Implement elevation gain via barometer.

src/androidTest/java/de/dennisguse/opentracks/services/sensors/ElevationSumManagerTest.java

@@ -0,0 +1,34 @@
+package de.dennisguse.opentracks.services.sensors;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * NOTE: Test data is completely artificial.
+ */
+public class ElevationSumManagerTest {
+
+    private ElevationSumManager elevationSumManager = new ElevationSumManager();
+
+    private static void addSensorValue(ElevationSumManager elevationSumManager, float[] values) {
+        for (float f : values) {
+            elevationSumManager.onSensorValueChanged(f);
+        }
+    }
+
+    @Before
+    public void setUp() {
+        elevationSumManager.reset();
+    }
+
+    @Test
+    public void getElevationGainLoss_downhill() {
+        // then
+        addSensorValue(elevationSumManager, new float[]{1015f, 1015.01f, 1015.02f, 1015.03f, 1015.04f, 1015.05f, 1015.06f, 1015.07f, 1015.08f, 1015.09f, 1015.10f, 1015.11f, 1015.12f, 1015.13f, 1015.14f, 1015.15f});
+
+        // then
+        Assert.assertEquals(0f, elevationSumManager.getElevationGain_m(), 0.01);
+        Assert.assertEquals(-1.08, elevationSumManager.getElevationLoss_m(), 0.01);
+    }
+}

