Develop Reference

Android Spinner - Differentiate manually and programmatically selection

I am looking for a way to differentiate selection type in OnItemSelectedListener of Spinner between manual selection by tapping and by setSelection(pos)
i tried by this, but no success
binding.spinner.onItemSelectedListener = object : OnItemSelectedListener {
override fun onItemSelected(
adapterView: AdapterView<*>,
view: View?,
position: Int,
id: Long
) {
if (adapterView.isPressed) {
Toast.makeText(this#SplashActivity, "Manually", Toast.LENGTH_SHORT).show()
} else {
Toast.makeText(this#SplashActivity, "Programmatically", Toast.LENGTH_SHORT)
.show()
}
}
For reference, similar functionality is already provided by Checkbox, and it is working perfectly for checkboxes
binding.checkbox.setOnCheckedChangeListener { compoundButton, bool ->
if (compoundButton.isPressed) {
//manually
Toast.makeText(this, "Manually", Toast.LENGTH_SHORT).show()
} else {
//Programmatically
Toast.makeText(this, "Programmatically", Toast.LENGTH_SHORT).show()
}
}

Popup menu when Item in list view is clicked

I am stuck trying to figure out how to make a popup menu appear when an Item in a list view is selected. I have attempted to put together various code segments together and a few different methods but this is what I have at the moment.
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.test)
val textView = findViewById<TextView>(R.id.textView)
var tl = arrayOf("a","a","a","a","a")
val listview = findViewById<ListView>(R.id.tlist)
val adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, tl)
listview.adapter = adapter
listview.onItemClickListener = object : OnItemClickListener{
override fun onItemClick(
parent: AdapterView<*>?,
view: View?,
position: Int,
id: Long
)
{
val listPopupmenu = View(tl+[position])
val showPopUp = PopupMenu(
this,
listPopupmenu
)
showPopUp.setOnMenuItemClickListener { menuItem ->
val id = menuItem.itemId
if (id == 0) {
textView.text = "Item 0"
} else if (id == 1) {
textView.text = "Item 1"
} else if (id == 2) {
textView.text = "Item 2"
} else if (id == 3) {
textView.text = "Item 3"
}
false
}
showPopUp.menu.add(Menu.NONE, 0, 0, "Item 0")
showPopUp.menu.add(Menu.NONE, 1, 1, "Item 1")
showPopUp.menu.add(Menu.NONE, 2, 2, "Item 2")
showPopUp.menu.add(Menu.NONE, 3, 3, "Item 3")
listPopupmenu.setOnClickListener {
showPopUp.show()
}
Toast.makeText(applicationContext, "${textView} was clicked", Toast.LENGTH_SHORT).show()
}
}
}
}
I am trying to make it so that when you select an item on the list, it has a drop down window with options. Then when you select an option it pops up at the bottom letting you know that option has been selected.
I can do the list bit and make it so that when you click a item on the list it appears at the bottom saying that item was clicked, I can also do the drop down menu when you click a button. When I put it together however it doesn't work and just crashes. Can someone help me out? Or at least let me know if my code is heading in the right direction? It would be very much appreciated!

What to return in this recursive method?

I'm creating a method to recursively search for a View inside an ArrayList. It will loop through this ArrayList and, if it contains an ArrayList, it will be searched for Views too, and so on, until finding a View to return. This is so I can make whatever View is inside there invisible.
fun searchForView(arrayList: ArrayList<*>): View {
arrayList.forEach { item ->
if (item is View) {
return item
} else if (item is ArrayList<*>) {
item.forEach {
searchForView(it as ArrayList<*>)
}
}
}
} // Error here, needs to return a View
So I will use it like this:
someArrayList.forEach {
searchForView(someArrayList).visibility = View.INVISIBLE
}
However it is giving me an error because there needs to be a return someView statement near the end of the method. Whenever I call it, the ArrayList being searched will always have a View. So what should I be returning here at the end, knowing that whatever View found will already be returned?

You can set inside function and don't return anything
fun searchForView(arrayList: ArrayList<*>){
arrayList.forEach { item ->
if (item is View) {
item.visibility = View.INVISIBLE // set here
} else if (item is ArrayList<*>) {
item.forEach {
searchForView(it as ArrayList<*>)
}
}
}
}
You should use searchForView(item) instead of item.forEach { searchForView(it as ArrayList<*>) } as #IR42 suggested since you don't know each item in arraylist is an arraylist or not.

