Refactor and optimize PreferencesHelper

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

@@ -17,7 +17,6 @@
 
 package org.y20k.trackbook
 
-import android.content.Context
 import android.content.SharedPreferences
 import android.os.Build
 import android.os.Bundle
@@ -26,7 +25,6 @@ import android.os.StrictMode.VmPolicy
 import androidx.appcompat.app.AppCompatActivity
 import androidx.navigation.fragment.NavHostFragment
 import androidx.navigation.ui.setupWithNavController
-import androidx.preference.PreferenceManager
 import com.google.android.material.bottomnavigation.BottomNavigationView
 import org.osmdroid.config.Configuration
 import org.y20k.trackbook.helpers.AppThemeHelper
@@ -91,7 +89,7 @@ class MainActivity : AppCompatActivity() {
         }
 
         // register listener for changes in shared preferences
-        PreferenceManager.getDefaultSharedPreferences(this as Context).registerOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
+        PreferencesHelper.registerPreferenceChangeListener(sharedPreferenceChangeListener)
     }
 
 
@@ -99,7 +97,7 @@ class MainActivity : AppCompatActivity() {
     override fun onDestroy() {
         super.onDestroy()
         // unregister listener for changes in shared preferences
-        PreferenceManager.getDefaultSharedPreferences(this as Context).unregisterOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
+        PreferencesHelper.unregisterPreferenceChangeListener(sharedPreferenceChangeListener)
     }
 
 
@@ -109,7 +107,7 @@ class MainActivity : AppCompatActivity() {
     private val sharedPreferenceChangeListener = SharedPreferences.OnSharedPreferenceChangeListener { sharedPreferences, key ->
         when (key) {
             Keys.PREF_THEME_SELECTION -> {
-                AppThemeHelper.setTheme(PreferencesHelper.loadThemeSelection(this@MainActivity))
+                AppThemeHelper.setTheme(PreferencesHelper.loadThemeSelection())
             }
         }
     }

app/src/main/java/org/y20k/trackbook/MapFragment.kt

@@ -32,7 +32,6 @@ import android.view.ViewGroup
 import androidx.core.content.ContextCompat
 import androidx.fragment.app.Fragment
 import androidx.navigation.fragment.findNavController
-import androidx.preference.PreferenceManager
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers.IO
 import kotlinx.coroutines.Dispatchers.Main
@@ -71,7 +70,7 @@ class MapFragment : Fragment(), YesNoDialog.YesNoDialogListener, MapOverlayHelpe
         // get current best location
         currentBestLocation = LocationHelper.getLastKnownLocation(activity as Context)
         // get saved tracking state
-        trackingState = PreferencesHelper.loadTrackingState(activity as Context)
+        trackingState = PreferencesHelper.loadTrackingState()
     }
 
 
@@ -260,7 +259,7 @@ class MapFragment : Fragment(), YesNoDialog.YesNoDialogListener, MapOverlayHelpe
     private fun handleServiceUnbind() {
         bound = false
         // unregister listener for changes in shared preferences
-        PreferenceManager.getDefaultSharedPreferences(activity as Context).unregisterOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
+        PreferencesHelper.unregisterPreferenceChangeListener(sharedPreferenceChangeListener)
         // stop receiving location updates
         handler.removeCallbacks(periodicLocationRequestRunnable)
     }
@@ -319,7 +318,7 @@ class MapFragment : Fragment(), YesNoDialog.YesNoDialogListener, MapOverlayHelpe
         when (key) {
             Keys.PREF_TRACKING_STATE -> {
                 if (activity != null) {
-                    trackingState = PreferencesHelper.loadTrackingState(activity as Context)
+                    trackingState = PreferencesHelper.loadTrackingState()
                     layout.updateRecordingButton(trackingState)
                 }
             }
@@ -343,7 +342,7 @@ class MapFragment : Fragment(), YesNoDialog.YesNoDialogListener, MapOverlayHelpe
             trackingState = trackerService.trackingState
             layout.updateRecordingButton(trackingState)
             // register listener for changes in shared preferences
-            PreferenceManager.getDefaultSharedPreferences(activity as Context).registerOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
+            PreferencesHelper.registerPreferenceChangeListener(sharedPreferenceChangeListener)
             // start listening for location updates
             handler.removeCallbacks(periodicLocationRequestRunnable)
             handler.postDelayed(periodicLocationRequestRunnable, 0)

