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

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

commit c60f33e229e31ab328ef6b59dab63b264954831c
Author: Alexandre Elias <aelias@google.com>
Date: Fri Jul 10 16:23:09 2020

Semantics no-op cleanups

Partly in response to lmr's broad code review, I did a pass of
superficial API/implementation cleanup. The main changes are:

- I changed each Boolean SemanticsProperty where false is equivalent to
not being present to take "Unit" instead. This is conceptually
clearer: it avoids questions like "can I cancel out a semantics from a
merged child by setting it to false?" Because "property = Unit" looks
weird, I also changed the style of these to "property()".

- I moved the Semantics id generator closer to where it's used, in
SemanticsModifierCore. I made it internal and an AtomicInt.
(Note that integer ids are heavily used in the Android
AccessibilityNodeInfo APIs so I can't simply remove them entirely.)

- I deleted dead code. Some examples include SemanticsHintOverrides,
a public API not connected to anything, and SemanticsPropertyKey
merge() open method which is never called. (In both cases I have
a different plan in mind for accessibility.)

Fixes: 145951226
Fixes: 145955412
Test: existing tests
Relnote: "Single-value semantics properties now use a calling style.
For example, 'semantics { hidden = true }' is now written as:
'semantics { hidden() }'."

Change-Id: Ic1afd12ea22c926babc9662f1804d80b33aa0cfc

M ui/integration-tests/benchmark/src/androidTest/java/androidx/ui/benchmark/test/LayoutNodeModifierBenchmark.kt
M ui/ui-core/api/0.1.0-dev15.txt
M ui/ui-core/api/current.txt
M ui/ui-core/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-core/api/public_plus_experimental_current.txt
M ui/ui-core/api/restricted_0.1.0-dev15.txt
M ui/ui-core/api/restricted_current.txt
M ui/ui-core/src/androidAndroidTest/kotlin/androidx/ui/graphics/vector/VectorTest.kt
M ui/ui-core/src/androidAndroidTest/kotlin/androidx/ui/semantics/SemanticsTests.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidActuals.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidComposeView.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidComposeViewAccessibilityDelegateCompat.kt
M ui/ui-core/src/androidMain/kotlin/androidx/ui/core/AndroidPopup.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/Expect.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsConfiguration.kt
D ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsHintOverrides.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsModifier.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsNode.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsOwner.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/core/semantics/SemanticsWrapper.kt
M ui/ui-core/src/commonMain/kotlin/androidx/ui/semantics/SemanticsProperties.kt
M ui/ui-foundation/api/0.1.0-dev15.txt
M ui/ui-foundation/api/current.txt
M ui/ui-foundation/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-foundation/api/public_plus_experimental_current.txt
M ui/ui-foundation/api/restricted_0.1.0-dev15.txt
M ui/ui-foundation/api/restricted_current.txt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Clickable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Dialog.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/Scroller.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/selection/Selectable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/selection/Toggleable.kt
M ui/ui-foundation/src/main/java/androidx/ui/foundation/semantics/FoundationSemanticsProperties.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ButtonTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/CardTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/CheckboxScreenshotTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/RadioButtonScreenshotTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ScaffoldTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/SnackbarTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/SurfaceTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/ripple/RippleIndicationTest.kt
M ui/ui-material/src/androidTest/java/androidx/ui/material/textfield/TextFieldScreenshotTest.kt
M ui/ui-material/src/main/java/androidx/ui/material/AppBar.kt
M ui/ui-material/src/main/java/androidx/ui/material/TextFieldImpl.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/AssertsTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/CallSemanticsActionTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/ErrorMessagesTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/FindersTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/PrintToStringTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/ScrollToTest.kt
M ui/ui-test/src/androidTest/java/androidx/ui/test/TextActionsTest.kt
M ui/ui-test/src/main/java/androidx/ui/test/Actions.kt
M ui/ui-test/src/main/java/androidx/ui/test/Filters.kt
M ui/ui-text/api/0.1.0-dev15.txt
M ui/ui-text/api/current.txt
M ui/ui-text/api/public_plus_experimental_0.1.0-dev15.txt
M ui/ui-text/api/public_plus_experimental_current.txt
M ui/ui-text/api/restricted_0.1.0-dev15.txt
M ui/ui-text/api/restricted_current.txt
M ui/ui-text/src/commonMain/kotlin/androidx/ui/text/CoreTextField.kt
M ui/ui-text/src/commonMain/kotlin/androidx/ui/text/TextSemanticsProperties.kt

