Recycler view doesn't update item with livedata - android

I have a fragment where use creates a budget for a specific category like this:
Here is how it works: user adds a new budget item in NewBudgetFragment. That item gets displayed in BudgetFragment in recyclerview. Budget item has amountSpent variable that should be updated each time user adds a new transaction(this happens in another fragment). But after creating the budget item, if the user spends money on that specific category, the amountSpent doesn't get updated in the recyclerview item. I have used both LiveData and DiffUtil in the BudgetAdapter but I can't figure out why it doesn't get updated.
Here is BudgetAdapter:
class BudgetAdapter() : ListAdapter<Budget, BudgetAdapter.BudgetViewHolder>(DiffCallback()) {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BudgetViewHolder {
val binding =
BudgetItemLayoutBinding.inflate(LayoutInflater.from(parent.context), parent, false)
return BudgetViewHolder(binding)
}
override fun onBindViewHolder(holder: BudgetViewHolder, position: Int) {
val currentItem = getItem(position)
holder.bind(currentItem, position)
}
class BudgetViewHolder(val binding: BudgetItemLayoutBinding) :
RecyclerView.ViewHolder(binding.root) {
fun bind(budget: Budget, position: Int) {
binding.apply {
tvBudgetName.text = budget.name
tvBudgetLimit.text = budget.limit.toString()
tvAmountSpent.text = budget.amountSpent.toString()
tvPercentageSpent.text = ((budget.amountSpent/budget.limit)*100).toInt().toString() + "%"
}
}
}
class DiffCallback : DiffUtil.ItemCallback<Budget>() {
override fun areItemsTheSame(oldItem: Budget, newItem: Budget): Boolean {
return oldItem.id == newItem.id
}
override fun areContentsTheSame(oldItem: Budget, newItem: Budget): Boolean {
return oldItem == newItem
}
}
}
This is how new budget item gets created:
NewBudgetFragment:
...
viewModel.transactions.observe(viewLifecycleOwner) { it ->
transactionList = it.filter { it.category == listCategory[selectedCategoryIndex].name }
amountSpent = transactionList.sumOf { it.amount }
}
...
if (budgetName.isNotEmpty() && budgetLimit.isNotEmpty() && budgetCategory != null) {
viewModel.addBudget(
name = budgetName,
limit = budgetLimit.toDouble(),
amountSpent=amountSpent,
category = budgetCategory.name)
This is BudgetFragment.kt where the adapter is:
class BudgetFragment : Fragment(R.layout.fragment_budget),BudgetAdapter.OnItemClickListener {
private lateinit var binding: FragmentBudgetBinding
private val viewModel: SharedViewModel by activityViewModels()
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
binding = FragmentBudgetBinding.bind(view)
val budgetAdapter = BudgetAdapter(this)
val toolbar = binding.toolbar.root
toolbar.title = "Budget"
(requireActivity() as MainActivity).setSupportActionBar(toolbar)
binding.apply {
rvBudget.apply {
adapter = budgetAdapter
setHasFixedSize(true)
}
}
viewModel.budgets.observe(viewLifecycleOwner){
if(it.isNotEmpty()){
binding.rvBudget.visibility = View.VISIBLE
binding.tvNoBudget.visibility = View.INVISIBLE
}else{
binding.rvBudget.visibility = View.INVISIBLE
binding.tvNoBudget.visibility = View.VISIBLE
}
budgetAdapter.submitList(it)
}
binding.btAddBudget.setOnClickListener {
val action = BudgetFragmentDirections.actionBudgetFragmentToNewBudgetFragment()
findNavController().navigate(action)
}
}

Asuming that your Budget Class is a data class, then the content comparison should work, so we should not have any problems with the object itself that is being used by the Adapter and the DiffUtil.
But:
I can't see the ViewModel Code - are you submitting the same List Instance to the Adapter with submitList? For example, are you mutating the items in a private List in the ViewModel and posting the same List on the same Live Data everytime?
If yes, then this is probably the reason why the items in the RecyclerView are not being refreshed. You need to create a new Instance of the List, with the content of the old List and then post this on the LiveData.
