For #9498: Replace navargs with viewModel to remember if scroll to tab

app/src/main/java/org/mozilla/fenix/browser/BaseBrowserFragment.kt

@@ -15,6 +15,7 @@ import androidx.annotation.CallSuper
 import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.core.net.toUri
 import androidx.fragment.app.Fragment
+import androidx.fragment.app.activityViewModels
 import androidx.lifecycle.lifecycleScope
 import androidx.navigation.fragment.findNavController
 import com.google.android.material.appbar.AppBarLayout
@@ -84,6 +85,7 @@ import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.ext.sessionsOfType
 import org.mozilla.fenix.ext.settings
+import org.mozilla.fenix.home.SharedViewModel
 import org.mozilla.fenix.settings.SupportUtils
 import org.mozilla.fenix.theme.ThemeManager
 import org.mozilla.fenix.wifi.SitePermissionsWifiIntegration
@@ -130,6 +132,8 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
     // We need this so we don't accidentally remove all external sessions on back press
     private var sessionRemoved = false
 
+    private val sharedViewModel: SharedViewModel by activityViewModels()
+
     @CallSuper
     override fun onCreateView(
         inflater: LayoutInflater,
@@ -206,7 +210,8 @@ abstract class BaseBrowserFragment : Fragment(), UserInteractionHandler, Session
                 bookmarkTapped = { lifecycleScope.launch { bookmarkTapped(it) } },
                 scope = lifecycleScope,
                 tabCollectionStorage = requireComponents.core.tabCollectionStorage,
-                topSiteStorage = requireComponents.core.topSiteStorage
+                topSiteStorage = requireComponents.core.topSiteStorage,
+                sharedViewModel = sharedViewModel
             )
 
             _browserInteractor = BrowserInteractor(

app/src/main/java/org/mozilla/fenix/components/toolbar/BrowserToolbarController.kt

@@ -37,6 +37,7 @@ import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.ext.getRootView
 import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.settings
+import org.mozilla.fenix.home.SharedViewModel
 import org.mozilla.fenix.lib.Do
 import org.mozilla.fenix.settings.deletebrowsingdata.deleteAndQuit
 
@@ -70,7 +71,8 @@ class DefaultBrowserToolbarController(
     private val bookmarkTapped: (Session) -> Unit,
     private val scope: CoroutineScope,
     private val tabCollectionStorage: TabCollectionStorage,
-    private val topSiteStorage: TopSiteStorage
+    private val topSiteStorage: TopSiteStorage,
+    private val sharedViewModel: SharedViewModel
 ) : BrowserToolbarController {
 
     private val currentSession
@@ -119,6 +121,7 @@ class DefaultBrowserToolbarController(
     }
 
     override fun handleTabCounterClick() {
+        sharedViewModel.shouldScrollToSelectedTab = true
         animateTabAndNavigateHome()
     }
 
@@ -128,7 +131,8 @@ class DefaultBrowserToolbarController(
                 ToolbarMenu.Item.AddToHomeScreen -> activity.settings().installPwaOpened = true
                 is ToolbarMenu.Item.ReaderMode -> activity.settings().readerModeOpened = true
                 ToolbarMenu.Item.OpenInApp -> activity.settings().openInAppOpened = true
-                else -> {}
+                else -> {
+                }
             }
         }
     }
@@ -302,10 +306,14 @@ class DefaultBrowserToolbarController(
             // Delay for a short amount of time so the browser has time to start animating out
             // before we transition the fragment. This makes the animation feel smoother
             delay(ANIMATION_DELAY)
-            val directions = BrowserFragmentDirections.actionBrowserFragmentToHomeFragmentPopUp(
-                shouldScrollToSelectedTab = true
-            )
-            navController.navigate(directions)
+            if (!navController.popBackStack(R.id.homeFragment, false)) {
+                val directions = BrowserFragmentDirections.actionBrowserFragmentToHomeFragment()
+                navController.nav(
+                    R.id.browserFragment,
+                    directions,
+                    null
+                )
+            }
         }
     }
 

app/src/main/java/org/mozilla/fenix/home/HomeFragment.kt

@@ -37,7 +37,6 @@ import androidx.lifecycle.OnLifecycleEvent
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.lifecycleScope
 import androidx.navigation.fragment.findNavController
-import androidx.navigation.fragment.navArgs
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
 import androidx.recyclerview.widget.RecyclerView.SCROLL_STATE_IDLE
@@ -116,6 +115,8 @@ class HomeFragment : Fragment() {
         ViewModelProvider.AndroidViewModelFactory(requireActivity().application)
     }
 
+    private val sharedViewModel: SharedViewModel by activityViewModels()
+
     private val snackbarAnchorView: View?
         get() {
             return if (requireContext().settings().shouldUseBottomToolbar) {
@@ -510,10 +511,9 @@ class HomeFragment : Fragment() {
             activity?.window?.setBackgroundDrawableResource(R.drawable.private_home_background_gradient)
         }
         hideToolbar()
-        val safeArguments = arguments?.let { navArgs<HomeFragmentArgs>().value }
-        val shouldScrollToSelectedTab = safeArguments?.shouldScrollToSelectedTab ?: false
-        if (shouldScrollToSelectedTab) {
+        if (sharedViewModel.shouldScrollToSelectedTab) {
             scrollToSelectedTab()
+            sharedViewModel.shouldScrollToSelectedTab = false
         }
     }
 

app/src/main/java/org/mozilla/fenix/home/SharedViewModel.kt

@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.home
+
+import androidx.lifecycle.ViewModel
+
+class SharedViewModel : ViewModel() {
+
+    /**
+     * Used to remember if we need to scroll to the selected tab in the homeFragment's recycleView see #7356
+     * */
+    var shouldScrollToSelectedTab: Boolean = false
+}

app/src/main/res/navigation/nav_graph.xml

@@ -63,10 +63,6 @@
         android:id="@+id/homeFragment"
         android:name="org.mozilla.fenix.home.HomeFragment"
         tools:layout="@layout/fragment_home">
-        <argument
-            android:name="shouldScrollToSelectedTab"
-            app:argType="boolean"
-            android:defaultValue="false" />
         <action
             android:id="@+id/action_homeFragment_to_turnOnSyncFragment"
             app:destination="@+id/turnOnSyncFragment" />
@@ -185,9 +181,8 @@
         app:exitAnim="@anim/fade_out"
         tools:layout="@layout/fragment_browser">
         <action
-            android:id="@+id/action_browserFragment_to_homeFragment_popUp"
-            app:destination="@id/homeFragment"
-            app:popUpTo="@id/homeFragment" />
+            android:id="@+id/action_browserFragment_to_homeFragment"
+            app:destination="@id/homeFragment" />
         <action
             android:id="@+id/action_browserFragment_to_searchFragment"
             app:enterAnim="@anim/fade_in_up"