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Recyclerview data disappears on scroll

I am trying to fetch the data from Google Spreadsheet and display it in a recyclerView in Kotlin. I could do that without any error but the issue I am facing is when I scroll up or down the data in the recyclerView get disappeared. When I scroll up and then scroll down I can see that all the data that went up is missing and the same with scrolling down. But if I scroll up for more I can see one line of data after every few scrolls.
Another issue I have is with the date that is being displayed. My data in the Google Spreadsheet starts from 01-Jan-2023 (this is how it's shown in the spreadsheet, and without time in it), when it's shown in the recyclerView, all dates are one day earlier. I mean, it shows 31-Dec-2022 for 01-Jan-2023, 01-Jan-2023 for 02-Jan-2023 and so on.
Can somebody help correct my mistakes and improve my code? I have been after this for a couple of days and I couldn't fix the issue.
My code is,
SalesData.kt
class SalesData : AppCompatActivity() {
private lateinit var binding: ActivitySalesDataBinding
#SuppressLint("NotifyDataSetChanged")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivitySalesDataBinding.inflate(layoutInflater)
setContentView(binding.root)
val salesList = arrayListOf<SalesDataModel>()
val queue = Volley.newRequestQueue(this)
val url = "https://script.google.com/macros/s/AKfsdaffdbghjhfWVM2FeIH3gZY5kAnb6JVeWpg2XeBOZyU6sghhfkuytytg/exec"
val jsonObjectRequest = object: JsonObjectRequest(
Request.Method.GET,url,null,
Response.Listener {
val data = it.getJSONArray("items")
for(i in 0 until data.length()){
val salesJasonObject = data.getJSONObject(i)
val dt = salesJasonObject.getString("Date")
val dateFmt = SimpleDateFormat("yyyy-MM-dd", Locale.US).parse(dt)
val formattedDatesString = dateFmt?.let { it1 -> SimpleDateFormat("dd-MMM-yyyy", Locale.US).format(it1) }
val salesObject = formattedDatesString?.let { it1 ->
SalesDataModel(
// salesJasonObject.getString("Date"),
it1,
salesJasonObject.getString("Branch"),
salesJasonObject.getDouble("NetSale"),
salesJasonObject.getDouble("Profit"),
)
}
if (salesObject != null) {
salesList.add(salesObject)
}
val adapter = SalesDataRecyclerAdapter(this#SalesData,salesList)
binding.rvSalesData.adapter = adapter
binding.rvSalesData.layoutManager = LinearLayoutManager(this#SalesData)
binding.rvSalesData.setHasFixedSize(true)
adapter.notifyDataSetChanged()
}
Toast.makeText(this#SalesData, "Data loaded successfully", Toast.LENGTH_LONG).show()
},Response.ErrorListener {
Toast.makeText(this#SalesData, it.toString(), Toast.LENGTH_LONG).show()
}
){
override fun getHeaders(): MutableMap<String, String> {
return super.getHeaders()
}
}
Toast.makeText(this#SalesData, "Hi", Toast.LENGTH_LONG).show()
queue.add(jsonObjectRequest)
}
}
SalesDataRecyclerAdapter.kt
class SalesDataRecyclerAdapter(
val context: Context,
private val saleDataList:ArrayList<SalesDataModel>
):RecyclerView.Adapter<RecyclerView.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
return MyViewHolder(
SalesDataLayoutBinding.inflate(
LayoutInflater.from(parent.context),
parent, false
)
)
}
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
val model = saleDataList[position]
if (holder is MyViewHolder){
holder.binding.tvSales.text = model.salesAmount.toString()
holder.binding.tvBranch.text = model.branch
holder.binding.tvDate.text = model.date
holder.binding.tvProfit.text = model.profit.toString()
}
}
override fun getItemCount(): Int {
return saleDataList.size
}
class MyViewHolder(val binding: SalesDataLayoutBinding) : RecyclerView.ViewHolder(binding.root)
}
activity_sales_data.xml
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
tools:context=".SalesData">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<!--
<androidx.core.widget.ContentLoadingProgressBar
android:id="#+id/progressbar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>-->
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/new_green"
android:padding="10dp"
android:text="SALES DATA"
android:textColor="#color/white"
android:textSize="24sp"
android:layout_gravity="bottom|end"/>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvSalesData"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
sales_data_layout.xml
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<TextView
android:id="#+id/tvDate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Date"
android:layout_weight="1"/>
<TextView
android:id="#+id/tvBranch"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Branch"
android:layout_weight="1"/>
<TextView
android:id="#+id/tvSales"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Sales"
android:layout_weight="1"/>
<TextView
android:id="#+id/tvProfit"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="20sp"
android:text="Profit"
android:layout_weight="1"/>
</LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