Example ViewModel, if you don't want to override the behavior of "submitList" where you clear the previous data and add the new one and then call by yourself notifiyDatasetChanged()
class MyBudgetViewModel : ViewModel() {
// Important that its a data class, to actually have a content sensistive equals comparison
// if you don't have an ID, you have to work with list indexes when finding
// and updating this item
data class Budget(val id: Int, val amount: Double)
private val _budgets = MutableLiveData<List<Budget>>()
val budgets: LiveData<List<Budget>>
get() = _budgets
init {
_budgets.value = listOf(Budget(1, 20.0))
}
fun onBudgetChanged(id: Int, newBudget: Double) {
// depends on your setup and how you fill the initial list, this maybe should never be null
// by the time you call onBudgetChanged or something similar
val oldList = _budgets.value ?: emptyList()
// unused example variable - if you want to copy the list 1 by 1, ArrayList takes another list as Constructor
val newListUnchanged = ArrayList(oldList)
// map returns a new instance of the list.
val newList = oldList.map { oldItem ->
if (oldItem.id == id) {
oldItem.copy(amount = newBudget)
} else oldItem
}
_budgets.value = newList
}
}

Related

RecyclerView is not updated when an update occurs in Room

I have a RecyclerView where an item can be edited via a DialogFragment, so when an item is clicked a Dialog is shown, then I can change some properties of that item, the issue is that RecyclerView is not updated with the updated properties and I have to force a notifyItemChanged when the Dialog is closed.
When an item in RecyclerView is clicked I set a MutableLiveData in my ViewModel so then it can be manipulated in the Dialog.
My ViewModel looks like this:
#HiltViewModel
class DocumentProductsViewModel #Inject constructor(private val repository: DocumentProductsRepository) :
ViewModel() {
val barcode = MutableLiveData<String>()
private val _selectedProduct = MutableLiveData<DocumentProduct>()
val selectedProduct: LiveData<DocumentProduct> = _selectedProduct
private val _selectedDocumentId = MutableLiveData<Long>()
val selectedDocumentId: LiveData<Long> = _selectedDocumentId
val products: LiveData<List<DocumentProduct>> = _selectedDocumentId.switchMap { documentId ->
repository.getDocumentProducts(documentId).asLiveData()
}
fun insert(documentProduct: DocumentProduct) = viewModelScope.launch {
repository.insert(documentProduct)
}
fun setProductQuantity(quantity: Float) {
_selectedProduct.value = _selectedProduct.value.also {
it?.timestamp = System.currentTimeMillis()
it?.quantity = quantity
}
update()
}
fun start(documentId: Long?) = viewModelScope.launch{
if (documentId == null) {
_selectedDocumentId.value = repository.getHeaderByType("Etichette")?.id
}
documentId?.let { documentId ->
_selectedDocumentId.value = documentId
}
}
fun select(product: DocumentProduct) {
_selectedProduct.value = product
}
fun delete() = viewModelScope.launch {
_selectedProduct.value?.let { repository.delete(it) }
}
private fun update() = viewModelScope.launch {
_selectedProduct.value?.let { repository.update(it) }
}
}
And in my fragment I'm subscribed to products as this:
private fun initRecyclerView() {
binding.rvProducts.adapter = adapter
viewModel.products.observe(viewLifecycleOwner) { products ->
val productsCount = products.count()
binding.tvProductsCount.text =
resources.getQuantityString(R.plurals.articoli, productsCount, productsCount)
// TODO: create amount string and set it with resources
binding.tvProductsAmount.text = productsCount.toEuro()
adapter.submitList(products)
binding.rvProducts.smoothScrollToPosition(adapter.itemCount - 1)
}
initSwipe(adapter)
}
When setProductQuantity is called the RecyclerView remains unchanged until notify is called while delete works fine without the necessity of calling any notify on RecyclerView.
UPDATE:
The item position is actually changed in RecyclerView as it's sorted by it's last changed timestamp BUT not the quantity field.
