For #3238: fixes race condition crash, nav destination unknown

app/src/main/java/org/mozilla/fenix/HomeActivity.kt

@@ -9,6 +9,7 @@ import android.content.Intent
 import android.os.Bundle
 import android.util.AttributeSet
 import android.view.View
+import androidx.annotation.IdRes
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.widget.Toolbar
 import androidx.navigation.fragment.NavHostFragment
@@ -29,6 +30,7 @@ import mozilla.components.support.ktx.kotlin.toNormalizedUrl
 import mozilla.components.support.utils.SafeIntent
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.home.HomeFragmentDirections
 import org.mozilla.fenix.library.bookmarks.BookmarkFragmentDirections
 import org.mozilla.fenix.library.bookmarks.selectfolder.SelectBookmarkFolderFragmentDirections
@@ -56,10 +58,12 @@ open class HomeActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         browsingModeManager = createBrowsingModeManager()
-        themeManager = createThemeManager(when (browsingModeManager.isPrivate) {
+        themeManager = createThemeManager(
-            true -> ThemeManager.Theme.Private
+            when (browsingModeManager.isPrivate) {
-            false -> ThemeManager.Theme.Normal
+                true -> ThemeManager.Theme.Private
-        })
+                false -> ThemeManager.Theme.Normal
+            }
+        )
 
         setTheme(themeManager.currentTheme)
         ThemeManager.applyStatusBarTheme(window, themeManager, this)
@@ -183,35 +187,55 @@ open class HomeActivity : AppCompatActivity() {
             sessionObserver = subscribeToSessions()
 
         if (navHost.navController.currentDestination?.id == R.id.browserFragment) return
+        @IdRes var fragmentId: Int? = null
         val directions = if (!navHost.navController.popBackStack(R.id.browserFragment, false)) {
             when (from) {
-                BrowserDirection.FromGlobal -> NavGraphDirections.actionGlobalBrowser(customTabSessionId)
+                BrowserDirection.FromGlobal ->
-                BrowserDirection.FromHome ->
+                    NavGraphDirections.actionGlobalBrowser(customTabSessionId)
+                BrowserDirection.FromHome -> {
+                    fragmentId = R.id.homeFragment
                     HomeFragmentDirections.actionHomeFragmentToBrowserFragment(customTabSessionId)
-                BrowserDirection.FromSearch ->
+                }
+                BrowserDirection.FromSearch -> {
+                    fragmentId = R.id.searchFragment
                     SearchFragmentDirections.actionSearchFragmentToBrowserFragment(customTabSessionId)
-                BrowserDirection.FromSettings ->
+                }
+                BrowserDirection.FromSettings -> {
+                    fragmentId = R.id.settingsFragment
                     SettingsFragmentDirections.actionSettingsFragmentToBrowserFragment(customTabSessionId)
-                BrowserDirection.FromBookmarks ->
+                }
+                BrowserDirection.FromBookmarks -> {
+                    fragmentId = R.id.bookmarkFragment
                     BookmarkFragmentDirections.actionBookmarkFragmentToBrowserFragment(customTabSessionId)
-                BrowserDirection.FromBookmarksFolderSelect ->
+                }
+                BrowserDirection.FromBookmarksFolderSelect -> {
+                    fragmentId = R.id.bookmarkSelectFolderFragment
                     SelectBookmarkFolderFragmentDirections
                         .actionBookmarkSelectFolderFragmentToBrowserFragment(customTabSessionId)
-                BrowserDirection.FromHistory ->
+                }
+                BrowserDirection.FromHistory -> {
+                    fragmentId = R.id.historyFragment
                     HistoryFragmentDirections.actionHistoryFragmentToBrowserFragment(customTabSessionId)
-                BrowserDirection.FromPair ->
+                }
+                BrowserDirection.FromPair -> {
+                    fragmentId = R.id.pairFragment
                     PairFragmentDirections.actionPairFragmentToBrowserFragment(customTabSessionId)
-                BrowserDirection.FromTurnOnSync ->
+                }
+                BrowserDirection.FromTurnOnSync -> {
+                    fragmentId = R.id.turnOnSyncFragment
                     TurnOnSyncFragmentDirections.actionTurnOnSyncFragmentToBrowserFragment(customTabSessionId)
-                BrowserDirection.FromAccountProblem ->
+                }
+                BrowserDirection.FromAccountProblem -> {
+                    fragmentId = R.id.turnOnSyncFragment
                     AccountProblemFragmentDirections.actionAccountProblemFragmentToBrowserFragment(customTabSessionId)
+                }
             }
         } else {
             null
         }
 
         directions?.let {
-            navHost.navController.navigate(it)
+            navHost.navController.nav(fragmentId, it)
         }
     }
 
