re-worked the resume functionality

app/proguard-rules.pro

@@ -15,8 +15,3 @@
 #-keepclassmembers class fqcn.of.javascript.interface.for.webview {
 #   public *;
 #}
-
-
-# needed for osmdroid v5.6.5 if using SDK version 26 TODO remove as soom as osmdroid v5.6.6 is released
-# see https://github.com/osmdroid/osmdroid/issues/633
-# -dontwarn org.osmdroid.tileprovider.modules.NetworkAvailabliltyCheck

app/src/main/java/org/y20k/trackbook/MainActivity.java

@@ -178,14 +178,15 @@ public class MainActivity extends AppCompatActivity implements TrackbookKeys {
     @Override
     protected void onPause() {
         super.onPause();
+
     }
 
 
     @Override
     protected void onStop() {
         super.onStop();
+        // unbind from TrackerService
         unbindService(mConnection);
-        mBound = false;
     }
 
 
@@ -269,14 +270,6 @@ public class MainActivity extends AppCompatActivity implements TrackbookKeys {
     }
 
 
-    /* Request the current Track from TrackerService */
-    public void requestTrack() {
-        if (mBound) {
-            mTrackerService.sendTrackUpdate();
-        }
-    }
-
-
     /* Handles the visual state after a save action */
     private void handleStateAfterSave() {
         // display and update tracks tab

app/src/main/java/org/y20k/trackbook/MainActivityMapFragment.java

@@ -225,19 +225,25 @@ public class MainActivityMapFragment extends Fragment implements TrackbookKeys {
         // load state of tracker service - see if anything changed
         loadTrackerServiceState(mActivity);
 
-        // CASE 1: recording active
-        if (mTrackerServiceRunning) {
-            // request an updated track recording from service
-            ((MainActivity)mActivity).requestTrack();
-        }
-
-        // CASE 2: recording stopped - temp file exists
-        else if (mStorageHelper.tempFileExists()) {
         // load track from temp file if it exists
+        if (mStorageHelper.tempFileExists()) {
             LoadTempTrackAsyncHelper loadTempTrackAsyncHelper = new LoadTempTrackAsyncHelper();
             loadTempTrackAsyncHelper.execute();
         }
 
+//        // CASE 1: recording active
+//        if (mTrackerServiceRunning) {
+//            // request an updated track recording from service
+//            ((MainActivity)mActivity).requestTrack();
+//        }
+//
+//        // CASE 2: recording stopped - temp file exists
+//        else if (mStorageHelper.tempFileExists()) {
+//            // load track from temp file if it exists
+//            LoadTempTrackAsyncHelper loadTempTrackAsyncHelper = new LoadTempTrackAsyncHelper();
+//            loadTempTrackAsyncHelper.execute();
+//        }
+
 //        // CASE 3: not recording and no temp file
 //        else if (mTrack != null) {
 //            // just draw existing track data (from saved instance)
@@ -551,7 +557,6 @@ public class MainActivityMapFragment extends Fragment implements TrackbookKeys {
             @Override
             public void onReceive(Context context, Intent intent) {
                 if (intent.hasExtra(EXTRA_TRACK) && intent.hasExtra(EXTRA_LAST_LOCATION)) {
-                    LogHelper.v(LOG_TAG, "Track update received.");
                     // draw track on map
                     mTrack = intent.getParcelableExtra(EXTRA_TRACK);
                     drawTrackOverlay(mTrack);

app/src/main/java/org/y20k/trackbook/TrackerService.java

@@ -37,7 +37,6 @@ import android.os.CountDownTimer;
 import android.os.Handler;
 import android.os.IBinder;
 import android.preference.PreferenceManager;
-import android.support.annotation.Nullable;
 import android.support.v4.app.NotificationCompat;
 import android.support.v4.content.LocalBroadcastManager;
 import android.widget.Toast;
@@ -51,7 +50,6 @@ import org.y20k.trackbook.helpers.StorageHelper;
 import org.y20k.trackbook.helpers.TrackbookKeys;
 
 import java.util.List;
-import java.util.Random;
 
 import static android.hardware.Sensor.TYPE_STEP_COUNTER;
 
@@ -115,17 +113,14 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
 
     @Override
     public boolean onUnbind(Intent intent) {
-        // All clients have unbound with unbindService()
+        // return true if you would like to have the service's onRebind(Intent) method later called when new clients bind to it.
-//        return mAllowRebind; // todo change
         return true;
     }
 
