Viewmodel function error

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1

Hi hivemind,

I’m trying to use a slider as input for a simplified function using a Viewmodel (to get the hang of proper MVVM architecture) but I’m getting ‘type mismatch’ and ‘no value passed’ errors - any ideas?

The function takes the float output of the slider (sliderP1) inverts it, and displays the output on the screen (cog).

MainScreen(
    sliderP1 = viewModel.sliderP1,
    onValueChange = {viewModel.sliderP1 = it},
    onValueChangeFinished = {},
    cog = viewModel.cog,
    calcs = {viewModel.calcs()}

)
}

@Composable
// builds UI
fun MainScreen(
    modifier: Modifier = Modifier,
    sliderP1: Float,
    onValueChange: (Float) -> Unit,
    onValueChangeFinished: () -> Unit,
    calcs:(Float) -> Unit,
    cog: Float
)

{
    Column(modifier = Modifier
        .fillMaxSize()
        .padding(20.dp),
        horizontalAlignment = Alignment.Start
    ) {

        Slider(
            value = sliderP1,
            onValueChange = onValueChange,
            onValueChangeFinished = calcs(),
            valueRange = 0f..10f
        )

        Text(text = "Raw slider value: $sliderP1")
        Spacer(modifier = Modifier.height(20.dp))
        Text(text = "Function output: $cog", modifier = Modifier.background(Color.Yellow))

    }

}

and my ViewModel:

class COGViewModel: ViewModel() {
    var sliderP1 by mutableStateOf(0f)
    var cog by mutableStateOf(0f) // result

    fun calcs(): Float {
        cog = sliderP1*-1
        return cog
    }
}