@ -446,33 +403,32 @@ public class TrackDataHub {
    * Reloads all track data received so far into the specified listeners.
    */
   public void reloadDataForListener(TrackDataListener listener) {
-    ListenerRegistration registration;
-    synchronized (dataListeners) {
-      registration = dataListeners.getRegistration(listener);
-      registration.resetState();
-      loadNewDataForListener(registration);
+    synchronized (trackDataManager) {
+      ListenerState listenerState = trackDataManager.getListenerState(listener);
+      listenerState.resetState();
+      loadNewDataForListener(listenerState);
     }
   }
 
   /**
    * Reloads all track data received so far into the specified listeners.
    *
-   * Assumes it's called from a block that synchronizes on {@link #dataListeners}.
+   * Assumes it's called from a block that synchronizes on {@link #trackDataManager}.
    */
-  private void loadNewDataForListener(final ListenerRegistration registration) {
+  private void loadNewDataForListener(final ListenerState listenerState) {
     if (!isStarted()) {
       Log.w(TAG, "Not started, not reloading");
       return;
     }
-    if (registration == null) {
-      Log.w(TAG, "Not reloading for null registration");
+    if (listenerState == null) {
+      Log.w(TAG, "Not reloading for null listener state");
       return;
     }
 
     // If a listener happens to be added after this method but before the Runnable below is
     // executed, it will have triggered a separate call to load data only up to the point this
     // listener got to. This is ensured by being synchronized on listeners.
-    final boolean isOnlyListener = (dataListeners.getNumListeners() == 1);
+    final boolean isOnlyListener = (trackDataManager.getNumberOfListeners() == 1);
 
     runInListenerThread(new Runnable() {
       @SuppressWarnings("unchecked")
@@ -480,30 +436,31 @@ public class TrackDataHub {
       public void run() {
         // Reload everything if either it's a different track, or the track has been resampled
         // (this also covers the case of a new registration).
-        boolean reloadAll = registration.lastTrackId != selectedTrackId ||
-                            registration.lastSamplingFrequency != lastSamplingFrequency;
-        Log.d(TAG, "Doing a " + (reloadAll ? "full" : "partial") + " reload for " + registration);
+        boolean reloadAll = listenerState.getLastTrackId() != selectedTrackId ||
+                            listenerState.getLastSamplingFrequency() != lastSamplingFrequency;
+        Log.d(TAG, "Doing a " + (reloadAll ? "full" : "partial") + " reload for " + listenerState);
 
-        TrackDataListener listener = registration.listener;
+        TrackDataListener listener = listenerState.getTrackDataListener();
         Set<TrackDataListener> listenerSet = Collections.singleton(listener);
 
-        if (registration.isInterestedIn(ListenerDataType.DISPLAY_PREFERENCES)) {
+        EnumSet<TrackDataType> trackDataTypes = listenerState.getTrackDataTypes();
+        
+        if (trackDataTypes.contains(TrackDataType.PREFERENCE)) {
           reloadAll |= listener.onUnitsChanged(metricUnits);
           reloadAll |= listener.onReportSpeedChanged(reportSpeed);
         }
 
-        if (reloadAll && registration.isInterestedIn(ListenerDataType.SELECTED_TRACK_CHANGED)) {
+        if (reloadAll && trackDataTypes.contains(TrackDataType.SELECTED_TRACK)) {
           notifySelectedTrackChanged(selectedTrackId, listenerSet);
         }
 
-        if (registration.isInterestedIn(ListenerDataType.TRACK_UPDATES)) {
+        if (trackDataTypes.contains(TrackDataType.TRACKS_TABLE)) {
           notifyTrackUpdated(listenerSet);
         }
 
-        boolean interestedInPoints =
-            registration.isInterestedIn(ListenerDataType.POINT_UPDATES);
-        boolean interestedInSampledOutPoints =
-            registration.isInterestedIn(ListenerDataType.SAMPLED_OUT_POINT_UPDATES);
+        boolean interestedInPoints = trackDataTypes.contains(TrackDataType.TRACK_POINTS_TABLE);
+        boolean interestedInSampledOutPoints = trackDataTypes.contains(
+            TrackDataType.SAMPLED_OUT_TRACK_POINTS);
         if (interestedInPoints || interestedInSampledOutPoints) {
           long minPointId = 0;
           int previousNumPoints = 0;
@@ -513,8 +470,8 @@ public class TrackDataHub {
             notifyPointsCleared(listenerSet);
           } else {
             // Send only new points
-            minPointId = registration.lastPointId + 1;
-            previousNumPoints = registration.numLoadedPoints;
+            minPointId = listenerState.getLastPointId() + 1;
+            previousNumPoints = listenerState.getNumberOfLoadedPoints();
           }
 
           // If this is the only listener we have registered, keep the state that we serve to it as
@@ -530,11 +487,11 @@ public class TrackDataHub {
               interestedInSampledOutPoints ? listenerSet : Collections.EMPTY_SET);
         }
 
-        if (registration.isInterestedIn(ListenerDataType.WAYPOINT_UPDATES)) {
+        if (trackDataTypes.contains(TrackDataType.WAYPOINTS_TABLE)) {
           notifyWaypointUpdated(listenerSet);
         }
 
-        if (registration.isInterestedIn(ListenerDataType.LOCATION_UPDATES)) {
+        if (trackDataTypes.contains(TrackDataType.LOCATION)) {
           if (lastSeenLocation != null) {
             notifyLocationChanged(lastSeenLocation, true, listenerSet);
           } else {
@@ -542,7 +499,7 @@ public class TrackDataHub {
           }
         }
 
