Unable to initialize NavBackStackEntry - IllegalStateException: Method addObserver must be called on the main thread [171125856]

Fixed

Bug

Status Update

No update yet.

Description

[Deleted User]

created issue #1

Oct 19, 2020 08:57AM

Component used: Navigation

Version used: 2.2.0, 2.3.0, 2.3.1

Devices/Android versions reproduced on: 10.0, 9.0 - probably not related

Description:

I've updated two dependencies in my project:

androidx.fragment:fragment 1.3.0-alpha06 -> 1.3.0-beta01
androidx.activity.activity 1.1.0 -> 1.2.0-beta01

and now I see that NavController::navigate needs to be called from the main thread. Otherwise NavBackStackEntry throws IllegalStateException when trying to register lifecycle observer.

Stacktrace:

Caused by: java.lang.IllegalStateException: Method addObserver must be called on the main thread
    at androidx.lifecycle.LifecycleRegistry.enforceMainThreadIfNeeded(LifecycleRegistry.java:317)
    at androidx.lifecycle.LifecycleRegistry.addObserver(LifecycleRegistry.java:172)
    at androidx.savedstate.SavedStateRegistryController.performRestore(SavedStateRegistryController.java:61)
    at androidx.navigation.NavBackStackEntry.<init>(NavBackStackEntry.java:84)
    at androidx.navigation.NavBackStackEntry.<init>(NavBackStackEntry.java:69)
    at androidx.navigation.NavController.navigate(NavController.java:970)
    at androidx.navigation.NavController.navigate(NavController.java:867)

There were no changes in documentation so I assume that this behavior is unintended.

Comments

il...@google.com <il...@google.com> #2Oct 19, 2020 08:10PM

The project uses plugin androidx.navigation.safeargs (version 1.0.0-alpha04) and that seems to change the version of the models to 3.2.0-beta03, causing the project to require an upgrade. If the plugin is removed from the project then the issue is gone. Can you confirm if the issue is gone after removing the plugin? I have attached a patch with the changes if needed.

[Deleted User] <[Deleted User]> #3Oct 20, 2020 07:19AM

So maybe this bug needs to be assigned to `androidx.navigation.safeargs` plugin team ?

ap...@google.com <ap...@google.com> #4Apr 6, 2021 10:13PM

We need to review this plugin and see what it does in general.

The fact that a non final plugin depend on a non final version of our plugin and breaks things is sad but not something we can solve easily on our end. (we need to have other plugin depend on a more stable API artifact rather than specific versions of our plugin.

il...@google.com <il...@google.com> #5Apr 6, 2021 10:17PM

Marked as fixed, reassigned to il...@google.com.

The source is available here:

https://android.googlesource.com/platform/frameworks/support/+/androidx-master-dev/navigation/safe-args-gradle-plugin/

ap...@google.com <ap...@google.com> #6Apr 12, 2021 11:58PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit d276ac5482afaf12a78ea357fffe40b2a7964301
Author: Daniel Santiago Rivera <danysantiago@google.com>
Date: Mon Oct 22 14:18:06 2018

Set fixed Android Gradle Plugin dependency version for SafeArgs.

Fixing the version makes it so that if the plugin is updated to a beta
or alpha version for frameworks/support we don't ship SafeArgs with
a non-stable dependency that can cause olders Android Studio versions
to reject syncing.

Bug: 113167627
Test: SafeArgs Tests
Change-Id: Id2de86e4ac724d6d812ea6bd383059737695e948

M buildSrc/src/main/kotlin/androidx/build/dependencies/Dependencies.kt
M navigation/safe-args-gradle-plugin/build.gradle

https://android-review.googlesource.com/798471

https://goto.google.com/android-sha1/d276ac5482afaf12a78ea357fffe40b2a7964301

Issue 171125856