Since your root view in sales_data_layout.xml has the size:
android:layout_width="match_parent"
android:layout_height="match_parent"
Each item will take up the whole parent area, which in your case will end up with each individual item taking up the whole screen, and thus needing multiple scrolls to see the next item. You probably want to change the height to wrap_content for the root view, to see more items on the screen at once.

Add a comparator that tells the recylcer view exactly when to redraw.
class WordsComparator : DiffUtil.ItemCallback<Word>() {
override fun areItemsTheSame(oldItem: Word, newItem: Word): Boolean {
//=== here doesn't work for complex objects
// simple high-speed code goes here it is called over and over
// my app the same item has the same id easy compare
return (oldItem._id == newItem._id)
}
override fun areContentsTheSame(oldItem: Word, newItem: Word): Boolean { // you developer have to compare the contents of complex objects
// you need high speed code here for best results
// if possible don't call any functions that could do other
// unecessary things.
// compare the contents of the complex items.
return (oldItem._id == newItem._id
&& oldItem.checked == newItem.checked
&& oldItem.word == newItem.word
&& oldItem.color == newItem.color
&& oldItem.recolor == newItem.recolor
&& oldItem.rechecked == newItem.rechecked)
}
}

Scroll view inside recyclerview item not working

I am using a Recycler view to show Some Card Views.
Each item of recycler view contains a long text.
I am trying to make that text scrollable.
I tried wrapping the text inside a Nested Scroll View.
But on swiping the item, the whole recycler view is scrolled, instead of the text inside the item.
simpler version of my recycler view item layout.
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/parent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:onClick="#{()->viewHolder.navigateToDetails()}"
android:paddingHorizontal="25dp"
android:paddingVertical="15dp">
<androidx.core.widget.NestedScrollView
android:id="#+id/crib_text_scroll_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constrainedHeight="true"
app:layout_constraintHeight_max="300dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/category">
<com.example.presentation.custom_views.ReadMoreTextView
android:id="#+id/crib_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
app:mainText="#{cribResponse.post}"
tools:mainText="#tools:sample/lorem[20]" />
</androidx.core.widget.NestedScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>
layout of the fragment that contains recycler view
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:id="#+id/swipe_refresh_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/crib_rv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:nestedScrollingEnabled="true"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
tools:listitem="#layout/item_text_crib" />
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Adapter class
class CribAdapter(private val rvHost: RVHost) :
PagingDataAdapter<CribResponse, CribViewHolder>(diffCallback) {
private val allAudioViewHolders: MutableList<AudioCribViewHolder> = mutableListOf()
var playingViewHolder: AudioCribViewHolder? = null
companion object {
val diffCallback = object : DiffUtil.ItemCallback<CribResponse>() {
override fun areItemsTheSame(oldItem: CribResponse, newItem: CribResponse): Boolean {
return oldItem == newItem
}
override fun areContentsTheSame(oldItem: CribResponse, newItem: CribResponse): Boolean {
return oldItem.postId == newItem.postId
}
}
}
override fun onBindViewHolder(holder: CribViewHolder, position: Int) {
val item = getItem(position)
item ?: return
holder.bind(item)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CribViewHolder {
return if (viewType == AUDIO_CRIB) {
AudioCribViewHolder(parent = parent, RVHost = rvHost).apply {
markCreated()
allAudioViewHolders.add(this)
}
} else {
TextCribViewHolder(parent = parent, rvHost = rvHost)
}
}
override fun getItemViewType(position: Int): Int {
val item = getItem(position)
val audio = item?.postAudio
return if (audio == null) TEXT_CRIB else AUDIO_CRIB
}
override fun onViewAttachedToWindow(holder: CribViewHolder) {
super.onViewAttachedToWindow(holder)
if (holder is AudioCribViewHolder) {
holder.markAttach()
}
}
override fun onViewDetachedFromWindow(holder: CribViewHolder) {
super.onViewDetachedFromWindow(holder)
if (holder is AudioCribViewHolder) {
val isPlaying = holder.playing.value ?: false
if (isPlaying) {
holder.resetUI()
playingViewHolder = null
rvHost.stop()
}
holder.markDetach()
}
}
fun selfLifecycleDestroyed() {
allAudioViewHolders.forEach {
it.markDestroyed()
}
}
fun getCrib(position: Int): CribResponse? {
return getItem(position)
}
}

