Navigation with Fragment should use popWithTransition() [238686802]

Fixed

Bug

Status Update

No update yet.

Description

jb...@google.com

created issue #1

Jul 12, 2022 12:04AM

Navigation 2.4 introduced new Navigator APIs that were equipped to handle transitions, ensuring that NavBackStackEntries would always be in the proper state. (i.e. STARTED until the incoming transition completes then moving RESUMED or CREATED until the outgoing transition completes and then moving to DESTROYED).

Now that these APIs are available, they should also be implemented in Navigation with Fragments. This would ensure that the state of Fragment also follows the same conventions of NavBackStackEntry and provides properly Lifecycle updates while handling animations, animators, and transitions.

Comments

jb...@google.com <jb...@google.com> #2Jul 12, 2022 12:05AM

Oh I forgot to mention that I thought it might be connected to this issue: https://issuetracker.google.com/issues/243778589. But after trying 2.5.2 I can say that the issue persists.

ap...@google.com <ap...@google.com> #3Feb 2, 2023 02:44AM

Please provide a minimal sample project along with the minimal steps to recreate the issue in the project.

ap...@google.com <ap...@google.com> #4Feb 2, 2023 02:44AM

Sorry for the delay. I got a working example here: https://github.com/Del-S/issues. The project is set up to crash when navigating to ThirdFragment (nested nav graph) with poping the graph.

I poked into it a little bit and it seems to be connected to SafeArgs gradle plugin. When safe args is used to navigate to ThirdFragment (with nested graph poped) it will try to recreate te parent but there were no arguments passed so it crashes.

Steps to reproduce:

Navigate from Second Fragment to Child nav graph (with non-nullable parameters).
Navigate to Third fragment using SafeArgs and the app crashes.

Crash log:

Process: cz.dels.issues, PID: 1743
java.lang.NullPointerException: null cannot be cast to non-null type kotlin.Long
at androidx.navigation.NavType$Companion$LongType$1.get(NavType.kt:352)
at androidx.navigation.NavType$Companion$LongType$1.get(NavType.kt:342)
at androidx.navigation.NavArgument.verify(NavArgument.kt:76)
at androidx.navigation.NavDestination.addInDefaultArgs(NavDestination.kt:502)
at androidx.navigation.NavController.addEntryToBackStack(NavController.kt:1865)
at androidx.navigation.NavController.addEntryToBackStack$default(NavController.kt:1813)
at androidx.navigation.NavController$navigate$4.invoke(NavController.kt:1721)
at androidx.navigation.NavController$navigate$4.invoke(NavController.kt:1719)
at androidx.navigation.NavController$NavControllerNavigatorState.push(NavController.kt:287)
at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.kt:246)
at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.kt:162)
at androidx.navigation.NavController.navigateInternal(NavController.kt:260)
at androidx.navigation.NavController.navigate(NavController.kt:1719)
at androidx.navigation.NavController.navigate(NavController.kt:1545)
at androidx.navigation.NavController.navigate(NavController.kt:1472)
at androidx.navigation.NavController.navigate(NavController.kt:1930)
at cz.dels.issues.SecondFragment.onViewCreated$lambda-0(SecondFragment.kt:38)
at cz.dels.issues.SecondFragment.$r8$lambda$XDYnOS_cYrafiNQ5rcCu1WCn0IE(Unknown Source:0)
at cz.dels.issues.SecondFragment$$ExternalSyntheticLambda0.onClick(Unknown Source:2)

Note: If in step 2 SaveArgs is not used then navigation works correctly. More information is here: https://github.com/Del-S/issues/blob/master/app/src/main/java/cz/dels/issues/SecondFragment.kt#L37.

ap...@google.com <ap...@google.com> #5Feb 2, 2023 02:44AM

Ups a typo: Navigate from ~~Second~~ First Fragment to Child nav graph (with non-nullable parameters).

Note: sorry for the spam but I am not able to edit my own comment.

jb...@google.com <jb...@google.com> #6Feb 2, 2023 03:04AM

Marked as fixed.

This has been fixed and will be available in navigation 2.6.0-alpha08

pr...@google.com <pr...@google.com> #7Feb 8, 2023 06:21PM

Project: platform/frameworks/support
Branch: androidx-main

commit 6b358154b794a0456b089ac8e548bfb830dd6c22
Author: Clara Fok <clarafok@google.com>
Date: Tue Mar 14 17:56:12 2023

Fix missing non-nullable arg when rebuilding hierarchy

When navigating with NavDirections, args is populated with an empty bundle. This causes issue when we rebuild parent hierarchy while adding a new entry to NavBackStack. If the Entry being rebuilt contains a non-nullalbe arg, i.e. Long, this empty bundle will cause an exception.

Test: ./gradlew navigation:navigation-runtime:cC
Bug: 249988437
Change-Id: I5c8ce739ad9a3428c8a8de13eae391bfff0db5df

M navigation/navigation-runtime/src/androidTest/java/androidx/navigation/NavControllerTest.kt
M navigation/navigation-runtime/src/main/java/androidx/navigation/NavController.kt

https://android-review.googlesource.com/2488855

Issue 238686802