 
-
     @Override
     public void onRebind(Intent intent) {
-        // A client is binding to the service with bindService(),
+        // a client is binding to the service with bindService(), after onUnbind() has already been called
-        // after onUnbind() has already been called
     }
 
 
@@ -141,68 +136,11 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
             resumeTracking();
         }
 
-//        // check if user did turn off location in device settings
-//        if (!mLocationSystemSetting) {
-//            LogHelper.i(LOG_TAG, "Location Setting is turned off.");
-//            Toast.makeText(getApplicationContext(), R.string.toast_message_location_offline, Toast.LENGTH_LONG).show();
-//            stopTracking();
-//            return START_STICKY;
-//        }
-//
-//        // RESTART CHECK:  checking for empty intent - try to get saved track
-//        if (intent == null || intent.getAction() == null) {
-//            LogHelper.w(LOG_TAG, "Null-Intent received. Trying to restart tracking.");
-//            startTracking(intent, false);
-//        }
-//
-//        // ACTION START
-//        else if (intent.getAction().equals(ACTION_START) && mLocationSystemSetting) {
-//            startTracking(intent, true);
-//        }
-//
-//        // ACTION RESUME
-//        else if (intent.getAction().equals(ACTION_RESUME) && mLocationSystemSetting) {
-//            startTracking(intent, false);
-//        }
-//
-//        // ACTION STOP
-//        else if (intent.getAction().equals(ACTION_STOP) || !mLocationSystemSetting) {
-//            mTrackerServiceRunning = false;
-//            if (mTrack != null && mTimer != null) {
-//                stopTracking();
-//            } else {
-//                // handle error - save state
-//                saveTrackerServiceState(mTrackerServiceRunning, FAB_STATE_DEFAULT);
-//            }
-//        }
-//
-//        // ACTION DISMISS
-//        else if (intent.getAction().equals(ACTION_DISMISS)) {
-//            // save state
-//            saveTrackerServiceState(mTrackerServiceRunning, FAB_STATE_DEFAULT);
-//            // dismiss notification
-//            mNotificationManager.cancel(TRACKER_SERVICE_NOTIFICATION_ID); // todo check if necessary?
-//            stopForeground(true);
-//        }
-//
-//        // ACTION TRACK REQUEST
-//        else if (intent.getAction().equals(ACTION_TRACK_REQUEST)) {
-//            // send track via broadcast
-//            sendTrackUpdate();
-//        }
-
         // START_STICKY is used for services that are explicitly started and stopped as needed
         return START_STICKY;
     }
 
 
-//    @Nullable
-//    @Override
-//    public IBinder onBind(Intent intent) {
-//        return null;
-//    }
-
-
     @Override
     public void onDestroy() {
         LogHelper.v(LOG_TAG, "onDestroy called.");
@@ -258,7 +196,7 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
             mStepCountOffset = 0;
 
             // begin recording
-            recordMovements();
+            startMovementRecording();
 
         } else {
             LogHelper.i(LOG_TAG, "Location Setting is turned off.");
@@ -299,7 +237,7 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
             mStepCountOffset = mTrack.getStepCount();
 
             // begin recording
-            recordMovements();
+            startMovementRecording();
 
         } else {
             LogHelper.i(LOG_TAG, "Location Setting is turned off.");
@@ -308,185 +246,17 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
     }
 