Viewpager2 inside Nestedscrollview consist two Fragment with Recyclerview having problem

I made a viewpager2 which has two Fragments, inside each Fragment there is a Recyclerview. The viewpager itself is inside a Nestedscrollview in order to hide the toolbar when scroll up. Here is my code:
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
>
<com.google.android.material.appbar.AppBarLayout
android:id="#+id/appbarlayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways">
</androidx.appcompat.widget.Toolbar>
<com.google.android.material.tabs.TabLayout
android:id="#+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAlignment="center"
app:tabGravity="fill"
app:tabMode="fixed"/>
</com.google.android.material.appbar.AppBarLayout>
<androidx.core.widget.NestedScrollView
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"/>
</LinearLayout>
</androidx.core.widget.NestedScrollView>
<include layout="#layout/material_design_floating_action_menu" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
As I said the viewPager2 have two fragment each of them have a recyclerview. Here problem is, fragment 2 recyclerView take the same height of fragment 1 recyclerView though both recyclerView have different list items and their height should be depends on the list items. I mean, I am expecting these recyclerViews height should act separately based on the list. How can I solve this issue? Please let me know if you need fragment code.
Edit:
Activity code which holds the viewPager2
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initToolbar();
init();
viewPager.setAdapter(createCardAdapter());
new TabLayoutMediator(tabLayout, viewPager,
new TabLayoutMediator.TabConfigurationStrategy() {
#Override public void onConfigureTab(#NonNull TabLayout.Tab tab, int position) {
//tab.setText("Tab " + (position + 1));
if(position == 0){
tab.setText("Home");
}else if(position == 1){
tab.setText("Events");
}
}
}).attach();
RunnTimePermissions.requestForAllRuntimePermissions(this);
showNotifyDialog();
}
ViewPager Adapter Code:
public class ViewPagerAdapter extends FragmentStateAdapter {
private static final int CARD_ITEM_SIZE = 2;
public ViewPagerAdapter(#NonNull FragmentActivity fragmentActivity) {
super(fragmentActivity);
}
#NonNull #Override public Fragment createFragment(int position) {
switch (position){
case 0:
return HomeFragment.newInstance("abc","abc");
// break;
case 1:
return EventListFragment.newInstance("abc","abc");
// break;
}
return HomeFragment.newInstance("abc","abc");
}
#Override public int getItemCount() {
return CARD_ITEM_SIZE;
}
}
Fragment 1 layout:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".fragment.EventListFragment">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rv_event_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:layout_marginTop="16dp"
/>
</FrameLayout>
Fragment 2 layout
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".fragment.MedicineListFragment">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rv_medicine_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:layout_marginTop="16dp"
/>
</FrameLayout>

