Implemented MarkerIterator.

src/main/java/de/dennisguse/opentracks/data/CachedTrackPointsIndexes.java

@@ -7,6 +7,7 @@ import de.dennisguse.opentracks.data.tables.TrackPointsColumns;
 /**
  * A cache of track points indexes.
  */
+//TOOD Check if this actually useful.
 class CachedTrackPointsIndexes {
     final int idIndex;
     final int typeIndex;

src/main/java/de/dennisguse/opentracks/data/ContentProviderUtils.java

@@ -430,6 +430,11 @@ public class ContentProviderUtils {
         return null;
     }
 
+    public AutoCloseableIterator<Marker> getMarkerIterator(@NonNull Track.Id trackId) {
+        return new MarkerIterator(this, trackId, -1);
+    }
+
+    //TODO Use MarkerIterator instead
     public Cursor getMarkerCursor(@NonNull Track.Id trackId) {
         return getMarkerCursor(trackId, -1);
     }
@@ -731,7 +736,7 @@ public class ContentProviderUtils {
      * @param trackId           the track id
      * @param startTrackPointId the starting trackPoint id. `null` to ignore
      */
-    public AutoCloseableIterator<TrackPoint> getTrackPointIterator(final Track.Id trackId, final TrackPoint.Id startTrackPointId) {
+    public AutoCloseableIterator<TrackPoint> getTrackPointIterator(Track.Id trackId, TrackPoint.Id startTrackPointId) {
         return new TrackPointIterator(this, trackId, startTrackPointId);
     }
 

src/main/java/de/dennisguse/opentracks/data/MarkerIterator.java

@@ -0,0 +1,67 @@
+package de.dennisguse.opentracks.data;
+
+import android.database.Cursor;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+
+import java.util.NoSuchElementException;
+
+import de.dennisguse.opentracks.data.models.Marker;
+import de.dennisguse.opentracks.data.models.Track;
+import de.dennisguse.opentracks.data.models.TrackPoint;
+import de.dennisguse.opentracks.util.AutoCloseableIterator;
+
+class MarkerIterator extends AutoCloseableIterator<Marker> {
+
+    private static final String TAG = MarkerIterator.class.getSimpleName();
+
+    private final ContentProviderUtils contentProviderUtils;
+    private Cursor cursor;
+
+    MarkerIterator(ContentProviderUtils contentProviderUtils, Track.Id trackId, int maxCount) {
+        this.contentProviderUtils = contentProviderUtils;
+
+        cursor = contentProviderUtils.getMarkerCursor(trackId, maxCount);
+    }
+
+    @Override
+    public boolean hasNext() {
+        if (cursor == null) {
+            return false;
+        }
+        return !cursor.isLast() && !cursor.isAfterLast();
+    }
+
+    @Override
+    @NonNull
+    public Marker next() {
+        if (cursor == null || !cursor.moveToNext()) {
+            throw new NoSuchElementException();
+        }
+        return contentProviderUtils.createMarker(cursor);
+    }
+
+    @Override
+    public int getPosition() {
+        return cursor.getPosition();
+    }
+
+    @VisibleForTesting
+    public int getCount() {
+        return cursor.getCount();
+    }
+
+    @Override
+    public void close() {
+        if (cursor != null) {
+            cursor.close();
+            cursor = null;
+        }
+    }
+
+    @Override
+    public void remove() {
+        throw new UnsupportedOperationException();
+    }
+}

src/main/java/de/dennisguse/opentracks/data/TrackPointIterator.java

@@ -17,16 +17,10 @@ import de.dennisguse.opentracks.util.AutoCloseableIterator;
 class TrackPointIterator extends AutoCloseableIterator<TrackPoint> {
 
     private static final String TAG = TrackPointIterator.class.getSimpleName();
-
-    private final ContentProviderUtils contentProviderUtils;
-    private final Track.Id trackId;
     private final CachedTrackPointsIndexes indexes;
     private Cursor cursor;
 
     TrackPointIterator(ContentProviderUtils contentProviderUtils, Track.Id trackId, TrackPoint.Id startTrackPointId) {
-        this.contentProviderUtils = contentProviderUtils;
-        this.trackId = trackId;
-
         cursor = contentProviderUtils.getTrackPointCursor(trackId, startTrackPointId);
         indexes = new CachedTrackPointsIndexes(cursor);
     }