fix(location): create preference for enabling GNSS in significant mode

- Background service checks this preference if Android >16 and sets
  HIGH_POWER if it's set
- Preference screen update

Author: growse

CHANGELOG.md

@@ -20,7 +20,7 @@ This release addresses a security advisory covering several intent-handling vuln
 - New **Remote Control** preferences screen showing the intent auth key (with a copy-to-clipboard button) for use with automation apps such as Tasker
 - Config import screen now shows a structured diff of what is changing, with human-readable preference names, highlighting new values alongside the current values — unchanged settings are summarised rather than listed in full
 - Waypoints in an imported config are listed individually in the import review screen
-- Preference setting to allow user to enable GNSS location source for Significant Monitoring mode (#2155)
+- Preference setting (Android 16 and later only) to allow user to enable GNSS location source for Significant Monitoring mode (#2155)
 
 ### Bug fixes
 

justfile

@@ -72,6 +72,10 @@ local-stack:
 mqtt-subscribe:
     mosquitto_sub -v -L mqtt://localhost/owntracks/# -u test -P test
 
+[group('device')]
+install: (gradle "app:assembleGmsDebug")
+    adb install -r project/app/build/outputs/apk/gms/debug/app-gms-debug.apk
+
 [group('device')]
 wipe-device:
     adb uninstall org.owntracks.android; adb uninstall org.owntracks.android.debug; adb uninstall androidx.test.orchestrator ; adb uninstall androidx.test.services; adb uninstall androidx.test.tools.crawler; adb uninstall androidx.test.tools.crawler.stubapp; echo "done"

project/app/src/main/java/org/owntracks/android/preferences/DefaultsProvider.kt

@@ -44,6 +44,7 @@ interface DefaultsProvider {
       Preferences::locatorDisplacement -> 500
       Preferences::locatorInterval -> 60
       Preferences::locatorPriority -> null
+      Preferences::useGNSSInSignificantMonitoringMode -> false
       Preferences::mode -> ConnectionMode.MQTT
       Preferences::monitoring -> MonitoringMode.Significant
       Preferences::moveModeLocatorInterval -> 10

project/app/src/main/java/org/owntracks/android/preferences/Preferences.kt

@@ -272,6 +272,8 @@ constructor(
 
   @Preference var locatorPriority: LocatorPriority? by preferencesStore
 
+  @Preference var useGNSSInSignificantMonitoringMode: Boolean by preferencesStore
+
   @Preference var mapLayerStyle: MapLayerStyle by preferencesStore
 
   @Preference var mode: ConnectionMode by preferencesStore

project/app/src/main/java/org/owntracks/android/services/BackgroundService.kt

@@ -536,10 +536,18 @@ class BackgroundService : LifecycleService(), Preferences.OnPreferenceChangeList
         MonitoringMode.Significant -> {
           interval = Duration.ofSeconds(preferences.locatorInterval.toLong())
           smallestDisplacement = preferences.locatorDisplacement.toFloat()
-          priority = preferences.locatorPriority ?: if(Build.VERSION.SDK_INT>Build.VERSION_CODES.Q) {
-            LocatorPriority.BalancedPowerAccuracy}
-            else  {LocatorPriority.BalancedPowerAccuracy
-          }
+          // QPR1 (where balanced-accuracy stopped using GNSS, per #2155) isn't separately
+          // detectable from the Android 16 GA release, so we gate on Android 16+ generally.
+          val useGnss =
+              Build.VERSION.SDK_INT >= Build.VERSION_CODES.BAKLAVA &&
+                  preferences.useGNSSInSignificantMonitoringMode
+          priority =
+              preferences.locatorPriority
+                  ?: if (useGnss) {
+                    LocatorPriority.HighAccuracy
+                  } else {
+                    LocatorPriority.BalancedPowerAccuracy
+                  }
         }
 
         MonitoringMode.Move -> {

project/app/src/main/java/org/owntracks/android/ui/preferences/AdvancedFragment.kt

@@ -1,12 +1,12 @@
 package org.owntracks.android.ui.preferences
 
 import android.content.Context
+import android.os.Build
 import android.os.Bundle
 import android.widget.TextView
 import androidx.preference.ListPreference
 import androidx.preference.Preference
 import androidx.preference.SwitchPreferenceCompat
-import org.owntracks.android.location.LocatorPriority
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import dagger.hilt.android.AndroidEntryPoint
 import javax.inject.Inject
@@ -60,14 +60,9 @@ class AdvancedFragment @Inject constructor() :
     findPreference<Preference>("autostartWarning")?.isVisible =
         !requirementsChecker.hasBackgroundLocationPermission()
 
