add UUID to to GPX with opentracks namespace

ensure that GPX has trackpoints
improve GPX track name if null

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/activities/ActivitySummariesGpsFragment.java

@@ -88,9 +88,11 @@ public class ActivitySummariesGpsFragment extends AbstractGBFragment {
                 }
 
                 if (gpxParser != null) {
+                    if (gpxParser.getPoints().toArray().length > 0) {
                         drawTrack(canvas, gpxParser.getPoints());
                     }
                 }
+            }
         }).start();
     }
     private void drawTrack(Canvas canvas, List<GPSCoordinate> trackPoints) {

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/export/GPXExporter.java

@@ -19,6 +19,9 @@ package nodomain.freeyourgadget.gadgetbridge.export;
 
 import android.util.Xml;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
 import org.xmlpull.v1.XmlSerializer;
 
 import java.io.File;
@@ -29,9 +32,8 @@ import java.math.RoundingMode;
 import java.nio.charset.StandardCharsets;
 import java.util.Date;
 import java.util.List;
+import java.util.UUID;
 
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 import nodomain.freeyourgadget.gadgetbridge.activities.HeartRateUtils;
 import nodomain.freeyourgadget.gadgetbridge.model.ActivityPoint;
 import nodomain.freeyourgadget.gadgetbridge.model.ActivityTrack;
@@ -45,6 +47,10 @@ public class GPXExporter implements ActivityTrackExporter {
     private static final String NS_TRACKPOINT_EXTENSION = "gpxtpx";
     private static final String NS_TRACKPOINT_EXTENSION_URI = "http://www.garmin.com/xmlschemas/TrackPointExtension/v1";
     private static final String NS_XSI_URI = "http://www.w3.org/2001/XMLSchema-instance";
+    private static final String TOPOGRAFIX_NAMESPACE_XSD = "http://www.topografix.com/GPX/1/1/gpx.xsd";
+    private static final String OPENTRACKS_PREFIX = "opentracks";
+    private static final String OPENTRACKS_NAMESPACE_URI = "http://opentracksapp.com/xmlschemas/v1";
+    private static final String OPENTRACKS_NAMESPACE_XSD = "http://opentracksapp.com/xmlschemas/OpenTracks_v1.xsd";
 
     private String creator;
     private boolean includeHeartRate = true;
@@ -66,11 +72,14 @@ public class GPXExporter implements ActivityTrackExporter {
             ser.setPrefix("xsi", NS_XSI_URI);
             ser.setPrefix(NS_TRACKPOINT_EXTENSION, NS_TRACKPOINT_EXTENSION_URI);
             ser.setPrefix(NS_GPX_PREFIX, NS_GPX_URI);
+            ser.setPrefix(OPENTRACKS_PREFIX, OPENTRACKS_NAMESPACE_URI);
 
             ser.startTag(NS_GPX_URI, "gpx");
             ser.attribute(null, "version", "1.1");
             ser.attribute(null, "creator", getCreator());
-            ser.attribute(NS_XSI_URI, "schemaLocation", NS_GPX_URI + " " + "http://www.topografix.com/GPX/1/1/gpx.xsd");
+            ser.attribute(NS_XSI_URI, "schemaLocation", NS_GPX_URI + " "
+                    + TOPOGRAFIX_NAMESPACE_XSD + " "
+                    + OPENTRACKS_NAMESPACE_URI + " " + OPENTRACKS_NAMESPACE_XSD);
 
             exportMetadata(ser, track);
             exportTrack(ser, track);
@@ -99,7 +108,12 @@ public class GPXExporter implements ActivityTrackExporter {
     }
 
     private void exportTrack(XmlSerializer ser, ActivityTrack track) throws IOException, GPXTrackEmptyException {
+        String uuid = UUID.randomUUID().toString();
         ser.startTag(NS_GPX_URI, "trk");
+        ser.startTag(NS_GPX_URI, "extensions");
+        ser.startTag(NS_GPX_URI, OPENTRACKS_PREFIX + ":trackid").text(uuid).endTag(NS_GPX_URI, OPENTRACKS_PREFIX + ":trackid");
+        ser.endTag(NS_GPX_URI, "extensions");
+
         ser.startTag(NS_GPX_URI, "trkseg");
 