app/src/main/java/org/y20k/trackbook/Trackbook.kt

@@ -22,6 +22,7 @@ import android.app.Application
 import org.y20k.trackbook.helpers.AppThemeHelper
 import org.y20k.trackbook.helpers.LogHelper
 import org.y20k.trackbook.helpers.PreferencesHelper
+import org.y20k.trackbook.helpers.PreferencesHelper.initPreferences
 
 
 /*
@@ -38,8 +39,9 @@ class Trackbook: Application() {
     override fun onCreate() {
         super.onCreate()
         LogHelper.v(TAG, "Trackbook application started.")
+        initPreferences()
         // set Dark / Light theme state
-        AppThemeHelper.setTheme(PreferencesHelper.loadThemeSelection(this))
+        AppThemeHelper.setTheme(PreferencesHelper.loadThemeSelection())
     }
 
 

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

@@ -37,7 +37,6 @@ import android.os.Bundle
 import android.os.Handler
 import android.os.IBinder
 import androidx.core.content.ContextCompat
-import androidx.preference.PreferenceManager
 import kotlinx.coroutines.*
 import kotlinx.coroutines.Dispatchers.IO
 import org.y20k.trackbook.core.Track
@@ -83,9 +82,9 @@ class TrackerService: Service(), SensorEventListener {
     /* Overrides onCreate from Service */
     override fun onCreate() {
         super.onCreate()
-        gpsOnly = PreferencesHelper.loadGpsOnly(this)
+        gpsOnly = PreferencesHelper.loadGpsOnly()
-        useImperial = PreferencesHelper.loadUseImperialUnits(this)
+        useImperial = PreferencesHelper.loadUseImperialUnits()
-        accuracyMultiplier = PreferencesHelper.loadAccuracyMultiplier(this)
+        accuracyMultiplier = PreferencesHelper.loadAccuracyMultiplier()
 
         locationManager = getSystemService(Context.LOCATION_SERVICE) as LocationManager
         sensorManager = this.getSystemService(Context.SENSOR_SERVICE) as SensorManager
@@ -95,11 +94,11 @@ class TrackerService: Service(), SensorEventListener {
         networkProviderActive = LocationHelper.isNetworkEnabled(locationManager)
         gpsLocationListener = createLocationListener()
         networkLocationListener = createLocationListener()
-        trackingState = PreferencesHelper.loadTrackingState(this)
+        trackingState = PreferencesHelper.loadTrackingState()
         currentBestLocation = LocationHelper.getLastKnownLocation(this)
         track = FileHelper.readTrack(this, FileHelper.getTempFileUri(this))
-        altitudeValues.capacity = PreferencesHelper.loadAltitudeSmoothingValue(this)
+        altitudeValues.capacity = PreferencesHelper.loadAltitudeSmoothingValue()
-        PreferenceManager.getDefaultSharedPreferences(this).registerOnSharedPreferenceChangeListener(
+        PreferencesHelper.registerPreferenceChangeListener(
             sharedPreferenceChangeListener
         )
     }
@@ -175,7 +174,7 @@ class TrackerService: Service(), SensorEventListener {
         // remove notification
         stopForeground(true)
         // stop listening for changes in shared preferences
-        PreferenceManager.getDefaultSharedPreferences(this).unregisterOnSharedPreferenceChangeListener(
+        PreferencesHelper.unregisterPreferenceChangeListener(
             sharedPreferenceChangeListener
         )
         // stop receiving location updates
@@ -239,7 +238,7 @@ class TrackerService: Service(), SensorEventListener {
         }
         // set state
         trackingState = Keys.STATE_TRACKING_ACTIVE
-        PreferencesHelper.saveTrackingState(this, trackingState)
+        PreferencesHelper.saveTrackingState(trackingState)
         // start recording steps and location fixes
         startStepCounter()
         handler.postDelayed(periodicTrackUpdate, 0)
@@ -255,7 +254,7 @@ class TrackerService: Service(), SensorEventListener {
         CoroutineScope(IO).launch { FileHelper.saveTempTrackSuspended(this@TrackerService, track) }
         // save state
         trackingState = Keys.STATE_TRACKING_STOPPED
-        PreferencesHelper.saveTrackingState(this, trackingState)
+        PreferencesHelper.saveTrackingState(trackingState)
         // reset altitude values queue
         altitudeValues.reset()
         // stop recording steps and location fixes
@@ -272,7 +271,7 @@ class TrackerService: Service(), SensorEventListener {
         track = Track()
         FileHelper.deleteTempFile(this)
         trackingState = Keys.STATE_TRACKING_NOT
-        PreferencesHelper.saveTrackingState(this, trackingState)
+        PreferencesHelper.saveTrackingState(trackingState)
         stopForeground(true)
     }
 