Your function is not compileable because it's supposed to return a View, but you aren't returning a View in the else branch or if you reach the end of the input list without finding a View.
However, if all this function does is return a View, then it is not usable for your requirement to set all views' visibility. It would only return a single View.
Instead, you can pass a function argument for what to do to each view it finds. There's no need to return anything.
fun ArrayList<*>.forEachViewDeep(block: (View) -> Unit) {
for (item in this) when (item) {
is View -> block(item)
is ArrayList<*> -> item.forEachViewDeep(block)
}
}
And use it like:
someArrayList.forEachViewDeep {
it.visibility = View.INVISIBLE
}
If it's very deeply nested, you might want to rearrange this function to be tail-recursive like this:
tailrec fun List<*>.forEachViewDeep(block: (View) -> Unit) {
for (item in this) {
if (item is View)
block(item)
}
filterIsInstance<ArrayList<*>>().flatten().forEachViewDeep(block)
}

I was trying to do the same thing like you before
and this is what I've made
class VisibilitySwitcher(private val mutableViewSet: MutableSet<View?>, private val onCondition: Boolean = true){
fun betweenVisibleOrGone(){
if(onCondition)
mutableViewSet.forEach {
when (it?.visibility) {
View.VISIBLE -> {it.visibility = View.GONE}
View.GONE -> {it.visibility = View.VISIBLE}
}
}
}
fun betweenVisibleOrInvisible(){
if(onCondition)
mutableViewSet.forEach {
when (it?.visibility) {
View.VISIBLE -> {it.visibility = View.INVISIBLE}
View.INVISIBLE -> {it.visibility = View.VISIBLE}
}
}
}
fun betweenInVisibleOrGone(){
if(onCondition)
mutableViewSet.forEach {
when (it?.visibility) {
View.INVISIBLE -> {it.visibility = View.GONE}
View.GONE -> {it.visibility = View.INVISIBLE}
}
}
}
}
Usage Example
class LoginActivity : BaseActivity() {
#Inject
#ViewModelInjection
lateinit var viewModel: LoginVM
private lateinit var mutableViewSet: MutableSet<View?>
override fun layoutRes() = R.layout.activity_login
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
facebookBtn.setOnClickListener { handleClickEvent(it) }
googleBtn.setOnClickListener { handleClickEvent(it) }
}
private fun handleClickEvent(view: View) {
when (view) {
facebookBtn -> { viewModel.smartLoginManager.onFacebookLoginClick() }
googleBtn -> { viewModel.smartLoginManager.onGoogleLoginClick() }
}
mutableViewSet = mutableSetOf(facebookBtn, googleBtn, progressBar)
VisibilitySwitcher(mutableViewSet).betweenVisibleOrGone() // <----- Use without Condition
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
VisibilitySwitcher(mutableViewSet, resultCode != -1).betweenVisibleOrGone() //<-- Use with Conditions
viewModel.smartLoginManager.onActivityResultCallBack(requestCode, resultCode, data)
super.onActivityResult(requestCode, resultCode, data)
}
}
The point is whenever you click login from facebook or google button
It will set visibility for facebook and google to be gone and set progressbar(the default of progressbar is View.GONE) to be visible
At override fun onActivityResult()
if the resultcode is not -1 it means that it got some error or cancel
so it will switch back the progressbar to be gone and change facebook and google button to be visible again
If you want to fix your own code I would do this
fun searchForView(mutableViewSet: MutableSet<View?>){
mutableViewSet.forEach {
when (it?.visibility) {
View.VISIBLE -> {it.visibility = View.INVISIBLE}
View.INVISIBLE -> {it.visibility = View.VISIBLE} //<-- you can delete this if you don't want
}
}
}
Or very short form
fun searchForView(mutableViewSet: MutableSet<View?>) = mutableViewSet.forEach { when (it?.visibility) {View.VISIBLE -> it.visibility = View.INVISIBLE } }
Usage
val mutableViewSet = mutableSetOf(your view1,2,3....)
searchForView(mutableViewSet)
if it has to use arrayList: ArrayList<*> Then
fun searchForView(arrayList: ArrayList<*>) = arrayList.forEach{ if (it is View) it.visibility = View.INVISIBLE

