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

Could you attach a video of this happening ?

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

I'll try to get more details, but wanted to bring it up at least.

Please specify your OS, CPU, GPU, the emulator version, the system image you use and how your start the emulator (standalone or embedded into AS).

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

I'm experiencing same issue. It happened randomly, the most often it froze after I resized the emulator window.
I'm on Macbook Pro M2 Max, MacOS Sonoma 14.1.1, Android Studio Iguana 2023.2.1 Canary 14.
I opened the emulator through the Device Manager and use the floating window emulator (not docked).
Screen record attached. The easiest way to reproduce is by resizing or zooming in/out the emulator.

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

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

Hi okynk91, thank you for screen recording, we will investigate. I see you run the emulator in the AS window. Could you please try running it in its own window (see the attached screenshot)?

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

#5 Hi, It seems working fine when it's running in its own window. It doesn't have the zoom in/out buttons, I couldn't reproduce the issue. Resizing the window seems working without issue.

Issue 171125856