Here is my Adapter:
class DocumentProductsListAdapter : ListAdapter<DocumentProduct, DocumentProductsListAdapter.ViewHolder>(ProductDiffCallback) {
override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ViewHolder {
val view: View = LayoutInflater.from(viewGroup.context)
.inflate(R.layout.layout_item, viewGroup, false)
return ViewHolder(view)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val product = getItem(position)
holder.bind(product)
}
class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
val barcode: TextView = itemView.findViewById(R.id.barcode)
val quantity: TextView = itemView.findViewById(R.id.quantity)
val description: TextView = itemView.findViewById(R.id.description)
val unitOfMeasure: TextView = itemView.findViewById(R.id.unitOfMeasure)
fun bind(product: DocumentProduct) {
barcode.text = product.barcode
quantity.text = product.quantity.formatForQta().replace(".", ",")
if (product.labelType != null && product.labelType != "") {
unitOfMeasure.text = product.labelType
} else {
unitOfMeasure.text = product.unitOfMeasure?.lowercase(Locale.ITALIAN)
}
description.text = product.description ?: "-"
}
}
}
object ProductDiffCallback : DiffUtil.ItemCallback<DocumentProduct>() {
override fun areItemsTheSame(oldItem: DocumentProduct, newItem: DocumentProduct): Boolean {
return oldItem.id == newItem.id
}
override fun areContentsTheSame(oldItem: DocumentProduct, newItem: DocumentProduct): Boolean {
return oldItem == newItem
}
}
data class DocumentProduct(
#PrimaryKey(autoGenerate = true)
var id: Long,
var barcode: String,
#Json(name = "desc")
var description: String?,
#ColumnInfo(defaultValue = "PZ")
#Json(name = "um")
var unitOfMeasure: String?,
#Json(name = "qta")
var quantity: Float,
#Json(name = "id_testata")
var documentId: Long,
#Json(name = "tipo_frontalino")
var labelType: String?,
var timestamp: Long?
) {
constructor(barcode: String, documentId: Long, labelType: String?) : this(
0,
barcode,
null,
"PZ",
1f,
documentId,
labelType,
null
)
override fun equals(other: Any?): Boolean {
return super.equals(other)
}
override fun hashCode(): Int {
return super.hashCode()
}
}
You have the implementations of areContentsTheSame() and areItemsTheSame() swapped.
areContentsTheSame() is asking if everything in the two items being compared is the same. Therefore, if the class has a proper equals()/hashcode() for all properties used by the ViewHolder, you can use oldItem == newItem. If you use a data class with all relevant properties in the primary constructor, then you don't need to manually override equals()/hashcode().
areItemsTheSame() is asking if the two items represent the same conceptual row item, with possible differences in their details. So it should be oldItem.id == newItem.id.
The problem with your data class is that you are overriding equals()/hashcode() without providing any implementation at all. This is effectively disabling the proper implementations that are provided by the data modifier by calling through to the super implementation in the Any class. You should not override them at all when you use data class.

Even if the address of the list changes, does the address value of the property remain the same?

Currently, I am making a task in Android that changes the unit value of the list according to the toggle button and shows the list with the changed value.
I am observing the list using a ViewModel and LiveData.
So i use toList() to return a new list and overwrite the old list to observe the values.
However, the screen is not updated even though it has returned a new list.
I've tried debugging and I'm getting some incomprehensible results.
Obviously, the address values ​​of the old list and the new list are different, but even the unit of the old list has changed.
What happened?
Even if the addresses of Lists are different, do the values ​​of the old list and the new list change at the same time because the properties refer to the same place?
I'll show you the minimal code.
Fragment
// Change Unit
toggleButton.addOnButtonCheckedListener { _, checkedId, isChecked ->
if(isChecked) {
when(checkedId) {
R.id.kg -> vm.changeUnit("kg")
R.id.lb -> vm.changeUnit("lbs")
}
}
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
vm.items.observe(viewLifecycleOwner) { newList ->
adapter.submitList(newList)
}
}
WorkoutSetInfo
#Entity(
foreignKeys = [
ForeignKey(
entity = Workout::class,
parentColumns = arrayOf("workoutId"),
childColumns = arrayOf("parentWorkoutId"),
onDelete = ForeignKey.CASCADE
)
]
)
data class WorkoutSetInfo(
#PrimaryKey(autoGenerate = true)
val id: Long = 0,
val set: Int,
var weight: String = "",
var reps: String = "",
var unit: String = "kg",
val parentWorkoutId: Long = 0
)
Adapter
class DetailAdapter
: ListAdapter<WorkoutSetInfo, DetailAdapter.ViewHolder>(DetailDiffCallback()) {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
return ViewHolder(
ItemRoutineDetailBinding.inflate(
LayoutInflater.from(parent.context),
parent,
false
)
)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bind(currentList[position])
}
inner class ViewHolder(val binding: ItemRoutineDetailBinding) : RecyclerView.ViewHolder(binding.root) {
private var weightTextWatcher: TextWatcher? = null
private var repTextWatcher: TextWatcher? = null
fun bind(item: WorkoutSetInfo) {
binding.set.text = item.set.toString()
binding.weight.removeTextChangedListener(weightTextWatcher)
binding.unit.text = item.unit
binding.rep.removeTextChangedListener(repTextWatcher)
weightTextWatcher = object : TextWatcher {
override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) { }
override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) { }
override fun afterTextChanged(w: Editable?) {
if(!binding.weight.hasFocus())
return
item.weight = w.toString()
}
}
repTextWatcher = object : TextWatcher {
override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) { }
override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) { }
override fun afterTextChanged(r: Editable?) {
if(!binding.rep.hasFocus())
return
item.reps = r.toString()
}
}
binding.apply {
weight.setTextIfDifferent(item.weight)
weight.addTextChangedListener(weightTextWatcher)
rep.setTextIfDifferent(item.reps)
rep.addTextChangedListener(repTextWatcher)
}
}
}
}
DiffUtil*
class DetailDiffCallback : DiffUtil.ItemCallback<WorkoutSetInfo>() {
override fun areItemsTheSame(
oldItem: WorkoutSetInfo,
newItem: WorkoutSetInfo
): Boolean {
return (oldItem.id == newItem.id)
}
override fun areContentsTheSame(
oldItem: WorkoutSetInfo,
newItem: WorkoutSetInfo
): Boolean {
return oldItem == newItem
}
}
ViewModel
class DetailViewModel(application: Application, title: String) : ViewModel() {
private val workoutDao = DetailDatabase.getDatabase(application)!!.workoutDao()
private val repository: WorkoutRepository = WorkoutRepository(workoutDao, title)
private val _items: MutableLiveData<List<WorkoutSetInfo>> = MutableLiveData()
val items = _items
fun changeUnit(unit: String) {
repository.changeUnit(unit)
_items.postValue(repository.getList())
}
fun addSet() {
viewModelScope.launch(Dispatchers.IO){
repository.add()
_items.postValue(repository.getList())
}
}
fun deleteSet() {
repository.delete()
_items.postValue(repository.getList())
}
fun save() {
viewModelScope.launch(Dispatchers.IO) {
repository.save()
}
}
}
Repository
class WorkoutRepository(private val workoutDao : WorkoutDao, title: String) {
private val workout = Workout(title = title)
private val setInfoList = ArrayList<WorkoutSetInfo>()
fun changeUnit(unit: String) {
setInfoList.map { setInfo ->
setInfo.unit = unit
}
}
fun add() {
val item = WorkoutSetInfo(set = setInfoList.size + 1)
setInfoList.add(item)
}
fun delete() {
if(setInfoList.size != 0)
setInfoList.removeLast()
return
}
fun save() {
val workoutId = workoutDao.insertWorkout(workout)
val newWorkoutSetInfoList = setInfoList.map { setInfo ->
setInfo.copy(parentWorkoutId = workoutId)
}
workoutDao.insertSetInfoList(newWorkoutSetInfoList)
}
fun getList() : List<WorkoutSetInfo> = setInfoList.toList()
}
You'd need to post your observer code for any help with why it's not updating.
As for the weird behaviour, setInfoList contains a few WorkoutSetInfo objects, right? Let's call them A, B and C. When you call setInfoList.toList() you're creating a new container, which holds the same references to objects A, B and C. Because it's a separate list, you can add and remove items without affecting the original list, but any changes to the objects that both share will be reflected in both lists - because they're both looking at the same thing.
So when you do setInfoList.map { setInfo -> setInfo.unit = unit } (which should be forEach really, map creates a new list you're discarding) you're modifying A, B and C. So every list you've made that contains those objects will see those changes, including your old list.
Basically if you want each list to be independent, when you modify the list you need to create new instances of the items, which means copying your WorkoutSetInfo objects to create new ones, instead of updating the current ones. If it's a data class then you can do that fairly easily (so long as you don't have nested objects that need copying themselves):
// var so we can replace it with a new list
private var setInfoList = listOf<WorkoutSetInfo>()
fun changeUnit(unit: String) {
// create a new list, copying each item with a change to the unit property
setInfoList = setInfoList.map { setInfo ->
setInfo.copy(unit = unit)
}
}
You don't need to do toList() on getList anymore, since you're just passing the current version of the list, and that list will never change (because you'll just create a new one). Meaning you don't need that function, you can just make setInfoList public - and because I changed it to listOf which creates an immutable List, it's safe to pass around because it can't be modified.