 
-    /* Record movements */
-    private void recordMovements() {
-        // add last location as WayPoint to track
-        addWayPointToTrack();
-
-        // put up notification
-        displayNotification(true);
-
-        // create gps and network location listeners
-        startFindingLocation();
-
-        // start timer that periodically request a location update
-        startIntervalTimer();
-
-        // start counting steps
-        startStepCounter();
-
-        // register content observer for changes in System Settings
-        this.getContentResolver().registerContentObserver(android.provider.Settings.Secure.CONTENT_URI, true, mSettingsContentObserver);
-
-        // start service in foreground
-        startForeground(TRACKER_SERVICE_NOTIFICATION_ID, mNotification);
-    }
-
-
-
-    private void startStepCounter() {
-        boolean stepCounterAvailable;
-        stepCounterAvailable = mSensorManager.registerListener(this, mSensorManager.getDefaultSensor(TYPE_STEP_COUNTER), SensorManager.SENSOR_DELAY_UI);
-        if (stepCounterAvailable) {
-            LogHelper.v(LOG_TAG, "Pedometer sensor available: Registering listener.");
-        } else {
-            LogHelper.i(LOG_TAG, "Pedometer sensor not available.");
-            mTrack.setStepCount(-1);
-        }
-    }
-
-
-
-    /* Set timer to retrieve new locations and to prevent endless tracking */
-    private void startIntervalTimer() {
-        mTimer = new CountDownTimer(EIGHT_HOURS_IN_MILLISECONDS, FIFTEEN_SECONDS_IN_MILLISECONDS) {
-            @Override
-            public void onTick(long millisUntilFinished) {
-                // update track duration - and add duration from previously interrupted / paused session
-                long previouslyRecordedDuration = mTrack.getTrackDuration();
-                long duration = EIGHT_HOURS_IN_MILLISECONDS - millisUntilFinished + previouslyRecordedDuration;
-                mTrack.setDuration(duration);
-                // try to add WayPoint to Track
-                addWayPointToTrack();
-                // update notification
-
-                mNotification = NotificationHelper.getUpdatedNotification(TrackerService.this, mNotificationBuilder, mTrack);
-                mNotificationManager.notify(TRACKER_SERVICE_NOTIFICATION_ID, mNotification);
-                // save a temp file in case the service has been killed by the system
-                SaveTempTrackAsyncHelper saveTempTrackAsyncHelper = new SaveTempTrackAsyncHelper();
-                saveTempTrackAsyncHelper.execute();
-            }
-
-            @Override
-            public void onFinish() {
-                // stop tracking after eight hours
-                stopTracking();
-            }
-        };
-        mTimer.start();
-    }
-
-
-    /* Display notification */
-    private void displayNotification(boolean trackingState) {
-        mNotificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANEL_ID_RECORDING_CHANNEL);
-        mNotification = NotificationHelper.getNotification(this, mNotificationBuilder, mTrack, trackingState);
-        mNotificationManager.notify(TRACKER_SERVICE_NOTIFICATION_ID, mNotification); // todo check if necessary in pre Android O
-    }
-
-
-
-    /* Start tracking location */ // todo remove
-    private void startTracking(@Nullable Intent intent, boolean createNewTrack) {
-        LogHelper.v(LOG_TAG, "Service received command: START");
-
-        // create a new track - if requested
-        if (createNewTrack) {
-            mTrack = new Track();
-        } else {
-            StorageHelper storageHelper = new StorageHelper(this);
-            if (storageHelper.tempFileExists()) {
-                // load temp track file
-                mTrack = storageHelper.loadTrack(FILE_TEMP_TRACK);
-                // try to mark last waypoint as stopover
-                int lastWayPoint = mTrack.getWayPoints().size() - 1;
-                if (lastWayPoint >= 0) {
-                    mTrack.getWayPoints().get(lastWayPoint).setIsStopOver(true);
-                }
-            } else {
-                // fallback, if tempfile did not exist
-                LogHelper.e(LOG_TAG, "Unable to find previously saved track temp file.");
-                mTrack = new Track();
-            }
-        }
-
-        // get last location
-        if (intent != null && ACTION_START.equals(intent.getAction()) && intent.hasExtra(EXTRA_LAST_LOCATION)) {
-            // received START intent and last location - unpack last location
-            mCurrentBestLocation = intent.getParcelableExtra(EXTRA_LAST_LOCATION);
-        } else if (ACTION_RESUME.equals(intent.getAction()) && mTrack.getSize() > 0) {
-            // received RESUME intent - use last waypoint
-            mCurrentBestLocation = mTrack.getWayPointLocation(mTrack.getSize() -1);
-        }
-
-        //  get last location - fallback
-        if (mCurrentBestLocation == null) {
-            mCurrentBestLocation = LocationHelper.determineLastKnownLocation(mLocationManager);
-        }
-
-        // add last location as WayPoint to track
-        addWayPointToTrack();
-
-        // put up notification
-        mNotificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANEL_ID_RECORDING_CHANNEL);
-        mNotification = NotificationHelper.getNotification(this, mNotificationBuilder, mTrack, true);
-        mNotificationManager.notify(TRACKER_SERVICE_NOTIFICATION_ID, mNotification); // todo check if necessary in pre Android O
-
-        // get duration of previously recorded track - in case this service has been restarted / resumed
-        final long previouslyRecordedDuration = mTrack.getTrackDuration();
-
-        // set timer to retrieve new locations and to prevent endless tracking
-        mTimer = new CountDownTimer(EIGHT_HOURS_IN_MILLISECONDS, FIFTEEN_SECONDS_IN_MILLISECONDS) {
-            @Override
-            public void onTick(long millisUntilFinished) {
-                // update track duration - and add duration from previously interrupted / paused session
-                long duration = EIGHT_HOURS_IN_MILLISECONDS - millisUntilFinished + previouslyRecordedDuration;
-                mTrack.setDuration(duration);
-                // try to add WayPoint to Track
-                addWayPointToTrack();
-                // update notification
-                mNotification = NotificationHelper.getUpdatedNotification(TrackerService.this, mNotificationBuilder, mTrack);
-                mNotificationManager.notify(TRACKER_SERVICE_NOTIFICATION_ID, mNotification);
-                // save a temp file in case the service has been killed by the system
-                SaveTempTrackAsyncHelper saveTempTrackAsyncHelper = new SaveTempTrackAsyncHelper();
-                saveTempTrackAsyncHelper.execute();
-            }
-
-            @Override
-            public void onFinish() {
-                // stop tracking after eight hours
-                stopTracking();
-            }
-        };
-        mTimer.start();
-
-        // initialize step counter
-        mStepCountOffset = 0;
-
-        boolean stepCounterAvailable;
-        stepCounterAvailable = mSensorManager.registerListener(this, mSensorManager.getDefaultSensor(TYPE_STEP_COUNTER), SensorManager.SENSOR_DELAY_UI);
-        if (stepCounterAvailable) {
-            LogHelper.v(LOG_TAG, "Pedometer sensor available: Registering listener.");
-        } else {
-            LogHelper.i(LOG_TAG, "Pedometer sensor not available.");
-            mTrack.setStepCount(-1);
-        }
-
-        // create gps and network location listeners
-        startFindingLocation();
-
-        // register content observer for changes in System Settings
-        this.getContentResolver().registerContentObserver(android.provider.Settings.Secure.CONTENT_URI, true, mSettingsContentObserver);
-
-        // start service in foreground
-        startForeground(TRACKER_SERVICE_NOTIFICATION_ID, mNotification);
-    }
-
-
     /* Stop tracking location */
     public void stopTracking() {
         LogHelper.v(LOG_TAG, "Recording stopped");
 