Dynamically created radio button is disappearing while clicking

I am getting the all views but when I click the button and scroll down at that time the it will be unchecked. I added the removeall views on the onBindViewHolder. because the radiobuttons are generated infinite times. Here I shared the code please check it.
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.radioGrp.setOrientation(RadioGroup.VERTICAL)
holder.radioGrp.removeAllViews()
holder.bindView(position)
}
inner class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val radioGrp = itemView.findViewById<RadioGroup>(R.id.radio_group)
fun bindView(position: Int) {
itemView.tv_question.text = feedback[position].questions
var newAnswer = feedback[position].answser as ArrayList<String>
if (newAnswer.isEmpty()) {
itemView.linear2.visibility = View.VISIBLE
} else {
newAnswer.forEach {
itemView.linear2.visibility = View.GONE
val rb = RadioButton(context)
rb.text = it
rb.id = position
radioGrp.addView(rb)
rb?.setOnCheckedChangeListener(CompoundButton.OnCheckedChangeListener {
buttonView, isChecked ->
if (isChecked) {
rb.isChecked = true
examinationListener.addAnswer(names)
} else {
rb.isChecked = false
examinationListener.removeAnswer(names as String)
}
})
}
}
}
}

You need to track the checked state of your answers externally to the views and apply the state when binding the views. Assuming the answers for each list item are all unique Strings, you could use a Map to store the states.
// In your adapter:
val answerStates = mutableMapOf<Int, MutableMap<String, Boolean>>()
inner class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val radioGrp = itemView.findViewById<RadioGroup>(R.id.radio_group)
fun bindView(position: Int) {
itemView.tv_question.text = feedback[position].questions
val newAnswer = feedback[position].answser as ArrayList<String>
if (newAnswer.isEmpty()) {
itemView.linear2.visibility = View.VISIBLE
} else {
itemView.linear2.visibility = View.GONE
// Lazily create answer states map for this list item
val answerStates = answerStates[position]
?: mutableMapOf<String, Boolean>().also { answerStates[position] = this }
newAnswer.forEach {
val rb = RadioButton(context)
rb.text = it
rb.id = position
rb.checked = answerStates[it] ?: false // Bind last known state, default false
radioGrp.addView(rb)
rb?.setOnCheckedChangeListener(CompoundButton.OnCheckedChangeListener {
buttonView, isChecked ->
answerStates[it] = isChecked // Save state
if (isChecked) {
rb.isChecked = true
examinationListener.addAnswer(names)
} else {
rb.isChecked = false
examinationListener.removeAnswer(names as String)
}
})
}
}
}
}
If your data can change, this gets more complicated. You would need to store this Boolean in your actual Feedback class so it can be restored when there is fresh data.

Android how to interact with nested recyclerView from fragment

How does one properly send data to child adapter in a fragment?
I'm basically trying to implement an Instagram like comments-section, e.g. a bunch of comments that can each have more comments (replies).
To do that, I use one main recyclerView + main adapter, which instances are retained in my fragment, and within the main adapter I bind the children comments (recyclerView + adapter).
Adding comments to the main adapter is easy since the object is always available in the fragment, so I just call mainAdapter.addComments(newComments):
MainAdapter
fun addComments(newComments: List<Comment>){
comments.addAll( 0, newComments) //loading comments or previous comments go to the beginning
notifyItemRangeInserted(0, newComments.size)
}
But how to call addComments of one particular nested-rV? I read I should not save the adapter instances and only use positions.
I'm trying to do that in my Fragment as follows:
val item = rVComments.findViewHolderForItemId(mAdapter.itemId)!!.itemView
val adapt = item.rVReplies.adapter as ChildCommentsAdapter
adapt.addComment(it.data.comment)
But that doesn't work very well: since we have only RecyclerViews, that particular ViewHolder is often already recycled if the user scrolled after posting or fetching items, which leads to a NullPointerException.
Hence the initial question: how does one properly interact with nested recyclerviews and their adapter? If the answer is via Interface, please provide an example as I've tried it without success since I shouldn't save adapter objects.