https://android-review.googlesource.com/1360099

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

Thanks! Somehow I've missed that.

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

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

commit 76230d4cbcf193ad3c01e2fb317a1bb3c571b1de
Author: Ian Lake <ilake@google.com>
Date: Tue Apr 06 12:53:25 2021

Mark navigate/setGraph as @MainThread

With the upgrade to Lifecycle 2.3.1,
Lifecycle now enforces that all creation and
changes to the Lifecycle state (including adding
and removing observers) should be done on the
main thread.

By marking navigate() and setGraph() as
`@MainThread`, we can give developeres better
visibility that these operations should only
be done on the main thread.

Relnote: "Navigation now depends on
[Lifecycle `2.3.1`](/jetpack/androidx/releases/lifecycle#2.3.1)
and now marks `setGraph()` and `navigate()`, the
methods that update the `NavBackStackEntry` `Lifecycle`,
as `@MainThread`, aligning Navigation with the main thread
enforcement introduced in Lifecycle `2.3.0`."
Test: existing and updated tests pass
BUG: 171125856

Change-Id: Ifcbe407d9cb186b50f05cbbd8bc5e11e19115a82

M navigation/navigation-dynamic-features-fragment/src/androidTest/java/androidx/navigation/dynamicfeatures/fragment/DynamicNavHostFragmentTest.kt
M navigation/navigation-runtime/api/current.txt
M navigation/navigation-runtime/api/public_plus_experimental_current.txt
M navigation/navigation-runtime/api/restricted_current.txt
M navigation/navigation-runtime/build.gradle
M navigation/navigation-runtime/src/main/java/androidx/navigation/NavController.kt

https://android-review.googlesource.com/1665821

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

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

For the upcoming Navigation 2.4.0-alpha01 release, we've made it explicit that setGraph() and navigate() should only be called on the main thread (by adding @MainThread annotations to the methods), thus aligning with the main thread enforcement of Lifecycle 2.3.

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

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

commit 00c608a86c44b066198bd8c1dc7e2aef6088d4e1
Author: Ian Lake <ilake@google.com>
Date: Mon Apr 12 14:04:54 2021

Mark popBackStack and navigateUp as @MainThread

In addition to the navigate() and setGraph()
methods updated in

https://android-review.googlesource.com/1665821
the methods for popping the back stack
should also be marked as @MainThread.

Relnote: "Navigation now depends on
[Lifecycle `2.3.1`](/jetpack/androidx/releases/lifecycle#2.3.1)
and now marks all of the methods that update the
`NavBackStackEntry` `Lifecycle`, including `setGraph()`,
`navigate()`, `popBackStack()`, and `navigateUp()`,
as `@MainThread`, aligning Navigation with the main thread
enforcement introduced in Lifecycle `2.3.0`."
Test: existing and updated tests pass
BUG: 171125856

Change-Id: Ib8bedbb3fe384b28c7441cbd57a0751eba307a2b

M navigation/navigation-runtime/api/current.txt
M navigation/navigation-runtime/api/public_plus_experimental_current.txt
M navigation/navigation-runtime/api/restricted_current.txt
M navigation/navigation-runtime/src/main/java/androidx/navigation/NavController.kt

https://android-review.googlesource.com/1673448

Issue 171125856