src/androidTest/java/de/dennisguse/opentracks/util/PressureSensorUtilsTest.java

@@ -0,0 +1,51 @@
+package de.dennisguse.opentracks.util;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+public class PressureSensorUtilsTest {
+
+    // real data at 500Hz stationary
+    @Test
+    public void elevationChanges_none() {
+        // given
+        float[] sensorValues_hPa = new float[]{1015.6876f, 1015.699f, 1015.70905f, 1015.71075f, 1015.7224f, 1015.72f, 1015.7373f, 1015.7481f, 1015.74133f, 1015.73553f, 1015.7462f, 1015.74896f, 1015.752f, 1015.754f, 1015.7456f, 1015.73303f, 1015.7288f, 1015.7239f, 1015.7298f, 1015.7387f, 1015.72534f, 1015.72577f, 1015.72797f, 1015.71796f, 1015.7113f, 1015.7097f, 1015.7096f, 1015.7013f, 1015.7072f, 1015.71063f, 1015.7088f, 1015.7115f, 1015.713f, 1015.7121f, 1015.7062f, 1015.7062f, 1015.6994f, 1015.69617f, 1015.68945f, 1015.698f, 1015.6913f, 1015.69696f, 1015.69293f, 1015.6955f, 1015.6928f, 1015.6939f, 1015.68787f, 1015.6881f, 1015.68536f, 1015.68726f, 1015.6879f, 1015.6904f, 1015.6937f, 1015.69476f, 1015.7046f, 1015.7019f, 1015.7079f, 1015.71124f, 1015.71216f, 1015.71436f, 1015.7171f, 1015.7186f, 1015.7186f, 1015.7246f, 1015.72046f, 1015.7211f, 1015.72375f, 1015.7194f, 1015.72125f, 1015.7161f, 1015.71185f, 1015.7188f, 1015.721f, 1015.7252f, 1015.72266f, 1015.7236f, 1015.72614f, 1015.7266f, 1015.7344f, 1015.7376f, 1015.7337f, 1015.7253f, 1015.71875f, 1015.7219f, 1015.7219f, 1015.7317f, 1015.7284f, 1015.73444f, 1015.73584f, 1015.7369f, 1015.73254f, 1015.7369f, 1015.7336f, 1015.73254f, 1015.73676f, 1015.74176f, 1015.74506f, 1015.7478f, 1015.755f, 1015.7515f, 1015.7543f, 1015.7459f, 1015.7468f, 1015.7492f, 1015.74585f, 1015.74756f, 1015.74756f, 1015.75085f, 1015.754f, 1015.75336f, 1015.7568f, 1015.75165f, 1015.761f, 1015.7527f, 1015.75684f, 1015.7635f, 1015.7585f, 1015.7552f, 1015.7475f, 1015.74506f, 1015.7542f, 1015.75586f, 1015.74176f, 1015.74414f, 1015.7501f, 1015.751f, 1015.7478f, 1015.755f, 1015.75836f, 1015.7592f, 1015.75256f, 1015.7559f, 1015.76654f, 1015.76154f, 1015.766f, 1015.77014f, 1015.76904f, 1015.76013f, 1015.7674f, 1015.76514f, 1015.7674f, 1015.7635f, 1015.76404f, 1015.7607f, 1015.754f, 1015.7574f, 1015.7607f, 1015.7607f, 1015.7607f, 1015.754f, 1015.7567f, 1015.7616f, 1015.7643f, 1015.7666f, 1015.7609f, 1015.766f, 1015.76764f, 1015.755f, 1015.75757f, 1015.74927f, 1015.74927f, 1015.7426f, 1015.745f, 1015.745f, 1015.7409f, 1015.7376f, 1015.7326f, 1015.74164f, 1015.74664f, 1015.745f, 1015.7459f, 1015.7502f, 1015.7493f, 1015.7476f, 1015.7493f, 1015.751f, 1015.7601f, 1015.76434f, 1015.766f, 1015.756f, 1015.7617f, 1015.7623f, 1015.76404f, 1015.76733f, 1015.7607f, 1015.7623f, 1015.76337f, 1015.7584f, 1015.7573f, 1015.7502f, 1015.7534f, 1015.7534f, 1015.7601f, 1015.75684f, 1015.7518f, 1015.75574f, 1015.7524f, 1015.7507f, 1015.7484f, 1015.7502f, 1015.7534f, 1015.7623f, 1015.75903f, 1015.75574f, 1015.75574f, 1015.7573f, 1015.7524f, 1015.75574f, 1015.75574f, 1015.7607f, 1015.7573f, 1015.754f, 1015.74677f, 1015.754f, 1015.75574f, 1015.75903f, 1015.7573f, 1015.7551f, 1015.7573f, 1015.754f, 1015.7507f, 1015.7374f, 1015.739f, 1015.73566f, 1015.73566f, 1015.7367f, 1015.7417f, 1015.7417f, 1015.739f, 1015.74835f, 1015.74567f, 1015.7517f, 1015.74066f, 1015.7374f, 1015.739f, 1015.7417f, 1015.73065f, 1015.72894f, 1015.73505f, 1015.73334f, 1015.74005f, 1015.74005f, 1015.7367f, 1015.7434f, 1015.744f, 1015.7423f, 1015.7384f, 1015.739f, 1015.7374f, 1015.7374f, 1015.7374f, 1015.7341f, 1015.73505f, 1015.7341f, 1015.7267f, 1015.72833f, 1015.7234f, 1015.7167f, 1015.725f, 1015.7217f, 1015.7234f, 1015.73004f, 1015.7324f, 1015.7423f, 1015.74005f, 1015.73505f, 1015.73004f, 1015.739f, 1015.7417f, 1015.74567f, 1015.74066f, 1015.74146f, 1015.74146f, 1015.73816f, 1015.7274f, 1015.72906f, 1015.7274f, 1015.7341f, 1015.739f, 1015.744f, 1015.7417f, 1015.7374f, 1015.7324f, 1015.73816f, 1015.74146f, 1015.7374f, 1015.7341f, 1015.7365f, 1015.7365f, 1015.74146f, 1015.74414f, 1015.7475f, 1015.7448f, 1015.74146f, 1015.74585f, 1015.7475f, 1015.75146f, 1015.75146f, 1015.7591f, 1015.75476f, 1015.7614f, 1015.75476f, 1015.7492f, 1015.74817f, 1015.7498f, 1015.7515f, 1015.75586f, 1015.7509f, 1015.7448f, 1015.7525f, 1015.7581f, 1015.7592f};
+        float firstSensorValue = sensorValues_hPa[0];
+
+        // when // then
+        for (float v : sensorValues_hPa) {
+            assertNull(PressureSensorUtils.computeChanges_m(firstSensorValue, v));
+        }
+    }
+
+    // test data
+    @Test
+    public void computeChanges_downhill() {
+        float[] sensorValues_hPa = new float[]{1015f, 1015.01f, 1015.02f, 1015.03f, 1015.04f, 1015.05f, 1015.06f, 1015.07f, 1015.08f, 1015.09f, 1015.10f, 1015.11f, 1015.12f, 1015.13f, 1015.14f, 1015.15f};
+        float firstSensorValue = sensorValues_hPa[0];
+
+        // when
+        float elevationGain_m = 0;
+        float elevationLoss_m = 0;
+        float lastUsedPressureValue_hPa = firstSensorValue;
+
+        for (float v : sensorValues_hPa) {
+            PressureSensorUtils.ElevationChange elevationChange = PressureSensorUtils.computeChanges_m(lastUsedPressureValue_hPa, v);
+            if (elevationChange != null) {
+                if (elevationChange.getElevationChange_m() > 0) {
+                    elevationGain_m += elevationChange.getElevationChange_m();
+                } else {
+                    elevationLoss_m += elevationChange.getElevationChange_m();
+                }
+                lastUsedPressureValue_hPa = elevationChange.getCurrentSensorValue_hPa();
+            }
+        }
+
+        // then
+        assertEquals(0f, elevationGain_m, 0.01);
+        assertEquals(-1.08f, elevationLoss_m, 0.01);
+        assertEquals(1015.13, lastUsedPressureValue_hPa, 0.01);
+    }
+}

src/main/java/de/dennisguse/opentracks/content/data/TrackPoint.java

@@ -32,6 +32,7 @@ public class TrackPoint {
     private Float heartRate_bpm = null;
     private Float cyclingCadence_rpm = null;
     private Float power = null;
+    private float elevationGain = Float.NaN;
 
     public TrackPoint() {
         this.location = new Location("");
@@ -92,6 +93,18 @@ public class TrackPoint {
         return location;
     }
 