@@ -469,7 +468,7 @@ class TrackerService: Service(), SensorEventListener {
             when (key) {
                 // preference "Restrict to GPS"
                 Keys.PREF_GPS_ONLY -> {
-                    gpsOnly = PreferencesHelper.loadGpsOnly(this@TrackerService)
+                    gpsOnly = PreferencesHelper.loadGpsOnly()
                     when (gpsOnly) {
                         true -> removeNetworkLocationListener()
                         false -> addNetworkLocationListener()
@@ -477,11 +476,11 @@ class TrackerService: Service(), SensorEventListener {
                 }
                 // preference "Use Imperial Measurements"
                 Keys.PREF_USE_IMPERIAL_UNITS -> {
-                    useImperial = PreferencesHelper.loadUseImperialUnits(this@TrackerService)
+                    useImperial = PreferencesHelper.loadUseImperialUnits()
                 }
                 // preference "Recording Accuracy"
                 Keys.PREF_RECORDING_ACCURACY_HIGH -> {
-                    accuracyMultiplier = PreferencesHelper.loadAccuracyMultiplier(this@TrackerService)
+                    accuracyMultiplier = PreferencesHelper.loadAccuracyMultiplier()
                 }
             }
         }

app/src/main/java/org/y20k/trackbook/TrackingToggleTileService.kt

@@ -23,7 +23,6 @@ import android.graphics.drawable.Icon
 import android.os.Build
 import android.service.quicksettings.Tile
 import android.service.quicksettings.TileService
-import androidx.preference.PreferenceManager
 import org.y20k.trackbook.helpers.LogHelper
 import org.y20k.trackbook.helpers.PreferencesHelper
 
@@ -47,7 +46,7 @@ class TrackingToggleTileService: TileService() {
     override fun onTileAdded() {
         super.onTileAdded()
         // get saved tracking state
-        trackingState = PreferencesHelper.loadTrackingState(this)
+        trackingState = PreferencesHelper.loadTrackingState()
         // set up tile
         updateTile()
     }
@@ -62,11 +61,11 @@ class TrackingToggleTileService: TileService() {
     override fun onStartListening() {
         super.onStartListening()
         // get saved tracking state
-        trackingState = PreferencesHelper.loadTrackingState(this)
+        trackingState = PreferencesHelper.loadTrackingState()
         // set up tile
         updateTile()
         // register listener for changes in shared preferences
-        PreferenceManager.getDefaultSharedPreferences(this@TrackingToggleTileService).registerOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
+        PreferencesHelper.registerPreferenceChangeListener(sharedPreferenceChangeListener)
     }
 
 
@@ -84,7 +83,7 @@ class TrackingToggleTileService: TileService() {
     override fun onStopListening() {
         super.onStopListening()
         // unregister listener for changes in shared preferences
-        PreferenceManager.getDefaultSharedPreferences(this@TrackingToggleTileService).unregisterOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
+        PreferencesHelper.unregisterPreferenceChangeListener(sharedPreferenceChangeListener)
     }
 
 
@@ -141,7 +140,7 @@ class TrackingToggleTileService: TileService() {
     private val sharedPreferenceChangeListener = SharedPreferences.OnSharedPreferenceChangeListener { sharedPreferences, key ->
         when (key) {
             Keys.PREF_TRACKING_STATE -> {
-                trackingState = PreferencesHelper.loadTrackingState(this)
+                trackingState = PreferencesHelper.loadTrackingState()
                 updateTile()
             }
         }

app/src/main/java/org/y20k/trackbook/helpers/AppThemeHelper.kt

@@ -77,7 +77,7 @@ object AppThemeHelper {
 
     /* Returns a readable String for currently selected App Theme */
     fun getCurrentTheme(context: Context): String {
-        return when (PreferencesHelper.loadThemeSelection(context)) {
+        return when (PreferencesHelper.loadThemeSelection()) {
             Keys.STATE_THEME_LIGHT_MODE -> context.getString(R.string.pref_theme_selection_mode_light)
             Keys.STATE_THEME_DARK_MODE -> context.getString(R.string.pref_theme_selection_mode_dark)
             else -> context.getString(R.string.pref_theme_selection_mode_device_default)

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

@@ -62,7 +62,7 @@ object LocationHelper {
     /* Tries to return the last location that the system has stored */
     fun getLastKnownLocation(context: Context): Location {
         // get last location that Trackbook has stored
-        var lastKnownLocation: Location = PreferencesHelper.loadCurrentBestLocation(context)
+        var lastKnownLocation: Location = PreferencesHelper.loadCurrentBestLocation()
         // try to get the last location the system has stored - it is probably more recent
         if (ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
             val locationManager = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager

app/src/main/java/org/y20k/trackbook/helpers/PreferencesHelper.kt

@@ -18,6 +18,7 @@
 package org.y20k.trackbook.helpers
 
 import android.content.Context
+import android.content.SharedPreferences
 import android.location.Location
 import android.location.LocationManager
 import androidx.core.content.edit
@@ -32,124 +33,108 @@ import org.y20k.trackbook.extensions.putDouble
  */
 object PreferencesHelper {
 
+    /* The sharedPreferences object to be initialized */
+    private lateinit var sharedPreferences: SharedPreferences
+
+    /* Initialize a single sharedPreferences object when the app is launched */
+    fun Context.initPreferences() {
+        sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this)
+    }
+
     /* Define log tag */
     private val TAG: String = LogHelper.makeLogTag(PreferencesHelper::class.java)
 
 
     /* Loads zoom level of map */
-    fun loadZoomLevel(context: Context): Double {
+    fun loadZoomLevel(): Double {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // load zoom level
-        return settings.getDouble(Keys.PREF_MAP_ZOOM_LEVEL, Keys.DEFAULT_ZOOM_LEVEL)
+        return sharedPreferences.getDouble(Keys.PREF_MAP_ZOOM_LEVEL, Keys.DEFAULT_ZOOM_LEVEL)
     }
 
 
     /* Saves zoom level of map */
-    fun saveZoomLevel(context: Context, zoomLevel: Double) {
+    fun saveZoomLevel(zoomLevel: Double) {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // save zoom level
-        settings.edit { putDouble(Keys.PREF_MAP_ZOOM_LEVEL, zoomLevel) }
+        sharedPreferences.edit { putDouble(Keys.PREF_MAP_ZOOM_LEVEL, zoomLevel) }
     }
 