-        if (registration.isInterestedIn(ListenerDataType.COMPASS_UPDATES)) {
+        if (trackDataTypes.contains(TrackDataType.COMPASS)) {
           notifyHeadingChanged(listenerSet);
         }
       }
@@ -557,8 +514,8 @@ public class TrackDataHub {
       Log.w(TAG, "Not started, not reloading");
       return;
     }
-    synchronized (dataListeners) {
-      if (!dataListeners.hasListeners()) {
+    synchronized (trackDataManager) {
+      if (trackDataManager.getNumberOfListeners() == 0) {
         Log.d(TAG, "No listeners, not reloading");
         return;
       }
@@ -569,33 +526,33 @@ public class TrackDataHub {
       public void run() {
         // Ignore the return values here, we're already sending the full data set anyway
         for (TrackDataListener listener :
-             getListenersFor(ListenerDataType.DISPLAY_PREFERENCES)) {
+             getListenersFor(TrackDataType.PREFERENCE)) {
           listener.onUnitsChanged(metricUnits);
           listener.onReportSpeedChanged(reportSpeed);
         }
 
         notifySelectedTrackChanged(selectedTrackId,
-            getListenersFor(ListenerDataType.SELECTED_TRACK_CHANGED));
+            getListenersFor(TrackDataType.SELECTED_TRACK));
 
-        notifyTrackUpdated(getListenersFor(ListenerDataType.TRACK_UPDATES));
+        notifyTrackUpdated(getListenersFor(TrackDataType.TRACKS_TABLE));
 
         Set<TrackDataListener> pointListeners =
-            getListenersFor(ListenerDataType.POINT_UPDATES);
+            getListenersFor(TrackDataType.TRACK_POINTS_TABLE);
         Set<TrackDataListener> sampledOutPointListeners =
-            getListenersFor(ListenerDataType.SAMPLED_OUT_POINT_UPDATES);
+            getListenersFor(TrackDataType.SAMPLED_OUT_TRACK_POINTS);
         notifyPointsCleared(pointListeners);
         notifyPointsUpdated(true, 0, 0, pointListeners, sampledOutPointListeners);
 
-        notifyWaypointUpdated(getListenersFor(ListenerDataType.WAYPOINT_UPDATES));
+        notifyWaypointUpdated(getListenersFor(TrackDataType.WAYPOINTS_TABLE));
 
         if (lastSeenLocation != null) {
           notifyLocationChanged(lastSeenLocation, true,
-              getListenersFor(ListenerDataType.LOCATION_UPDATES));
+              getListenersFor(TrackDataType.LOCATION));
         } else {
           notifyFixType();
         }
 
-        notifyHeadingChanged(getListenersFor(ListenerDataType.COMPASS_UPDATES));
+        notifyHeadingChanged(getListenersFor(TrackDataType.COMPASS));
       }
     });
   }
@@ -630,12 +587,12 @@ public class TrackDataHub {
       @Override
       public void run() {
         Set<TrackDataListener> displayListeners =
-            getListenersFor(ListenerDataType.DISPLAY_PREFERENCES);
+            getListenersFor(TrackDataType.PREFERENCE);
 
         for (TrackDataListener listener : displayListeners) {
           // TODO: Do the reloading just once for all interested listeners
           if (listener.onReportSpeedChanged(reportSpeed)) {
-            synchronized (dataListeners) {
+            synchronized (trackDataManager) {
               reloadDataForListener(listener);
             }
           }
@@ -651,11 +608,11 @@ public class TrackDataHub {
     runInListenerThread(new Runnable() {
       @Override
       public void run() {
-        Set<TrackDataListener> displayListeners = getListenersFor(ListenerDataType.DISPLAY_PREFERENCES);
+        Set<TrackDataListener> displayListeners = getListenersFor(TrackDataType.PREFERENCE);
 
         for (TrackDataListener listener : displayListeners) {
           if (listener.onUnitsChanged(metricUnits)) {
-            synchronized (dataListeners) {
+            synchronized (trackDataManager) {
               reloadDataForListener(listener);
             }
           }
@@ -683,7 +640,7 @@ public class TrackDataHub {
         // Notify to everyone.
         Log.d(TAG, "Notifying fix type: " + state);
         for (TrackDataListener listener :
-             getListenersFor(ListenerDataType.LOCATION_UPDATES)) {
+             getListenersFor(TrackDataType.LOCATION)) {
           listener.onProviderStateChange(state);
         }
       }
@@ -945,9 +902,9 @@ public class TrackDataHub {
 
       Log.i(TAG, "Resampling point set after " + numLoadedPoints + " points.");
       resetState();
-      synchronized (dataListeners) {
-        sampledListeners = getListenersFor(ListenerDataType.POINT_UPDATES);
-        sampledOutListeners = getListenersFor(ListenerDataType.SAMPLED_OUT_POINT_UPDATES);
+      synchronized (trackDataManager) {
+        sampledListeners = getListenersFor(TrackDataType.TRACK_POINTS_TABLE);
+        sampledOutListeners = getListenersFor(TrackDataType.SAMPLED_OUT_TRACK_POINTS);
       }
       maxPointId = -1;
       minPointId = 0;
@@ -1030,12 +987,10 @@ public class TrackDataHub {
       listener.onNewTrackPointsDone();
 
       // Update the listener state
-      ListenerRegistration registration = dataListeners.getRegistration(listener);
-      if (registration != null) {
-        registration.lastTrackId = currentSelectedTrackId;
-        registration.lastPointId = localLastSeenLocationId;
-        registration.lastSamplingFrequency = pointSamplingFrequency;
-        registration.numLoadedPoints = localNumLoadedPoints;
+      ListenerState listenerState = trackDataManager.getListenerState(listener);
+      if (listenerState != null) {
+        listenerState.setState(currentSelectedTrackId, localLastSeenLocationId,
+            pointSamplingFrequency, localNumLoadedPoints);
       }
     }
   }
@@ -1089,17 +1044,17 @@ public class TrackDataHub {
     listenerHandler.post(runnable);
   }
 