You can achieve that using a single multi-view type adapter by placing the comments
as part of the parent item, with that, you add the child items below the parent item and call notifyItemRangeInserted.
That way you don't have to deal with most of the recycling issues.
When you want to update a comment you just update the comment inside the parent item and call notifyItemChanged.
If you want I created a library that can generate that code for you in compile time.
It supports the exact case you wanted and much more.

Using #Gil Goldzweig's suggestion, here is what I did: in case of an Instagram like comments' system with replies, I did use a nested recyclerView system. It just makes it easier to add and remove items. However, as for the question How does one properly send data to child adapter in a fragment? You don't. It gets super messy. From my fragment, I sent the data to my mainAdapter, which in turn sent the data to the relevant childAdapter. The key to make it smooth is using notifyItemRangeInserted when adding a comment to the mainAdapter and then notifyItemChanged when adding replies to a comment. The second event will allow sending data to the child adapter using the payload. Here's the code in case other people are interested:
Fragment
class CommentsFragment : androidx.fragment.app.Fragment(), Injectable,
SendCommentButton.OnSendClickListener, CommentsAdapter.Listener {
#Inject
lateinit var viewModelFactory: ViewModelProvider.Factory
private val viewModel by lazy {
ViewModelProviders.of(requireActivity(), viewModelFactory).get(CommentsViewModel::class.java)
}
private val searchViewModel by lazy {
ViewModelProviders.of(requireActivity(), viewModelFactory).get(SearchViewModel::class.java)
}
private val mAdapter = CommentsAdapter(this)
private var contentid: Int = 0 //store the contentid to process further posts or requests for more comments
private var isLoadingMoreComments: Boolean = false //used to check if we should fetch more comments
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_comments, container, false)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
//hide the action bar
activity?.findViewById<BottomNavigationView>(R.id.bottomNavView)?.visibility = View.GONE
contentid = arguments!!.getInt("contentid") //argument is mandatory, since comment is only available on content
ivBackArrow.setOnClickListener{ activity!!.onBackPressed() }
viewModel.initComments(contentid) //fetch comments
val layoutManager = LinearLayoutManager(this.context)
layoutManager.stackFromEnd = true
rVComments.layoutManager = layoutManager
mAdapter.setHasStableIds(true)
rVComments.adapter = mAdapter
setupObserver() //observe initial comments response
setupSendCommentButton()
post_comment_text.setSearchViewModel(searchViewModel)
setupScrollListener(layoutManager) //scroll listener to load more comments
iVCancelReplyTo.setOnClickListener{
//reset ReplyTo function
resetReplyLayout()
}
}
private fun loadMoreComments(){
viewModel.fetchMoreComments(contentid, mAdapter.itemCount)
setupObserver()
}
/*
1.check if not already loading
2.check scroll position 0
3.check total visible items != total recycle items
4.check itemcount to make sure we can still make request
*/
private fun setupScrollListener(layoutManager: LinearLayoutManager){
rVComments.addOnScrollListener(object: RecyclerView.OnScrollListener(){
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
super.onScrolled(recyclerView, dx, dy)
val visibleItemCount = rVComments.childCount
val totalItemCount = layoutManager.itemCount
val pos = layoutManager.findFirstCompletelyVisibleItemPosition()
if(!isLoadingMoreComments && pos==0 && visibleItemCount!=totalItemCount && mAdapter.itemCount%10==0){
//fetch more comments
isLoadingMoreComments = true
loadMoreComments()
}
}
})
}
private fun setupSendCommentButton() {
btnSendComment.setOnSendClickListener(this)
}
override fun onSendClickListener(v: View?) {
if(isInputValid(post_comment_text.text.toString())) {
val isReply = mAdapter.commentid!=null
viewModel.postComment(post_comment_text.text.toString(), mAdapter.commentid?: contentid, isReply) //get reply ID, otherwise contentID