The WorkoutSetInfo objects inside that list could still be modified externally though (e.g. by changing one of the items' unit value), so instead of making a new copy when you call changeUnit, you might want to do it when you call getList instead:
class WorkoutRepository(private val workoutDao : WorkoutDao, title: String) {
private val workout = Workout(title = title)
private val setInfoList = ArrayList<WorkoutSetInfo>()
// store the current unit here
private var currentUnit = "kg"
fun changeUnit(unit: String) {
currentUnit = unit
}
// return new List
fun getList() : List<WorkoutSetInfo> = setInfoList.map { it.copy(unit = currentUnit) }
}
Now everything that calls getList gets a unique list with unique objects, so they're all separate from each other. And if you don't actually need to store the current unit value, you could pass it in to getList instead of having a changeUnit function:
fun getList(unit: String) = setInfoList.map { it.copy(unit = unit) }

RecyclerView only displaying correct data when using breakpoints

I am trying to make my RecylerView display data from a database, however the recyclerView displays nothing, unless i walk through the code with breakpoints, in which case it displays as expected. In the EssayPlanDialogFragment i inisialised an empty arrayList to store the essay lists which then has essayParagrpahs added to it either if the dialogFragemnt is called from the previous essayFragment, in which case the fillIn() function is called to turn database data into paragraphs or if the add paragraph is pressed to add a new empty paragraph. The breakpoint that seem to make it work is on the var paragraphList = ArrayList() and triggers 8 times before displaying the data
RecyclerView Adapter
class EssayPlanAdapter(): RecyclerView.Adapter<EssayPlanAdapter.ViewHolder>() {
var paragraphList = ArrayList<essayParagraph>()
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
var view = LayoutInflater.from(parent.context).inflate(R.layout.essay_paragraph_layout, parent, false)
return ViewHolder(view)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
///code
}
override fun getItemCount(): Int {
return paragraphList.size
}
fun setData(paragraph: ArrayList<essayParagraph>) {
this.paragraphList = paragraph
notifyDataSetChanged()
}
//more code ViewHolder Class and code help with adding essayPlan to databse
}
EssayPlanDialogFragment
class essayPlayDialogFragment(questionId:Int,fromEssay:Int): DialogFragment() {
var paragraphs = ArrayList<essayParagraph>()
var fromEssay = fromEssay
lateinit var introduction: LinearLayout
lateinit var title:EditText
var questionId = questionId
override fun onCreateView(){
//code
}
override fun onViewCreated(view: View, #Nullable savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val adapter = EssayPlanAdapter()
title = view.findViewById(R.id.essayTitle)
introduction = view.findViewById(R.id.introduction)
val viewModle = ViewModelProvider(this).get(essayViewModle::class.java)
val paragraphRecycler: RecyclerView = view.findViewById(R.id.essayPlanRecycler)
val closeBtn: ImageButton = view.findViewById(R.id.closeButton)
val finishBtn:ImageButton = view.findViewById(R.id.finnishButton)
//if Dialog fragment opened from previousEssays prafment fromEssay == 1, if from makeNewEssayPragment == 0
if (fromEssay == 1){
val essay = viewModle.checkId(questionId) //returns essay with aprriate essayId
paragraphRecycler.adapter = adapter
paragraphRecycler.layoutManager = LinearLayoutManager(requireContext())
var tempEssays = fillIn(essay,introduction)
adapter.setData(tempEssay)
}
else{
paragraphRecycler.adapter = adapter
paragraphRecycler.layoutManager = LinearLayoutManager(requireContext())
adapter.setData(paragraphs)
}
val button: Button = view.findViewById(R.id.addParagraph)
button.setOnClickListener(){
paragraphs.add(essayParagraph("","","",""))
adapter.setData(paragraphs)
}
finishBtn.setOnClickListener {
//add essay to database
}
fun constructEssayPlanData(adapter: EssayPlanAdapter,intro:LinearLayout,ID:Int):EssayPlan{
//make essayPlan to be added to database
}
fun fillIn(essay:EssayPlan,intro: LinearLayout): ArrayList<essayParagraph>{
intro.lineOfThought.setText(essay.LOT.toString())
intro.relaventPlot.setText(essay.intro.toString())
title.setText("TestTest")
var topicSentences = essay.topicSentences.split("+").toMutableList()
topicSentences.removeAt(0)
var firstQuotes = essay.firstQuotes.split("+").toMutableList()
firstQuotes.removeAt(0)
var secondQuotes = essay.SecondQuotes.split("+").toMutableList()
secondQuotes.removeAt(0)
var thirdQuotes = essay.ThirdQuotes.split("+").toMutableList()
thirdQuotes.removeAt(0)
for(i in 0..(essay.numParagraph -1)){
var essayTemp = essayParagraph(topicSentences[i],firstQuotes[i],secondQuotes[i],thirdQuotes[i])
paragraphs.add(essayTemp)
}
return paragraphs
}
}
ViewModel
fun checkId(id:Int):EssayPlan{
var essay = EssayPlan(id,"","","","","","","",0)
viewModelScope.launch(Dispatchers.IO) {
essay = repository.check(id)
}
return essay
}
repository
fun check(id:Int):EssayPlan{
var essayPlans: EssayPlan = essayPlanDao.checkExist(id)
return essayPlans
}
DAO
#Query("SELECT * FROM plans WHERE id == :id LIMIT 1")
fun checkExist(id:Int):EssayPlan

Implement SearchView inside recyclerview header

I wanted to add a SearchView to my recyclerview. I wanted it to be at the top and scrollable with the items. To achieve this, I created separate adapter for my header and it contains the Searchview as well. Then I used a ConcatAdapter to combine this header adapter with the contents below it.
Initially I want all the items to be visible under the SearchView from _onBoardingState which is a MutableStateFlow and when user searches for a tag then the results for it get added to _onSearch which is also a MutableStateFlow.
I have this MutableStateFlow, _onBoardingState inside my ViewModel that gets the value from Firestore in the init of ViewModel. The number of results is less (~ 20) so there is no pagination implemented and all items get loaded at once.
Now, whenever user wants to search an item by a tag, the SearchView returns a Flow of the typed value and also a Flow that updates about if the SearchView is still open or closed. I used these extension functions for this:
fun SearchView.getQueryTextChangeStateFlow(onSubmit: ()-> Unit): StateFlow<String> {
val query = MutableStateFlow("")
setOnQueryTextListener(object : SearchView.OnQueryTextListener {
override fun onQueryTextSubmit(query: String?): Boolean {
onSubmit()
return true
}
override fun onQueryTextChange(newText: String): Boolean {
query.value = newText
return true
}
})
return query
}
fun SearchView.getActiveStateFlow(): StateFlow<Boolean> {
val isOpen = MutableStateFlow(false)
setOnSearchClickListener {
isOpen.value = true
}
setOnCloseListener {
isOpen.value = false
false
}
return isOpen
}
Inside my ViewModel I have
...
private val _onBoardingState: MutableStateFlow<Model?> = MutableStateFlow(null)
private val _onSearch: MutableStateFlow<Model?> = MutableStateFlow(null)
private val _isActive: MutableStateFlow<Boolean> = MutableStateFlow(false)
fun toggleSearchViewState(isActive: Boolean) {
_isActive.value = isActive
}
val cuurentFlow: Flow<Model?> =
_isActive.flatMapLatest { isActive ->
if (isActive) {
_onSearch
} else {
_onBoardingState
}
}
...
Now the issue here is, whenever the recyclerview is scrolled down, the SearchView gets recycled and hence the setOnCloseListener gets called for it. This causes the _isActive value to be set to false by the Header's Adapter so the value of cuurentFlow gets toggled which should not be happening.
