Fix crash when user disables Market tab

Author: rafaelekol

app/src/main/java/io/horizontalsystems/bankwallet/modules/main/MainFragment.kt

@@ -192,8 +192,8 @@ private fun MainScreen(
         }
     ) { paddingValues ->
         Column {
-            Crossfade(uiState.selectedTabIndex) {
-                when (uiState.mainNavItems[it].mainNavItem) {
+            Crossfade(uiState.selectedTabItem) { navItem ->
+                when (navItem) {
                     MainNavigation.Market -> MarketScreen(fragmentNavController)
                     MainNavigation.Balance -> BalanceScreen(fragmentNavController)
                     MainNavigation.Transactions -> TransactionsScreen(

app/src/main/java/io/horizontalsystems/bankwallet/modules/main/MainModule.kt

@@ -89,7 +89,6 @@ object MainModule {
     }
 
     data class UiState(
-        val selectedTabIndex: Int,
         val deeplinkPage: DeeplinkPage?,
         val mainNavItems: List<NavigationViewItem>,
         val showRateAppDialog: Boolean,
@@ -98,6 +97,7 @@ object MainModule {
         val torEnabled: Boolean,
         val wcSupportState: WCManager.SupportState?,
         val openSend: OpenSendTokenSelect?,
+        val selectedTabItem: MainNavigation
     )
 }
 

app/src/main/java/io/horizontalsystems/bankwallet/modules/main/MainViewModel.kt

@@ -87,6 +87,9 @@ class MainViewModel(
                 MainNavigation.Settings,
             )
         }
+    private val selectedTabItem: MainNavigation
+        get() = mainNavItems.firstOrNull { it.selected }?.mainNavItem
+            ?: MainNavigation.Balance
 
     private var selectedTabIndex = getTabIndexToOpen()
     private var deeplinkPage: DeeplinkPage? = null
@@ -100,15 +103,7 @@ class MainViewModel(
 
     init {
         localStorage.marketsTabEnabledFlow.collectWith(viewModelScope) { enabled ->
-            var navItemSize = items.size
             marketsTabEnabled = enabled
-            if (navItemSize != items.size) {
-                if (enabled) {
-                    selectedTabIndex += 1
-                } else {
-                    selectedTabIndex -= 1
-                }
-            }
             syncNavigation()
         }
 
@@ -165,7 +160,6 @@ class MainViewModel(
     }
 
     override fun createState() = MainModule.UiState(
-        selectedTabIndex = selectedTabIndex,
         deeplinkPage = deeplinkPage,
         mainNavItems = mainNavItems,
         showRateAppDialog = showRateAppDialog,
@@ -174,6 +168,7 @@ class MainViewModel(
         wcSupportState = wcSupportState,
         torEnabled = torEnabled,
         openSend = openSendTokenSelect,
+        selectedTabItem = selectedTabItem,
     )
 
     private fun isTransactionsTabEnabled(): Boolean = !accountManager.isAccountsEmpty
@@ -379,6 +374,10 @@ class MainViewModel(
     }
 
     private fun syncNavigation() {
+        val currentNavItem = mainNavItems.getOrNull(selectedTabIndex)?.mainNavItem
+        val newIndex = currentNavItem?.let { items.indexOf(it) } ?: -1
+        selectedTabIndex = if (newIndex >= 0) newIndex else items.indexOf(MainNavigation.Balance).coerceAtLeast(0)
+
         val newNavItems = navigationItems()
 
         // Only update if structure changed