observePost()
post_comment_text.setText("")
btnSendComment.setCurrentState(SendCommentButton.STATE_DONE)
}
}
override fun postCommentAsReply(username: String) {
//main adapter method to post a reply
val replyText = "${getString(R.string.replyingTo)} $username"
tVReplyTo.text = replyText
layoutReplyTo.visibility=View.VISIBLE
post_comment_text.requestFocus()
}
override fun fetchReplies(commentid: Int, commentsCount: Int) {
//main adapter method to fetch replies
if(!isLoadingMoreComments){ //load one series at a time
isLoadingMoreComments = true
viewModel.fetchReplies(commentid, commentsCount)
viewModel.replies.observe(this, Observer<Resource<List<Comment>>> {
if (it?.data != null) when (it.status) {
Resource.Status.LOADING -> {
//showProgressBar(true)
}
Resource.Status.ERROR -> {
//showProgressBar(false)
isLoadingMoreComments = false
}
Resource.Status.SUCCESS -> {
isLoadingMoreComments = false
mAdapter.addReplies(mAdapter.replyCommentPosition!!, it.data)
rVComments.scrollToPosition(mAdapter.replyCommentPosition!!)
}
}
})
}
}
private fun isInputValid(text: String): Boolean = text.isNotEmpty()
private fun observePost(){
viewModel.postComment.observe(this, Observer<Resource<PostCommentResponse>> {
if (it?.data != null) when (it.status) {
Resource.Status.LOADING -> {
//showProgressBar(true)
}
Resource.Status.ERROR -> {
//showProgressBar(false)
}
Resource.Status.SUCCESS -> {
if(it.data.asReply){
//dispatch comment to child adapter via main adapter
mAdapter.addReply(mAdapter.replyCommentPosition!!, it.data.comment)
rVComments.scrollToPosition(mAdapter.replyCommentPosition!!)
}else{
mAdapter.addComment(it.data.comment)
}
resetReplyLayout()
//showProgressBar(false)
}
}
})
}
private fun setupObserver(){
viewModel.comments.observe(this, Observer<Resource<List<Comment>>> {
if (it?.data != null) when (it.status) {
Resource.Status.LOADING -> {
//showProgressBar(true)
}
Resource.Status.ERROR -> {
isLoadingMoreComments = false
//showProgressBar(false)
}
Resource.Status.SUCCESS -> {
mAdapter.addComments(it.data)
isLoadingMoreComments = false
//showProgressBar(false)
}
}
})
}
private fun resetReplyLayout(){
layoutReplyTo.visibility=View.GONE
mAdapter.replyCommentPosition = null
mAdapter.commentid = null
}
override fun onStop() {
super.onStop()
activity?.findViewById<BottomNavigationView>(R.id.bottomNavView)?.visibility = View.VISIBLE
}
}
MainAdapter
class CommentsAdapter(private val listener: Listener) : RecyclerView.Adapter<CommentsAdapter.ViewHolder>(), ChildCommentsAdapter.ChildListener {
//method from child adapter
override fun postChildReply(replyid: Int, username: String, position: Int) {
commentid = replyid
replyCommentPosition = position
listener.postCommentAsReply(username)
}
interface Listener {
fun postCommentAsReply(username: String)
fun fetchReplies(commentid: Int, commentsCount: Int=0)
}
class ViewHolder(val view: View) : RecyclerView.ViewHolder(view)
private var comments = mutableListOf<Comment>()
private var repliesVisibility = mutableListOf<Boolean>() //used to store visibility state for replies
var replyCommentPosition: Int? = null //store the main comment's position
var commentid: Int? = null //used to indicate which comment is replied to
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val view = LayoutInflater.from(parent.context)
.inflate(R.layout.item_comment, parent, false)
return ViewHolder(view)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val comment = comments[position]
with(holder.view) {
//reset visibilities (rebinding purpose)
rVReplies.visibility = View.GONE
iVMoreReplies.visibility = View.GONE
tVReplies.visibility = View.GONE
content.loadUserPhoto(comment.avatarThumbnailURL)
text.setCaptionText(comment.username!!, comment.comment)
tvTimestamp.setTimeStamp(comment.timestamp!!)
val child = ChildCommentsAdapter(
//we pass parent commentid and position to child to be able to pass it again on click
this#CommentsAdapter, comments[holder.adapterPosition].id!!, holder.adapterPosition
)
val layoutManager = LinearLayoutManager(this.context)
rVReplies.layoutManager = layoutManager
rVReplies.adapter = child
