android: progress indicator on migrations w/t confirmation (#2393)

Co-authored-by: Evgeny Poberezkin <2769109+epoberezkin@users.noreply.github.com>

apps/android/app/src/main/java/chat/simplex/app/MainActivity.kt

@@ -30,6 +30,7 @@ import chat.simplex.app.views.SplashView
 import chat.simplex.app.views.call.ActiveCallView
 import chat.simplex.app.views.call.IncomingCallAlertView
 import chat.simplex.app.views.chat.ChatView
+import chat.simplex.app.views.chat.group.ProgressIndicator
 import chat.simplex.app.views.chatlist.*
 import chat.simplex.app.views.database.DatabaseErrorView
 import chat.simplex.app.views.helpers.*
@@ -443,7 +444,9 @@ fun MainPage(
   Box {
     val onboarding = chatModel.onboardingStage.value
     val userCreated = chatModel.userCreated.value
+    var showInitializationView by remember { mutableStateOf(false) }
     when {
+      chatModel.chatDbStatus.value == null && showInitializationView -> InitializationView()
       showChatDatabaseError -> {
         chatModel.chatDbStatus.value?.let {
           DatabaseErrorView(chatModel.chatDbStatus, chatModel.controller.appPrefs)
@@ -525,6 +528,13 @@ fun MainPage(
     val invitation = chatModel.activeCallInvitation.value
     if (invitation != null) IncomingCallAlertView(invitation, chatModel)
     AlertManager.shared.showInView()
+
+    LaunchedEffect(Unit) {
+      delay(1000)
+      if (chatModel.chatDbStatus.value == null) {
+        showInitializationView = true
+      }
+    }
   }
 
   DisposableEffectOnRotate {
@@ -536,6 +546,22 @@ fun MainPage(
   }
 }
 
+@Composable
+private fun InitializationView() {
+  Box(Modifier.fillMaxSize(), contentAlignment = Alignment.Center) {
+    Column(horizontalAlignment = Alignment.CenterHorizontally) {
+      CircularProgressIndicator(
+        Modifier
+          .padding(bottom = DEFAULT_PADDING)
+          .size(30.dp),
+        color = MaterialTheme.colors.secondary,
+        strokeWidth = 2.5.dp
+      )
+      Text(stringResource(R.string.opening_database))
+    }
+  }
+}
+
 fun processNotificationIntent(intent: Intent?, chatModel: ChatModel) {
   val userId = getUserIdFromIntent(intent)
   when (intent?.action) {

apps/android/app/src/main/res/values/strings.xml

@@ -11,6 +11,9 @@
   <string name="you_will_join_group">You will join a group this link refers to and connect to its group members.</string>
   <string name="connect_via_link_verb">Connect</string>
 
+  <!-- MainActivity.kt -->
+  <string name="opening_database">Opening database…</string>
+
   <!-- Server info - ChatModel.kt -->
   <string name="server_connected">connected</string>
   <string name="server_error">error</string>