feat: add significat motion sensor support

project/app/src/main/java/org/owntracks/android/model/messages/MessageLocation.kt

@@ -134,6 +134,7 @@ open class MessageLocation(
     BEACON("b"), // Generated by iOS beacons
     IOS_FREQUENT_LOCATIONS("v"), // Generated by iOS frequent locations
     IOS_FOLLOW_CIRCULAR("C"), // Generated by iOS follow circular region
+    SIGNIFICANT_MOTION("m"), // Triggered by significant motion sensor
     DEFAULT("")
   }
 }

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

@@ -429,11 +429,14 @@ constructor(
     const val EXPERIMENTAL_FEATURE_SHOW_EXPERIMENTAL_PREFERENCE_UI = "showExperimentalPreferenceUI"
     const val EXPERIMENTAL_FEATURE_LOCATION_PING_USES_HIGH_ACCURACY_LOCATION_REQUEST =
         "locationPingUsesHighAccuracyLocationRequest"
+    const val EXPERIMENTAL_FEATURE_REQUEST_LOCATION_ON_SIGNIFICANT_MOTION =
+        "requestLocationOnSignificantMotion"
 
     internal val EXPERIMENTAL_FEATURES =
         setOf(
             EXPERIMENTAL_FEATURE_SHOW_EXPERIMENTAL_PREFERENCE_UI,
-            EXPERIMENTAL_FEATURE_LOCATION_PING_USES_HIGH_ACCURACY_LOCATION_REQUEST)
+            EXPERIMENTAL_FEATURE_LOCATION_PING_USES_HIGH_ACCURACY_LOCATION_REQUEST,
+            EXPERIMENTAL_FEATURE_REQUEST_LOCATION_ON_SIGNIFICANT_MOTION)
 
     val SYSTEM_NIGHT_AUTO_MODE by lazy {
       if (SDK_INT > Build.VERSION_CODES.Q) {

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

@@ -142,6 +142,9 @@ class BackgroundService : LifecycleService(), Preferences.OnPreferenceChangeList
         }
       }
 
+  // Significant motion sensor for triggering location requests when device movement is detected
+  private lateinit var significantMotionSensor: SignificantMotionSensor
+
   @EntryPoint
   @InstallIn(SingletonComponent::class)
   internal interface ServiceEntrypoint {
@@ -172,6 +175,16 @@ class BackgroundService : LifecycleService(), Preferences.OnPreferenceChangeList
 
     preferences.registerOnPreferenceChangedListener(this)
 
+    // Initialize significant motion sensor
+    significantMotionSensor =
+        SignificantMotionSensor(
+            this,
+            preferences,
+            locationProviderClient,
+            requirementsChecker,
+            callbackForReportType[MessageLocation.ReportType.SIGNIFICANT_MOTION]!!.value,
+            runThingsOnOtherThreads.getBackgroundLooper())
+
     registerReceiver(
         powerBroadcastReceiver,
         IntentFilter().apply {
@@ -234,6 +247,7 @@ class BackgroundService : LifecycleService(), Preferences.OnPreferenceChangeList
     Timber.v("Backgroundservice onDestroy")
     stopForeground(STOP_FOREGROUND_REMOVE)
     unregisterReceiver(powerBroadcastReceiver)
+    significantMotionSensor.cancel()
     preferences.unregisterOnPreferenceChangedListener(this)
     messageProcessor.stopSendingMessages()
     super.onDestroy()
@@ -351,6 +365,7 @@ class BackgroundService : LifecycleService(), Preferences.OnPreferenceChangeList
     startForegroundService()
     setupLocationRequest()
     scheduler.scheduleLocationPing()
+    significantMotionSensor.setup()
     messageProcessor.initialize()
   }
 
@@ -630,6 +645,17 @@ class BackgroundService : LifecycleService(), Preferences.OnPreferenceChangeList
     if (properties.intersect(PREFERENCES_THAT_WIPE_QUEUE_AND_CONTACTS).isNotEmpty()) {
       lifecycleScope.launch { contactsRepo.clearAll() }
     }
+    if (properties.contains(Preferences::experimentalFeatures.name)) {
+      // Handle significant motion sensor based on experimental feature toggle
+      if (preferences.experimentalFeatures.contains(
+          Preferences.EXPERIMENTAL_FEATURE_REQUEST_LOCATION_ON_SIGNIFICANT_MOTION)) {
+        Timber.d("Significant motion feature enabled, setting up sensor")
+        significantMotionSensor.setup()
+      } else {
+        Timber.d("Significant motion feature disabled, cancelling sensor")
+        significantMotionSensor.cancel()
+      }
+    }
   }
 