@@ -265,10 +289,12 @@ open class HomeActivity : AppCompatActivity() {
             CustomTabBrowsingModeManager()
         } else {
             DefaultBrowsingModeManager(Settings.getInstance(this).createBrowserModeStorage()) {
-                themeManager.setTheme(when (it.isPrivate()) {
+                themeManager.setTheme(
-                    true -> ThemeManager.Theme.Private
+                    when (it.isPrivate()) {
-                    false -> ThemeManager.Theme.Normal
+                        true -> ThemeManager.Theme.Private
-                })
+                        false -> ThemeManager.Theme.Normal
+                    }
+                )
             }
         }
     }

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

@@ -17,7 +17,6 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.coordinatorlayout.widget.CoordinatorLayout
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.ViewModelProviders
-import androidx.navigation.Navigation
 import androidx.navigation.fragment.NavHostFragment.findNavController
 import androidx.transition.TransitionInflater
 import com.google.android.material.snackbar.Snackbar
@@ -78,6 +77,7 @@ import org.mozilla.fenix.components.toolbar.ToolbarUIView
 import org.mozilla.fenix.components.toolbar.ToolbarViewModel
 import org.mozilla.fenix.customtabs.CustomTabsIntegration
 import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.ext.urlToTrimmedHost
 import org.mozilla.fenix.home.sessioncontrol.Tab
@@ -443,13 +443,12 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
             .subscribe {
                 when (it) {
                     is SearchAction.ToolbarClicked -> {
-                        Navigation
+                        nav(
-                            .findNavController(toolbarComponent.getView())
+                            R.id.browserFragment,
-                            .navigate(
+                            BrowserFragmentDirections.actionBrowserFragmentToSearchFragment(
-                                BrowserFragmentDirections.actionBrowserFragmentToSearchFragment(
+                                getSessionById()?.id
-                                    getSessionById()?.id
-                                )
                             )
+                        )
 
                         requireComponents.analytics.metrics.track(
                             Event.SearchBarTapped(Event.SearchBarTapped.Source.BROWSER)
@@ -533,11 +532,11 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
                 val found = existing.isNotEmpty() && existing[0].url == session.url
                 if (found) {
                     launch(Main) {
-                        Navigation.findNavController(requireActivity(), R.id.container)
+                        nav(
-                            .navigate(
+                            R.id.browserFragment,
-                                BrowserFragmentDirections
+                            BrowserFragmentDirections
-                                    .actionBrowserFragmentToBookmarkEditFragment(existing[0].guid)
+                                .actionBrowserFragmentToBookmarkEditFragment(existing[0].guid)
-                            )
+                        )
                     }
                 } else {
                     val guid = components.core.bookmarksStorage
@@ -558,16 +557,13 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
                             )
                                 .setAnchorView(toolbarComponent.uiView.view)
                                 .setAction(getString(R.string.edit_bookmark_snackbar_action)) {
-                                    Navigation.findNavController(
+                                    nav(
-                                        requireActivity(),
+                                        R.id.browserFragment,
-                                        R.id.container
+                                        BrowserFragmentDirections
+                                            .actionBrowserFragmentToBookmarkEditFragment(
+                                                guid
+                                            )
                                     )
-                                        .navigate(
-                                            BrowserFragmentDirections
-                                                .actionBrowserFragmentToBookmarkEditFragment(
-                                                    guid
-                                                )
-                                        )
                                 }
                                 .setText(getString(R.string.bookmark_saved_snackbar))
                                 .show()
@@ -687,10 +683,14 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
             ToolbarMenu.Item.Forward -> sessionUseCases.goForward.invoke(getSessionById())
             ToolbarMenu.Item.Reload -> sessionUseCases.reload.invoke(getSessionById())
             ToolbarMenu.Item.Stop -> sessionUseCases.stopLoading.invoke(getSessionById())
-            ToolbarMenu.Item.Settings -> Navigation.findNavController(toolbarComponent.getView())
+            ToolbarMenu.Item.Settings -> nav(
-                .navigate(BrowserFragmentDirections.actionBrowserFragmentToSettingsFragment())
+                R.id.browserFragment,
-            ToolbarMenu.Item.Library -> Navigation.findNavController(toolbarComponent.getView())
+                BrowserFragmentDirections.actionBrowserFragmentToSettingsFragment()
-                .navigate(BrowserFragmentDirections.actionBrowserFragmentToLibraryFragment())
+            )
+            ToolbarMenu.Item.Library -> nav(
+                R.id.browserFragment,
+                BrowserFragmentDirections.actionBrowserFragmentToLibraryFragment()
+            )
             is ToolbarMenu.Item.RequestDesktop -> sessionUseCases.requestDesktopSite.invoke(action.item.isChecked)
             ToolbarMenu.Item.Share -> getSessionById()?.let { session ->
                 session.url.apply {
@@ -700,7 +700,7 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
             ToolbarMenu.Item.NewPrivateTab -> {
                 val directions = BrowserFragmentDirections
                     .actionBrowserFragmentToSearchFragment(null)
-                Navigation.findNavController(view!!).navigate(directions)
+                nav(R.id.browserFragment, directions)
                 (activity as HomeActivity).browsingModeManager.mode = BrowsingModeManager.Mode.Private
             }
             ToolbarMenu.Item.FindInPage -> {
@@ -724,7 +724,7 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
             ToolbarMenu.Item.NewTab -> {
                 val directions = BrowserFragmentDirections
                     .actionBrowserFragmentToSearchFragment(null)
-                Navigation.findNavController(view!!).navigate(directions)
+                nav(R.id.browserFragment, directions)
                 (activity as HomeActivity).browsingModeManager.mode =
                     BrowsingModeManager.Mode.Normal
             }
@@ -759,7 +759,7 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
             viewModel?.snackbarAnchorView = nestedScrollQuickAction
             view?.let {
                 val directions = BrowserFragmentDirections.actionBrowserFragmentToCreateCollectionFragment()
-                Navigation.findNavController(it).navigate(directions)
+                nav(R.id.browserFragment, directions)
             }
         }
     }
@@ -793,7 +793,7 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
                         sitePermissions = sitePermissions,
                         gravity = getAppropriateLayoutGravity()
                     )
-                    Navigation.findNavController(it).navigate(directions)
+                    nav(R.id.browserFragment, directions)
                 }
             }
         }
@@ -876,7 +876,7 @@ class BrowserFragment : Fragment(), BackHandler, CoroutineScope {
 