+    public boolean hasElevationGain() {
+        return !Float.isNaN(elevationGain);
+    }
+
+    public float getElevationGain() {
+        return elevationGain;
+    }
+
+    public void setElevationGain(float elevationGain) {
+        this.elevationGain = elevationGain;
+    }
+
     public double getLatitude() {
         return location.getLatitude();
     }

src/main/java/de/dennisguse/opentracks/fragments/StatisticsRecordedFragment.java

@@ -87,6 +87,10 @@ public class StatisticsRecordedFragment extends Fragment {
     private TextView speedMovingValue;
     private TextView speedMovingUnit;
 
+    private TextView elevationCurrentGroup;
+    private TextView elevationTotalGainValue;
+    private TextView elevationTotalGainUnit;
+
     public static StatisticsRecordedFragment newInstance(Track.Id trackId) {
         Bundle bundle = new Bundle();
         bundle.putParcelable(TRACK_ID_KEY, trackId);
@@ -130,6 +134,11 @@ public class StatisticsRecordedFragment extends Fragment {
         speedMovingLabel = view.findViewById(R.id.stats_moving_speed_label);
         speedMovingValue = view.findViewById(R.id.stats_moving_speed_value);
         speedMovingUnit = view.findViewById(R.id.stats_moving_speed_unit);
+
+        elevationCurrentGroup = view.findViewById(R.id.stats_elevation_current_group);
+
+        elevationTotalGainValue = view.findViewById(R.id.stats_elevation_gain_value);
+        elevationTotalGainUnit = view.findViewById(R.id.stats_elevation_gain_unit);
     }
 
     @Override
@@ -187,6 +196,9 @@ public class StatisticsRecordedFragment extends Fragment {
         speedMovingLabel = null;
         speedMovingValue = null;
         speedMovingUnit = null;
+
+        elevationTotalGainValue = null;
+        elevationTotalGainUnit = null;
     }
 
     public void loadStatistics() {
@@ -264,5 +276,14 @@ public class StatisticsRecordedFragment extends Fragment {
             speedMovingValue.setText(parts.first);
             speedMovingUnit.setText(parts.second);
         }
+
+        // Set elevation gain
+        {
+            double elevationGain_m = trackStatistics != null ? trackStatistics.getTotalElevationGain() : 0f;
+
+            Pair<String, String> parts = StringUtils.formatElevation(getContext(), elevationGain_m, metricUnits);
+            elevationTotalGainValue.setText(parts.first);
+            elevationTotalGainUnit.setText(parts.second);
+        }
     }
 }

src/main/java/de/dennisguse/opentracks/fragments/StatisticsRecordingFragment.java

@@ -132,12 +132,14 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
     private TextView speedMovingLabel;
     private TextView speedMovingValue;
     private TextView speedMovingUnit;
-    private Group elevationGroup;
     private TextView speedLabel;
     private TextView speedValue;
     private TextView speedUnit;
-    private TextView elevationValue;
+    private Group elevationCurrentGroup;
-    private TextView elevationUnit;
+    private TextView elevationCurrentValue;
+    private TextView elevationCurrentUnit;
+    private TextView elevationTotalGainValue;
+    private TextView elevationTotalGainUnit;
     private Group coordinateGroup;
     private TextView latitudeValue;
     private TextView longitudeValue;
@@ -178,14 +180,16 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
         speedMovingValue = view.findViewById(R.id.stats_moving_speed_value);
         speedMovingUnit = view.findViewById(R.id.stats_moving_speed_unit);
 
-        elevationGroup = view.findViewById(R.id.stats_elevation_current_group);
-
         speedLabel = view.findViewById(R.id.stats_speed_label);
         speedValue = view.findViewById(R.id.stats_speed_value);
         speedUnit = view.findViewById(R.id.stats_speed_unit);
 
-        elevationValue = view.findViewById(R.id.stats_elevation_current_value);
+        elevationCurrentGroup = view.findViewById(R.id.stats_elevation_current_group);
-        elevationUnit = view.findViewById(R.id.stats_elevation_current_unit);
+        elevationCurrentValue = view.findViewById(R.id.stats_elevation_current_value);
+        elevationCurrentUnit = view.findViewById(R.id.stats_elevation_current_unit);
+
+        elevationTotalGainValue = view.findViewById(R.id.stats_elevation_gain_value);
+        elevationTotalGainUnit = view.findViewById(R.id.stats_elevation_gain_unit);
 
         coordinateGroup = view.findViewById(R.id.stats_coordinate_group);
 
@@ -276,14 +280,16 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
         speedMovingValue = null;
         speedMovingUnit = null;
 