         List<ActivityPoint> trackPoints = track.getTrackPoints();

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/HuamiActivityDetailsParser.java

@@ -70,7 +70,7 @@ public class HuamiActivityDetailsParser {
         this.activityTrack = new ActivityTrack();
         activityTrack.setUser(summary.getUser());
         activityTrack.setDevice(summary.getDevice());
-        activityTrack.setName(summary.getName() + "-" + summary.getId());
+        activityTrack.setName(createActivityName(summary));
     }
 
     public ActivityTrack parse(byte[] bytes) throws GBException {
@@ -295,4 +295,14 @@ public class HuamiActivityDetailsParser {
         LOG.debug("got packet type 8 (swimming?): " + GB.hexdump(bytes, offset, 6));
         return 6;
     }
+
+    private String createActivityName(BaseActivitySummary summary) {
+        String name = summary.getName();
+        String nameText = "";
+        Long id = summary.getId();
+        if (name != null) {
+            nameText = name + " - ";
+        }
+        return nameText + id;
+    }
 }

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/util/GpxParser.java

@@ -16,6 +16,8 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 package nodomain.freeyourgadget.gadgetbridge.util;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 import org.xmlpull.v1.XmlPullParserFactory;
@@ -28,8 +30,9 @@ import java.util.List;
 import nodomain.freeyourgadget.gadgetbridge.model.GPSCoordinate;
 
 public class GpxParser {
+    private static final Logger LOG = LoggerFactory.getLogger(GpxParser.class);
     private XmlPullParser parser;
-    private List<GPSCoordinate> points;
+    private List<GPSCoordinate> points = new ArrayList<>();
     private int eventType;
 
     public GpxParser(InputStream stream) {
@@ -52,13 +55,15 @@ public class GpxParser {
 
     private void parseGpx() throws XmlPullParserException, IOException {
         eventType = parser.getEventType();
+
         while (eventType != XmlPullParser.END_DOCUMENT) {
-            if (eventType == XmlPullParser.START_TAG && parser.getName().equals("trkpt"))
+            if (eventType == XmlPullParser.START_TAG && parser.getName().equals("trkpt")) {
                 points.add(parsePoint(parser));
-            else
+            } else {
                 eventType = parser.next();
             }
         }
+    }
 
     private double parseElevation(XmlPullParser parser) throws XmlPullParserException, IOException {
         String eleString = "";

app/src/test/resources/gpx-exporter-test-SampleTrack.gpx

@@ -1,13 +1,16 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<gpx xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:gpxtpx="http://www.garmin.com/xmlschemas/TrackPointExtension/v1" xmlns="http://www.topografix.com/GPX/1/1" version="1.1" creator="Gadgetbridge Test" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd">
+<gpx xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:gpxtpx="http://www.garmin.com/xmlschemas/TrackPointExtension/v1" xmlns="http://www.topografix.com/GPX/1/1" xmlns:opentracks="http://opentracksapp.com/xmlschemas/v1" version="1.1" creator="Gadgetbridge Test" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd http://opentracksapp.com/xmlschemas/v1 http://opentracksapp.com/xmlschemas/OpenTracks_v1.xsd">
   <metadata>
     <name>Test Track</name>
     <author>
       <name>Test User</name>
     </author>
-    <time>2020-10-25T14:44:45+01:00</time>
+    <time>2021-01-16T23:27:34+01:00</time>
   </metadata>
   <trk>
+    <extensions>
+      <opentracks:trackid>0555e104-e8ea-4e10-b3e9-8b58abae257f</opentracks:trackid>
+    </extensions>
     <trkseg>
       <trkpt lon="-68.200293" lat="44.152462">
         <ele>40.000000</ele>