     private fun shareUrl(url: String) {
         val directions = BrowserFragmentDirections.actionBrowserFragmentToShareFragment(url)
-        Navigation.findNavController(view!!).navigate(directions)
+        nav(R.id.browserFragment, directions)
     }
 
     companion object {

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

@@ -23,6 +23,7 @@ import mozilla.components.support.ktx.android.view.hideKeyboard
 import org.mozilla.fenix.R
 import org.mozilla.fenix.ThemeManager
 import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.utils.Settings
 
 class ToolbarIntegration(
@@ -67,8 +68,18 @@ class ToolbarIntegration(
                                 )
                                 .build()
                         val navController = Navigation.findNavController(toolbar)
-                        if (!navController.popBackStack(R.id.homeFragment, false)) {
+                        if (!navController.popBackStack(
-                            navController.navigate(R.id.action_browserFragment_to_homeFragment, null, options, extras)
+                                R.id.homeFragment,
+                                false
+                            )
+                        ) {
+                            navController.nav(
+                                R.id.browserFragment,
+                                R.id.action_browserFragment_to_homeFragment,
+                                null,
+                                options,
+                                extras
+                            )
                         }
                     },
                     isPrivate

app/src/main/java/org/mozilla/fenix/ext/Fragment.kt

@@ -4,10 +4,28 @@
 
 package org.mozilla.fenix.ext
 
+import androidx.annotation.IdRes
+import androidx.fragment.app.Fragment
+import androidx.navigation.NavDirections
+import androidx.navigation.NavOptions
+import androidx.navigation.Navigator
+import androidx.navigation.fragment.NavHostFragment.findNavController
 import org.mozilla.fenix.components.Components
 
 /**
  * Get the requireComponents of this application.
  */
-val androidx.fragment.app.Fragment.requireComponents: Components
+val Fragment.requireComponents: Components
     get() = requireContext().components
+
+fun Fragment.nav(@IdRes id: Int?, directions: NavDirections) {
+    findNavController(this).nav(id, directions)
+}
+
+fun Fragment.nav(@IdRes id: Int?, directions: NavDirections, extras: Navigator.Extras) {
+    findNavController(this).nav(id, directions, extras)
+}
+
+fun Fragment.nav(@IdRes id: Int?, directions: NavDirections, options: NavOptions) {
+    findNavController(this).nav(id, directions, options)
+}