-        elevationGroup = null;
-
         speedLabel = null;
         speedValue = null;
         speedUnit = null;
 
-        elevationValue = null;
+        elevationCurrentGroup = null;
-        elevationUnit = null;
+        elevationCurrentValue = null;
+        elevationCurrentUnit = null;
+
+        elevationTotalGainValue = null;
+        elevationTotalGainUnit = null;
 
         coordinateGroup = null;
 
@@ -406,20 +412,25 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
 
     /**
      * Tries to fetch most recent {@link SensorDataSet} from {@link de.dennisguse.opentracks.services.TrackRecordingService}.
+     * Also sets elevation gain.
      */
     private void updateSensorDataUI() {
         TrackRecordingServiceInterface trackRecordingService = trackRecordingServiceConnection.getServiceIfBound();
 
         SensorDataSet sensorDataSet = null;
+        Float elevationGain_m = null;
         if (trackRecordingService == null) {
             Log.d(TAG, "Cannot get the track recording service.");
         } else {
             sensorDataSet = trackRecordingService.getSensorData();
+            elevationGain_m = trackRecordingService.getElevationGain_m();
         }
 
         setHeartRateSensorData(sensorDataSet);
         setCadenceSensorData(sensorDataSet);
         setSpeedSensorData(sensorDataSet, isSelectedTrackRecording());
+
+        setElevationGainFromSensor(elevationGain_m);
     }
 
     private void setHeartRateSensorData(SensorDataSet sensorDataSet) {
@@ -468,6 +479,33 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
         cadenceValueView.setText(sensorValue);
     }
 
+    // Set elevation gain
+    public void setTotalElevationGain(Float elevationGain_m) {
+        boolean metricUnits = PreferencesUtils.isMetricUnits(getContext());
+
+        if (elevationGain_m == null) {
+            elevationGain_m = 0f;
+        }
+        if (lastTrackStatistics != null) {
+            elevationGain_m += (float) lastTrackStatistics.getTotalElevationGain();
+        }
+
+        Pair<String, String> parts = StringUtils.formatElevation(getContext(), elevationGain_m, metricUnits);
+        elevationTotalGainValue.setText(parts.first);
+        elevationTotalGainUnit.setText(parts.second);
+    }
+
+    public void setElevationGainFromSensor(Float elevationGain_m) {
+        float totalElevationGain = 0;
+        if (elevationGain_m != null) {
+            totalElevationGain = elevationGain_m;
+        }
+        if (lastTrackStatistics != null) {
+            totalElevationGain += (float) lastTrackStatistics.getTotalElevationGain();
+        }
+        setTotalElevationGain(totalElevationGain);
+    }
+
     /**
      * If cadence and hear rate groups are invisible then sensor horizontal line hast to be invisible too.
      */
@@ -475,7 +513,6 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
         if (cadenceGroup.getVisibility() != View.VISIBLE && heartRateGroup.getVisibility() != View.VISIBLE) {
             sensorHorizontalLine.setVisibility(View.GONE);
         }
-
     }
 
     private void setSpeedSensorData(SensorDataSet sensorDataSet, boolean isRecording) {
@@ -555,10 +592,11 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
             speedMovingUnit.setText(parts.second);
         }
 
-        // Make elevation visible?
+        // Set elevation (gain)
         {
+            // Make elevation visible?
             boolean showElevation = PreferencesUtils.isShowStatsElevation(getContext());
-            elevationGroup.setVisibility(showElevation ? View.VISIBLE : View.GONE);
+            elevationCurrentGroup.setVisibility(showElevation ? View.VISIBLE : View.GONE);
         }
     }
 
@@ -594,14 +632,14 @@ public class StatisticsRecordingFragment extends Fragment implements TrackDataLi
 
         // Set elevation
         boolean showElevation = PreferencesUtils.isShowStatsElevation(getContext());
-        elevationGroup.setVisibility(showElevation ? View.VISIBLE : View.GONE);
+        elevationCurrentGroup.setVisibility(showElevation ? View.VISIBLE : View.GONE);
 
         if (showElevation) {
+            // Current elevation
             double altitude = lastTrackPoint != null && lastTrackPoint.hasAltitude() ? lastTrackPoint.getAltitude() : Double.NaN;
             Pair<String, String> parts = StringUtils.formatElevation(getContext(), altitude, metricUnits);
-
+            elevationCurrentValue.setText(parts.first);
-            elevationValue.setText(parts.first);
+            elevationCurrentUnit.setText(parts.second);
-            elevationUnit.setText(parts.second);
         }
 
