Hi! I stuck with one problem. I'm not sure if it i...

# mvikotlin

[bartosz.malkowski]

Hi! I stuck with one problem. I'm not sure if it is caused by Decompose or Compose Desktop, but I'm not able to reproduce it without router.

I have master-detail application. When I click on master menu item, then I replace ruter configuration:

when (menuItem) {
	is SideMenu.MenuItem.DirectChatMenuItem -> router.replaceCurrent(Configuration.Conversation(menuItem.chat.openChatId))
	else -> router.replaceCurrent(Configuration.Nothing)
}

Here is child factory:

private fun createChild(
	configuration: Configuration, componentContext: ComponentContext,
): Child = when (configuration) {
	is Configuration.Conversation -> Child.Chat(
		ConversationMainComponent(componentContext, configuration.chatId, storeFactory)
	)
	is Configuration.Nothing -> Child.WelcomeScreen
}

ConversationMainComponent contains TextField .

When I show ConversationMainComponent first time and I make text field focused, then everything works fine. When I switch to different DirectChatMenuItem what creates different ConversationMainComponent and then I try to focus text field, I see exception:

Exception in thread "AWT-EventQueue-0" kotlin.UninitializedPropertyAccessException: lateinit property relocationRequesterNode has not been initialized
	at androidx.compose.ui.layout.RelocationRequesterModifier.getRelocationRequesterNode(RelocationRequesterModifier.kt:32)
	at androidx.compose.ui.layout.RelocationRequester.bringIntoView(RelocationRequester.kt:61)
	at androidx.compose.ui.layout.RelocationRequester.bringIntoView$default(RelocationRequester.kt:59)
	at androidx.compose.foundation.FocusableKt$focusable$2$4$1.invokeSuspend(Focusable.kt:108)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
	at androidx.compose.ui.platform.FlushCoroutineDispatcher$dispatch$2.invokeSuspend(CoroutineDispatchers.desktop.kt:55)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
	at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:313)
	at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:770)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
	at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
	at java.base/java.security.AccessController.doPrivileged(Native Method)
	at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
	at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:740)
	at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
	at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
	at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

Funny is, that when I select one direct chat, make field focused, then I select something else (Child.WelcomeScreen) and I select direct chat again, then everything works fine.

Any advice? :-)

[Arkadii Ivanov]

Hello! To me it looks like the issue is in Compose for Desktop. I would try on of the fresh Compose versions, e.g. Decompose 0.4.0 and 1.0.0-alpha4-build348. If the issue is still there, then I suggest to file an issue to https://github.com/JetBrains/compose-jb/issues
Decompose does no magic here, I guess. Bu just in case, how the configurations are defined?

[bartosz.malkowski]

private val router = router<Configuration, Child>(
		key = "MainRouter",
		initialConfiguration = Configuration.Roster, handleBackButton = true, childFactory = ::createChild,
	)


	sealed class Configuration : Parcelable {

		@Parcelize
		object Nothing : Configuration()

		@Parcelize
		object Roster : Configuration()

		@Parcelize
		object Settings : Configuration()

		@Parcelize
		data class Conversation(val chatId: Long) : Configuration()
	}

[bartosz.malkowski]

It seems will be good if I prepare project to reproduce this error 🙂

[Arkadii Ivanov]

Looks perfectly fine. Yeah a reproducer would be good. Also you can start reducing the error by the following steps, check the error is still there after every step:
1. Remove the Children(animation=) argument, if set
2. Remove the Children function at all, and use just usual routerState.subscribeAsState() + when (...)
3. Remove the Router and use just usual State<Pair<Configuration, Child>> (if compose only) or StateFlow (otherwise), and replace configurations and components manually. If you need a back stack (seems like you don't, but still), then it should be State<List<Pair<Configuration, Child>>>.

[Arkadii Ivanov]

Regardless, I think the issue is in Compose for Desktop, it should not crash. Recently I experienced another crash with focusable input fields: https://github.com/JetBrains/compose-jb/issues/1157
Seems unrelated, but still, maybe try different versions of Compose.

[bartosz.malkowski]

https://github.com/bmalkow/compose-desktop-error-demo

[Arkadii Ivanov]

Thanks, I will try to check it today

[Arkadii Ivanov]

So it looks like a bug in Compose. Also reproduced in normal Jetpack Compose. Filed an issue: https://issuetracker.google.com/issues/203433629