-  private Set<TrackDataListener> getListenersFor(ListenerDataType type) {
-    synchronized (dataListeners) {
-      return dataListeners.getListenersFor(type);
+  private Set<TrackDataListener> getListenersFor(TrackDataType type) {
+    synchronized (trackDataManager) {
+      return trackDataManager.getListeners(type);
     }
   }
 
-  private EnumSet<ListenerDataType> getNeededListenerTypes() {
-    EnumSet<ListenerDataType> neededTypes = dataListeners.getAllRegisteredTypes();
+  private EnumSet<TrackDataType> getNeededListenerTypes() {
+    EnumSet<TrackDataType> neededTypes = trackDataManager.getRegisteredTrackDataTypes();
 
     // We always want preference updates.
-    neededTypes.add(ListenerDataType.DISPLAY_PREFERENCES);
+    neededTypes.add(TrackDataType.PREFERENCE);
 
     return neededTypes;
   }
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataListeners.java b/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataListeners.java
deleted file mode 100644
index 7a85b9eef..000000000
--- a/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataListeners.java
+++ /dev/null
@@ -1,159 +0,0 @@
-/*
- * Copyright 2011 Google Inc.
- *
- * 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.google.android.apps.mytracks.content;
-
-import static com.google.android.apps.mytracks.Constants.TAG;
-
-import com.google.android.apps.mytracks.content.TrackDataHub.ListenerDataType;
-
-import android.util.Log;
-
-import java.util.EnumMap;
-import java.util.EnumSet;
-import java.util.HashMap;
-import java.util.LinkedHashSet;
-import java.util.Map;
-import java.util.Set;
-
-/**
- * Manager for the external data listeners and their listening types.
- *
- * @author Rodrigo Damazio
- */
-class TrackDataListeners {
-
-  /** Internal representation of a listener's registration. */
-  static class ListenerRegistration {
-    final TrackDataListener listener;
-    final EnumSet<ListenerDataType> types;
-
-    // State that was last notified to the listener, for resuming after a pause.
-    long lastTrackId;
-    long lastPointId;
-    int lastSamplingFrequency;
-    int numLoadedPoints;
-
-    public ListenerRegistration(TrackDataListener listener,
-        EnumSet<ListenerDataType> types) {
-      this.listener = listener;
-      this.types = types;
-    }
-
-    public boolean isInterestedIn(ListenerDataType type) {
-      return types.contains(type);
-    }
-
-    public void resetState() {
-      lastTrackId = 0L;
-      lastPointId = 0L;
-      lastSamplingFrequency = 0;
-      numLoadedPoints = 0;
-    }
-
-    @Override
-    public String toString() {
-      return "ListenerRegistration [listener=" + listener + ", types=" + types
-          + ", lastTrackId=" + lastTrackId + ", lastPointId=" + lastPointId
-          + ", lastSamplingFrequency=" + lastSamplingFrequency
-          + ", numLoadedPoints=" + numLoadedPoints + "]";
-    }
-  }
-
-  /** Map of external listener to its registration details. */
-  private final Map<TrackDataListener, ListenerRegistration> registeredListeners =
-      new HashMap<TrackDataListener, ListenerRegistration>();
-
-  /** Map of data type to external listeners interested in it. */
-  private final Map<ListenerDataType, Set<TrackDataListener>> listenerSetsPerType =
-      new EnumMap<ListenerDataType, Set<TrackDataListener>>(ListenerDataType.class);
-
-  public TrackDataListeners() {
-    // Create sets for all data types at startup.
-    for (ListenerDataType type : ListenerDataType.values()) {
-      listenerSetsPerType.put(type, new LinkedHashSet<TrackDataListener>());
-    }
-  }
-
-  /**
-   * Registers a listener to send data to.
-   * It is ok to call this method before {@link TrackDataHub#start}, and in that case
-   * the data will only be passed to listeners when {@link TrackDataHub#start} is called.
-   *
-   * @param listener the listener to register
-   * @param dataTypes the type of data that the listener is interested in
-   */
-  public ListenerRegistration registerTrackDataListener(final TrackDataListener listener, EnumSet<ListenerDataType> dataTypes) {
-    Log.d(TAG, "Registered track data listener: " + listener);
-    if (registeredListeners.containsKey(listener)) {
-      throw new IllegalStateException("Listener already registered");
-    }
-
-    ListenerRegistration registration = new ListenerRegistration(listener, dataTypes);
-    registeredListeners.put(listener, registration);
-
-    for (ListenerDataType type : dataTypes) {
-      // This is guaranteed not to be null.
-      Set<TrackDataListener> typeSet = listenerSetsPerType.get(type);
-      typeSet.add(listener);
-    }
-
-    return registration;
-  }
-
-  /**
-   * Unregisters a listener to send data to.
-   *
-   * @param listener the listener to unregister
-   */
-  public void unregisterTrackDataListener(TrackDataListener listener) {
-    Log.d(TAG, "Unregistered track data listener: " + listener);
-    // Remove and keep the corresponding registration.
-    ListenerRegistration match = registeredListeners.remove(listener);
-    if (match == null) {
-      Log.w(TAG, "Tried to unregister listener which is not registered.");
-      return;
-    }
-
-    // Remove it from the per-type sets
-    for (ListenerDataType type : match.types) {
-      listenerSetsPerType.get(type).remove(listener);
-    }
-  }
-
-  public ListenerRegistration getRegistration(TrackDataListener listener) {
-    return registeredListeners.get(listener);
-  }
-
-  public Set<TrackDataListener> getListenersFor(ListenerDataType type) {
-    return listenerSetsPerType.get(type);
-  }
-
-  public EnumSet<ListenerDataType> getAllRegisteredTypes() {
-    EnumSet<ListenerDataType> listeners = EnumSet.noneOf(ListenerDataType.class);
-    for (ListenerRegistration registration : this.registeredListeners.values()) {
-      listeners.addAll(registration.types);
-    }
-    return listeners;
-  }
-
-  public boolean hasListeners() {
-    return !registeredListeners.isEmpty();
-  }
-
-  public int getNumListeners() {
-    return registeredListeners.size();
-  }
-}
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataManager.java b/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataManager.java
new file mode 100644
index 000000000..9c3ededd7
--- /dev/null
+++ b/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataManager.java
