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);
     }

src/main/java/de/dennisguse/opentracks/io/file/exporter/GPXTrackExporter.java

@@ -238,17 +238,12 @@ public class GPXTrackExporter implements TrackExporter {
     }
 
     private void writeMarkers(Track track) throws InterruptedException {
-        try (Cursor cursor = contentProviderUtils.getMarkerCursor(track.getId())) {
-            if (cursor != null && cursor.moveToFirst()) {
-                for (int i = 0; i < cursor.getCount(); i++) {
-                    if (Thread.interrupted()) {
-                        throw new InterruptedException();
-                    }
-                    Marker marker = contentProviderUtils.createMarker(cursor);
-                    writeMarker(track.getZoneOffset(), marker);
+        try (AutoCloseableIterator<Marker> markerIterator = contentProviderUtils.getMarkerIterator(track.getId())) {
+            while (markerIterator.hasNext()) {
+                if (Thread.interrupted()) throw new InterruptedException();
 
-                    cursor.moveToNext();
-                }
+
+                writeMarker(track.getZoneOffset(), markerIterator.next());
             }
         }
     }

src/main/java/de/dennisguse/opentracks/io/file/exporter/KMLTrackExporter.java

@@ -136,21 +136,16 @@ public class KMLTrackExporter implements TrackExporter {
 
     private void writeMarkers(Track track) throws InterruptedException {
         boolean hasMarkers = false;
-        try (Cursor cursor = contentProviderUtils.getMarkerCursor(track.getId())) {
-            if (cursor != null && cursor.moveToFirst()) {
-                for (int i = 0; i < cursor.getCount(); i++) {
-                    if (Thread.interrupted()) {
-                        throw new InterruptedException();
-                    }
-                    if (!hasMarkers) {
-                        writeBeginMarkers(track);
-                        hasMarkers = true;
-                    }
-                    Marker marker = contentProviderUtils.createMarker(cursor);
-                    writeMarker(marker, track.getZoneOffset());
+        try (AutoCloseableIterator<Marker> markerIterator = contentProviderUtils.getMarkerIterator(track.getId())) {
+            while (markerIterator.hasNext()) {
+                if (Thread.interrupted()) throw new InterruptedException();
 
-                    cursor.moveToNext();
+                if (!hasMarkers) {
+                    writeBeginMarkers(track);
+                    hasMarkers = true;
                 }
+
+                writeMarker(markerIterator.next(), track.getZoneOffset());
             }
         }
         if (hasMarkers) {

src/main/java/de/dennisguse/opentracks/io/file/exporter/KMZTrackExporter.java

@@ -36,6 +36,7 @@ import de.dennisguse.opentracks.data.ContentProviderUtils;
 import de.dennisguse.opentracks.data.models.Marker;
 import de.dennisguse.opentracks.data.models.Track;
 import de.dennisguse.opentracks.ui.markers.MarkerUtils;
+import de.dennisguse.opentracks.util.AutoCloseableIterator;
 import de.dennisguse.opentracks.util.FileUtils;
 
 /**
@@ -89,22 +90,17 @@ public class KMZTrackExporter implements TrackExporter {
 
     private void addImages(Context context, List<Track> tracks, ZipOutputStream zipOutputStream) throws InterruptedException, IOException {
         for (Track track : tracks) {
-            try (Cursor cursor = contentProviderUtils.getMarkerCursor(track.getId())) {
-                if (cursor != null && cursor.moveToFirst()) {
-                    for (int i = 0; i < cursor.getCount(); i++) {
-                        if (Thread.interrupted()) {
-                            throw new InterruptedException();
-                        }
-                        Marker marker = contentProviderUtils.createMarker(cursor);
-                        if (marker.hasPhoto()) {
-                            Uri uriPhoto = marker.getPhotoUrl();
-                            boolean existsPhoto = MarkerUtils.buildInternalPhotoFile(context, track.getId(), uriPhoto) != null;
-                            if (existsPhoto) {
-                                addImage(context, zipOutputStream, uriPhoto, marker);
-                            }
-                        }
+            try (AutoCloseableIterator<Marker> markerIterator = contentProviderUtils.getMarkerIterator(track.getId())) {
+                while (markerIterator.hasNext()) {
+                    if (Thread.interrupted()) throw new InterruptedException();
 
-                        cursor.moveToNext();
+                    Marker marker = markerIterator.next();
+                    if (marker.hasPhoto()) {
+                        Uri uriPhoto = marker.getPhotoUrl();
+                        boolean existsPhoto = MarkerUtils.buildInternalPhotoFile(context, track.getId(), uriPhoto) != null;
+                        if (existsPhoto) {
+                            addImage(context, zipOutputStream, uriPhoto, marker);
+                        }
                     }
                 }
             }

src/main/java/de/dennisguse/opentracks/io/file/importer/KMZTrackImporter.java

@@ -31,6 +31,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Consumer;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 
@@ -38,6 +39,7 @@ import de.dennisguse.opentracks.R;
 import de.dennisguse.opentracks.data.ContentProviderUtils;
 import de.dennisguse.opentracks.data.models.Marker;
 import de.dennisguse.opentracks.data.models.Track;
+import de.dennisguse.opentracks.util.AutoCloseableIterator;
 import de.dennisguse.opentracks.util.FileUtils;
 
 /**
@@ -188,13 +190,14 @@ public class KMZTrackImporter {
     private void deleteOrphanImages(Track.Id trackId) {
         // 1.- Gets all photo names in the markers of the track identified by id.
         ContentProviderUtils contentProviderUtils = new ContentProviderUtils(context);
-        List<Marker> markers = contentProviderUtils.getMarkers(trackId);
         List<String> photosName = new ArrayList<>();
-        for (Marker marker : markers) {
-            if (marker.hasPhoto()) {
-                String photoUrl = Uri.decode(marker.getPhotoUrl().toString()); //TODO Why Uri.decode()?
-                photosName.add(photoUrl.substring(photoUrl.lastIndexOf(File.separatorChar) + 1));
-            }
+        try (AutoCloseableIterator<Marker> markerIterator = new ContentProviderUtils(context).getMarkerIterator(trackId)) {
+            markerIterator.forEachRemaining(marker -> {
+                if (marker.hasPhoto()) {
+                    String photoUrl = Uri.decode(marker.getPhotoUrl().toString()); //TODO Why Uri.decode()?
+                    photosName.add(photoUrl.substring(photoUrl.lastIndexOf(File.separatorChar) + 1));
+                }
+            });
         }
 
         // 2.- Deletes all orphan photos from external storage.