//initial visibility block when binding the viewHolder
val txtMore = this.resources.getString(R.string.show_more_replies)
if(comment.repliesCount>0) {
tVReplies.visibility = View.VISIBLE
if (repliesVisibility[position]) {
//replies are to be shown directly
rVReplies.visibility = View.VISIBLE
child.addComments(comment.replies!!)
tVReplies.text = resources.getString(R.string.hide_replies)
if (comment.repliesCount > comment.replies!!.size) {
//show the load more replies arrow if we can fetch more replies
iVMoreReplies.visibility = View.VISIBLE
}
} else {
//replies all hidden
val txt = txtMore + " (${comment.repliesCount})"
tVReplies.text = txt
}
}
//second visibility block when toggling with the show more/hide textView
tVReplies.setOnClickListener{
//toggle child recyclerView visibility and change textView text
if(holder.view.rVReplies.visibility == View.GONE){
//show stuff
if(comment.replies!!.isEmpty()){
Timber.d(holder.adapterPosition.toString())
//fetch replies if none were fetched yet
replyCommentPosition = holder.adapterPosition
listener.fetchReplies(comments[holder.adapterPosition].id!!)
}else{
//load comments into adapter if not already
if(comment.replies!!.size>child.comments.size){child.addComments(comment.replies!!)}
}
repliesVisibility[position] = true
holder.view.rVReplies.visibility = View.VISIBLE
holder.view.tVReplies.text = holder.view.resources.getString(R.string.hide_replies)
if (comment.repliesCount > comment.replies!!.size && comment.replies!!.isNotEmpty()) {
//show the load more replies arrow if we can fetch more replies
iVMoreReplies.visibility = View.VISIBLE
}
}else{
//hide replies and change text
repliesVisibility[position] = false
holder.view.rVReplies.visibility = View.GONE
holder.view.iVMoreReplies.visibility = View.GONE
val txt = txtMore + " (${comment.repliesCount})"
holder.view.tVReplies.text = txt
}
}
tvReply.setOnClickListener{
replyCommentPosition = holder.adapterPosition
commentid = comments[holder.adapterPosition].id!!
listener.postCommentAsReply(comments[holder.adapterPosition].username!!)
}
iVMoreReplies.setOnClickListener{
replyCommentPosition = holder.adapterPosition
listener.fetchReplies(comments[holder.adapterPosition].id!!, layoutManager.itemCount) //pass amount of replies too
}
}
}
#Suppress("UNCHECKED_CAST")
override fun onBindViewHolder(holder: ViewHolder, position: Int, payloads: MutableList<Any>) {
if(payloads.isNotEmpty()){
//add reply to child adapter
with(holder.view){
Timber.d(payloads.toString())
val adapter = rVReplies.adapter as ChildCommentsAdapter
if(payloads[0] is Comment){
adapter.addComment(payloads[0] as Comment)
}else{
//will be of type List<Comment>
adapter.addComments(payloads[0] as List<Comment>)
val comment = comments[position]
if (comment.repliesCount > comment.replies!!.size) {
//show the load more replies arrow if we can fetch more replies
iVMoreReplies.visibility = View.VISIBLE
}else{
iVMoreReplies.visibility = View.GONE
}
}
}
}else{
super.onBindViewHolder(holder,position, payloads) //delegate to normal binding process
}
}
override fun getItemCount(): Int = comments.size
//add multiple replies to child adapter at pos 0
fun addReplies(position: Int, newComments: List<Comment>){
comments[position].replies!!.addAll(0, newComments)
notifyItemChanged(position, newComments)
}
//add a single reply to child adapter at last position
fun addReply(position: Int, newComment: Comment){
comments[position].replies!!.add(newComment)
comments[position].repliesCount += 1 //update replies count in case viewHolder gets rebinded
notifyItemChanged(position, newComment)
}
//add a new comment to main adapter at last position
fun addComment(comment: Comment){
comments.add(comment) //new comment just made goes to the end
repliesVisibility.add(false)
notifyItemInserted(itemCount-1)
}
//add multiple new comments to main adapter at pos 0
fun addComments(newComments: List<Comment>){
comments.addAll( 0, newComments) //loading comments or previous comments go to the beginning
repliesVisibility.addAll(0, List(newComments.size) { false })
notifyItemRangeInserted(0, newComments.size)
}
}
The childAdapter is very basic and has nearly 0 logic.