I try using `vectorXmlResource` but it fails with a NPE form

Question

I try using `vectorXmlResource` but it fails with a NPE form `openResourceStream` I guess my problem comes from my Gradle configuration not packaging my assets in the final Jar file but I don t know how to fix that Any clue `desktop app src main kotlin` for the source code `desktop app src main resources` for the assets I put an `icons ` dir within `resources ` which contains my Android Vector drawables and then I use `vectorXmlResource icons ic settings xml `

Olivier Patry · Answer

`desktop app build gradle kts` ```import org jetbrains compose compose import org jetbrains kotlin gradle tasks KotlinCompile plugins kotlin jvm id org jetbrains compose application group = org acme version = 1 0 0 dependencies implementation compose desktop currentOs tasks withType lt KotlinCompile gt kotlinOptions jvmTarget = 1 8 application mainClass set MainKt ```

Olivier Patry · Answer

Android Studio properly sees the `resources ` dir as an assets directory

Igor Demin · Answer

Can you attach a project with a minimal reproducer I checked xml resources work in <https github com JetBrains compose jb tree master templates desktop template|this> template Configuration is the same as you described

Olivier Patry · Answer

I started a project from scratch close to my setup and it works I ll dig from here to understand the diff

Olivier Patry · Answer

It s madness with the toy project everything works like a charm I managed to make it working in my app but it s totally RANDOM It seems `Modifier size 48 dp ` make the crash easier but even without that I have random crashes If Iaunch it several times in sequence

Olivier Patry · Answer

In fact it s as random with or without `Modifier size 48 dp `

Igor Demin · Answer

We use `Thread currentThread contextClassLoader` Maybe something somewhere overrides it Try to call this before `vectorXmlResource` ```Thread currentThread contextClassLoader = ClassLoader getSystemClassLoader ``` just to be sure that this is because of `contextClassLoader`

Olivier Patry · Answer

Yes you found it

Olivier Patry · Answer

It s now 100 reliable

Olivier Patry · Answer

I m surprised Compose runtime is multithreaded

Olivier Patry · Answer

Do you consider this as a bug on Compose side or should I manage this on my side

Igor Demin · Answer

gt I m surprised Compose runtime is multithreaded It is single threaded for now but there are plans to make it multi threaded gt this as a bug on Compose side or should I manage this on my side I think we can replace `Thread currentThread contextClassLoader` by `ClassLoader getSystemClassLoader ` in Compose we just need to be sure that everything will work as before You also can manage this on your side if somewhere in your code `contextClassLoader` is changed Usually we need to override `contextClassLoader` only for some part of the code and then revert it ``` val contextClassLoader = Thread currentThread contextClassLoader try Thread currentThread contextClassLoader = finally Thread currentThread contextClassLoader = contextClassLoader ``` Things get complicated if some third party library changes it and forgets to revert

Olivier Patry · Answer

So something I don t understand is If Compose is monothreaded why did I have random failure I don t tweak any classloaders

Olivier Patry · Answer

What I do though is launching asynchronous work using `Executors newSingleThreadExecutor ` but all of this is wrapped using `suspendCoroutine ` In other circumstances such background tasks invokes callback on their thread which I delegate to a view model class which itself updates a `MutableStateFlow` with `MainScope` coroutine scope ``` private val viewModelScope CoroutineScope = MainScope private val collections = MutableStateFlow lt LibraryState gt LibraryState Unloaded val collections Flow lt LibraryState gt get = collections something called from background viewModelScope launch context = Dispatchers Main collections value = LibraryState Updated collectionModels ``` Then on compose side ```val state by libraryViewModel collections collectAsState LibraryState Unloaded ``` So maybe this setup leads to odd behavior

Olivier Patry · Answer

I can t apply you suggestion with the try finally gt Try catch is not supported around composable function invocations I ll do it another way

Olivier Patry · Answer

I might have another lead for the root cause of the issue The code I mentioned which triggers the data update triggering `collectAsState` recomposition comes from a native library I know on Android there are some oddities with class loaders and JNI for threads created from native side Maybe it s something linked to this too on desktop

Igor Demin · Answer

gt Maybe it s something linked to this too on desktop Yes threads created from native side have no `contextClassLoader` Do you control the code which is called from native side You can call `Thread currentThread contextClassLoader = ClassLoader getSystemClassLoader ` there not in Composable function

Olivier Patry · Answer

Given that I have a custom `icon` helper I ll do the trick here for now There are to much code being called from native callbacks right now Thanks +1