 
     /* Loads tracking state */
-    fun loadTrackingState(context: Context): Int {
+    fun loadTrackingState(): Int {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // load tracking state
-        return settings.getInt(Keys.PREF_TRACKING_STATE, Keys.STATE_TRACKING_NOT)
+        return sharedPreferences.getInt(Keys.PREF_TRACKING_STATE, Keys.STATE_TRACKING_NOT)
     }
 
 
     /* Saves tracking state */
-    fun saveTrackingState(context: Context, trackingState: Int) {
+    fun saveTrackingState(trackingState: Int) {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // save tracking state
-        settings.edit { putInt(Keys.PREF_TRACKING_STATE, trackingState) }
+        sharedPreferences.edit { putInt(Keys.PREF_TRACKING_STATE, trackingState) }
     }
 
 
     /* Loads length unit system - metric or imperial */
-    fun loadUseImperialUnits(context: Context): Boolean {
+    fun loadUseImperialUnits(): Boolean {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // load length unit system
-        return settings.getBoolean(Keys.PREF_USE_IMPERIAL_UNITS, LengthUnitHelper.useImperialUnits())
+        return sharedPreferences.getBoolean(Keys.PREF_USE_IMPERIAL_UNITS, LengthUnitHelper.useImperialUnits())
     }
 
 
     /* Loads length unit system - metric or imperial */
-    fun loadGpsOnly(context: Context): Boolean {
+    fun loadGpsOnly(): Boolean {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // load length unit system
-        return settings.getBoolean(Keys.PREF_GPS_ONLY, false)
+        return sharedPreferences.getBoolean(Keys.PREF_GPS_ONLY, false)
     }
 
     /* Loads accuracy threshold used to determine if location is good enough */
-    fun loadAccuracyThreshold(context: Context): Int {
+    fun loadAccuracyThreshold(): Int {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // load tracking state
-        return settings.getInt(Keys.PREF_LOCATION_ACCURACY_THRESHOLD, Keys.DEFAULT_THRESHOLD_LOCATION_ACCURACY)
+        return sharedPreferences.getInt(Keys.PREF_LOCATION_ACCURACY_THRESHOLD, Keys.DEFAULT_THRESHOLD_LOCATION_ACCURACY)
     }
 
 
 
     /* Loads state of recording accuracy */
-    fun loadRecordingAccuracyHigh(context: Context): Boolean {
+    fun loadRecordingAccuracyHigh(): Boolean {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // load current setting
-        return settings.getBoolean(Keys.PREF_RECORDING_ACCURACY_HIGH, false)
+        return sharedPreferences.getBoolean(Keys.PREF_RECORDING_ACCURACY_HIGH, false)
     }
 
 
     /* Loads current accuracy multiplier */
-    fun loadAccuracyMultiplier(context: Context): Int {
+    fun loadAccuracyMultiplier(): Int {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // load current setting
-        val recordingAccuracyHigh: Boolean = settings.getBoolean(Keys.PREF_RECORDING_ACCURACY_HIGH, false)
+        val recordingAccuracyHigh: Boolean = sharedPreferences.getBoolean(Keys.PREF_RECORDING_ACCURACY_HIGH, false)
         // return multiplier based on state
         return if (recordingAccuracyHigh) 2 else 1
     }
 
 
     /* Load altitude smoothing value */
-    fun loadAltitudeSmoothingValue(context: Context): Int {
+    fun loadAltitudeSmoothingValue(): Int {
-        // get preferences
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
         // load current setting
-        return settings.getInt(Keys.PREF_ALTITUDE_SMOOTHING_VALUE, Keys.DEFAULT_ALTITUDE_SMOOTHING_VALUE)
+        return sharedPreferences.getInt(Keys.PREF_ALTITUDE_SMOOTHING_VALUE, Keys.DEFAULT_ALTITUDE_SMOOTHING_VALUE)
     }
 
 
     /* Loads the state of a map */
-    fun loadCurrentBestLocation(context: Context): Location {
+    fun loadCurrentBestLocation(): Location {
-        // get preferences
+        val provider: String = sharedPreferences.getString(Keys.PREF_CURRENT_BEST_LOCATION_PROVIDER, LocationManager.NETWORK_PROVIDER) ?: LocationManager.NETWORK_PROVIDER
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
-        val provider: String = settings.getString(Keys.PREF_CURRENT_BEST_LOCATION_PROVIDER, LocationManager.NETWORK_PROVIDER) ?: LocationManager.NETWORK_PROVIDER
         // create location
-        val currentBestLocation: Location = Location(provider)
+        return Location(provider).apply {
             // load location attributes
-        currentBestLocation.latitude = settings.getDouble(Keys.PREF_CURRENT_BEST_LOCATION_LATITUDE, Keys.DEFAULT_LATITUDE)
+            latitude = sharedPreferences.getDouble(Keys.PREF_CURRENT_BEST_LOCATION_LATITUDE, Keys.DEFAULT_LATITUDE)
-        currentBestLocation.longitude = settings.getDouble(Keys.PREF_CURRENT_BEST_LOCATION_LONGITUDE, Keys.DEFAULT_LONGITUDE)
+            longitude = sharedPreferences.getDouble(Keys.PREF_CURRENT_BEST_LOCATION_LONGITUDE, Keys.DEFAULT_LONGITUDE)
-        currentBestLocation.accuracy = settings.getFloat(Keys.PREF_CURRENT_BEST_LOCATION_ACCURACY, Keys.DEFAULT_ACCURACY)
+            accuracy = sharedPreferences.getFloat(Keys.PREF_CURRENT_BEST_LOCATION_ACCURACY, Keys.DEFAULT_ACCURACY)
-        currentBestLocation.altitude = settings.getDouble(Keys.PREF_CURRENT_BEST_LOCATION_ALTITUDE, Keys.DEFAULT_ALTITUDE)
+            altitude = sharedPreferences.getDouble(Keys.PREF_CURRENT_BEST_LOCATION_ALTITUDE, Keys.DEFAULT_ALTITUDE)
-        currentBestLocation.time = settings.getLong(Keys.PREF_CURRENT_BEST_LOCATION_TIME, Keys.DEFAULT_TIME)
+            time = sharedPreferences.getLong(Keys.PREF_CURRENT_BEST_LOCATION_TIME, Keys.DEFAULT_TIME)
-        return currentBestLocation
+        }
     }
 
 
     /* Saves the state of a map */
-    fun saveCurrentBestLocation(context: Context, currentBestLocation: Location) {
+    fun saveCurrentBestLocation(currentBestLocation: Location) {
-        // get preferences
+        sharedPreferences.edit {
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
-        settings.edit {
             // save location
             putDouble(Keys.PREF_CURRENT_BEST_LOCATION_LATITUDE, currentBestLocation.latitude)
             putDouble(Keys.PREF_CURRENT_BEST_LOCATION_LONGITUDE, currentBestLocation.longitude)
@@ -161,22 +146,29 @@ object PreferencesHelper {
 
 
     /* Load currently selected app theme */
-    fun loadThemeSelection(context: Context): String {
+    fun loadThemeSelection(): String {
-        return PreferenceManager.getDefaultSharedPreferences(context).getString(Keys.PREF_THEME_SELECTION, Keys.STATE_THEME_FOLLOW_SYSTEM) ?: Keys.STATE_THEME_FOLLOW_SYSTEM
+        return sharedPreferences.getString(Keys.PREF_THEME_SELECTION, Keys.STATE_THEME_FOLLOW_SYSTEM) ?: Keys.STATE_THEME_FOLLOW_SYSTEM
     }
 
 
     /* Checks if housekeeping work needs to be done - used usually in DownloadWorker "REQUEST_UPDATE_COLLECTION" */
-    fun isHouseKeepingNecessary(context: Context): Boolean {
+    fun isHouseKeepingNecessary(): Boolean {
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
+        return sharedPreferences.getBoolean(Keys.PREF_ONE_TIME_HOUSEKEEPING_NECESSARY, true)
-        return settings.getBoolean(Keys.PREF_ONE_TIME_HOUSEKEEPING_NECESSARY, true)
     }
 
