Show Toast when offline in Download

ground/src/main/java/com/google/android/ground/ui/offlineareas/selector/OfflineAreaSelectorFragment.kt

@@ -26,15 +26,18 @@
 import androidx.compose.ui.platform.ComposeView
 import androidx.lifecycle.lifecycleScope
 import androidx.navigation.fragment.findNavController
+import com.google.android.ground.R
 import com.google.android.ground.databinding.OfflineAreaSelectorFragBinding
 import com.google.android.ground.ui.common.AbstractMapContainerFragment
 import com.google.android.ground.ui.common.BaseMapViewModel
+import com.google.android.ground.ui.common.EphemeralPopups
 import com.google.android.ground.ui.common.MapConfig
 import com.google.android.ground.ui.home.mapcontainer.HomeScreenMapContainerViewModel
 import com.google.android.ground.ui.map.MapFragment
 import com.google.android.ground.ui.map.MapType
 import com.google.android.ground.ui.theme.AppTheme
 import dagger.hilt.android.AndroidEntryPoint
+import javax.inject.Inject
 import kotlinx.coroutines.launch
 
 /** Map UI used to select areas for download and viewing offline. */
@@ -44,6 +47,8 @@
   private lateinit var viewModel: OfflineAreaSelectorViewModel
   private lateinit var mapContainerViewModel: HomeScreenMapContainerViewModel
 
+  @Inject lateinit var popups: EphemeralPopups
+
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     mapContainerViewModel = getViewModel(HomeScreenMapContainerViewModel::class.java)
@@ -81,6 +86,12 @@
         }
       }
     }
+
+    lifecycleScope.launch {
+      viewModel.networkUnavailableEvent.collect {
+        popups.ErrorPopup().show(R.string.connect_to_download_message)
+      }
+    }
   }
 
   override fun getMapConfig(): MapConfig =

ground/src/main/java/com/google/android/ground/ui/offlineareas/selector/OfflineAreaSelectorViewModel.kt

@@ -25,6 +25,7 @@
 import com.google.android.ground.repository.OfflineAreaRepository
 import com.google.android.ground.repository.SurveyRepository
 import com.google.android.ground.system.LocationManager
+import com.google.android.ground.system.NetworkManager
 import com.google.android.ground.system.PermissionsManager
 import com.google.android.ground.system.SettingsManager
 import com.google.android.ground.ui.common.BaseMapViewModel
@@ -56,6 +57,7 @@
   settingsManager: SettingsManager,
   permissionsManager: PermissionsManager,
   locationOfInterestRepository: LocationOfInterestRepository,
+  private val networkManager: NetworkManager,
 ) :
   BaseMapViewModel(
     locationManager,
@@ -79,7 +81,15 @@
   private val _navigate = MutableSharedFlow<UiState>(replay = 0)
   val navigate = _navigate.asSharedFlow()
 
+  private val _networkUnavailableEvent = MutableSharedFlow<Unit>()
+  val networkUnavailableEvent = _networkUnavailableEvent.asSharedFlow()
+
   fun onDownloadClick() {
+    if (!networkManager.isNetworkConnected()) {
+      viewModelScope.launch { _networkUnavailableEvent.emit(Unit) }
+      return
+    }
+
     if (viewport == null) {
       // Download was likely clicked before map was ready.
       return

ground/src/main/res/values/strings.xml

@@ -56,6 +56,7 @@
   <!-- Label of button used enter the offline area selector. -->
   <string name="offline_area_selector_select">Select area</string>
   <string name="no_basemaps_downloaded">No map imagery downloaded for offline use</string>
+  <string name="connect_to_download_message">You are offline. Connect to download offline map imager</string>
   <string name="signing_in">Signing in</string>
   <!-- Precedes the build number shown in the side menu of debug builds. -->
   <string name="build">Build %s</string>