Jetpack compose not recomposing view on value change - kotlin

Question

I am using objectbox and attempting to force recomp on my lazy column with information from the viewModel.
I currently use a method that has been state hoisted to the view model but can't seem to retrieve the value in the view model and force recomp.
In my view model (DataFieldsViewModel), I've obtained all the Data Fields like this:
private val _dataFieldsBox = ObjectBox.get().boxFor(DataField::class.java)
var dataFieldsBox: Box<DataField> = _dataFieldsBox
and then it is passed in the composable screen using
fields = viewModel.dataFieldsBox
and the data fields object removed with
is DataFieldEvent.ConfirmDelete -> {
_deletedDataField.value = event.dataField
_dataFieldsBox.remove(deletedDataField.value)
}
the reference for deletedDataField is kept so that it can be restored from a snack bar.
The delete works, the restore works, it's just that the lazy column does not update until I click another view that forces recomp. I've even mocked up a simple button with state hoisted increment and decrement methods and a value in the view model to test out recomp and got that working pretty quick, just don't know how to do it for these ObjectBox DataField objects
Edit 18/08
Tried using mutableStateOf
private var _dataFieldsBox = ObjectBox.get().boxFor(DataField::class.java)
var dataFieldsBox = mutableStateOf(_dataFieldsBox)
and then attempting to collect the value with
val fields by viewModel.dataFieldsBox
and then deleting with
_deletedDataField.value = event.dataField
_dataFieldsBox.remove(event.dataField)
only fix right now is the two hacky ways which i don't like. I read something about despite the values in a mutable list changing because the reference is the same the recomp doesn't happen to save on recomps.
So tried to amend the list and then duplicate with new values which also did nothing.
is DataFieldEvent.ConfirmDelete -> {
_deletedDataField.value = event.dataField
_dataFieldsBox.remove(event.dataField)
val newList = _dataFieldsBox
dataFieldsBox = mutableStateOf(newList)
}

Answer 1

Would be helpful if you update viewmodel code you are having.
Not worked on ObjectBox. With your current code, here is the thing.
Composable function will recompose when it is able to listen to changes. For normal variable it does not listen to changes. You can make them listen in several ways.
You can do it with mutableStateOf(). You can have mutableState variable which takes type of _dataFieldsBox . And so can access it by viewModel._dataFieldsBox.value.
private val _dataFieldsBox = ObjectBox.get().boxFor(DataField::class.java
var _dataFieldsBox = mutableStateOf(_dataFieldsBox)
And then in view model,
_dataFieldsBox.value.remove(_dataFieldsBox) // This will remove the value in the state variable and composable function will recompose.
You can also use LiveData and observe for the changes and it will recompose.