-    findPreference<SwitchPreferenceCompat>("useGnss")?.apply {
-      isChecked = preferences.locatorPriority == LocatorPriority.HighAccuracy
-      onPreferenceChangeListener = Preference.OnPreferenceChangeListener { _, newValue ->
-        preferences.locatorPriority =
-            if (newValue as Boolean) LocatorPriority.HighAccuracy else null
-        true
-      }
-    }
+    findPreference<SwitchPreferenceCompat>(
+            Preferences::useGNSSInSignificantMonitoringMode.name)
+        ?.isVisible = Build.VERSION.SDK_INT >= Build.VERSION_CODES.BAKLAVA
 
     findPreference<ListPreference>(Preferences::reverseGeocodeProvider.name)
         ?.onPreferenceChangeListener =
@@ -104,9 +99,5 @@ class AdvancedFragment @Inject constructor() :
     if (properties.contains(Preferences::reverseGeocodeProvider.name)) {
       setOpenCageAPIKeyPreferenceVisibility()
     }
-    if (properties.contains(Preferences::locatorPriority.name)) {
-      findPreference<SwitchPreferenceCompat>("useGnss")?.isChecked =
-          preferences.locatorPriority == LocatorPriority.HighAccuracy
-    }
   }
 }

project/app/src/main/java/org/owntracks/android/ui/preferences/load/PreferenceKeyLabels.kt

@@ -65,6 +65,8 @@ val PREFERENCE_KEY_LABELS: Map<String, Int> =
         "tlsClientCertInstall" to R.string.preferencesClientCrtInstall,
         "tlsClientCrt" to R.string.preferencesClientCrt,
         "url" to R.string.preferencesUrl,
+        "useGNSSInSignificantMonitoringMode" to
+            R.string.preferencesUseGNSSInSignificantMonitoringMode,
         "username" to R.string.preferencesUsername,
         "ws" to R.string.preferencesWebsocket,
     )

project/app/src/main/res/values/strings.xml

@@ -273,8 +273,8 @@ To allow this, please enable Location in the device settings."</string>
     <string name="preferencesParameters">"Parameters"</string>
     <string name="preferencesPegLocatorFastestIntervalToInterval">"Limit max locator frequency"</string>
     <string name="preferencesPegLocatorFastestIntervalToIntervalSummary">"Request that the location provider deliver updates no faster than the requested locator interval"</string>
-    <string name="preferencesGnssInSignificantMode">"Use GNSS in significant mode"</string>
-    <string name="preferencesGnssInSignificantModeSummary">"Request GPS-level accuracy in significant monitoring mode. Required for accurate location on Android 16 and later. Disable to save battery at the cost of accuracy."</string>
+    <string name="preferencesUseGNSSInSignificantMonitoringMode">"Use GNSS in significant mode"</string>
+    <string name="preferencesUseGNSSInSignificantMonitoringModeSummary">"Request GPS-level accuracy in significant monitoring mode. Some Android 16 versions (from QPR1) stop using GNSS for the default accuracy mode, so this is required for accurate location on those versions. Disable to save battery at the cost of accuracy."</string>
     <string name="preferencesPort">"Port"</string>
     <string name="preferencesPortValidationError">"Port must be a number between 1 and 65535"</string>
     <string name="preferencesProfileId">"Mode"</string>

project/app/src/main/res/xml/preferences_advanced.xml

@@ -43,10 +43,9 @@
             app:title="@string/preferencesPegLocatorFastestIntervalToInterval" />
         <androidx.preference.SwitchPreferenceCompat
             app:iconSpaceReserved="false"
-            app:key="useGnss"
-            app:persistent="false"
-            app:summary="@string/preferencesGnssInSignificantModeSummary"
-            app:title="@string/preferencesGnssInSignificantMode" />
+            app:key="useGNSSInSignificantMonitoringMode"
+            app:summary="@string/preferencesUseGNSSInSignificantMonitoringModeSummary"
+            app:title="@string/preferencesUseGNSSInSignificantMonitoringMode" />
     </androidx.preference.PreferenceCategory>
     <androidx.preference.PreferenceCategory
         app:iconSpaceReserved="false"

project/app/src/test/java/org/owntracks/android/preferences/PreferencesGettersAndSetters.kt

@@ -135,6 +135,7 @@ class PreferencesGettersAndSetters(private val parameter: Parameter) {
                   LocatorPriority::class,
                   false,
                   preferenceValueInConfiguration = "HighAccuracy"),
+              Parameter("useGNSSInSignificantMonitoringMode", true, Boolean::class, false),
               Parameter(
                   "mode",
                   ConnectionMode.HTTP,