I thought of a solution as to set the setOnCloseListener of SearchView inside the header adapter's onViewRecycled() to null, but this didn't help. Below is code for my Header Adapter as well if needed.
class OnBoardingHeaderAdapter(
private val context: Context,
) : RecyclerView.Adapter<OnBoardingHeaderAdapter.HeaderViewHolder>() {
private var queryTextListener: ((StateFlow<String>) -> Unit)? = null
private var searchViewListener: ((StateFlow<Boolean>) -> Unit)? = null
inner class HeaderViewHolder(binding: OnboardingHeaderItemBinding) :
RecyclerView.ViewHolder(binding.root) {
private val root = binding.headerRoot
val search = binding.search
fun bind(headerMetaData: HeaderMetaData) {
root.visibility =
if (headerMetaData.shouldShow)
View.VISIBLE
else
View.GONE
val searchEditText: EditText =
search.findViewById(androidx.appcompat.R.id.search_src_text)
searchEditText.setHintTextColor(context.resources.getColor(R.color.white))
searchEditText.setTextColor(context.resources.getColor(R.color.white))
}
}
fun setQueryTextListener(listener: (StateFlow<String>) -> Unit) {
this.queryTextListener = listener
}
fun setSearchViewListener(listener: (StateFlow<Boolean>) -> Unit) {
this.searchViewListener = listener
}
private val RECYCLER_COMPARATOR = object : DiffUtil.ItemCallback<HeaderMetaData>() {
override fun areItemsTheSame(oldItem: HeaderMetaData, newItem: HeaderMetaData) =
oldItem.id == newItem.id
override fun areContentsTheSame(oldItem: HeaderMetaData, newItem: HeaderMetaData) =
oldItem == newItem
}
val headerDiffer = AsyncListDiffer(this, RECYCLER_COMPARATOR)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): HeaderViewHolder {
val binding = OnboardingHeaderItemBinding.inflate(
LayoutInflater.from(parent.context), parent, false
)
return HeaderViewHolder(binding)
}
override fun onBindViewHolder(holder: HeaderViewHolder, position: Int) {
//holder.setIsRecyclable(false)
if (position < 1) {
val header = headerDiffer.currentList[position]
holder.bind(header)
}
queryTextListener?.let {
it(holder.search.getQueryTextChangeStateFlow() {
val imm = context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
val view: View = holder.search
imm.hideSoftInputFromWindow(view.windowToken,0)
})
}
searchViewListener?.let {
it(holder.search.getActiveStateFlow())
}
}
override fun getItemCount(): Int = headerDiffer.currentList.size
override fun onViewRecycled(holder: HeaderViewHolder) {
super.onViewRecycled(holder)
holder.search.setOnCloseListener(null)
}
}
I wanted to know what is the best approach to solve this issue, I think even if i use a recyclerview with multiple view types here for the header then still the recycling issue will be there.

Realm query update not reflected in RealmRecyclerViewAdapter

Been using realm and it's awesome.
Came up against something. Wondering if I'm doing something wrong.
I have a RealmRecyclerViewAdapter that I'm using to show the results of a realm query. This works perfectly if I add or update records in the realm. I had to setHasFixedSize(false) on the recycler view to get it to update on the fly. Not sure if this is correct but it worked.
Anyway, that's not my issue.
I'm experimenting with filtering my data. I have the following query:
realm.where(Person::class.java).contains("name", nameFilter, Case.INSENSITIVE).findAllSorted("name")
I'm passing this RealmResults to my recycler view and it works great on add/update.
However, when I attempt a filter, it doesn't update automatically.
Am I right in saying that simply changing my filter (specified by nameFilter) isn't enough for the query to be re-run? This would be fair enough I suppose. Since I guess there's no trigger for realm to know I've changed the value of the string.
However, even if I recalculate my query, it doesn't seem to update in the Recycler View unless I explicitly call updateData on my adapter. I'm not sure if this is the best or most efficient way to do this. Is there a better way?
Complete Code:
Main Activity
class MainActivity : AppCompatActivity(), View.OnClickListener {
private val TAG: String = this::class.java.simpleName
private val realm: Realm = Realm.getInstance(RealmConfiguration.Builder().deleteRealmIfMigrationNeeded().build())
private var nameFilter = ""
private var allPersons: RealmResults<Person> = realm.where(Person::class.java).contains("name", nameFilter, Case.INSENSITIVE).findAllSorted("name")
private val adapter: PersonRecyclerViewAdapter = PersonRecyclerViewAdapter(allPersons)
private lateinit var disposable: Disposable
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
realm.executeTransaction({
// realm.deleteAll()
})
Log.i(TAG, "Deleted all objects from Realm")
buttonAddOrUpdatePerson.setOnClickListener(this)
setUpRecyclerView()
disposable = RxTextView.textChangeEvents(editTextNameFilter)
// .debounce(400, TimeUnit.MILLISECONDS) // default Scheduler is Computation
.observeOn(AndroidSchedulers.mainThread())
.subscribeWith<DisposableObserver<TextViewTextChangeEvent>>(getSearchObserver())
}
private fun getSearchObserver(): DisposableObserver<TextViewTextChangeEvent> {
return object : DisposableObserver<TextViewTextChangeEvent>() {
override fun onComplete() {
Log.i(TAG,"--------- onComplete")
}
override fun onError(e: Throwable) {
Log.i(TAG, "--------- Woops on error!")