app/src/main/java/org/mozilla/fenix/ext/NavController.kt

@@ -0,0 +1,58 @@
+/* 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.ext
+
+import android.os.Bundle
+import androidx.annotation.IdRes
+import androidx.navigation.NavController
+import androidx.navigation.NavDirections
+import androidx.navigation.NavOptions
+import androidx.navigation.Navigator
+import io.sentry.Sentry
+import org.mozilla.fenix.BuildConfig
+
+fun NavController.nav(@IdRes id: Int?, directions: NavDirections) {
+    if (id == null || this.currentDestination?.id == id) {
+        this.navigate(directions)
+    } else {
+        recordIdException(this.currentDestination?.id, id)
+    }
+}
+
+fun NavController.nav(@IdRes id: Int?, directions: NavDirections, extras: Navigator.Extras) {
+    if (id == null || this.currentDestination?.id == id) {
+        this.navigate(directions, extras)
+    } else {
+        recordIdException(this.currentDestination?.id, id)
+    }
+}
+
+fun NavController.nav(@IdRes id: Int?, directions: NavDirections, options: NavOptions) {
+    if (id == null || this.currentDestination?.id == id) {
+        this.navigate(directions, options)
+    } else {
+        recordIdException(this.currentDestination?.id, id)
+    }
+}
+
+fun NavController.nav(
+    @IdRes id: Int?,
+    @IdRes destId: Int,
+    args: Bundle?,
+    navOptions: NavOptions?,
+    extras: Navigator.Extras?
+) {
+    if (id == null || this.currentDestination?.id == id) {
+        this.navigate(destId, args, navOptions, extras)
+    } else {
+        recordIdException(this.currentDestination?.id, id)
+    }
+}
+
+fun recordIdException(actual: Int?, expected: Int?) {
+    if (!BuildConfig.SENTRY_TOKEN.isNullOrEmpty()) {
+        Sentry.capture("Fragment id $actual did not match expected $expected")
+    }
+}

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

@@ -18,7 +18,6 @@ import androidx.constraintlayout.widget.ConstraintLayout.LayoutParams.PARENT_ID
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Observer
 import androidx.lifecycle.ViewModelProviders
-import androidx.navigation.Navigation
 import androidx.navigation.fragment.FragmentNavigator
 import androidx.navigation.fragment.NavHostFragment.findNavController
 import androidx.transition.TransitionInflater
@@ -50,6 +49,7 @@ import org.mozilla.fenix.collections.CreateCollectionViewModel
 import org.mozilla.fenix.collections.SaveCollectionStep
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.ext.urlToTrimmedHost
 import org.mozilla.fenix.home.sessioncontrol.CollectionAction
@@ -220,7 +220,7 @@ class HomeFragment : Fragment(), CoroutineScope, AccountObserver {
                 FragmentNavigator.Extras.Builder()
                     .addSharedElement(toolbar_wrapper, "toolbar_wrapper_transition")
                     .build()
-            Navigation.findNavController(it).navigate(directions, extras)
+            nav(R.id.homeFragment, directions, extras)
             requireComponents.analytics.metrics.track(Event.SearchBarTapped(Event.SearchBarTapped.Source.HOME))
         }
 
@@ -328,7 +328,7 @@ class HomeFragment : Fragment(), CoroutineScope, AccountObserver {
                     FragmentNavigator.Extras.Builder()
                         .addSharedElement(action.tabView, "$TAB_ITEM_TRANSITION_NAME${action.sessionId}")
                         .build()
-                Navigation.findNavController(action.tabView).navigate(directions, extras)
+                nav(R.id.homeFragment, directions, extras)
             }
             is TabAction.Close -> {
                 if (deleteSessionJob == null) removeTabWithUndo(action.sessionId) else {
@@ -362,7 +362,7 @@ class HomeFragment : Fragment(), CoroutineScope, AccountObserver {
             is TabAction.Add -> {
                 invokePendingDeleteJobs()
                 val directions = HomeFragmentDirections.actionHomeFragmentToSearchFragment(null)
-                Navigation.findNavController(view!!).navigate(directions)
+                nav(R.id.homeFragment, directions)
             }
             is TabAction.ShareTabs -> {
                 invokePendingDeleteJobs()
@@ -504,14 +504,16 @@ class HomeFragment : Fragment(), CoroutineScope, AccountObserver {
                 HomeMenu.Item.Settings -> {
                     invokePendingDeleteJobs()
                     onboarding.finish()
-                    Navigation.findNavController(homeLayout).navigate(
+                    nav(
+                        R.id.homeFragment,
                         HomeFragmentDirections.actionHomeFragmentToSettingsFragment()
                     )
                 }
                 HomeMenu.Item.Library -> {
                     invokePendingDeleteJobs()
                     onboarding.finish()
-                    Navigation.findNavController(homeLayout).navigate(
+                    nav(
+                        R.id.homeFragment,
                         HomeFragmentDirections.actionHomeFragmentToLibraryFragment()
                     )
                 }
@@ -673,14 +675,14 @@ class HomeFragment : Fragment(), CoroutineScope, AccountObserver {
 
