Hey! I am trying to update an `AndroidView` based ...

# compose

[Paulo Martins]

Hey! I am trying to update an AndroidView based on my CustomViewModel changes.

@Composable
fun FilamentViewer(viewModel: CustomViewModel) {
    var modelViewer by remember { mutableStateOf<ModelViewer?>(null) }

    launchInComposition {
        while (true) {
            withFrameNanos { frameTimeNanos ->
                modelViewer?.render(frameTimeNanos)
            }
        }
    }

    AndroidView({ context ->
        LayoutInflater.from(context).inflate(
            R.layout.filament_host, FrameLayout(context), false
        ).apply {
            val (engine) = scenes[product.material]!!
            modelViewer = ModelViewer(engine, this as SurfaceView).also {
                setupModelViewer(it)
            }
        }
    })
}

how can I make it change dynamically? I need to update the modelViewer.scene entity

[Zach Klippenstein (he/him) [MOD]]

Which version of compose are you using? I thought launchInComposition was from over a year ago

[Zach Klippenstein (he/him) [MOD]]

AndroidView takes two function parameters: the first one creates the view, and is only called the first time the call is composed, the second one updates the view and is called on every composition (including the first one).

[Paulo Martins]

I was using a Filament project as reference

[Paulo Martins]

If I remove

launchInComposition {
        while (true) {
            withFrameNanos { frameTimeNanos ->
                modelViewer?.render(frameTimeNanos)
            }
        }
    }

it won't render

[Zach Klippenstein (he/him) [MOD]]

I don’t know what compose version filament uses, but I would recommend upgrading to at least 1.0.2 before trying to go any further.

[Zach Klippenstein (he/him) [MOD]]

launchInComposition is now called LaunchedEffect.

[Paulo Martins]

Updating it

[Антон X]

Btw, should we wrap creation of our AndroidViews into compose state { TextView(...) } ? I've seen some example on codelab where it's used.

[Paulo Martins]

Already upgraded every library and using LaunchedEffect. Result is the same. If I delete line

modelViewer?.render(frameTimeNanos)

It won't render nothing

[Zach Klippenstein (he/him) [MOD]]

That makes sense, if your view model requires that method to be called – i never said anything about removing that line. I don't know how Filament expects to get updates, but the general pattern for using AndroidView looks something like this:

AndroidView(
  // This function is only called once.
  factory = { context ->
    LayoutInflater.from(context)
      .inflate(…)
      .apply {
        // Initialize view.
      }
  },
  // This function is called on every composition.
  update = { view ->
    // Set view properties that can change based on the
    // current composition (e.g. read State values,
    // parameters to your composable, etc.)
  }
)

[Paulo Martins]

Will update block be executed when my viewModel is updated?

[Zach Klippenstein (he/him) [MOD]]

If you read the viewModel state in the update function, then yes. See these docs for more info: https://developer.android.com/jetpack/compose/interop/interop-apis