Alright buddy. I did it! I have the solution to this issue.
First off, here's the official response from Google after I opened an issue.
https://issuetracker.google.com/issues/188474850?pli=1
Anyway, on to the fix. Replace the NestedScrollView with this class:
https://gist.github.com/AfzalivE/fdce03eeee8e16203bcc37ba26d7abf3
The idea is to basically create a very light-weight version of NestedScrollView. Instead of messing with child heights, we listen to the children's scroll and either let them scroll, or forward the scrolling to the BottomSheetBehavior. For example when the RecyclerView has been scrolled all the way to the top, then it doesn't consume any of the scrolling, so we can forward that to the bottom sheet so it can scroll. And we only allow the RecyclerView to scroll when the Bottom sheet is expanded.
Also, I must add that this scenario works out of the box with Jetpack Compose + Accompanist-pager so just do that if you really need perfect functionality.
class BottomSheetScrollView(context: Context, attrs: AttributeSet?) : FrameLayout(context, attrs),
NestedScrollingParent2 {
private val TAG = "NestedScroll3"
private val childHelper = NestedScrollingChildHelper(this).apply {
isNestedScrollingEnabled = true
}
private var behavior: BottomSheetBehavior<*>? = null
var started = false
var canScroll = false
var pendingCanScroll = false
var dyPreScroll = 0
init {
ViewCompat.setNestedScrollingEnabled(this, true)
}
private val bottomSheetCallback = object : BottomSheetBehavior.BottomSheetCallback() {
override fun onStateChanged(bottomSheet: View, newState: Int) {
onNextScrollStop(newState == BottomSheetBehavior.STATE_EXPANDED)
Log.d(
"BottomSheet",
"Can scroll CHANGED to: $canScroll, because bottom sheet state is ${
getBottomSheetStateString(newState)
}"
)
}
override fun onSlide(bottomSheet: View, slideOffset: Float) = Unit
}
fun onNextScrollStop(canScroll: Boolean) {
pendingCanScroll = canScroll
}
override fun onStartNestedScroll(child: View, target: View, axes: Int, type: Int): Boolean {
// ViewPager2's RecyclerView does not participate in this nested scrolling.
// This allows it to show it's overscroll indicator.
if (target is RecyclerView) {
val layoutManager = target.layoutManager as LinearLayoutManager
if (layoutManager.orientation == LinearLayoutManager.HORIZONTAL) {
target.isNestedScrollingEnabled = false
}
}
if (!started) {
Log.d(TAG, "started nested scroll from $target")
childHelper.startNestedScroll(axes, type)
started = true
}
return true
}
override fun onNestedScrollAccepted(child: View, target: View, axes: Int, type: Int) {
Log.d(TAG, "accepted nested scroll from $target")
}
override fun onStopNestedScroll(target: View, type: Int) {
if (started) {
childHelper.stopNestedScroll(type)
started = false
Log.d(
TAG,
"stopped nested scroll from $target, changing canScroll from $canScroll to $pendingCanScroll"
)
canScroll = pendingCanScroll
}
}
override fun onNestedScroll(
target: View,
dxConsumed: Int,
dyConsumed: Int,
dxUnconsumed: Int,
dyUnconsumed: Int,
type: Int
) {
Log.d(
TAG,
"onNestedScroll: dxC: $dxConsumed, dyC: $dyConsumed, dxU: $dxUnconsumed, dyU: $dyUnconsumed"
)
if (dyUnconsumed == dyPreScroll && dyPreScroll < 0) {
canScroll = false
Log.d(TAG, "Can scroll CHANGED to: $canScroll, because scrolled to the top of the list")
}
}
override fun onNestedPreScroll(target: View, dx: Int, dy: Int, consumed: IntArray, type: Int) {
Log.d(
TAG,
"onNestedPreScroll: dx: $dx, dy: $dy, consumed: [ ${consumed.joinToString(", ")} ]"
)
if (!canScroll) {
childHelper.dispatchNestedPreScroll(dx, dy, consumed, null, type)
// Ensure all dy is consumed to prevent premature scrolling when not allowed.
consumed[1] = dy
} else {
dyPreScroll = dy
}
}
override fun onAttachedToWindow() {
super.onAttachedToWindow()
behavior = findBottomSheetBehaviorParent(parent) as BottomSheetBehavior<*>?
behavior?.addBottomSheetCallback(bottomSheetCallback)
}
override fun onDetachedFromWindow() {
super.onDetachedFromWindow()
behavior?.removeBottomSheetCallback(bottomSheetCallback)
}
private fun findBottomSheetBehaviorParent(parent: ViewParent?): CoordinatorLayout.Behavior<*>? {
if (parent !is View) {
throw IllegalArgumentException(
"None of this view's ancestors are associated with BottomSheetBehavior"
)
}
val layoutParams = parent.layoutParams
return if (layoutParams is CoordinatorLayout.LayoutParams && layoutParams.behavior != null) {
layoutParams.behavior
} else {
findBottomSheetBehaviorParent((parent as View).parent)
}
}
private fun getBottomSheetStateString(state: Int): String {
return when (state) {
1 -> "STATE_DRAGGING"
2 -> "STATE_SETTLING"
3 -> "STATE_EXPANDED"
4 -> "STATE_COLLAPSED"
5 -> "STATE_HIDDEN"
6 -> "STATE_HALF_EXPANDED"
else -> "0"
}
}
}

