Package structure: moved models and database.

Part of #963.

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

@@ -0,0 +1,72 @@
+package de.dennisguse.opentracks.data;
+
+import android.database.Cursor;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+import de.dennisguse.opentracks.data.models.Track;
+import de.dennisguse.opentracks.data.models.TrackPoint;
+
+/**
+ * A lightweight wrapper around the original {@link Cursor}.
+ */
+public class TrackPointIterator implements Iterator<TrackPoint>, AutoCloseable {
+
+    private static final String TAG = TrackPointIterator.class.getSimpleName();
+
+    private final ContentProviderUtils contentProviderUtils;
+    private final Track.Id trackId;
+    private final CachedTrackPointsIndexes indexes;
+    private Cursor cursor;
+
+    public TrackPointIterator(ContentProviderUtils contentProviderUtils, Track.Id trackId, TrackPoint.Id startTrackPointId) {
+        this.contentProviderUtils = contentProviderUtils;
+        this.trackId = trackId;
+
+        cursor = getCursor(startTrackPointId);
+        indexes = new CachedTrackPointsIndexes(cursor);
+    }
+
+    private Cursor getCursor(TrackPoint.Id trackPointId) {
+        return contentProviderUtils.getTrackPointCursor(trackId, trackPointId);
+    }
+
+    @Override
+    public boolean hasNext() {
+        if (cursor == null) {
+            return false;
+        }
+        return !cursor.isLast() && !cursor.isAfterLast();
+    }
+
+    @Override
+    @NonNull
+    public TrackPoint next() {
+        if (cursor == null || !cursor.moveToNext()) {
+            throw new NoSuchElementException();
+        }
+        return ContentProviderUtils.fillTrackPoint(cursor, indexes);
+    }
+
+    @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();
+    }
+}