         // Set coordinate

src/main/java/de/dennisguse/opentracks/services/TrackRecordingService.java

@@ -49,6 +49,7 @@ import de.dennisguse.opentracks.content.sensor.SensorDataSet;
 import de.dennisguse.opentracks.services.handlers.GpsStatusValue;
 import de.dennisguse.opentracks.services.handlers.HandlerServer;
 import de.dennisguse.opentracks.services.sensors.BluetoothRemoteSensorManager;
+import de.dennisguse.opentracks.services.sensors.ElevationSumManager;
 import de.dennisguse.opentracks.services.tasks.AnnouncementPeriodicTaskFactory;
 import de.dennisguse.opentracks.services.tasks.PeriodicTaskExecutor;
 import de.dennisguse.opentracks.stats.TrackStatistics;
@@ -115,6 +116,7 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
     // The following variables are set when recording:
     private WakeLock wakeLock;
     private BluetoothRemoteSensorManager remoteSensorManager;
+    private ElevationSumManager elevationSumManager;
 
     private TrackStatisticsUpdater trackStatisticsUpdater;
     private TrackPoint lastTrackPoint;
@@ -174,6 +176,11 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
             remoteSensorManager = null;
         }
 
+        if (elevationSumManager != null) {
+            elevationSumManager.stop(this);
+            elevationSumManager = null;
+        }
+
         // Reverse order from onCreate
         showNotification(false); //TODO Why?
 
@@ -371,6 +378,10 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
         // Update instance variables
         remoteSensorManager = new BluetoothRemoteSensorManager(this);
         remoteSensorManager.start();
+
+        elevationSumManager = new ElevationSumManager();
+        elevationSumManager.start(this);
+
         lastTrackPoint = null;
         isIdle = false;
 
@@ -456,6 +467,11 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
             remoteSensorManager.stop();
             remoteSensorManager = null;
         }
+        if (elevationSumManager != null) {
+            elevationSumManager.stop(this);
+            elevationSumManager = null;
+        }
+
         lastTrackPoint = null;
 
         handlerServer.stop(this);
@@ -533,6 +549,10 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
         //TODO Figure out how to avoid loading the lastValidTrackPoint from the database
         TrackPoint lastValidTrackPoint = getLastValidTrackPointInCurrentSegment(track.getId());
 
+        if (elevationSumManager != null) {
+            trackPoint.setElevationGain(elevationSumManager.getElevationGain_m());
+        }
+
         //Storing trackPoint
 
         // Always insert the first segment location
@@ -556,15 +576,19 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
             insertTrackPoint(track, TrackPoint.createPause());
 
             insertTrackPoint(track, trackPoint);
-            isIdle = false;
+            elevationSumManager.reset();
 
+            isIdle = false;
             lastTrackPoint = trackPoint;
             return;
         }
 
         if (trackPoint.hasSensorData() || distanceToLastTrackLocation >= recordingDistanceInterval) {
             insertTrackPointIfNewer(track, lastTrackPoint);
+
             insertTrackPoint(track, trackPoint);
+            elevationSumManager.reset();
+
             isIdle = false;
 
             lastTrackPoint = trackPoint;
@@ -573,7 +597,10 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
 
         if (!isIdle && !TrackPointUtils.isMoving(trackPoint)) {
             insertTrackPointIfNewer(track, lastTrackPoint);
+
             insertTrackPoint(track, trackPoint);
+            elevationSumManager.reset();
+
             isIdle = true;
 
             lastTrackPoint = trackPoint;
@@ -582,7 +609,10 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
 
         if (isIdle && TrackPointUtils.isMoving(trackPoint)) {
             insertTrackPointIfNewer(track, lastTrackPoint);
+
             insertTrackPoint(track, trackPoint);
+            elevationSumManager.reset();
+
             isIdle = false;
 
             lastTrackPoint = trackPoint;
@@ -672,6 +702,17 @@ public class TrackRecordingService extends Service implements HandlerServer.Hand
         }
     }
 
+    /**
+     * Returns the relative elevation gain (since last trackpoint).
+     */
+    Float getElevationGain_m() {
+        if (elevationSumManager == null || !elevationSumManager.isConnected()) {
+            return null;
+        }
+
+        return elevationSumManager.getElevationGain_m();
+    }
+
     private void showNotification(boolean isGpsStarted) {
         if (isRecording()) {
             Intent intent = IntentUtils.newIntent(this, TrackRecordingActivity.class)

src/main/java/de/dennisguse/opentracks/services/TrackRecordingServiceBinder.java

@@ -99,6 +99,11 @@ class TrackRecordingServiceBinder extends android.os.Binder implements TrackReco
         return trackRecordingService.getSensorDataSet();
     }
 
+    @Override
+    public Float getElevationGain_m() {
+        return trackRecordingService.getElevationGain_m();
+    }
+
     @VisibleForTesting
     @Override
     public void setRemoteSensorManager(BluetoothRemoteSensorManager remoteSensorManager) {

src/main/java/de/dennisguse/opentracks/services/TrackRecordingServiceInterface.java

@@ -65,12 +65,19 @@ public interface TrackRecordingServiceInterface {
     Marker.Id insertMarker(String name, String category, String description, String photoUrl);
 
     /**
-     * Gets the current sensor data. Returns null if there is no data.
+     * Gets the current sensor data.
      *
-     * @return SensorDataSet object.
+     * @return SensorDataSet object or null.
      */
     SensorDataSet getSensorData();
 
+    /**
+     * Gets the current elevation gain.
+     *
+     * @return elevation gain in m or null.
+     */
+    Float getElevationGain_m();
+
     @VisibleForTesting
     void setRemoteSensorManager(BluetoothRemoteSensorManager remoteSensorManager);
 

src/main/java/de/dennisguse/opentracks/services/sensors/ElevationSumManager.java

@@ -0,0 +1,102 @@
+package de.dennisguse.opentracks.services.sensors;
+
+import android.content.Context;
+import android.hardware.Sensor;
+import android.hardware.SensorEvent;
+import android.hardware.SensorEventListener;
+import android.hardware.SensorManager;
+import android.util.Log;
+
+import androidx.annotation.VisibleForTesting;
+
+import de.dennisguse.opentracks.util.PressureSensorUtils;
+import de.dennisguse.opentracks.util.UnitConversions;
+
+/**
+ * Estimates the elevation gain and elevation loss using the device's pressure sensor (i.e., barometer).
+ */
+public class ElevationSumManager implements SensorEventListener {
+
+    private static final String TAG = ElevationSumManager.class.getSimpleName();
+
+    private static final int SAMPLING_RATE = 3 * (int) UnitConversions.ONE_SECOND_US;
+
+    private boolean isConnected = false;
+
+    private float lastUsedPressureValue_hPa;
+
+    private float elevationGain_m;
+    private float elevationLoss_m;
+
+    public void start(Context context) {
+        SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
+
+        Sensor pressureSensor = sensorManager.getDefaultSensor(Sensor.TYPE_PRESSURE);
+        if (pressureSensor == null) {
+            Log.w(TAG, "No pressure sensor available.");
+            isConnected = false;
+        }
+
+        isConnected = sensorManager.registerListener(this, pressureSensor, SAMPLING_RATE);
+        lastUsedPressureValue_hPa = Float.NaN;
+        reset();
+    }
+
+    public void stop(Context context) {
+        Log.d(TAG, "Stop");
+
+        SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
+        sensorManager.unregisterListener(this);
+
+        isConnected = false;
+        reset();
+    }
+
+    public boolean isConnected() {
+        return isConnected;
+    }
+
+    public float getElevationGain_m() {
+        return elevationGain_m;
+    }
+
+    public float getElevationLoss_m() {
+        return elevationLoss_m;
+    }
+
+    public void reset() {
+        Log.d(TAG, "Reset");
+        elevationGain_m = 0;
+        elevationLoss_m = 0;
+    }
+
+    @Override
+    public void onAccuracyChanged(Sensor sensor, int accuracy) {
+        Log.w(TAG, "Sensor accuracy changes are (currently) ignored.");
+    }
+
+    @Override
+    public void onSensorChanged(SensorEvent event) {
+        onSensorValueChanged(event.values[0]);
+    }
+
+    @VisibleForTesting
+    void onSensorValueChanged(float value_hPa) {
+        if (Float.isNaN(lastUsedPressureValue_hPa)) {
+            lastUsedPressureValue_hPa = value_hPa;
+            return;
+        }
+
+        PressureSensorUtils.ElevationChange elevationChange = PressureSensorUtils.computeChanges_m(lastUsedPressureValue_hPa, value_hPa);
+        if (elevationChange != null) {
+            if (elevationChange.getElevationChange_m() > 0) {
+                elevationGain_m += elevationChange.getElevationChange_m();
+            } else {
+                elevationLoss_m += elevationChange.getElevationChange_m();
+            }
+            lastUsedPressureValue_hPa = elevationChange.getCurrentSensorValue_hPa();
+        }
+
+        Log.v(TAG, "elevation gain: " + elevationGain_m);
+    }
+}

src/main/java/de/dennisguse/opentracks/stats/TrackStatistics.java

@@ -228,7 +228,7 @@ public class TrackStatistics {
     }
 
     /**
-     * Gets the total elevation gain in meters. This is calculated as the sum of all positive differences in the smoothed elevation.
+     * Gets the total elevation gain in meters.
      */
     public double getTotalElevationGain() {
         return totalElevationGain_m;

src/main/java/de/dennisguse/opentracks/stats/TrackStatisticsUpdater.java

@@ -112,7 +112,7 @@ public class TrackStatisticsUpdater {
      * Adds a trackPoint.
      * TODO: This assume trackPoint has a valid time.
      *
-     * @param trackPoint             the trackPoint
+     * @param trackPoint           the trackPoint
      * @param minRecordingDistance the min recording distance
      */
     public void addTrackPoint(TrackPoint trackPoint, int minRecordingDistance) {
@@ -134,8 +134,16 @@ public class TrackStatisticsUpdater {
             return;
         }
 