I do not understand why you have recyclerview inside FrameLayout .
Here problem is, fragment 2 recyclerView take the same height of
fragment 1 recyclerView though both recyclerView have different list
items and their height should be depends on the list items
RecyclerView generally always depends on the item_layout until we have not fixed its height n width to match_parent.
In your case you have fixed RecyclerView android:layout_width and android:layout_width to match_parent in both the Fragment .
Try this:
Fragment 1
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".fragment.EventListFragment">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rv_event_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
/>
</FrameLayout>
Fragment 2
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".fragment.MedicineListFragment">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rv_medicine_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
/>
</FrameLayout>
P.S: assuming each reacyclerView's item_layout would be having height as wrap_content

Recyclerview - onCreateViewHolder called for each list item

I have implemented a simple adapter but it is causing RecyclerView not to recycler views and calls onCreateViewHolder() for every list item when scrolled. This causes jank
whenever I scroll the list. Few points listed below are not related to excessive calls of onCreateViewHolder(), but I tried them to improve scroll performance and avoid jank. Things I have tried so far:
recyclerView.setHasFixedSize(true)
recyclerView.recycledViewPool.setMaxRecycledViews(1, 10) with recyclerView.setItemViewCacheSize(10)
recyclerView.setDrawingCacheEnabled(true) with recyclerView.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH)
setting RecyclerView height to "match_parent"
Was previously using Kotlin's synthetic, now moved to Android's ViewBinding
Rewrite complex nested layouts to Constraint Layout
override onFailedToRecycleView() to see if it is called, but it was never called
Here is my adapter:
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.example.suppstore.R
import com.example.suppstore.common.Models.Brand
import com.example.suppstore.databinding.LiBrandBinding
import com.google.firebase.perf.metrics.AddTrace
class BrandsAdapter(list: ArrayList<Brand>, var listener: BrandClickListener?) :
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
private val VIEW_TYPE_LOADING = 0
private val VIEW_TYPE_NORMAL = 1
private var brandsList: ArrayList<Brand> = list
#AddTrace(name = "Brands - onCreateViewHolder", enabled = true)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
return if (viewType == VIEW_TYPE_NORMAL) {
ViewHolder(
LiBrandBinding.inflate(
LayoutInflater.from(parent.context),
parent, false
)
)
} else {
LoaderHolder(
LayoutInflater.from(parent.context)
.inflate(R.layout.li_loader, parent, false)
)
}
}
#AddTrace(name = "Brands - onBindViewHolder", enabled = true)
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
if (holder is ViewHolder)
holder.setData(brandsList[position], listener!!)
}
class ViewHolder(itemView: LiBrandBinding) : RecyclerView.ViewHolder(itemView.root) {
private val binding: LiBrandBinding = itemView
#AddTrace(name = "Brands - ViewHolder-setData", enabled = true)
fun setData(brand: Brand, listener: BrandClickListener) {
binding.cardItem.setOnClickListener { listener.onItemClick(brand) }
binding.tvBrandName.text = brand.name
binding.tvCount.text = brand.count.toString() + " Products"
}
}
class LoaderHolder(itemView: View) : RecyclerView.ViewHolder(itemView.rootView) {
}
#AddTrace(name = "Brands - addLoader", enabled = true)
fun addLoader() {
brandsList.add(Brand())