         view?.let {
             val directions = HomeFragmentDirections.actionHomeFragmentToCreateCollectionFragment()
-            Navigation.findNavController(it).navigate(directions)
+            nav(R.id.homeFragment, directions)
         }
     }
 
     private fun share(url: String? = null, tabs: List<ShareTab>? = null) {
         val directions =
             HomeFragmentDirections.actionHomeFragmentToShareFragment(url = url, tabs = tabs?.toTypedArray())
-        Navigation.findNavController(view!!).navigate(directions)
+        nav(R.id.homeFragment, directions)
     }
 
     private fun currentMode(): Mode = if (!onboarding.userHasBeenOnboarded()) {
@@ -696,11 +698,25 @@ class HomeFragment : Fragment(), CoroutineScope, AccountObserver {
         Mode.Normal
     }
 
-    override fun onAuthenticationProblems() { emitAccountChanges() }
+    override fun onAuthenticationProblems() {
-    override fun onAuthenticated(account: OAuthAccount) { emitAccountChanges() }
+        emitAccountChanges()
-    override fun onError(error: Exception) { emitAccountChanges() }
+    }
-    override fun onLoggedOut() { emitAccountChanges() }
+
-    override fun onProfileUpdated(profile: Profile) { emitAccountChanges() }
+    override fun onAuthenticated(account: OAuthAccount) {
+        emitAccountChanges()
+    }
+
+    override fun onError(error: Exception) {
+        emitAccountChanges()
+    }
+
+    override fun onLoggedOut() {
+        emitAccountChanges()
+    }
+
+    override fun onProfileUpdated(profile: Profile) {
+        emitAccountChanges()
+    }
 
     companion object {
         private const val SHARED_TRANSITION_MS = 200L

app/src/main/java/org/mozilla/fenix/library/LibraryFragment.kt

@@ -22,6 +22,7 @@ import mozilla.appservices.places.BookmarkRoot
 import org.mozilla.fenix.R
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.ext.getColorFromAttr
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 
 class LibraryFragment : Fragment() {
@@ -53,15 +54,16 @@ class LibraryFragment : Fragment() {
         libraryHistory.setOnClickListener {
             requireComponents.analytics.metrics
                 .track(Event.LibrarySelectedItem(view.context.getString(R.string.library_history)))
-            Navigation.findNavController(view)
+            nav(R.id.libraryFragment, LibraryFragmentDirections.actionLibraryFragmentToHistoryFragment())
-                .navigate(LibraryFragmentDirections.actionLibraryFragmentToHistoryFragment())
         }
 
         libraryBookmarks.setOnClickListener {
             requireComponents.analytics.metrics
                 .track(Event.LibrarySelectedItem(view.context.getString(R.string.library_bookmarks)))
-            Navigation.findNavController(view)
+            nav(
-                .navigate(LibraryFragmentDirections.actionLibraryFragmentToBookmarksFragment(BookmarkRoot.Mobile.id))
+                R.id.libraryFragment,
+                LibraryFragmentDirections.actionLibraryFragmentToBookmarksFragment(BookmarkRoot.Mobile.id)
+            )
         }
 
         requireComponents.analytics.metrics.track(Event.LibraryOpened)
@@ -95,6 +97,6 @@ class LibraryFragment : Fragment() {
         toolbar.setBackgroundColor(backgroundColor)
         toolbar.setTitleTextColor(foregroundColor)
         toolbar.navigationIcon?.colorFilter =
-                PorterDuffColorFilter(foregroundColor, PorterDuff.Mode.SRC_IN)
+            PorterDuffColorFilter(foregroundColor, PorterDuff.Mode.SRC_IN)
     }
 }