   fun reInitializeLocationRequests() {

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

@@ -0,0 +1,144 @@
+// Assisted-by: Claude Code IDE; model: claude-4.5-sonnet
+
+package org.owntracks.android.services
+
+import android.content.Context
+import android.hardware.Sensor
+import android.hardware.SensorManager
+import android.hardware.TriggerEvent
+import android.hardware.TriggerEventListener
+import android.os.Looper
+import android.os.SystemClock
+import java.util.concurrent.TimeUnit
+import org.owntracks.android.location.LocationCallback
+import org.owntracks.android.location.LocationProviderClient
+import org.owntracks.android.preferences.Preferences
+import org.owntracks.android.preferences.types.MonitoringMode
+import org.owntracks.android.support.RequirementsChecker
+import timber.log.Timber
+
+/**
+ * Manages the significant motion sensor for triggering location requests when device movement is
+ * detected.
+ *
+ * The significant motion sensor is a one-shot wake-up sensor that triggers when the device detects
+ * significant movement (like walking). After triggering, the listener must be re-registered.
+ */
+class SignificantMotionSensor(
+    private val context: Context,
+    private val preferences: Preferences,
+    private val locationProviderClient: LocationProviderClient,
+    private val requirementsChecker: RequirementsChecker,
+    private val locationCallback: LocationCallback,
+    private val looper: Looper
+) {
+  private val sensorManager by lazy {
+    context.getSystemService(Context.SENSOR_SERVICE) as SensorManager
+  }
+
+  private val significantMotionSensor: Sensor? by lazy {
+    sensorManager.getDefaultSensor(Sensor.TYPE_SIGNIFICANT_MOTION)
+  }
+
+  // Track when we last requested location due to significant motion (for rate limiting)
+  @Volatile private var lastSignificantMotionLocationRequestTime: Long = 0L
+
+  private val significantMotionTriggerListener =
+      object : TriggerEventListener() {
+        override fun onTrigger(event: TriggerEvent?) {
+          Timber.d("Significant motion detected")
+          onSignificantMotionDetected()
+        }
+      }
+
+  /**
+   * Sets up the significant motion sensor listener. This sensor triggers a location request when
+   * significant movement is detected.
+   */
+  fun setup() {
+    if (!preferences.experimentalFeatures.contains(
+        Preferences.EXPERIMENTAL_FEATURE_REQUEST_LOCATION_ON_SIGNIFICANT_MOTION)) {
+      Timber.d("Significant motion sensor disabled (experimental feature not enabled)")
+      return
+    }
+    significantMotionSensor?.let { sensor ->
+      Timber.d(
+          "Found significant motion sensor: ${sensor.name} (vendor: ${sensor.vendor}, isWakeUpSensor: ${sensor.isWakeUpSensor})")
+      // Cancel any existing registration before requesting a new one
+      // (requestTriggerSensor fails if listener is already registered)
+      sensorManager.cancelTriggerSensor(significantMotionTriggerListener, sensor)
+      val success = sensorManager.requestTriggerSensor(significantMotionTriggerListener, sensor)
+      if (success) {
+        Timber.d("Significant motion sensor listener registered successfully")
+      } else {
+        Timber.w("Failed to register significant motion sensor listener")
+      }
+    }
+        ?: run {
+          // Log available sensors to help diagnose issues
+          val allSensors = sensorManager.getSensorList(Sensor.TYPE_ALL)
+          val motionRelatedSensors =
+              allSensors.filter {
+                it.type == Sensor.TYPE_SIGNIFICANT_MOTION ||
+                    it.name.contains("motion", ignoreCase = true) ||
+                    it.name.contains("movement", ignoreCase = true)
+              }
+          Timber.w(
+              "Significant motion sensor not available. Motion-related sensors found: ${motionRelatedSensors.map { "${it.name} (type=${it.type})" }}")
+        }
+  }
+
+  /**
+   * Cancels the significant motion sensor listener. Should be called when the feature is disabled
+   * or when cleaning up resources.
+   */
+  fun cancel() {
+    significantMotionSensor?.let { sensor ->
+      sensorManager.cancelTriggerSensor(significantMotionTriggerListener, sensor)
+      Timber.d("Significant motion sensor listener cancelled")
+    }
+  }
+
+  /**
+   * Called when significant motion is detected. Requests a high-accuracy GPS location if enough
+   * time has passed since the last request (rate limited based on
+   * pegLocatorFastestIntervalToInterval, locatorInterval and moveModeLocatorInterval). Always
+   * re-registers the trigger listener (since TYPE_SIGNIFICANT_MOTION is a one-shot sensor).
+   */
+  private fun onSignificantMotionDetected() {
+    // Re-register the trigger listener first (TYPE_SIGNIFICANT_MOTION is a one-shot sensor)
+    // We do this regardless of rate limiting so we don't miss future motion events
+    setup()
+
+    // Rate limit: use the same interval logic as BackgroundService location requests
+    val now = SystemClock.elapsedRealtime()
+    val intervalSeconds =
+        if (preferences.monitoring == MonitoringMode.Move) {
+          preferences.moveModeLocatorInterval
+        } else {
+          preferences.locatorInterval
+        }
+    val minIntervalMs =
+        if (preferences.pegLocatorFastestIntervalToInterval) {
+          TimeUnit.SECONDS.toMillis(intervalSeconds.toLong())
+        } else {
+          TimeUnit.SECONDS.toMillis(1)
+        }
+    val timeSinceLastRequest = now - lastSignificantMotionLocationRequestTime
+
+    if (timeSinceLastRequest < minIntervalMs) {
+      Timber.d(
+          "Significant motion detected but rate limited. " +
+              "Time since last request: ${timeSinceLastRequest}ms, min interval: ${minIntervalMs}ms")
+      return
+    }
+
+    if (requirementsChecker.hasLocationPermissions()) {
+      Timber.d("Requesting high-accuracy location due to significant motion detection")
+      lastSignificantMotionLocationRequestTime = now
+      locationProviderClient.singleHighAccuracyLocation(locationCallback, looper)
+    } else {
+      Timber.w("Missing location permission, cannot request location for significant motion")
+    }
+  }
+}