-        //TODO Use Barometer to compute elevation gain.
+        //Update absolute (GPS-based) elevation
-        double elevationDifference = trackPoint.hasAltitude() ? updateElevation(trackPoint.getAltitude()) : 0.0;
+        if (trackPoint.hasAltitude()) {
+            updateAbsoluteElevation(trackPoint.getAltitude());
+        }
+
+        //Get elevation gain
+        if (trackPoint.hasElevationGain()) {
+            currentSegment.addTotalElevationGain(trackPoint.getElevationGain());
+            Log.d(TAG, "elevation gain: " + trackPoint.getElevationGain());
+        }
 
         if (lastTrackPoint == null || lastMovingTrackPoint == null) {
             lastTrackPoint = trackPoint;
@@ -207,23 +215,21 @@ public class TrackStatisticsUpdater {
     }
 
     /**
-     * Updates an elevation reading. Returns the difference.
+     * Updates an elevation reading.
      *
      * @param elevation the elevation
+     * @return the difference
      */
     @VisibleForTesting
-    private double updateElevation(double elevation) {
+    private double updateAbsoluteElevation(double elevation) {
         // Update elevation using the smoothed average
         double oldAverage = elevationBuffer_m.getAverage();
         elevationBuffer_m.setNext(elevation);
         double newAverage = elevationBuffer_m.getAverage();
 
         currentSegment.updateElevationExtremities(newAverage);
-        double difference = newAverage - oldAverage;
+
-        if (difference > 0) {
+        return newAverage - oldAverage;
-            currentSegment.addTotalElevationGain(difference);
-        }
-        return difference;
     }
 
     private TrackStatistics init(long time) {

src/main/java/de/dennisguse/opentracks/util/PressureSensorUtils.java

@@ -0,0 +1,49 @@
+package de.dennisguse.opentracks.util;
+
+import android.hardware.SensorManager;
+
+public class PressureSensorUtils {
+
+    //Everything above is considered a meaningful change in elevation.
+    private static float ELEVATION_CHANGE_DIFF_M = 5.0f;
+
+    private PressureSensorUtils() {
+    }
+
+    public static class ElevationChange {
+
+        private float currentSensorValue_hPa;
+
+        private float elevationChange_m;
+
+        public ElevationChange(float currentSensorValue_hPa, float elevationChange_m) {
+            this.currentSensorValue_hPa = currentSensorValue_hPa;
+            this.elevationChange_m = elevationChange_m;
+        }
+
+        public float getCurrentSensorValue_hPa() {
+            return currentSensorValue_hPa;
+        }
+
+        public float getElevationChange_m() {
+            return elevationChange_m;
+        }
+    }
+
+    /**
+     * Computes the elevation gain and elevation loss.
+     *
+     * @return null if no meaningful elevation change occurred.
+     */
+    public static ElevationChange computeChanges_m(float lastSensorValue_hPa, float currentSensorValue_hPa) {
+        float lastSensorValue_m = SensorManager.getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, lastSensorValue_hPa);
+        float currentSensorValue_m = SensorManager.getAltitude(SensorManager.PRESSURE_STANDARD_ATMOSPHERE, currentSensorValue_hPa);
+
+        float elevationChange_m = currentSensorValue_m - lastSensorValue_m;
+        if (Math.abs(elevationChange_m) < ELEVATION_CHANGE_DIFF_M) {
+            return null;
+        }
+
+        return new ElevationChange(currentSensorValue_hPa, elevationChange_m);
+    }
+}

src/main/java/de/dennisguse/opentracks/util/UnitConversions.java

@@ -26,7 +26,8 @@ public class UnitConversions {
     public static final long S_TO_MS = 1000;
 
     // Time
-    // 1 second in milliseconds
+    // TODO Use int instead of long.
+    public static final long ONE_SECOND_US = UnitConversions.S_TO_MS * 1000;
     public static final long ONE_SECOND_MS = UnitConversions.S_TO_MS;
     public static final long ONE_MINUTE_MS = (long) (UnitConversions.MIN_TO_S * UnitConversions.S_TO_MS);
     public static final long ONE_HOUR_MS = 60 * ONE_MINUTE_MS;

src/main/res/layout/statistics_recorded.xml

@@ -209,6 +209,48 @@
             app:layout_constraintRight_toLeftOf="@+id/guideline3"
             tools:text="km/h" />
 