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * 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.google.android.apps.mytracks.content;
+
+import static com.google.android.apps.mytracks.Constants.TAG;
+
+import android.util.Log;
+
+import java.util.EnumMap;
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * Manages register/unregister {@link TrackDataListener} and keeping the state
+ * for each registered listener.
+ * 
+ * @author Rodrigo Damazio
+ */
+public class TrackDataManager {
+
+  // Map of listener to its state
+  private final Map<TrackDataListener, ListenerState>
+      listenerToStateMap = new HashMap<TrackDataListener, ListenerState>();
+
+  // Map of track data type to listeners
+  private final Map<TrackDataType, Set<TrackDataListener>>
+      typeToListenersMap = new EnumMap<TrackDataType, Set<TrackDataListener>>(TrackDataType.class);
+
+  public TrackDataManager() {
+    for (TrackDataType trackDataType : TrackDataType.values()) {
+      typeToListenersMap.put(trackDataType, new LinkedHashSet<TrackDataListener>());
+    }
+  }
+
+  /**
+   * Registers a listener.
+   * 
+   * @param listener the listener
+   * @param trackDataTypes the track data types the listener is interested
+   */
+  public ListenerState registerListener(
+      TrackDataListener listener, EnumSet<TrackDataType> trackDataTypes) {
+    if (listenerToStateMap.containsKey(listener)) {
+      throw new IllegalStateException("Listener is already registered");
+    }
+
+    ListenerState listenerState = new ListenerState(listener, trackDataTypes);
+    listenerToStateMap.put(listener, listenerState);
+
+    for (TrackDataType trackDataType : trackDataTypes) {
+      typeToListenersMap.get(trackDataType).add(listener);
+    }
+
+    return listenerState;
+  }
+
+  /**
+   * Unregisters a listener.
+   * 
+   * @param listener the listener
+   */
+  public void unregisterListener(TrackDataListener listener) {
+    ListenerState removed = listenerToStateMap.remove(listener);
+    if (removed == null) {
+      Log.w(TAG, "Tried to unregister a listener that is not registered.");
+      return;
+    }
+
+    // Remove the listener from the typeToListenersMap
+    for (TrackDataType trackDataType : removed.getTrackDataTypes()) {
+      typeToListenersMap.get(trackDataType).remove(listener);
+    }
+  }
+
+  /**
+   * Gets the number of {@link TrackDataListener}.
+   */
+  public int getNumberOfListeners() {
+    return listenerToStateMap.size();
+  }
+
+  /**
+   * Gets the track listener state.
+   * 
+   * @param listener the listener
+   */
+  public ListenerState getListenerState(TrackDataListener listener) {
+    return listenerToStateMap.get(listener);
+  }
+
+  /**
+   * Gets the listeners for a {@link TrackDataType}.
+   * 
+   * @param type the type
+   */
+  public Set<TrackDataListener> getListeners(TrackDataType type) {
+    return typeToListenersMap.get(type);
+  }
+
+  /**
+   * Gets all the registered {@link TrackDataType}.
+   */
+  public EnumSet<TrackDataType> getRegisteredTrackDataTypes() {
+    EnumSet<TrackDataType> types = EnumSet.noneOf(TrackDataType.class);
+    for (ListenerState registration : this.listenerToStateMap.values()) {
+      types.addAll(registration.getTrackDataTypes());
+    }
+    return types;
+  }
+}
diff --git a/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataType.java b/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataType.java
new file mode 100644
index 000000000..319b5bbc0
--- /dev/null
+++ b/MyTracks/src/com/google/android/apps/mytracks/content/TrackDataType.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * 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.google.android.apps.mytracks.content;
+
+/**
+ * Types of track data.
+ * 
+ * @author Jimmy Shih
+ */
+public enum TrackDataType {
+
+  SELECTED_TRACK, // selected track changes
+  TRACKS_TABLE, // tracks table changes
+  WAYPOINTS_TABLE, // waypoints table changes
+  TRACK_POINTS_TABLE, // track points table changes
+  SAMPLED_OUT_TRACK_POINTS, // sampled-out track points changes
+  LOCATION, // location changes
+  COMPASS, // compass changes
+  PREFERENCE; // preference changes
+}
\ No newline at end of file
diff --git a/MyTracks/src/com/google/android/apps/mytracks/fragments/ChartFragment.java b/MyTracks/src/com/google/android/apps/mytracks/fragments/ChartFragment.java
index be9c1ff28..e1dab8720 100644
--- a/MyTracks/src/com/google/android/apps/mytracks/fragments/ChartFragment.java
+++ b/MyTracks/src/com/google/android/apps/mytracks/fragments/ChartFragment.java
@@ -19,12 +19,12 @@ package com.google.android.apps.mytracks.fragments;
 import com.google.android.apps.mytracks.ChartView;
 import com.google.android.apps.mytracks.Constants;
 import com.google.android.apps.mytracks.MyTracksApplication;
+import com.google.android.apps.mytracks.content.TrackDataType;
 import com.google.android.apps.mytracks.content.MyTracksLocation;
 import com.google.android.apps.mytracks.content.Sensor;
 import com.google.android.apps.mytracks.content.Sensor.SensorDataSet;
 import com.google.android.apps.mytracks.content.Track;
 import com.google.android.apps.mytracks.content.TrackDataHub;
-import com.google.android.apps.mytracks.content.TrackDataHub.ListenerDataType;
 import com.google.android.apps.mytracks.content.TrackDataListener;
 import com.google.android.apps.mytracks.content.Waypoint;
 import com.google.android.apps.mytracks.stats.DoubleBuffer;
@@ -360,12 +360,12 @@ public class ChartFragment extends Fragment implements TrackDataListener {
   private synchronized void resumeTrackDataHub() {
     trackDataHub = ((MyTracksApplication) getActivity().getApplication()).getTrackDataHub();
     trackDataHub.registerTrackDataListener(this, EnumSet.of(
-        ListenerDataType.SELECTED_TRACK_CHANGED,
-        ListenerDataType.TRACK_UPDATES,
-        ListenerDataType.WAYPOINT_UPDATES,
-        ListenerDataType.POINT_UPDATES,
-        ListenerDataType.SAMPLED_OUT_POINT_UPDATES,
-        ListenerDataType.DISPLAY_PREFERENCES));
+        TrackDataType.SELECTED_TRACK,
+        TrackDataType.TRACKS_TABLE,
+        TrackDataType.WAYPOINTS_TABLE,
+        TrackDataType.TRACK_POINTS_TABLE,
+        TrackDataType.SAMPLED_OUT_TRACK_POINTS,
+        TrackDataType.PREFERENCE));
   }
 
