[Chat][UI] Participants count shows actual count (#498)

* Call requestParticipants when chat is initialized, unit tests included

* Removed the unnecessary remoteParticipants variable in preview

Co-authored-by: ShaunaSong <93549644+ShaunaSong@users.noreply.github.com>

azure-communication-ui/chat/src/main/java/com/azure/android/communication/ui/chat/presentation/ui/chat/components/TypingIndicatorView.kt

@@ -24,7 +24,7 @@ import com.azure.android.communication.ui.chat.models.RemoteParticipantInfoModel
 import com.azure.android.communication.ui.chat.service.sdk.wrapper.CommunicationIdentifier
 
 @Composable
-internal fun TypingIndicatorView(participants: List<RemoteParticipantInfoModel>) {
+internal fun TypingIndicatorView(participants: Collection<RemoteParticipantInfoModel>) {
     val typers = participants.filter { it.isTyping }
 
     AnimatedVisibility(

azure-communication-ui/chat/src/main/java/com/azure/android/communication/ui/chat/presentation/ui/chat/screens/ChatScreen.kt

@@ -35,7 +35,7 @@ internal fun ChatScreen(viewModel: ChatScreenViewModel) {
         topBar = {
             val dispatcher = LocalOnBackPressedDispatcherOwner.current?.onBackPressedDispatcher
             ActionBarView(
-                participantCount = 4,
+                participantCount = viewModel.participants.count(),
                 topic = stringResource(R.string.azure_communication_ui_chat_chat_action_bar_title)
             ) {
                 dispatcher?.onBackPressed()
@@ -57,8 +57,8 @@ internal fun ChatScreen(viewModel: ChatScreenViewModel) {
                 )
             }
 
-            viewModel.remoteParticipants?.also { remoteParticipants ->
+            viewModel.participants.also { remoteParticipants ->
-                TypingIndicatorView(participants = remoteParticipants)
+                TypingIndicatorView(participants = remoteParticipants.values)
             }
         },
         bottomBar = { BottomBarView(viewModel.postMessage) }
@@ -100,16 +100,17 @@ internal fun ChatScreenPreview() {
                 state = ChatStatus.INITIALIZED.name,
                 buildCount = 2,
                 postMessage = {},
+                participants = listOf(
+                    RemoteParticipantInfoModel(CommunicationIdentifier.UnknownIdentifier("7A13DD2C-B49F-4521-9364-975F12F6E333"), "John Smith"),
+                    RemoteParticipantInfoModel(CommunicationIdentifier.UnknownIdentifier("931804B1-D72E-4E70-BFEA-7813C7761BD2"), "William Brown"),
+                    RemoteParticipantInfoModel(CommunicationIdentifier.UnknownIdentifier("152D5D76-3DDC-44BE-873F-A4575F8C91DF"), "James Miller"),
+                    RemoteParticipantInfoModel(CommunicationIdentifier.UnknownIdentifier("85FF2697-2ABB-480E-ACCA-09EBE3D6F5EC"), "George Johnson"),
+                    RemoteParticipantInfoModel(CommunicationIdentifier.UnknownIdentifier("DB75F1F0-65E4-46B0-A213-DA4F574659A5"), "Henry Jones"),
+                ).associateBy({ it.userIdentifier.id })
 
                 // error = ChatStateError(
                 //    errorCode = ErrorCode.CHAT_JOIN_FAILED
                 // )
-                remoteParticipants = listOf(
-                    RemoteParticipantInfoModel(
-                        CommunicationIdentifier.CommunicationUserIdentifier(""),
-                        displayName = "John Doe", isTyping = true
-                    )
-                )
             )
         )
     }

azure-communication-ui/chat/src/main/java/com/azure/android/communication/ui/chat/presentation/ui/viewmodel/ChatScreenViewModel.kt

@@ -21,7 +21,7 @@ internal data class ChatScreenViewModel(
     var buildCount: Int,
     val postMessage: (String) -> Unit,
     private val error: ChatStateError? = null,
-    val remoteParticipants: List<RemoteParticipantInfoModel>? = null
+    val participants: Map<String, RemoteParticipantInfoModel>
 ) {
     val showError get() = error != null
     val errorMessage get() = error?.errorCode?.toString() ?: ""
@@ -52,5 +52,6 @@ internal fun buildChatScreenViewModel(
                     )
                 )
             )
-        }
+        },
+        participants = store.getCurrentState().participantState.participants
     )