}
override fun onNext(onTextChangeEvent: TextViewTextChangeEvent) {
nameFilter = editTextNameFilter.text.toString()
allPersons = realm.where(Person::class.java).contains("name", nameFilter, Case.INSENSITIVE).findAllSorted("name")
// this is necessary or the recycler view doesn't update
adapter.updateData(allPersons)
Log.d(TAG, "Filter: $nameFilter")
}
}
}
override fun onDestroy() {
super.onDestroy()
realm.close()
}
override fun onClick(view: View?) {
if(view == null) return
when(view) {
buttonAddOrUpdatePerson -> handleAddOrUpdatePerson()
}
}
private fun handleAddOrUpdatePerson() {
val personToAdd = Person()
personToAdd.name = editTextName.text.toString()
personToAdd.email = editTextEmail.text.toString()
realm.executeTransactionAsync({
bgRealm -> bgRealm.copyToRealmOrUpdate(personToAdd)
})
}
private fun setUpRecyclerView() {
recyclerViewPersons.layoutManager = LinearLayoutManager(this)
recyclerViewPersons.adapter = adapter
recyclerViewPersons.setHasFixedSize(false)
recyclerViewPersons.addItemDecoration(DividerItemDecoration(this, LinearLayoutManager.VERTICAL))
}
}
PersonRecyclerViewAdapter
internal class PersonRecyclerViewAdapter(data: OrderedRealmCollection<Person>?, autoUpdate: Boolean = true) : RealmRecyclerViewAdapter<Person, PersonRecyclerViewAdapter.PersonViewHolder>(data, autoUpdate) {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): PersonViewHolder {
val itemView = LayoutInflater.from(parent.context).inflate(R.layout.person_row, parent, false)
return PersonViewHolder(itemView)
}
override fun onBindViewHolder(holder: PersonViewHolder?, position: Int) {
if(holder == null || data == null) return
val personList = data ?: return
val person = personList[position]
holder.bind(person)
}
internal class PersonViewHolder(view: View) : RecyclerView.ViewHolder(view) {
var textViewName: TextView = view.findViewById(R.id.textViewNameDisplay)
var textViewEmail: TextView = view.findViewById(R.id.textViewEmailDisplay)
internal fun bind(person: Person) {
textViewEmail.text = person.email
textViewName.text = person.name
}
}
}
Yeah, updateData() is the way to do it. Since you updated the query, the Results you want to show becomes a different object. updateData() has to be called to notify the adapter that the data source is changed.
However, you may lose the nice animation for the RecyclerView in this way since the whole view will be refreshed because of the data source is changed. There are some ways to work around this.
eg.: You can add one field isSelected to Person. Query the results by isSelected field and pass it to the adaptor:
allPersons = realm.where(Person::class.java).equalTo("isSelected", true).findAllSorted("name")
adapter = PersonRecyclerViewAdapter(allPersons)
When changing the query:
realm.executeTransactionAsync({
var allPersons = realm.where(Person::class.java).equalTo("isSelected", true).findAllSorted("name")
for (person in allPersons) person.isSelected = false; // Clear the list first
allPersons = realm.where(Person::class.java).contains("name", nameFilter, Case.INSENSITIVE).findAllSorted("name") // new query
for (person in allPersons) person.isSelected = true;
})
It depends on your use case, if the list to show is long, this approach might be slow, you could try to add all the filtered person to a RealmList and set the RealmList as the data source of the adapter. RealmList.clear() is a fast opration than iterating the whole results set to set the isSelected field.
If the filter will mostly cause the whole view gets refreshed, updateData() is simply good enough, just use it then.

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