   /**
diff --git a/MyTracks/src/com/google/android/apps/mytracks/fragments/MapFragment.java b/MyTracks/src/com/google/android/apps/mytracks/fragments/MapFragment.java
index d0196a512..5a5e5c72c 100644
--- a/MyTracks/src/com/google/android/apps/mytracks/fragments/MapFragment.java
+++ b/MyTracks/src/com/google/android/apps/mytracks/fragments/MapFragment.java
@@ -19,11 +19,11 @@ package com.google.android.apps.mytracks.fragments;
 import com.google.android.apps.mytracks.MapOverlay;
 import com.google.android.apps.mytracks.MyTracksApplication;
 import com.google.android.apps.mytracks.TrackDetailActivity;
+import com.google.android.apps.mytracks.content.TrackDataType;
 import com.google.android.apps.mytracks.content.MyTracksProviderUtils;
 import com.google.android.apps.mytracks.content.MyTracksProviderUtils.Factory;
 import com.google.android.apps.mytracks.content.Track;
 import com.google.android.apps.mytracks.content.TrackDataHub;
-import com.google.android.apps.mytracks.content.TrackDataHub.ListenerDataType;
 import com.google.android.apps.mytracks.content.TrackDataListener;
 import com.google.android.apps.mytracks.content.Waypoint;
 import com.google.android.apps.mytracks.stats.TripStatistics;
@@ -420,11 +420,11 @@ public class MapFragment extends Fragment
   private synchronized void resumeTrackDataHub() {
     trackDataHub = ((MyTracksApplication) getActivity().getApplication()).getTrackDataHub();
     trackDataHub.registerTrackDataListener(this, EnumSet.of(
-        ListenerDataType.SELECTED_TRACK_CHANGED,
-        ListenerDataType.WAYPOINT_UPDATES,
-        ListenerDataType.POINT_UPDATES,
-        ListenerDataType.LOCATION_UPDATES,
-        ListenerDataType.COMPASS_UPDATES));
+        TrackDataType.SELECTED_TRACK,
+        TrackDataType.WAYPOINTS_TABLE,
+        TrackDataType.TRACK_POINTS_TABLE,
+        TrackDataType.LOCATION,
+        TrackDataType.COMPASS));
   }
   
   /**
diff --git a/MyTracks/src/com/google/android/apps/mytracks/fragments/StatsFragment.java b/MyTracks/src/com/google/android/apps/mytracks/fragments/StatsFragment.java
index 8a00c3c2e..0eaf01a89 100644
--- a/MyTracks/src/com/google/android/apps/mytracks/fragments/StatsFragment.java
+++ b/MyTracks/src/com/google/android/apps/mytracks/fragments/StatsFragment.java
@@ -17,9 +17,9 @@
 package com.google.android.apps.mytracks.fragments;
 
 import com.google.android.apps.mytracks.MyTracksApplication;
+import com.google.android.apps.mytracks.content.TrackDataType;
 import com.google.android.apps.mytracks.content.Track;
 import com.google.android.apps.mytracks.content.TrackDataHub;
-import com.google.android.apps.mytracks.content.TrackDataHub.ListenerDataType;
 import com.google.android.apps.mytracks.content.TrackDataListener;
 import com.google.android.apps.mytracks.content.Waypoint;
 import com.google.android.apps.mytracks.stats.TripStatistics;
@@ -257,10 +257,10 @@ public class StatsFragment extends Fragment implements TrackDataListener {
   private synchronized void resumeTrackDataHub() {
     trackDataHub = ((MyTracksApplication) getActivity().getApplication()).getTrackDataHub();
     trackDataHub.registerTrackDataListener(this, EnumSet.of(
-        ListenerDataType.SELECTED_TRACK_CHANGED,
-        ListenerDataType.TRACK_UPDATES,
-        ListenerDataType.LOCATION_UPDATES,
-        ListenerDataType.DISPLAY_PREFERENCES));
+        TrackDataType.SELECTED_TRACK,
+        TrackDataType.TRACKS_TABLE,
+        TrackDataType.LOCATION,
+        TrackDataType.PREFERENCE));
   }
 
   /**
diff --git a/MyTracksTest/src/com/google/android/apps/mytracks/content/TrackDataHubTest.java b/MyTracksTest/src/com/google/android/apps/mytracks/content/TrackDataHubTest.java
index da068091d..e6ab88ef0 100644
--- a/MyTracksTest/src/com/google/android/apps/mytracks/content/TrackDataHubTest.java
+++ b/MyTracksTest/src/com/google/android/apps/mytracks/content/TrackDataHubTest.java
@@ -15,23 +15,21 @@
  */
 package com.google.android.apps.mytracks.content;
 
