IssueTracker

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

commit 8aea0fa4e7bed4d9dee1f03482328014e4dd86c2
Author: John Nichol <jnichol@google.com>
Date:   Fri Oct 21 17:21:35 2022

    Correct ScalingLazyListState.centerItemIndex calculation
   
    Change the calculation of centerItemIndex/centerItemOffset to ensure that the closest item to the center of the viewport is returned.
   
    The previous (incorrect) behaviour found the first items that had its itemEnd below the center line.
   
    As a result it was possible in some edge conditions for an items which sat just above the center line to be ignored and the first items below the center line to be selected - even it was further away from the center line.
   
    Bug: 254257769
    Test: ./gradlew :wear:compose:compose-material:connectedCheck --info --daemon
    Relnote: "We have corrected the calculation of `ScalingLazyListState.centerItemIndex/centerItemOffset` so that if two items sit either side of the viewport center line the one that is closest will be considered as the centerItem."
    Change-Id: I307091167e04914d1ae29d5324f84ec18ed7b8a8

M       wear/compose/compose-material/src/androidAndroidTest/kotlin/androidx/wear/compose/material/ScalingLazyListLayoutInfoTest.kt
M       wear/compose/compose-material/src/commonMain/kotlin/androidx/wear/compose/material/ScalingLazyListItemInfo.kt
M       wear/compose/compose-material/src/commonMain/kotlin/androidx/wear/compose/material/ScalingLazyListState.kt
M       wear/compose/integration-tests/demos/src/main/java/androidx/wear/compose/integration/demos/ScalingLazyColumnDemo.kt

https://android-review.googlesource.com/2263181

Hi,

Can you repro this bug locally?
> We don't have reproduce steps locally for this. We will let you know if we can manage to reproduce it consistently locally.

Does this happen on a specific Screen of yours, or on some, many, all?
> We don't know which screen this happens. We do see this crash happen very frequently among our beta users.

We use builder.build() in all the getTemplate() methods, can builder.build() ever return null? Do we need to do null check there and return a special screen?

In our code, we have  "getLifecycle().addObserver(this)" in all the screen constructors, like it is used in the sample apps, but, not doing removeObserver(this) anywhere. Could this be a problem? What is the best practice here? Is it necessary to do removeObserver? Perhaps in finalize()?

Are there any best practice on how the screen should be used that we perhaps missed?

Hope you have received the code Snippet I sent to N, if not, I can send to you directly.

Cheers!

Maybe a bit naive here, but, is it possibly to just do a null pointer check in your code?

Template template = XXX.getTemplate();

if (template !=null) {
 template.getClass()
} else {
 Log.E(TAG, "template should not be null")
}

Hi,  these following steps might help reproduce the issue:

Cheers!

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

commit 076857f2f01e8e30f8186cad44ce22192438073a
Author: Rafael Lima <therafael@google.com>
Date:   Thu Feb 25 23:28:48 2021

    Improvements to shutdown scenarios
   
    1. Do not send calls to app level callbacks if the app is not at least
    in created state
    2. Do not crash the app if the host is dead while trying to send an IPC
   
    Follow up review will stop dispatching calls from template related
    callbacks (i.e. onClick, etc)
   
    Relnote: "Improvements to not dispatch calls to app if its lifecycle is
    not at least in a created state"
    Test: Unit tests
    Bug:180530156
    Bug:179800224
    Bug:177921120
    Bug:178516889
   
    Change-Id: I8696503d1a9859411c4a52fa73d2852c8b3383d9

M       car/app/app-testing/src/main/java/androidx/car/app/testing/TestAppManager.java
M       car/app/app-testing/src/main/java/androidx/car/app/testing/TestCarContext.java
M       car/app/app-testing/src/main/java/androidx/car/app/testing/navigation/TestNavigationManager.java
M       car/app/app/src/main/java/androidx/car/app/AppManager.java
M       car/app/app/src/main/java/androidx/car/app/CarAppService.java
M       car/app/app/src/main/java/androidx/car/app/CarContext.java
M       car/app/app/src/main/java/androidx/car/app/HostDispatcher.java
M       car/app/app/src/main/java/androidx/car/app/ScreenManager.java
M       car/app/app/src/main/java/androidx/car/app/model/OnCheckedChangeDelegateImpl.java
M       car/app/app/src/main/java/androidx/car/app/model/OnClickDelegateImpl.java
M       car/app/app/src/main/java/androidx/car/app/model/OnItemVisibilityChangedDelegateImpl.java
M       car/app/app/src/main/java/androidx/car/app/model/OnSelectedDelegateImpl.java
M       car/app/app/src/main/java/androidx/car/app/model/SearchCallbackDelegateImpl.java
M       car/app/app/src/main/java/androidx/car/app/navigation/NavigationManager.java
M       car/app/app/src/main/java/androidx/car/app/utils/LogTags.java
M       car/app/app/src/main/java/androidx/car/app/utils/RemoteUtils.java
M       car/app/app/src/test/java/androidx/car/app/AppManagerTest.java
M       car/app/app/src/test/java/androidx/car/app/CarAppServiceTest.java
M       car/app/app/src/test/java/androidx/car/app/CarContextTest.java
M       car/app/app/src/test/java/androidx/car/app/HostDispatcherTest.java
M       car/app/app/src/test/java/androidx/car/app/navigation/NavigationManagerTest.java

https://android-review.googlesource.com/1607842