CardsViewModelStart.kt

class CardsViewModel : ViewModel() {

    private val _cards = MutableStateFlow(listOf<ExpandableCardModel>())
    val cards: StateFlow<List<ExpandableCardModel>> get() = _cards

    private val _expandedCardIdsList = MutableStateFlow(listOf<Int>())
    val expandedCardIdsList: StateFlow<List<Int>> get() = _expandedCardIdsList

    init {
        getFakeData()
    }

    private fun getFakeData() {
        viewModelScope.launch {
            withContext(Dispatchers.Default) {
                val testList = arrayListOf<ExpandableCardModel>()
                repeat(20) { testList += ExpandableCardModel(id = it, title = "Card $it") }
                _cards.emit(testList)
            }
        }
    }

    fun onCardArrowClicked(cardId: Int) {
        _expandedCardIdsList.value = _expandedCardIdsList.value.toMutableList().also { list ->
            if (list.contains(cardId)) list.remove(cardId) else list.add(cardId)
        }
    }
}