+        // catches a bug that leaves the ui in a incorrect state after a crash
+        if (!mTrackerServiceRunning) {
+            saveTrackerServiceState(mTrackerServiceRunning, FAB_STATE_SAVE);
+            broadcastTrackingStateChange();
+            return;
+        }
+
         // store current date and time
         mTrack.setRecordingEnd();
 
@@ -494,7 +264,7 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
         mTimer.cancel();
 
         // broadcast an updated track
-        sendTrackUpdate();
+        broadcastTrackUpdate();
 
         // save a temp file in case the activity has been killed
         SaveTempTrackAsyncHelper saveTempTrackAsyncHelper = new SaveTempTrackAsyncHelper();
@@ -525,6 +295,80 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
     }
 
 
+    /* Starts to record movements */
+    private void startMovementRecording() {
+        // add last location as WayPoint to track
+        addWayPointToTrack();
+
+        // put up notification
+        displayNotification(true);
+
+        // create gps and network location listeners
+        startFindingLocation();
+
+        // start timer that periodically request a location update
+        startRequestingLocationChanges();
+
+        // start counting steps
+        startStepCounter();
+
+        // register content observer for changes in System Settings
+        this.getContentResolver().registerContentObserver(android.provider.Settings.Secure.CONTENT_URI, true, mSettingsContentObserver);
+
+        // start service in foreground
+        startForeground(TRACKER_SERVICE_NOTIFICATION_ID, mNotification);
+    }
+
+
+    /* Registers a step counter listener */
+    private void startStepCounter() {
+        boolean stepCounterAvailable;
+        stepCounterAvailable = mSensorManager.registerListener(this, mSensorManager.getDefaultSensor(TYPE_STEP_COUNTER), SensorManager.SENSOR_DELAY_UI);
+        if (stepCounterAvailable) {
+            LogHelper.v(LOG_TAG, "Pedometer sensor available: Registering listener.");
+        } else {
+            LogHelper.i(LOG_TAG, "Pedometer sensor not available.");
+            mTrack.setStepCount(-1);
+        }
+    }
+
+
+    /* Set timer to periodically retrieve new locations and to prevent endless tracking */
+    private void startRequestingLocationChanges() {
+        final long previouslyRecordedDuration = mTrack.getTrackDuration();
+        mTimer = new CountDownTimer(EIGHT_HOURS_IN_MILLISECONDS, FIFTEEN_SECONDS_IN_MILLISECONDS) {
+            @Override
+            public void onTick(long millisUntilFinished) {
+                // update track duration - and add duration from previously interrupted / paused session
+                long duration = EIGHT_HOURS_IN_MILLISECONDS - millisUntilFinished + previouslyRecordedDuration;
+                mTrack.setDuration(duration);
+                // try to add WayPoint to Track
+                addWayPointToTrack();
+                // update notification
+                mNotification = NotificationHelper.getUpdatedNotification(TrackerService.this, mNotificationBuilder, mTrack);
+                mNotificationManager.notify(TRACKER_SERVICE_NOTIFICATION_ID, mNotification);
+                // save a temp file in case the service has been killed by the system
+                SaveTempTrackAsyncHelper saveTempTrackAsyncHelper = new SaveTempTrackAsyncHelper();
+                saveTempTrackAsyncHelper.execute();
+            }
+
+            @Override
+            public void onFinish() {
+                // stop tracking after eight hours
+                stopTracking();
+            }
+        };
+        mTimer.start();
+    }
+
+
+    /* Display notification */
+    private void displayNotification(boolean trackingState) {
+        mNotificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANEL_ID_RECORDING_CHANNEL);
+        mNotification = NotificationHelper.getNotification(this, mNotificationBuilder, mTrack, trackingState);
+        mNotificationManager.notify(TRACKER_SERVICE_NOTIFICATION_ID, mNotification); // todo check if necessary in pre Android O
+    }
+
 