notifyItemInserted(brandsList.size - 1)
}
#AddTrace(name = "Brands - setData", enabled = true)
fun setData(newList: ArrayList<Brand>) {
this.brandsList = newList
notifyDataSetChanged()
}
#AddTrace(name = "Brands - removeLoader", enabled = true)
fun removeLoader() {
if (brandsList.size == 0)
return
val pos = brandsList.size - 1
brandsList.removeAt(pos)
notifyItemRemoved(pos)
}
override fun getItemViewType(position: Int): Int {
return if (brandsList.get(position).count == -1) {
VIEW_TYPE_LOADING
} else
VIEW_TYPE_NORMAL
}
interface BrandClickListener {
fun onItemClick(brand: Brand)
}
override fun getItemCount(): Int {
return brandsList.size
}
}
Here is the list item (li_brand):
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/cardItem"
android:layout_width="match_parent"
android:layout_height="85dp"
android:background="#color/app_black">
<TextView
android:id="#+id/tvBrandName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="15dp"
android:textColor="#color/app_yellow"
android:textSize="18sp"
android:textStyle="bold"
app:layout_constraintBottom_toTopOf="#id/tvCount"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed" />
<TextView
android:id="#+id/tvCount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="15dp"
android:layout_marginTop="2dp"
android:textColor="#color/app_grey"
android:textSize="12sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toBottomOf="#id/tvBrandName" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="20dp"
android:layout_gravity="center_vertical"
android:layout_marginEnd="15dp"
android:src="#drawable/ic_baseline_arrow_forward_ios_24"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<View
android:layout_width="match_parent"
android:layout_height="3dp"
android:background="#color/app_bg"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
Here are related functions in Fragment
class BrandsFragment : Fragment() {
private val adapter = BrandsAdapter(ArrayList(), brandClickListener())
fun brandClickListener(): BrandsAdapter.BrandClickListener {
return object : BrandsAdapter.BrandClickListener {
override fun onItemClick(brand: Brand) {
activityViewModel?.setSelectedBrand(brand)
}
}
}
fun setupRecyclerView() {
val llManager = LinearLayoutManager(context, LinearLayoutManager.VERTICAL, false)
binding.recyclerView.layoutManager = llManager
binding.recyclerView.setHasFixedSize(true)
binding.recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrolled(recyclerView: RecyclerView, dx: Int, dy: Int) {
if (dy > 0) { //check for scroll down
val visibleItemCount = llManager.childCount
val totalItemCount = llManager.itemCount
val firstVisibleItemPos = llManager.findFirstVisibleItemPosition()
if (loadWhenScrolled
&& visibleItemCount + firstVisibleItemPos >= totalItemCount
&& firstVisibleItemPos >= 0
) {
//ensures that last item was visible, so fetch next page
loadWhenScrolled = false
viewModel.nextPage()
}
}
}
})
binding.recyclerView.adapter = adapter
}
}
And here is the fragment xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/app_black"
android:focusableInTouchMode="true"
android:orientation="vertical"
tools:context=".Brands.BrandsFragment">
<androidx.appcompat.widget.SearchView
android:id="#+id/searchView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:layout_marginBottom="5dp"
android:background="#drawable/bottom_line_yellow"
android:theme="#style/SearchViewTheme"
app:closeIcon="#drawable/ic_baseline_close_24"
app:iconifiedByDefault="false"
app:queryBackground="#android:color/transparent"
app:queryHint="Atleast 3 characters to search"
app:searchIcon="#drawable/ic_baseline_search_24" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>

