Addressed comments + new method getLocationId()

MyTracks/AndroidManifest.xml

@@ -158,11 +158,9 @@ limitations under the License.
   <uses-permission android:name="com.google.android.apps.mytracks.TRACK_NOTIFICATIONS" />
 
   <!-- Features required -->
-  <!--
   <uses-feature android:name="android.hardware.location" android:required="true"/>
   <uses-feature android:name="android.hardware.location.gps" android:required="true"/>
   <uses-feature android:name="android.hardware.touchscreen" android:required="true"/>
-  -->
   
   <!-- Features optional -->
   <uses-feature android:name="android.hardware.bluetooth" android:required="false"/>

MyTracksLib/src/com/google/android/apps/mytracks/content/MyTracksProviderUtils.java

@@ -315,6 +315,13 @@ public interface MyTracksProviderUtils {
    * A lightweight wrapper around the original {@link Cursor} with a method to clean up.
    */
   interface LocationIterator extends Iterator<Location> {
+    /**
+     * Returns ID of the most recently retrieved track point through a call to {@link #next()}.
+     * 
+     * @return the ID of the most recent track point ID.
+     */
+    long getLocationId();
+    
     /**
      * Should be called in case the underlying iterator hasn't reached the last record.
      */
@@ -336,8 +343,7 @@ public interface MyTracksProviderUtils {
   }
   
   /**
-   * The default {@class Location}s factory, which creates a new location of 'gps' type each
+   * The default {@class Location}s factory, which creates a new location of 'gps' type.
-   * time the user advances to the next element using {@link LocationIterator#next()} method.
    */
   LocationFactory DEFAULT_LOCATION_FACTORY = new LocationFactory() {
     @Override
@@ -352,7 +358,11 @@ public interface MyTracksProviderUtils {
    * limitations. Since it's a read-only iterator, {@link Iterator#remove()} always throws
    * {@class UnsupportedOperationException}.
    * 
-   * Once constructed, the user must call {@link LocationIterator#close()} to make sure that all
+   * Each call to {@link LocationIterator#next()} may advance to the next DB record, and if so,
+   * the iterator calls {@link LocationFactory#createLocation()} and populates it with information
+   * retrieved from the record.
+   * 
+   * When done with iteration, you must call {@link LocationIterator#close()} to make sure that all
    * resources are properly deallocated.
    * 
    * Example use:
@@ -371,10 +381,16 @@ public interface MyTracksProviderUtils {
    * </code>
    * 
    * @param trackId the ID of a track to retrieve locations for.
+   * @param startTrackPointId the ID of the first track point to load, or -1 to start from
+   *        the first point.
+   * @param descending if true the results will be returned in descending ID
+   *        order (latest location first).
    * @param locationFactory the factory for creating new locations.
+   * 
    * @return the read-only iterator over the given track's points.
    */
-  LocationIterator getLocationIterator(long trackId, LocationFactory locationFactory);
+  LocationIterator getLocationIterator(long trackId, long startTrackPointId, boolean descending,
+      LocationFactory locationFactory);
 
   /**
    * A factory which can produce instances of {@link MyTracksProviderUtils},

MyTracksLib/src/com/google/android/apps/mytracks/content/MyTracksProviderUtilsImpl.java

@@ -937,16 +937,16 @@ public class MyTracksProviderUtilsImpl implements MyTracksProviderUtils {
   }
 
   @Override
-  public LocationIterator getLocationIterator(final long trackId,
+  public LocationIterator getLocationIterator(final long trackId, final long startTrackPointId,
-      final LocationFactory locationFactory) {
+      final boolean descending, final LocationFactory locationFactory) {
     return new LocationIterator() {
-      private long lastTrackPointId = -1;
+      private long lastTrackPointId = startTrackPointId - 1;
       private Cursor cursor = getCursor();
       private final int idColumnIdx = cursor != null ?
           cursor.getColumnIndexOrThrow(TrackPointsColumns._ID) : -1;
           
       private Cursor getCursor() {
-        return getLocationsCursor(trackId, lastTrackPointId + 1, 2000, false);
+        return getLocationsCursor(trackId, lastTrackPointId + 1, 2000, descending);
       }
 
       private boolean advanceCursorToNextBatch() {
@@ -954,7 +954,12 @@ public class MyTracksProviderUtilsImpl implements MyTracksProviderUtils {
         cursor = getCursor();
         return cursor != null && cursor.moveToNext();
       }
-          
+        
+      @Override
+      public long getLocationId() {
+        return lastTrackPointId;
+      }
+
       @Override
       public boolean hasNext() {
         return cursor != null && !cursor.isAfterLast();