     /* Adds a new WayPoint to current track */
     private void addWayPointToTrack() {
@@ -550,7 +394,7 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
                 Location firstWayPoint = mTrack.getWayPointLocation(0);
                 float distance = firstWayPoint.distanceTo(lastWayPoint);
                 long timeDifference = lastWayPoint.getElapsedRealtimeNanos() - firstWayPoint.getElapsedRealtimeNanos();
-                averageSpeed = distance / ((float) timeDifference / ONE_NANOSECOND);
+                averageSpeed = distance / ((float) timeDifference / ONE_SECOND_IN_NANOSECOND);
             }
 
             if (LocationHelper.isNewWayPoint(lastWayPoint, mCurrentBestLocation, averageSpeed)) {
@@ -561,14 +405,14 @@ public class TrackerService extends Service implements TrackbookKeys, SensorEven
 
         // send local broadcast if new WayPoint added
         if (newWayPoint != null) {
-            sendTrackUpdate();
+            broadcastTrackUpdate();
         }
 
     }
 
 
     /* Broadcasts a track update */
-    public void sendTrackUpdate() {
+    private void broadcastTrackUpdate() {
         if (mTrack != null) {
             Intent i = new Intent();
             i.setAction(ACTION_TRACK_UPDATED);

app/src/main/java/org/y20k/trackbook/helpers/LocationHelper.java

@@ -143,7 +143,7 @@ public final class LocationHelper implements TrackbookKeys {
         if (newLocation.getProvider().equals(LocationManager.NETWORK_PROVIDER)) {
             // calculate speed difference
             float speedDifference;
-            float currentSpeed = distance / ((float)timeDifference / ONE_NANOSECOND);
+            float currentSpeed = distance / ((float)timeDifference / ONE_SECOND_IN_NANOSECOND);
             if (currentSpeed > averageSpeed) {
                 speedDifference = currentSpeed / averageSpeed;
             } else {
@@ -163,11 +163,11 @@ public final class LocationHelper implements TrackbookKeys {
             }
 
             // DEFAULT network: distance is bigger than 30 meters and time difference bigger than 12 seconds
-            return distance > 30 && timeDifference >= 12 * ONE_NANOSECOND; // TODO add minimal accuracy
+            return distance > 30 && timeDifference >= 12 * ONE_SECOND_IN_NANOSECOND; // TODO add minimal accuracy
 
         } else {
             // DEFAULT GPS: distance is bigger than 10 meters and time difference bigger than 12 seconds
-            return distance > 10 && timeDifference >= 12 * ONE_NANOSECOND;
+            return distance > 10 && timeDifference >= 12 * ONE_SECOND_IN_NANOSECOND;
         }
 
     }

app/src/main/java/org/y20k/trackbook/helpers/NotificationHelper.java

@@ -51,9 +51,6 @@ public final class NotificationHelper implements TrackbookKeys {
         // create notification channel
         createNotificationChannel(context);
 