app/src/main/java/org/mozilla/fenix/library/bookmarks/BookmarkFragment.kt

@@ -45,6 +45,7 @@ import org.mozilla.fenix.components.FenixSnackbar
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.components.metrics.MetricController
 import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.urlToTrimmedHost
 import org.mozilla.fenix.mvi.ActionBusFactory
 import org.mozilla.fenix.mvi.getAutoDisposeObservable
@@ -197,18 +198,20 @@ class BookmarkFragment : Fragment(), CoroutineScope, BackHandler, AccountObserve
                         metrics()?.track(Event.OpenedBookmark)
                     }
                     is BookmarkAction.Expand -> {
-                        navigation
+                        nav(
-                            .navigate(BookmarkFragmentDirections.actionBookmarkFragmentSelf(it.folder.guid))
+                            R.id.bookmarkFragment,
+                            BookmarkFragmentDirections.actionBookmarkFragmentSelf(it.folder.guid)
+                        )
                     }
                     is BookmarkAction.BackPressed -> {
                         navigation.popBackStack()
                     }
                     is BookmarkAction.Edit -> {
-                        navigation
+                        nav(
-                            .navigate(
+                            R.id.bookmarkFragment,
-                                BookmarkFragmentDirections
+                            BookmarkFragmentDirections
-                                    .actionBookmarkFragmentToBookmarkEditFragment(it.item.guid)
+                                .actionBookmarkFragmentToBookmarkEditFragment(it.item.guid)
-                            )
+                        )
                     }
                     is BookmarkAction.Select -> {
                         getManagedEmitter<BookmarkChange>().onNext(BookmarkChange.IsSelected(it.item))
@@ -224,7 +227,8 @@ class BookmarkFragment : Fragment(), CoroutineScope, BackHandler, AccountObserve
                     }
                     is BookmarkAction.Share -> {
                         it.item.url?.apply {
-                            navigation.navigate(
+                            nav(
+                                R.id.bookmarkFragment,
                                 BookmarkFragmentDirections.actionBookmarkFragmentToShareFragment(
                                     this,
                                     it.item.title
@@ -308,18 +312,17 @@ class BookmarkFragment : Fragment(), CoroutineScope, BackHandler, AccountObserve
 
                 (activity as HomeActivity).browsingModeManager.mode = BrowsingModeManager.Mode.Normal
                 (activity as HomeActivity).supportActionBar?.hide()
-                navigation
+                nav(R.id.bookmarkFragment, BookmarkFragmentDirections.actionBookmarkFragmentToHomeFragment())
-                    .navigate(BookmarkFragmentDirections.actionBookmarkFragmentToHomeFragment())
                 metrics()?.track(Event.OpenedBookmarksInNewTabs)
                 true
             }
             R.id.edit_bookmark_multi_select -> {
                 val bookmark = getSelectedBookmarks().first()
-                navigation
+                nav(
-                    .navigate(
+                    R.id.bookmarkFragment,
-                        BookmarkFragmentDirections
+                    BookmarkFragmentDirections
-                            .actionBookmarkFragmentToBookmarkEditFragment(bookmark.guid)
+                        .actionBookmarkFragmentToBookmarkEditFragment(bookmark.guid)
-                    )
+                )
                 true
             }
             R.id.open_bookmarks_in_private_tabs_multi_select -> {
@@ -331,8 +334,7 @@ class BookmarkFragment : Fragment(), CoroutineScope, BackHandler, AccountObserve
 
                 (activity as HomeActivity).browsingModeManager.mode = BrowsingModeManager.Mode.Private
                 (activity as HomeActivity).supportActionBar?.hide()
-                navigation
+                nav(R.id.bookmarkFragment, BookmarkFragmentDirections.actionBookmarkFragmentToHomeFragment())
-                    .navigate(BookmarkFragmentDirections.actionBookmarkFragmentToHomeFragment())
                 metrics()?.track(Event.OpenedBookmarksInPrivateTabs)
                 true
             }
@@ -422,8 +424,8 @@ class BookmarkFragment : Fragment(), CoroutineScope, BackHandler, AccountObserve
                 children = childrenWithVirtualFolder
             )
 
-        // If we're looking at the root, that means we're in the "Desktop Bookmarks" folder.
+            // If we're looking at the root, that means we're in the "Desktop Bookmarks" folder.
-        // Rename its child roots and remove the mobile root.
+            // Rename its child roots and remove the mobile root.
         } else if (node.guid == BookmarkRoot.Root.id) {
             return BookmarkNode(
                 type = node.type,
@@ -434,7 +436,7 @@ class BookmarkFragment : Fragment(), CoroutineScope, BackHandler, AccountObserve
                 url = node.url,
                 children = processDesktopRoots(node.children)
             )
-        // If we're looking at one of the desktop roots, change their titles to friendly names.
+            // If we're looking at one of the desktop roots, change their titles to friendly names.
         } else if (node.guid in listOf(BookmarkRoot.Menu.id, BookmarkRoot.Toolbar.id, BookmarkRoot.Unfiled.id)) {
             return BookmarkNode(
                 type = node.type,

app/src/main/java/org/mozilla/fenix/library/bookmarks/addfolder/AddBookmarkFolderFragment.kt