 
     /* Saves state of housekeeping */
-    fun saveHouseKeepingNecessaryState(context: Context, state: Boolean = false) {
+    fun saveHouseKeepingNecessaryState(state: Boolean = false) {
-        val settings = PreferenceManager.getDefaultSharedPreferences(context)
+        sharedPreferences.edit { putBoolean(Keys.PREF_ONE_TIME_HOUSEKEEPING_NECESSARY, state) }
-        settings.edit { putBoolean(Keys.PREF_ONE_TIME_HOUSEKEEPING_NECESSARY, state) }
     }
 
+    /* Start watching for changes in shared preferences - context must implement OnSharedPreferenceChangeListener */
+    fun registerPreferenceChangeListener(listener: SharedPreferences.OnSharedPreferenceChangeListener) {
+        sharedPreferences.registerOnSharedPreferenceChangeListener(listener)
+    }
+
+    /* Stop watching for changes in shared preferences - context must implement OnSharedPreferenceChangeListener */
+    fun unregisterPreferenceChangeListener(listener: SharedPreferences.OnSharedPreferenceChangeListener) {
+        sharedPreferences.unregisterOnSharedPreferenceChangeListener(listener)
+    }
 }

app/src/main/java/org/y20k/trackbook/tracklist/TracklistAdapter.kt

@@ -51,7 +51,7 @@ class TracklistAdapter(private val fragment: Fragment) : RecyclerView.Adapter<Re
     /* Main class variables */
     private val context: Context = fragment.activity as Context
     private lateinit var tracklistListener: TracklistAdapterListener
-    private var useImperial: Boolean = PreferencesHelper.loadUseImperialUnits(context)
+    private var useImperial: Boolean = PreferencesHelper.loadUseImperialUnits()
     private var tracklist: Tracklist = Tracklist()
 
 

app/src/main/java/org/y20k/trackbook/ui/MapFragmentLayoutHolder.kt

@@ -94,7 +94,7 @@ data class MapFragmentLayoutHolder(private var context: Context, private var mar
         mapView.setTileSource(TileSourceFactory.MAPNIK)
         mapView.setMultiTouchControls(true)
         mapView.zoomController.setVisibility(org.osmdroid.views.CustomZoomButtonsController.Visibility.NEVER)
-        zoomLevel = PreferencesHelper.loadZoomLevel(context)
+        zoomLevel = PreferencesHelper.loadZoomLevel()
         controller.setZoom(zoomLevel)
 
         // set dark map tiles, if necessary
@@ -149,8 +149,8 @@ data class MapFragmentLayoutHolder(private var context: Context, private var mar
 
     /* Save current best location and state of map to shared preferences */
     fun saveState(currentBestLocation: Location) {
-        PreferencesHelper.saveCurrentBestLocation(context, currentBestLocation)
+        PreferencesHelper.saveCurrentBestLocation(currentBestLocation)
-        PreferencesHelper.saveZoomLevel(context, mapView.zoomLevelDouble)
+        PreferencesHelper.saveZoomLevel(mapView.zoomLevelDouble)
         // reset user interaction state
         userInteraction = false
     }

app/src/main/java/org/y20k/trackbook/ui/TrackFragmentLayoutHolder.kt

@@ -137,7 +137,7 @@ data class TrackFragmentLayoutHolder(private var context: Context, private var m
         trackManagementViews = rootView.findViewById(R.id.management_icons)
 
         // get measurement unit system
-        useImperialUnits = PreferencesHelper.loadUseImperialUnits(context)
+        useImperialUnits = PreferencesHelper.loadUseImperialUnits()
 
         // set dark map tiles, if necessary
         if (AppThemeHelper.isDarkModeOn(context as Activity)) {