(FormInputContainer) ShoppingListScreen.kt

@Composable
fun FormInputContainer(
    onAddItem: (ShoppingItem) -> Unit
) {
    var newItem by remember { mutableStateOf("") }
    val focusManager = LocalFocusManager.current

    Row(
        modifier = Modifier
            .fillMaxWidth(1f)
            .height(IntrinsicSize.Min)
            .padding(8.dp)
    ) {
        // Field input
        TextField(
            label = { Text("Item belanja baru") },
            singleLine = true,
            onValueChange = { newItem = it },
            value = newItem
        )

        // Margin / spacer
        Spacer(modifier = Modifier.width(8.dp))

        // Button add item
        Button(
            enabled = newItem.isNotBlank(),
            onClick = {
                onAddItem(ShoppingItem(name = newItem))
                newItem = ""
                focusManager.clearFocus()
            },
            modifier = Modifier.fillMaxHeight()
        ) {
            Text(text = "Tambah")
        }
    }
}