-import static com.google.android.testing.mocking.AndroidMock.anyInt;
 import static com.google.android.testing.mocking.AndroidMock.capture;
 import static com.google.android.testing.mocking.AndroidMock.eq;
 import static com.google.android.testing.mocking.AndroidMock.expect;
 import static com.google.android.testing.mocking.AndroidMock.isA;
 import static com.google.android.testing.mocking.AndroidMock.leq;
-import static com.google.android.testing.mocking.AndroidMock.same;
 
 import com.google.android.apps.mytracks.Constants;
 import com.google.android.apps.mytracks.content.MyTracksProviderUtils.LocationFactory;
 import com.google.android.apps.mytracks.content.MyTracksProviderUtils.LocationIterator;
-import com.google.android.apps.mytracks.content.TrackDataHub.ListenerDataType;
 import com.google.android.apps.mytracks.content.TrackDataListener.ProviderState;
 import com.google.android.apps.mytracks.services.TrackRecordingServiceTest.MockContext;
 import com.google.android.apps.mytracks.util.PreferencesUtils;
 import com.google.android.maps.mytracks.R;
 import com.google.android.testing.mocking.AndroidMock;
+import com.google.android.testing.mocking.UsesMocks;
 
 import android.content.Context;
 import android.content.SharedPreferences;
@@ -69,8 +67,8 @@ public class TrackDataHubTest extends AndroidTestCase {
 
   private MyTracksProviderUtils providerUtils;
   private TrackDataHub hub;
-  private TrackDataListeners listeners;
-  private DataSourcesWrapper dataSources;
+  private TrackDataManager trackDataManager;
+  private DataSource dataSource;
   private SharedPreferences sharedPreferences;
   private TrackDataListener listener1;
   private TrackDataListener listener2;
@@ -79,6 +77,7 @@ public class TrackDataHubTest extends AndroidTestCase {
   private MockContext context;
   private float declination;
 
+  @UsesMocks({MyTracksProviderUtils.class, DataSource.class, TrackDataListener.class})
   @Override
   protected void setUp() throws Exception {
     super.setUp();
@@ -90,13 +89,13 @@ public class TrackDataHubTest extends AndroidTestCase {
 
     sharedPreferences = context.getSharedPreferences(Constants.SETTINGS_NAME, Context.MODE_PRIVATE);
     providerUtils = AndroidMock.createMock("providerUtils", MyTracksProviderUtils.class);
-    dataSources = AndroidMock.createNiceMock("dataSources", DataSourcesWrapper.class);
+    dataSource = AndroidMock.createMock("dataSource", DataSource.class, context);
 
-    listeners = new TrackDataListeners();
-    hub = new TrackDataHub(context, listeners, sharedPreferences, providerUtils, TARGET_POINTS) {
+    trackDataManager = new TrackDataManager();
+    hub = new TrackDataHub(context, trackDataManager, providerUtils, TARGET_POINTS) {
       @Override
-      protected DataSourcesWrapper newDataSources() {
-        return dataSources;
+      protected DataSource newDataSource() {
+        return dataSource;
       }
 
       @Override
@@ -119,18 +118,18 @@ public class TrackDataHubTest extends AndroidTestCase {
 
   @Override
   protected void tearDown() throws Exception {
-    AndroidMock.reset(dataSources);
+    AndroidMock.reset(dataSource);
 
     // Expect everything to be unregistered.
     if (preferenceListenerCapture.hasCaptured()) {
-      dataSources.unregisterOnSharedPreferenceChangeListener(preferenceListenerCapture.getValue());
+      dataSource.unregisterOnSharedPreferenceChangeListener(preferenceListenerCapture.getValue());
     }
-    dataSources.removeLocationUpdates(isA(LocationListener.class));
-    dataSources.unregisterSensorListener(isA(SensorEventListener.class));
-    dataSources.unregisterContentObserver(isA(ContentObserver.class));
+    dataSource.unregisterLocationListener(isA(LocationListener.class));
+    dataSource.unregisterCompassListener(isA(SensorEventListener.class));
+    dataSource.unregisterContentObserver(isA(ContentObserver.class));
     AndroidMock.expectLastCall().times(3);
 
-    AndroidMock.replay(dataSources);
+    AndroidMock.replay(dataSource);
 
     hub.stop();
     hub = null;
@@ -143,8 +142,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     Track track = new Track();
     expect(providerUtils.getTrack(TRACK_ID)).andStubReturn(track);
     expectStart();
-    dataSources.registerContentObserver(
-        eq(TracksColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(eq(TracksColumns.CONTENT_URI), capture(observerCapture));
 
     // Expect the initial loading.
     // Both listeners (registered before and after start) should get the same data.
@@ -153,9 +151,9 @@ public class TrackDataHubTest extends AndroidTestCase {
 
     replay();
 
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.TRACK_UPDATES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.TRACKS_TABLE));
     hub.start();
-    hub.registerTrackDataListener(listener2, EnumSet.of(ListenerDataType.TRACK_UPDATES));
+    hub.registerTrackDataListener(listener2, EnumSet.of(TrackDataType.TRACKS_TABLE));
 
     verifyAndReset();
 
@@ -185,7 +183,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     verifyAndReset();
 
     // Unregister the other, expect internal unregistration
-    dataSources.unregisterContentObserver(observer);
+    dataSource.unregisterContentObserver(observer);
 
     replay();
 
@@ -321,8 +319,7 @@ public class TrackDataHubTest extends AndroidTestCase {
         .andReturn(wpt2);
 
     expectStart();
-    dataSources.registerContentObserver(
-        eq(WaypointsColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(eq(WaypointsColumns.CONTENT_URI), capture(observerCapture));
 
     // Expect the initial loading.
     // Both listeners (registered before and after start) should get the same data.
@@ -337,9 +334,9 @@ public class TrackDataHubTest extends AndroidTestCase {
 
     replay();
 
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.WAYPOINT_UPDATES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.WAYPOINTS_TABLE));
     hub.start();
-    hub.registerTrackDataListener(listener2, EnumSet.of(ListenerDataType.WAYPOINT_UPDATES));
+    hub.registerTrackDataListener(listener2, EnumSet.of(TrackDataType.WAYPOINTS_TABLE));
 
     verifyAndReset();
 
@@ -398,7 +395,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     verifyAndReset();
 
     // Unregister the other, expect internal unregistration
-    dataSources.unregisterContentObserver(observer);
+    dataSource.unregisterContentObserver(observer);
 
     replay();
 
@@ -412,8 +409,8 @@ public class TrackDataHubTest extends AndroidTestCase {
     Capture<ContentObserver> observerCapture = new Capture<ContentObserver>();
 
     expectStart();
-    dataSources.registerContentObserver(
-        eq(TrackPointsColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(
+        eq(TrackPointsColumns.CONTENT_URI), capture(observerCapture));
 
     FixedSizeLocationIterator locationIterator = new FixedSizeLocationIterator(1, 10, 5);
     expect(providerUtils.getLocationIterator(
@@ -428,7 +425,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     hub.start();
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.POINT_UPDATES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.TRACK_POINTS_TABLE));
 
     verifyAndReset();
 
@@ -446,7 +443,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     hub.start();
-    hub.registerTrackDataListener(listener2, EnumSet.of(ListenerDataType.POINT_UPDATES));
+    hub.registerTrackDataListener(listener2, EnumSet.of(TrackDataType.TRACK_POINTS_TABLE));
 
     verifyAndReset();
 
@@ -497,8 +494,8 @@ public class TrackDataHubTest extends AndroidTestCase {
     Capture<ContentObserver> observerCapture = new Capture<ContentObserver>();
 
     expectStart();
-    dataSources.registerContentObserver(
-        eq(TrackPointsColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(
+        eq(TrackPointsColumns.CONTENT_URI), capture(observerCapture));
 
     FixedSizeLocationIterator locationIterator = new FixedSizeLocationIterator(1, 10, 5);
     expect(providerUtils.getLocationIterator(
@@ -513,13 +510,13 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     hub.start();
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.POINT_UPDATES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.TRACK_POINTS_TABLE));
 
     verifyAndReset();
 
     // Unregister
     ContentObserver observer = observerCapture.getValue();
-    dataSources.unregisterContentObserver(observer);
+    dataSource.unregisterContentObserver(observer);
 
     replay();
 
@@ -528,8 +525,8 @@ public class TrackDataHubTest extends AndroidTestCase {
     verifyAndReset();
 
     // Register again, except only points since unregistered.
-    dataSources.registerContentObserver(
-        eq(TrackPointsColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(
+        eq(TrackPointsColumns.CONTENT_URI), capture(observerCapture));
 
     locationIterator = new FixedSizeLocationIterator(1, 10, 5);
     expect(providerUtils.getLocationIterator(
@@ -543,7 +540,7 @@ public class TrackDataHubTest extends AndroidTestCase {
 
     replay();
 
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.POINT_UPDATES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.TRACK_POINTS_TABLE));
 
     verifyAndReset();
   }
@@ -552,8 +549,8 @@ public class TrackDataHubTest extends AndroidTestCase {
     Capture<ContentObserver> observerCapture = new Capture<ContentObserver>();
 
     expectStart();
-    dataSources.registerContentObserver(
-        eq(TrackPointsColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(
+        eq(TrackPointsColumns.CONTENT_URI), capture(observerCapture));
 
     FixedSizeLocationIterator locationIterator = new FixedSizeLocationIterator(1, 10, 5);
     expect(providerUtils.getLocationIterator(
@@ -568,13 +565,13 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     hub.start();
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.POINT_UPDATES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.TRACK_POINTS_TABLE));
 
     verifyAndReset();
 
     // Unregister
     ContentObserver observer = observerCapture.getValue();
-    dataSources.unregisterContentObserver(observer);
+    dataSource.unregisterContentObserver(observer);
 
     replay();
 
@@ -583,8 +580,8 @@ public class TrackDataHubTest extends AndroidTestCase {
     verifyAndReset();
 
     // Register again after track changed, expect all points.
-    dataSources.registerContentObserver(
-        eq(TrackPointsColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(
+        eq(TrackPointsColumns.CONTENT_URI), capture(observerCapture));
 
     locationIterator = new FixedSizeLocationIterator(1, 10);
     expect(providerUtils.getLocationIterator(
@@ -599,7 +596,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     hub.loadTrack(TRACK_ID + 1);
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.POINT_UPDATES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.TRACK_POINTS_TABLE));
 
     verifyAndReset();
   }
@@ -608,8 +605,8 @@ public class TrackDataHubTest extends AndroidTestCase {
     Capture<ContentObserver> observerCapture = new Capture<ContentObserver>();
 
     expectStart();
-    dataSources.registerContentObserver(
-        eq(TrackPointsColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(
+        eq(TrackPointsColumns.CONTENT_URI), capture(observerCapture));
 