@@ -28,6 +28,7 @@ import mozilla.appservices.places.BookmarkRoot
 import org.mozilla.fenix.R
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.ext.getColorFromAttr
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.library.bookmarks.BookmarksSharedViewModel
 import kotlin.coroutines.CoroutineContext
@@ -65,14 +66,14 @@ class AddBookmarkFolderFragment : Fragment(), CoroutineScope {
             launch(Main) {
                 bookmark_add_folder_parent_selector.text = sharedViewModel.selectedFolder!!.title
                 bookmark_add_folder_parent_selector.setOnClickListener {
-                    Navigation.findNavController(requireActivity(), R.id.container)
+                    nav(
-                        .navigate(
+                        R.id.bookmarkAddFolderFragment,
-                            AddBookmarkFolderFragmentDirections
+                        AddBookmarkFolderFragmentDirections
-                                .actionBookmarkAddFolderFragmentToBookmarkSelectFolderFragment(
+                            .actionBookmarkAddFolderFragmentToBookmarkSelectFolderFragment(
-                                    BookmarkRoot.Root.id,
+                                BookmarkRoot.Root.id,
-                                    true
+                                true
-                                )
+                            )
-                        )
+                    )
                 }
             }
         }

app/src/main/java/org/mozilla/fenix/library/bookmarks/edit/EditBookmarkFragment.kt

@@ -39,6 +39,7 @@ import mozilla.components.concept.storage.BookmarkNodeType
 import org.mozilla.fenix.R
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.ext.getColorFromAttr
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.library.bookmarks.BookmarksSharedViewModel
 import java.util.concurrent.TimeUnit
@@ -106,7 +107,8 @@ class EditBookmarkFragment : Fragment(), CoroutineScope {
                     bookmark_folder_selector.text = node.title
                     bookmark_folder_selector.setOnClickListener {
                         sharedViewModel.selectedFolder = null
-                        Navigation.findNavController(requireActivity(), R.id.container).navigate(
+                        nav(
+                            R.id.bookmarkEditFragment,
                             EditBookmarkFragmentDirections
                                 .actionBookmarkEditFragmentToBookmarkSelectFolderFragment(null)
                         )

app/src/main/java/org/mozilla/fenix/library/bookmarks/selectfolder/SelectBookmarkFolderFragment.kt

@@ -16,8 +16,6 @@ import android.view.ViewGroup
 import androidx.appcompat.app.AppCompatActivity
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.ViewModelProviders
-import androidx.navigation.Navigation
-import kotlinx.android.synthetic.main.fragment_bookmark.view.*
 import kotlinx.android.synthetic.main.fragment_select_bookmark_folder.*
 import kotlinx.android.synthetic.main.fragment_select_bookmark_folder.view.*
 import kotlinx.coroutines.CoroutineScope
@@ -36,6 +34,7 @@ import org.mozilla.fenix.FenixViewModelProvider
 import org.mozilla.fenix.HomeActivity
 import org.mozilla.fenix.R
 import org.mozilla.fenix.ext.getColorFromAttr
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.library.bookmarks.BookmarksSharedViewModel
 import org.mozilla.fenix.library.bookmarks.SignInAction
@@ -145,7 +144,8 @@ class SelectBookmarkFolderFragment : Fragment(), CoroutineScope, AccountObserver
         return when (item.itemId) {
             R.id.add_folder_button -> {
                 launch(Main) {
-                    Navigation.findNavController(requireActivity(), R.id.container).navigate(
+                    nav(
+                        R.id.bookmarkSelectFolderFragment,
                         SelectBookmarkFolderFragmentDirections
                             .actionBookmarkSelectFolderFragmentToBookmarkAddFolderFragment()
                     )

