[fenix] For https://github.com/mozilla-mobile/fenix/issues/16424 - Focus the right item in tabs tray when using Talkback (https://github.com/mozilla-mobile/fenix/pull/16472)

To get the index of the current selected browser tab when using reverse layout
we should also account for items placed below of the browser tabs.
The patch here unifies the logic already used for some calls but not all.

app/src/main/java/org/mozilla/fenix/tabtray/TabTrayDialogFragment.kt

@@ -291,7 +291,7 @@ class TabTrayDialogFragment : AppCompatDialogFragment(), UserInteractionHandler
             getString(R.string.snackbar_deleted_undo),
             {
                 requireComponents.useCases.tabsUseCases.undo.invoke()
-                _tabTrayView?.scrollToTab(tab.id)
+                _tabTrayView?.scrollToSelectedBrowserTab(tab.id)
             },
             operation = { },
             elevation = ELEVATION,

app/src/main/java/org/mozilla/fenix/tabtray/TabTrayView.kt

@@ -157,9 +157,6 @@ class TabTrayView(
 
         val tabs = getTabs(isPrivate)
 
-        val selectedBrowserTabIndex = tabs
-            .indexOfFirst { it.id == view.context.components.core.store.state.selectedTabId }
-
         updateBottomSheetBehavior()
 
         setTopOffset(isInLandscape())
@@ -208,14 +205,14 @@ class TabTrayView(
                 }
                 if (!hasLoaded) {
                     hasLoaded = true
-                    scrollToTab(view.context.components.core.store.state.selectedTabId)
+                    scrollToSelectedBrowserTab()
                     if (view.context.settings().accessibilityServicesEnabled) {
                         lifecycleScope.launch {
                             delay(SELECTION_DELAY.toLong())
                             lifecycleScope.launch(Main) {
-                                layoutManager?.findViewByPosition(selectedBrowserTabIndex)
+                                layoutManager?.findViewByPosition(getSelectedBrowserTabViewIndex())
                                     ?.requestFocus()
-                                layoutManager?.findViewByPosition(selectedBrowserTabIndex)
+                                layoutManager?.findViewByPosition(getSelectedBrowserTabViewIndex())
                                     ?.sendAccessibilityEvent(
                                         AccessibilityEvent.TYPE_VIEW_FOCUSED
                                     )
@@ -367,7 +364,7 @@ class TabTrayView(
         toggleSaveToCollectionButton(isPrivateModeSelected)
 
         updateUINormalMode(view.context.components.core.store.state)
-        scrollToTab(view.context.components.core.store.state.selectedTabId)
+        scrollToSelectedBrowserTab()
 
         if (isPrivateModeSelected) {
             components.analytics.metrics.track(Event.TabsTrayPrivateModeTapped)
@@ -682,28 +679,39 @@ class TabTrayView(
         return interactor.onBackPressed()
     }
 
-    fun scrollToTab(sessionId: String?) {
+    fun scrollToSelectedBrowserTab(selectedTabId: String? = null) {
         view.tabsTray.apply {
+            val recyclerViewIndex = getSelectedBrowserTabViewIndex(selectedTabId)
+
+            layoutManager?.scrollToPosition(recyclerViewIndex)
+            smoothScrollBy(
+                0,
+                - resources.getDimensionPixelSize(R.dimen.tab_tray_tab_item_height) / 2
+            )
+        }
+    }
+
+    private fun getSelectedBrowserTabViewIndex(sessionId: String? = null): Int {
         val tabs = if (isPrivateModeSelected) {
             view.context.components.core.store.state.privateTabs
         } else {
             view.context.components.core.store.state.normalTabs
         }
 
-            val selectedBrowserTabIndex = tabs
-                .indexOfFirst { it.id == sessionId }
+        val selectedBrowserTabIndex = if (sessionId != null) {
+            tabs.indexOfFirst { it.id == sessionId }
+        } else {
+            tabs.indexOfFirst { it.id == view.context.components.core.store.state.selectedTabId }
+        }
 
         // We offset the tab index by the number of items in the other adapters.
         // We add the offset, because the layoutManager is initialized with `reverseLayout`.
-            val recyclerViewIndex = selectedBrowserTabIndex +
+        return if (view.context.settings().listTabView) {
+            selectedBrowserTabIndex +
                     collectionsButtonAdapter.itemCount +
                     syncedTabsController.adapter.itemCount
-
-            layoutManager?.scrollToPosition(recyclerViewIndex)
-            smoothScrollBy(
-                0,
-                - resources.getDimensionPixelSize(R.dimen.tab_tray_tab_item_height) / 2
-            )
+        } else {
+            selectedBrowserTabIndex
         }
     }