-        // build context text for notification builder
-        String contentText = getContextString(context, track);
-
         // ACTION: NOTIFICATION TAP & BUTTON SHOW
         Intent tapActionIntent = new Intent(context, MainActivity.class);
         tapActionIntent.setAction(ACTION_SHOW_MAP);

app/src/main/java/org/y20k/trackbook/helpers/StorageHelper.java

@@ -17,6 +17,7 @@
 package org.y20k.trackbook.helpers;
 
 import android.content.Context;
+import android.location.Location;
 import android.os.Environment;
 import android.support.annotation.Nullable;
 import android.support.v4.os.EnvironmentCompat;
@@ -369,8 +370,8 @@ public class StorageHelper implements TrackbookKeys {
         double negativeElevation = 0;
 
         if (track != null && track.getWayPoints().size() > 0) {
-            double previousLocationHeight;
+            double previousLocationAltitude;
-            double currentLocationHeight;
+            double currentLocationAltitude;
             long previousTimeStamp;
             long currentTimeStamp;
 
@@ -379,7 +380,7 @@ public class StorageHelper implements TrackbookKeys {
             minAltitude = maxAltitude;
 
             // apply filter & smooth data
-//            track = lowPass(track, 15f, 35f);
+//            track = smoothTrack(track, 15f, 35f);
 
             // iterate over track
             for (int i = 1; i < track.getWayPoints().size(); i++ ) {
@@ -393,23 +394,23 @@ public class StorageHelper implements TrackbookKeys {
                 double timeDiffFactor = timeDiff / FIFTEEN_SECONDS_IN_MILLISECONDS;
 
                 // height of previous and current waypoints
-                previousLocationHeight = track.getWayPointLocation(i -1).getAltitude();
+                previousLocationAltitude = track.getWayPointLocation(i -1).getAltitude();
-                currentLocationHeight = track.getWayPointLocation(i).getAltitude();
+                currentLocationAltitude = track.getWayPointLocation(i).getAltitude();
 
                 // check for new min and max heights
-                if (currentLocationHeight > maxAltitude) {
+                if (currentLocationAltitude > maxAltitude) {
-                    maxAltitude = currentLocationHeight;
+                    maxAltitude = currentLocationAltitude;
                 }
-                if (minAltitude == 0 || currentLocationHeight < minAltitude) {
+                if (minAltitude == 0 || currentLocationAltitude < minAltitude) {
-                    minAltitude = currentLocationHeight;
+                    minAltitude = currentLocationAltitude;
                 }
 
                 // get elevation difference and sum it up
-                double altitudeDiff = currentLocationHeight - previousLocationHeight;
+                double altitudeDiff = currentLocationAltitude - previousLocationAltitude;
-                if (altitudeDiff > 0 && altitudeDiff < MEASUREMENT_ERROR_THRESHOLD * timeDiffFactor && currentLocationHeight != 0) {
+                if (altitudeDiff > 0 && altitudeDiff < MEASUREMENT_ERROR_THRESHOLD * timeDiffFactor && currentLocationAltitude != 0) {
                     positiveElevation = positiveElevation + altitudeDiff;
                 }
-                if (altitudeDiff < 0 && altitudeDiff > -MEASUREMENT_ERROR_THRESHOLD * timeDiffFactor && currentLocationHeight != 0) {
+                if (altitudeDiff < 0 && altitudeDiff > -MEASUREMENT_ERROR_THRESHOLD * timeDiffFactor && currentLocationAltitude != 0) {
                     negativeElevation = negativeElevation + altitudeDiff;
                 }
 
@@ -424,8 +425,9 @@ public class StorageHelper implements TrackbookKeys {
         return track;
     }
 
+
     /* Tries to smooth the elevation data using a low pass filter */
-    private Track lowPass(Track input, float dt, float rc) {
+    private Track smoothTrack(Track input, float dt, float rc) {
 
         // The following code is adapted from https://en.wikipedia.org/wiki/Low-pass_filter
         //

app/src/main/java/org/y20k/trackbook/helpers/TrackbookKeys.java

@@ -86,7 +86,7 @@ public interface TrackbookKeys {
     int RESULT_EXPORT_DIALOG = 4;
 
     /* CONSTANTS */
-    long ONE_NANOSECOND = 1000000000L;
+    long ONE_SECOND_IN_NANOSECOND = 1000000000L;
     long EIGHT_HOURS_IN_MILLISECONDS = 43200000; // maximum tracking duration
     long FIFTEEN_SECONDS_IN_MILLISECONDS = 15000; // timer interval for tracking
     long FIVE_MINUTES_IN_NANOSECONDS = 5L * 60000000000L; // determines a stop over