Show alert if user has not beacon and beaconInfo permissions in the room.

ElementX/Sources/Generated/Strings.swift

@@ -3265,6 +3265,8 @@ internal enum L10n {
   internal static var screenShareLocationLiveLocationDisclaimerTitle: String { return L10n.tr("Localizable", "screen_share_location_live_location_disclaimer_title") }
   /// Choose how long to share your live location.
   internal static var screenShareLocationLiveLocationDurationPickerTitle: String { return L10n.tr("Localizable", "screen_share_location_live_location_duration_picker_title") }
+  /// You do not have permissions to share your live location in this room
+  internal static var screenShareLocationLiveLocationMissingPermissions: String { return L10n.tr("Localizable", "screen_share_location_live_location_missing_permissions") }
   /// Share location
   internal static var screenShareLocationTitle: String { return L10n.tr("Localizable", "screen_share_location_title") }
   /// Share my location

ElementX/Sources/Screens/LocationSharing/LocationSharingScreenModels.swift

@@ -13,6 +13,7 @@ import MatrixRustSDK
 enum LocationSharingViewAlert: Hashable {
     case missingAuthorization
     case missingAlwaysAuthorization
+    case missingLiveLocationSharingPermission
     case liveLocationDisclaimer
     case liveLocationDurationSelection
     case mapError(MapLibreError)
@@ -213,6 +214,10 @@ extension AlertInfo where T == LocationSharingViewAlert {
                       message: L10n.dialogPermissionLiveLocationDescriptionIos(InfoPlistReader.main.bundleDisplayName),
                       primaryButton: primaryButton,
                       secondaryButton: secondaryButton)
+        case .missingLiveLocationSharingPermission:
+            self.init(id: alertID,
+                      title: L10n.screenShareLocationLiveLocationMissingPermissions,
+                      primaryButton: primaryButton)
         case .liveLocationDisclaimer:
             self.init(id: alertID,
                       title: L10n.screenShareLocationLiveLocationDisclaimerTitle,

ElementX/Sources/Screens/LocationSharing/LocationSharingScreenViewModel.swift

@@ -68,7 +68,7 @@ class LocationSharingScreenViewModel: LocationSharingScreenViewModelType, Locati
         case .close:
             actionsSubject.send(.close)
         case .startLiveLocation:
-            checkAlwaysShareLocationPermission()
+            startLiveLocation()
         case .selectLocation:
             guard let coordinate = state.bindings.mapCenterLocation else { return }
             let uncertainty = state.isSharingUserLocation ? context.geolocationUncertainty : nil
@@ -171,13 +171,17 @@ class LocationSharingScreenViewModel: LocationSharingScreenViewModelType, Locati
         }
     }
     
-    private static let durationFormatter: DateComponentsFormatter = {
-        let formatter = DateComponentsFormatter()
-        formatter.unitsStyle = .full
-        formatter.allowedUnits = [.hour, .minute]
-        return formatter
-    }()
+    private func startLiveLocation() {
+        guard let powerLevels = roomProxy.infoPublisher.value.powerLevels,
+              powerLevels.canOwnUser(sendStateEvent: .beaconInfo),
+              powerLevels.canOwnUser(sendMessage: .beacon) else {
+            state.bindings.alertInfo = .init(alertID: .missingLiveLocationSharingPermission)
+            return
+        }
         
+        checkAlwaysShareLocationPermission()
+    }
+    
     private func checkAlwaysShareLocationPermission() {
         authorizationStatusSubscription = nil
         let authorizationStatus = liveLocationManager.authorizationStatus.value
@@ -231,6 +235,15 @@ class LocationSharingScreenViewModel: LocationSharingScreenViewModelType, Locati
         }
     }
     
+    /// It's easier to achieve the format we want with a DateComponentsFormatter
+    /// than using the `.formatted` function of Duration.
+    private static let durationFormatter: DateComponentsFormatter = {
+        let formatter = DateComponentsFormatter()
+        formatter.unitsStyle = .full
+        formatter.allowedUnits = [.hour, .minute]
+        return formatter
+    }()
+    
     private func showLiveLocationDurationPicker() {
         let durations: [Duration] = [.seconds(15 * 60), // 15 minutes
                                      .seconds(60 * 60), // 1 hour