+        <!-- Elevation gain -->
+        <View
+            android:id="@+id/stats_elevation_horizontal_line"
+            style="@style/StatsHorizontalLine"
+            android:layout_marginBottom="8dp"
+            app:layout_constraintLeft_toRightOf="@+id/guideline"
+            app:layout_constraintRight_toLeftOf="@+id/guideline3"
+            app:layout_constraintTop_toBottomOf="@+id/stats_moving_speed_value" />
+
+        <androidx.constraintlayout.widget.Group
+            android:id="@+id/stats_elevation_gain_group"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            app:constraint_referenced_ids="stats_elevation_current_label,stats_elevation_current_value,stats_elevation_current_unit,stats_elevation_horizontal_line" />
+
+        <TextView
+            android:id="@+id/stats_elevation_gain_label"
+            style="@style/StatsSmallLabel"
+            android:text="@string/stats_gain"
+            app:layout_constrainedWidth="true"
+            app:layout_constraintLeft_toRightOf="@+id/guideline2"
+            app:layout_constraintRight_toLeftOf="@+id/guideline3"
+            app:layout_constraintTop_toBottomOf="@id/stats_elevation_horizontal_line" />
+
+        <TextView
+            android:id="@+id/stats_elevation_gain_value"
+            style="@style/StatsSmallValue"
+            android:value="@string/value_unknown"
+            app:layout_constraintHorizontal_chainStyle="packed"
+            app:layout_constraintLeft_toRightOf="@+id/guideline2"
+            app:layout_constraintRight_toLeftOf="@+id/stats_elevation_gain_unit"
+            app:layout_constraintTop_toBottomOf="@+id/stats_elevation_gain_label"
+            tools:text="100" />
+
+        <TextView
+            android:id="@+id/stats_elevation_gain_unit"
+            style="@style/StatsUnit"
+            app:layout_constraintBottom_toBottomOf="@+id/stats_elevation_gain_value"
+            app:layout_constraintLeft_toRightOf="@+id/stats_elevation_gain_value"
+            app:layout_constraintRight_toLeftOf="@+id/guideline3"
+            tools:text="m" />
+
         <!-- Horizontal line -->
         <View
             android:id="@+id/stats_speed_horizontal_end_line"

src/main/res/layout/statistics_recording.xml

@@ -258,8 +258,8 @@
             style="@style/StatsSmallLabel"
             android:text="@string/stats_elevation"
             app:layout_constrainedWidth="true"
-            app:layout_constraintLeft_toRightOf="@+id/guideline2"
+            app:layout_constraintLeft_toRightOf="@+id/guideline"
-            app:layout_constraintRight_toLeftOf="@+id/guideline3"
+            app:layout_constraintRight_toLeftOf="@+id/guideline2"
             app:layout_constraintTop_toBottomOf="@id/stats_elevation_horizontal_line" />
 
         <TextView
@@ -267,7 +267,7 @@
             style="@style/StatsSmallValue"
             android:value="@string/value_unknown"
             app:layout_constraintHorizontal_chainStyle="packed"
-            app:layout_constraintLeft_toRightOf="@+id/guideline2"
+            app:layout_constraintLeft_toRightOf="@+id/guideline"
             app:layout_constraintRight_toLeftOf="@+id/stats_elevation_current_unit"
             app:layout_constraintTop_toBottomOf="@+id/stats_elevation_current_label"
             tools:text="100" />
@@ -277,6 +277,40 @@
             style="@style/StatsUnit"
             app:layout_constraintBottom_toBottomOf="@+id/stats_elevation_current_value"
             app:layout_constraintLeft_toRightOf="@+id/stats_elevation_current_value"
+            app:layout_constraintRight_toLeftOf="@+id/guideline2"
+            tools:text="m" />
+
+        <!-- Current elevation -->
+        <androidx.constraintlayout.widget.Group
+            android:id="@+id/stats_elevation_gain_group"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            app:constraint_referenced_ids="stats_elevation_current_label,stats_elevation_current_value,stats_elevation_current_unit,stats_elevation_horizontal_line" />
+
+        <TextView
+            android:id="@+id/stats_elevation_gain_label"
+            style="@style/StatsSmallLabel"
+            android:text="@string/stats_gain"
+            app:layout_constrainedWidth="true"
+            app:layout_constraintLeft_toRightOf="@+id/guideline2"
+            app:layout_constraintRight_toLeftOf="@+id/guideline3"
+            app:layout_constraintTop_toBottomOf="@id/stats_elevation_horizontal_line" />
+
+        <TextView
+            android:id="@+id/stats_elevation_gain_value"
+            style="@style/StatsSmallValue"
+            android:value="@string/value_unknown"
+            app:layout_constraintHorizontal_chainStyle="packed"
+            app:layout_constraintLeft_toRightOf="@+id/guideline2"
+            app:layout_constraintRight_toLeftOf="@+id/stats_elevation_gain_unit"
+            app:layout_constraintTop_toBottomOf="@+id/stats_elevation_gain_label"
+            tools:text="100" />
+
+        <TextView
+            android:id="@+id/stats_elevation_gain_unit"
+            style="@style/StatsUnit"
+            app:layout_constraintBottom_toBottomOf="@+id/stats_elevation_gain_value"
+            app:layout_constraintLeft_toRightOf="@+id/stats_elevation_gain_value"
             app:layout_constraintRight_toLeftOf="@+id/guideline3"
             tools:text="m" />