When selecting automatic monitor-mode, check if the user has selected a device address, if not pop up the selection dialog.

app/src/main/java/eu/darken/capod/main/ui/settings/general/GeneralSettingsEvents.kt

@@ -0,0 +1,5 @@
+package eu.darken.capod.main.ui.settings.general
+
+sealed class GeneralSettingsEvents {
+    object SelectDeviceAddressEvent : GeneralSettingsEvents()
+}

app/src/main/java/eu/darken/capod/main/ui/settings/general/GeneralSettingsFragment.kt

@@ -61,6 +61,13 @@ class GeneralSettingsFragment : PreferenceFragment3() {
                 true
             }
         }
+
+        vm.events.observe2 {
+            when (it) {
+                GeneralSettingsEvents.SelectDeviceAddressEvent -> mainDeviceAddressPref.performClick()
+            }
+        }
+
         mainDeviceModelPref.setOnPreferenceClickListener {
             val dialog = ModelSelectionDialogFactory(requireContext()).create(
                 PodDevice.Model.values().toList(),

app/src/main/java/eu/darken/capod/main/ui/settings/general/GeneralSettingsFragmentVM.kt

@@ -5,21 +5,41 @@ import dagger.hilt.android.lifecycle.HiltViewModel
 import eu.darken.capod.common.bluetooth.BluetoothManager2
 import eu.darken.capod.common.coroutine.DispatcherProvider
 import eu.darken.capod.common.debug.logging.logTag
+import eu.darken.capod.common.flow.withPrevious
+import eu.darken.capod.common.livedata.SingleLiveEvent
 import eu.darken.capod.common.uix.ViewModel3
+import eu.darken.capod.main.core.GeneralSettings
+import eu.darken.capod.main.core.MonitorMode
+import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.flow.onEach
 import javax.inject.Inject
 
 @HiltViewModel
 class GeneralSettingsFragmentVM @Inject constructor(
-    private val handle: SavedStateHandle,
-    private val dispatcherProvider: DispatcherProvider,
-    private val bluetoothManager: BluetoothManager2,
+    @Suppress("unused") private val handle: SavedStateHandle,
+    dispatcherProvider: DispatcherProvider,
+    bluetoothManager: BluetoothManager2,
+    private val generalSettings: GeneralSettings,
 ) : ViewModel3(dispatcherProvider) {
 
     val bondedDevices = bluetoothManager.bondedDevices()
         .map { it.toList() }
         .asLiveData2()
 
+    val events = SingleLiveEvent<GeneralSettingsEvents>()
+
+    init {
+
+        generalSettings.monitorMode.flow
+            .withPrevious()
+            .filter { (old, new) ->
+                old != new && new == MonitorMode.AUTOMATIC && generalSettings.mainDeviceAddress.value == null
+            }
+            .onEach { events.postValue(GeneralSettingsEvents.SelectDeviceAddressEvent) }
+            .launchInViewModel()
+    }
+
     companion object {
         private val TAG = logTag("Settings", "General", "VM")
     }