     FixedSizeLocationIterator locationIterator = new FixedSizeLocationIterator(1, 200, 4, 25, 71, 120);
     expect(providerUtils.getLocationIterator(
@@ -627,9 +624,9 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     hub.registerTrackDataListener(listener1,
-        EnumSet.of(ListenerDataType.POINT_UPDATES));
+        EnumSet.of(TrackDataType.TRACK_POINTS_TABLE));
     hub.registerTrackDataListener(listener2,
-        EnumSet.of(ListenerDataType.POINT_UPDATES, ListenerDataType.SAMPLED_OUT_POINT_UPDATES));
+        EnumSet.of(TrackDataType.TRACK_POINTS_TABLE, TrackDataType.SAMPLED_OUT_TRACK_POINTS));
     hub.start();
 
     verifyAndReset();
@@ -639,8 +636,8 @@ public class TrackDataHubTest extends AndroidTestCase {
     Capture<ContentObserver> observerCapture = new Capture<ContentObserver>();
 
     expectStart();
-    dataSources.registerContentObserver(
-        eq(TrackPointsColumns.CONTENT_URI), eq(false), capture(observerCapture));
+    dataSource.registerContentObserver(
+        eq(TrackPointsColumns.CONTENT_URI), capture(observerCapture));
 
     // Deliver 30 points (no sampling happens)
     FixedSizeLocationIterator locationIterator = new FixedSizeLocationIterator(1, 30, 5);
@@ -656,7 +653,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     hub.start();
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.POINT_UPDATES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.TRACK_POINTS_TABLE));
 
     verifyAndReset();
 
@@ -702,16 +699,14 @@ public class TrackDataHubTest extends AndroidTestCase {
   public void testCompassListen() throws Exception {
     AndroidMock.resetToDefault(listener1);
 
-    Sensor compass = newSensor();
-    expect(dataSources.getSensor(Sensor.TYPE_ORIENTATION)).andReturn(compass);
+    expectStart();
     Capture<SensorEventListener> listenerCapture = new Capture<SensorEventListener>();
-    dataSources.registerSensorListener(capture(listenerCapture), same(compass), anyInt());
+    dataSource.registerCompassListener(capture(listenerCapture));
 
     Capture<LocationListener> locationListenerCapture = new Capture<LocationListener>();
-    dataSources.requestLocationUpdates(capture(locationListenerCapture));
+    dataSource.registerLocationListener(capture(locationListenerCapture));
 
     SensorEvent event = newSensorEvent();
-    event.sensor = compass;
 
     // First, get a dummy heading update.
     listener1.onCurrentHeadingChanged(0.0);
@@ -726,7 +721,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     hub.registerTrackDataListener(listener1,
-        EnumSet.of(ListenerDataType.COMPASS_UPDATES, ListenerDataType.LOCATION_UPDATES));
+        EnumSet.of(TrackDataType.COMPASS, TrackDataType.LOCATION));
     hub.start();
 
     SensorEventListener sensorListener = listenerCapture.getValue();
@@ -786,9 +781,7 @@ public class TrackDataHubTest extends AndroidTestCase {
     PreferencesUtils.setBoolean(context, R.string.report_speed_key, true);
     PreferencesUtils.setBoolean(context, R.string.metric_units_key, true);
 
-    Capture<OnSharedPreferenceChangeListener> listenerCapture =
-        new Capture<OnSharedPreferenceChangeListener>();
-    dataSources.registerOnSharedPreferenceChangeListener(capture(listenerCapture));
+    expectStart();
 
     expect(listener1.onUnitsChanged(true)).andReturn(false);
     expect(listener2.onUnitsChanged(true)).andReturn(false);
@@ -797,9 +790,9 @@ public class TrackDataHubTest extends AndroidTestCase {
 
     replay();
 
-    hub.registerTrackDataListener(listener1, EnumSet.of(ListenerDataType.DISPLAY_PREFERENCES));
+    hub.registerTrackDataListener(listener1, EnumSet.of(TrackDataType.PREFERENCE));
     hub.start();
-    hub.registerTrackDataListener(listener2, EnumSet.of(ListenerDataType.DISPLAY_PREFERENCES));
+    hub.registerTrackDataListener(listener2, EnumSet.of(TrackDataType.PREFERENCE));
 
     verifyAndReset();
 
@@ -809,12 +802,12 @@ public class TrackDataHubTest extends AndroidTestCase {
     replay();
 
     PreferencesUtils.setBoolean(context, R.string.report_speed_key, false);
-    OnSharedPreferenceChangeListener listener = listenerCapture.getValue();
+    OnSharedPreferenceChangeListener listener = preferenceListenerCapture.getValue();
     listener.onSharedPreferenceChanged(
         sharedPreferences, PreferencesUtils.getKey(context, R.string.report_speed_key));
 
-    AndroidMock.verify(dataSources, providerUtils, listener1, listener2);
-    AndroidMock.reset(dataSources, providerUtils, listener1, listener2);
+    AndroidMock.verify(dataSource, providerUtils, listener1, listener2);
+    AndroidMock.reset(dataSource, providerUtils, listener1, listener2);
 
     expect(listener1.onUnitsChanged(false)).andReturn(false);
     expect(listener2.onUnitsChanged(false)).andReturn(false);
@@ -829,15 +822,15 @@ public class TrackDataHubTest extends AndroidTestCase {
   }
 
   private void expectStart() {
-    dataSources.registerOnSharedPreferenceChangeListener(capture(preferenceListenerCapture));
+    dataSource.registerOnSharedPreferenceChangeListener(capture(preferenceListenerCapture));
   }
 
   private void replay() {
-    AndroidMock.replay(dataSources, providerUtils, listener1, listener2);
+    AndroidMock.replay(dataSource, providerUtils, listener1, listener2);
   }
 
   private void verifyAndReset() {
-    AndroidMock.verify(listener1, listener2, dataSources, providerUtils);
-    AndroidMock.reset(listener1, listener2, dataSources, providerUtils);
+    AndroidMock.verify(listener1, listener2, dataSource, providerUtils);
+    AndroidMock.reset(listener1, listener2, dataSource, providerUtils);
   }
 }