app/src/main/java/org/mozilla/fenix/library/history/HistoryFragment.kt

@@ -38,6 +38,7 @@ import org.mozilla.fenix.R
 import org.mozilla.fenix.components.Components
 import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.ext.getHostFromUrl
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.mvi.ActionBusFactory
 import org.mozilla.fenix.mvi.getAutoDisposeObservable
@@ -161,7 +162,7 @@ class HistoryFragment : Fragment(), CoroutineScope by MainScope(), BackHandler {
                 browsingModeManager.mode = BrowsingModeManager.Mode.Normal
                 supportActionBar?.hide()
             }
-            navigation.navigate(HistoryFragmentDirections.actionHistoryFragmentToHomeFragment())
+            nav(R.id.historyFragment, HistoryFragmentDirections.actionHistoryFragmentToHomeFragment())
             true
         }
         R.id.open_history_in_private_tabs_multi_select -> {
@@ -176,7 +177,7 @@ class HistoryFragment : Fragment(), CoroutineScope by MainScope(), BackHandler {
                 browsingModeManager.mode = BrowsingModeManager.Mode.Private
                 supportActionBar?.hide()
             }
-            navigation.navigate(HistoryFragmentDirections.actionHistoryFragmentToHomeFragment())
+            nav(R.id.historyFragment, HistoryFragmentDirections.actionHistoryFragmentToHomeFragment())
             true
         }
         else -> super.onOptionsItemSelected(item)
@@ -297,7 +298,7 @@ class HistoryFragment : Fragment(), CoroutineScope by MainScope(), BackHandler {
     private fun share(url: String? = null, tabs: List<ShareTab>? = null) {
         val directions =
             HistoryFragmentDirections.actionHistoryFragmentToShareFragment(url = url, tabs = tabs?.toTypedArray())
-        Navigation.findNavController(view!!).navigate(directions)
+        nav(R.id.historyFragment, directions)
     }
 
     private inline fun emitChange(producer: () -> HistoryChange) {

app/src/main/java/org/mozilla/fenix/settings/PairInstructionsFragment.kt

@@ -16,6 +16,7 @@ import androidx.fragment.app.DialogFragment
 import androidx.navigation.fragment.NavHostFragment.findNavController
 import com.google.android.material.bottomsheet.BottomSheetDialogFragment
 import org.mozilla.fenix.R
+import org.mozilla.fenix.ext.nav
 
 class PairInstructionsFragment : BottomSheetDialogFragment() {
 
@@ -46,7 +47,7 @@ class PairInstructionsFragment : BottomSheetDialogFragment() {
         val openCamera = view.findViewById(R.id.pair_open_camera) as Button
         openCamera.setOnClickListener {
             val directions = PairInstructionsFragmentDirections.actionPairInstructionsFragmentToPairFragment()
-            findNavController(this@PairInstructionsFragment).navigate(directions)
+            nav(R.id.pairInstructionsFragment, directions)
         }
 
         val cancelCamera = view.findViewById(R.id.pair_cancel) as Button

app/src/main/java/org/mozilla/fenix/settings/SitePermissionsExceptionsFragment.kt

@@ -15,7 +15,6 @@ import android.widget.TextView
 import androidx.appcompat.app.AppCompatActivity
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Observer
-import androidx.navigation.Navigation
 import androidx.paging.LivePagedListBuilder
 import androidx.paging.PagedList
 import androidx.paging.PagedListAdapter
@@ -38,6 +37,7 @@ import org.mozilla.fenix.ext.components
 import kotlin.coroutines.CoroutineContext
 import android.graphics.drawable.BitmapDrawable
 import android.widget.ImageView
+import org.mozilla.fenix.ext.nav
 
 private const val MAX_ITEMS_PER_PAGE = 50
 
@@ -135,7 +135,7 @@ class SitePermissionsExceptionsFragment : Fragment(), View.OnClickListener, Coro
         val sitePermissions = view?.tag as SitePermissions
         val directions = SitePermissionsExceptionsFragmentDirections
             .actionSitePermissionsToExceptionsToSitePermissionsDetails(sitePermissions)
-        Navigation.findNavController(requireNotNull(view)).navigate(directions)
+        nav(R.id.sitePermissionsExceptionsFragment, directions)
     }
 }
 

app/src/main/java/org/mozilla/fenix/share/ShareFragment.kt

@@ -16,7 +16,6 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatDialogFragment
-import androidx.navigation.fragment.NavHostFragment.findNavController
 import kotlinx.android.parcel.Parcelize
 import kotlinx.android.synthetic.main.fragment_share.view.*
 import kotlinx.coroutines.CoroutineScope
@@ -26,6 +25,7 @@ import mozilla.components.concept.sync.DeviceEventOutgoing
 import mozilla.components.concept.sync.OAuthAccount
 import org.mozilla.fenix.FenixViewModelProvider
 import org.mozilla.fenix.R
+import org.mozilla.fenix.ext.nav
 import org.mozilla.fenix.ext.requireComponents
 import org.mozilla.fenix.mvi.ActionBusFactory
 import org.mozilla.fenix.mvi.getAutoDisposeObservable
@@ -87,7 +87,7 @@ class ShareFragment : AppCompatDialogFragment(), CoroutineScope {
                 }
                 ShareAction.SignInClicked -> {
                     val directions = ShareFragmentDirections.actionShareFragmentToTurnOnSyncFragment()
-                    findNavController(this@ShareFragment).navigate(directions)
+                    nav(R.id.shareFragment, directions)
                     dismiss()
                 }
                 ShareAction.AddNewDeviceClicked -> {