Have you tried RecyclerView Diffutil class? Hope it will resolve smooth scrolling issue and overwhelm recreation of items.
https://developer.android.com/reference/androidx/recyclerview/widget/DiffUtil
"DiffUtil is a utility class that calculates the difference between two lists and outputs a list of update operations that converts the first list into the second one."

Very long image being cut when the height of the image is not enough

Here are the 2 situations I have in my app -
as you can see, the image is being centered when it is being enlarged.
The wanted result is that I would like to have see the left side of the image always, meaning let's say the 40% left side of the image.
Here is my holder xml -
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/vendors_row_item_root_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.cardview.widget.CardView
android:id="#+id/search_image_contact_cardview"
android:layout_width="152dp"
android:layout_height="match_parent"
android:layout_margin="5dp"
app:cardCornerRadius="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<ImageView
android:id="#+id/vendors_row_item_imageview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
tools:src="#mipmap/ic_launcher" />
</androidx.cardview.widget.CardView>
</androidx.constraintlayout.widget.ConstraintLayout>
here is my holder class -
class VendorsHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
var vendorImageView: ImageView = itemView.findViewById(R.id.vendors_row_item_imageview)
var rootLayout: ConstraintLayout = itemView.findViewById(R.id.vendors_row_item_root_layout)
var vendorHolderCardview: CardView = itemView.findViewById(R.id.search_image_contact_cardview)
}
adapter -
class VendorAdapter(private val miniVendorModels: List<MiniVendorModel>, private val context: Context) : RecyclerView.Adapter<VendorsHolder>() {
companion object {
const val EXTRA_VENDOR_MODEL = "EVM"
}
private val vendorsHoldersList = mutableListOf<VendorsHolder>()
override fun onCreateViewHolder(viewGroup: ViewGroup, i: Int): VendorsHolder {
val view = LayoutInflater.from(viewGroup.context).inflate(R.layout.fragment_marketplace_vendor_row_item, viewGroup, false)
val vendorsHolder = VendorsHolder(view)
vendorsHoldersList.add(vendorsHolder)
return vendorsHolder
}
override fun onBindViewHolder(vendorsHolder: VendorsHolder, i: Int) {
val model = miniVendorModels[i]
Picasso.get().load(model.bannerPicture).into(vendorsHolder.vendorImageView)
vendorsHolder.vendorImageView.setOnClickListener { v: View? ->
try {
val intent = Intent(context, VendorPageActivity::class.java)
intent.putExtra(EXTRA_VENDOR_MODEL, model)
context.startActivity(intent)
} catch (e: Exception) {
e.printStackTrace()
Toast.makeText(context, ResourceHelper.getString(R.string.marketplace_vendor_unavailable), Toast.LENGTH_SHORT).show()
}
}
}
override fun getItemCount(): Int = miniVendorModels.size
fun resizeAllHolders(height : Int){
vendorsHoldersList.forEach { holder ->
holder.rootLayout.updateLayoutParams {
this.height = height
}
}
}
}
any ideas of how to implement this one?

try changing
<ImageView
android:id="#+id/vendors_row_item_imageview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
tools:src="#mipmap/ic_launcher" />
to
<ImageView
android:id="#+id/vendors_row_item_imageview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitCenter"
tools:src="#mipmap/ic_launcher" />