Why my composable not recomposing on changing value for MutableState of HashMap?

Question

Why my composable not recomposing on changing value for MutableState of HashMap.

ViewModel

 val imageList: MutableState<HashMap<Int, Uri>> = mutableStateOf(HashMap())
    fun setImage(imageUri: Uri) {
        imageList.value[imagePosition] = imageUri
    }

Fragment

if (viewModel.imageList.value[stepNo] != null && !TextUtils.isEmpty(
                                            viewModel.imageList.value[stepNo].toString()
                                        )
                                    ) {
                                        Image(
                                            contentDescription = "Recipe",
                                            painter = painterResource(R.drawable.ic_baseline_fastfood_24),
                                            modifier = Modifier
                                                .padding(8.dp)
                                        )
                                    }

fun permissionCallbacks() {
        imagePickerListener =
            registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
                if (result.resultCode == Activity.RESULT_OK) {
                    // There are no request codes
                    val data: Intent? = result.data
                    val selectedImageUri = data?.data
                    selectedImageUri?.let { viewModel.setImage(it) }
                }
            }
        requestPermissionLauncher =
            registerForActivityResult(
                ActivityResultContracts.RequestPermission()
            ) { isGranted: Boolean ->
                if (isGranted) {
                    val galleryIntent = Intent(
                        Intent.ACTION_PICK,
                        MediaStore.Images.Media.EXTERNAL_CONTENT_URI
                    )
                    galleryIntent.type = "image/*"
                    imagePickerListener?.launch(galleryIntent)
                } else {
                   
                }
            }
    }

I see by debugging that value correctly set inside setImage() method but if condition for viewModel.imageList.value[stepNo] is not called again when value for hashmap is changed.

Answer 1

mutableStateOf can only track when you replace one value with an other one. If you change state of current value no way it can handle it

You can use mutableStateMapOf instead of mutableStateOf(HashMap()):

val imageList = mutableStateMapOf<Int, Uri>()
---
fun setImage(imageUri: Uri) {
    imageList[imagePosition] = imageUri
}

Answer 2

Use SnapshotStateMap instead of HashMap: