Develop Reference

Dynamically add item into recyclerview when button pressed

I am trying to build a layout in which there is a recyclerview where each item has three edittexts horizontally aligned. I want to add the next item when a button is pressed.
This the design I am trying to build
This is the Adapter class for the recycler view
class AddProjectAdapter(private val itemsList : ArrayList<ItemDetails>) : RecyclerView.Adapter<AddProjectAdapter.AddProjectViewHolder>() {
inner class AddProjectViewHolder(private val binding : AddProjectItemViewBinding) : RecyclerView.ViewHolder(binding.root) {
fun bind(item : ItemDetails){
binding.item = item
}
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): AddProjectViewHolder{
return AddProjectViewHolder(AddProjectItemViewBinding.inflate(LayoutInflater.from(parent.context), parent, false))
}
override fun onBindViewHolder(holder: AddProjectViewHolder, position: Int) {
holder.bind(itemsList[position])
}
override fun getItemCount(): Int = itemsList.size
}
Layout file for the item add_project_item_view.xml
`
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<variable
name="item"
type="com.example.hero.models.ItemDetails" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.card.MaterialCardView
android:id="#+id/item_name_cardview"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:flow_horizontalBias="3"
app:cardBackgroundColor="#color/light_background"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="#id/g_v_1"
android:layout_marginRight="5dp">
<EditText
android:id="#+id/item_name_edittext"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Item Name"
android:text="#={item.itemName}"
android:textColor="#color/t_dark"
android:fontFamily="#font/metropolislight"
android:textSize="14dp"
android:textColorHint="#color/t_dark"
android:background="#null"
android:padding="10dp" />
</com.google.android.material.card.MaterialCardView>
<com.google.android.material.card.MaterialCardView
android:id="#+id/rate_unit_cardview"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:flow_horizontalBias="2"
android:layout_marginRight="5dp"
app:cardBackgroundColor="#color/light_background"
app:layout_constraintStart_toEndOf="#id/g_v_1"
app:layout_constraintEnd_toEndOf="#id/g_v_2">
<EditText
android:id="#+id/rate_unit_edittext"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Rate/Unit"
android:text="#={item.rate}"
android:textColorHint="#color/t_dark"
android:textColor="#color/t_dark"
android:fontFamily="#font/metropolislight"
android:textSize="14dp"
android:padding="10dp"
android:background="#null" />
</com.google.android.material.card.MaterialCardView>
<com.google.android.material.card.MaterialCardView
android:id="#+id/unit_cardview"
android:layout_width="0dp"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:flow_horizontalBias="2"
app:cardBackgroundColor="#color/light_background"
app:layout_constraintStart_toEndOf="#id/g_v_2"
app:layout_constraintEnd_toEndOf="parent">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/unit_textview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:background="#null"
android:fontFamily="#font/metropolislight"
android:hint="Unit"
android:padding="10dp"
android:text="#={item.unit}"
android:textColor="#color/t_dark"
android:textColorHint="#color/t_dark"
android:textSize="14dp" />
<ImageView
android:id="#+id/drop_down_imageview"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:src="#drawable/dropdown"
android:layout_centerVertical="true" />
</RelativeLayout>
</com.google.android.material.card.MaterialCardView>
<androidx.constraintlayout.widget.Guideline
android:id="#+id/g_v_1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.4" />
<androidx.constraintlayout.widget.Guideline
android:id="#+id/g_v_2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
app:layout_constraintGuide_percent="0.8" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
`
//code of the activity in which the recycler view is present
private val itemsList : ArrayList<ItemDetails> = ArrayList()
private lateinit var addProjectAdapter: AddProjectAdapter
private lateinit var binding: ActivityAddProjectBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = ActivityAddProjectBinding.inflate(layoutInflater)
setContentView(binding.root)
setAdapter()
setListner()
}
private fun setAdapter(){
addProjectAdapter = AddProjectAdapter(itemsList)
binding.itemDetailsRecyclerview.apply {
layoutManager = LinearLayoutManager(this#AddProject)
adapter = addProjectAdapter
}
}
override fun onClick(v : View?) {
when(v?.id){
binding.addItemButton.id -> {
itemsList.add(ItemDetails())
addProjectAdapter.notifyItemInserted(itemsList.size-1)
}
}
}
private fun setListner(){
binding.addItemButton.setOnClickListener(this)
}
data class ItemDetails(
var itemName : String = "",
var rate : String = "",
var unit : String = "")
And my recyclerview id is item_details_recyclerview.
Output for the above code
When I click the add button the item added is not visible but the add button moves down.
Can someone help me out with this issue? And also if you could provide some better approach it would be great.
Thanks in advance.

Change height of ConstraintLayout from add_project_item_view.xml
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
to this
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">

RecyclerView doesn't display all data

I am working on an application with multiple recycler views inside a fragment. Everything is working properly, except from one recycler view which doesn't display all data. I get the data after an API call, and I have already checked that they are loaded successfully. Any help would be much appreciated, thank you in advance!!
Here is the recycler view inside the fragment:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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="wrap_content"
android:background="#color/white"
tools:context=".ui.fragments.ExploreFragment">
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentTop="true"
android:fillViewport="true"
android:scrollbars="none">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvExploreFragmentFeaturedProducts"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="30dp"
>
</androidx.recyclerview.widget.RecyclerView>
</RelativeLayout>
</ScrollView>
</RelativeLayout>
Here is the cardview which will be loaded repeatedly inside the recycler view, which is not properly displayed (only the image view and shapeable image view gets displayed):
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView 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/layoutFeaturedProductRowCardView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:cardCornerRadius="10dp"
app:cardElevation="5dp"
android:layout_marginBottom="40dp">
<RelativeLayout
android:id="#+id/rlFeaturedProducts"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:background="#drawable/rounded_frame_recommproducts_explore">
<com.google.android.material.imageview.ShapeableImageView
android:id="#+id/ivFeaturedProduct"
android:layout_width="335dp"
android:layout_height="180dp"
android:scaleType="centerCrop"
app:shapeAppearanceOverlay="#style/rounded_cornersTop"
tools:src="#tools:sample/backgrounds/scenic" />
<ImageView
android:id="#+id/imageViewFavorite"
android:layout_width="wrap_content"
android:layout_height="26dp"
android:layout_alignEnd="#id/ivFeaturedProduct"
android:layout_marginTop="20dp"
android:layout_marginEnd="20dp"
android:src="#drawable/ic_favorite_up"/>
<TextView
android:id="#+id/textViewProductTitle"
android:layout_width="295dp"
android:layout_height="wrap_content"
android:layout_below="#+id/ivFeaturedProduct"
android:layout_marginStart="15dp"
android:layout_marginTop="20dp"
android:fontFamily="#font/semibold"
android:textColor="#color/colorPrimaryDarkV2"
android:textSize="16sp" />
<TextView
android:id="#+id/textViewCategory"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/textViewProductTitle"
android:layout_alignStart="#id/textViewProductTitle"
android:fontFamily="#font/semibold"
android:textSize="12sp"/>
<TextView
android:id="#+id/textViewDuration"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/textViewCategory"
android:layout_alignStart="#id/textViewCategory"
android:layout_marginTop="20dp"
android:drawablePadding="10dp"
android:fontFamily="#font/medium"
android:text="#string/durationlabel"
android:textColor="#color/colorPrimaryLightV2"
android:textSize="12sp"
app:drawableLeftCompat="#drawable/ic_time_icon" />
<TextView
android:id="#+id/textViewDurationValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toEndOf="#id/textViewDuration"
android:layout_alignBaseline="#id/textViewDuration"
android:layout_marginStart="2dp"
android:fontFamily="#font/medium"
android:textColor="#color/colorPrimaryDarkV2"
android:textSize="12sp"/>
<TextView
android:id="#+id/textViewLanguage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/textViewDuration"
android:layout_alignStart="#id/textViewDuration"
android:layout_marginTop="12dp"
android:drawablePadding="10dp"
android:fontFamily="#font/medium"
android:text="#string/languagelabel"
android:textColor="#color/colorPrimaryLightV2"
android:textSize="12sp"
app:drawableLeftCompat="#drawable/ic_audio_icon" />
<TextView
android:id="#+id/textViewLanguageValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toEndOf="#id/textViewLanguage"
android:layout_alignBaseline="#id/textViewLanguage"
android:layout_marginStart="2dp"
android:fontFamily="#font/medium"
android:textColor="#color/colorPrimaryDarkV2"
android:textSize="12sp" />
<TextView
android:id="#+id/textViewThreeSixtyImages"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/textViewLanguage"
android:layout_alignStart="#id/textViewLanguage"
android:layout_marginTop="12dp"
android:drawablePadding="10dp"
android:fontFamily="#font/medium"
android:text="#string/theesixtylabel"
android:textColor="#color/colorPrimaryLightV2"
android:textSize="12sp"
app:drawableLeftCompat="#drawable/ic_images_icon"
android:visibility="gone"/>
<TextView
android:id="#+id/ratingLabel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBaseline="#id/ratingValue"
android:layout_toStartOf="#id/ratingValue"
android:layout_marginTop="2dp"
android:drawablePadding="10dp"
android:fontFamily="#font/semibold"
android:textColor="#color/colorPrimaryDarkV2"
android:textSize="14sp"
app:drawableLeftCompat="#drawable/ic_rating_small_tag" />
<TextView
android:id="#+id/ratingValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toStartOf="#id/ratingCount"
android:layout_alignBaseline="#id/ratingCount"
android:layout_marginEnd="2dp"
android:fontFamily="#font/semibold"
android:textColor="#color/colorPrimaryDarkV2"
android:textSize="14sp"
/>
<TextView
android:id="#+id/ratingCount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/ivFeaturedProduct"
android:layout_alignTop="#id/textViewCategory"
android:layout_alignRight="#id/ivFeaturedProduct"
android:layout_marginEnd="15dp"
android:fontFamily="#font/semibold"
android:textColor="#color/colorPrimaryLightV2"
android:textSize="14sp" />
<TextView
android:id="#+id/priceLabel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/ratingCount"
android:layout_alignEnd="#id/ratingCount"
android:layout_marginTop="20dp"
android:fontFamily="#font/medium"
android:text="#string/fromLabel"
android:textColor="#color/colorPrimaryLightV2"
android:textSize="12sp" />
<TextView
android:id="#+id/salesValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignEnd="#id/priceLabel"
android:layout_below="#id/priceLabel"
android:layout_marginTop="2dp"
android:fontFamily="#font/medium"
android:textSize="12sp"
android:textColor="#color/colorPrimaryV2"
android:visibility="gone"/>
<TextView
android:id="#+id/priceValue"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/priceLabel"
android:layout_alignEnd="#id/priceLabel"
android:layout_marginTop="18dp"
android:fontFamily="#font/bold"
android:textColor="#color/colorPrimaryDarkV2"
android:textSize="18sp" />
<TextView
android:id="#+id/perPersonLabel"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#id/priceValue"
android:layout_alignBaseline="#id/textViewThreeSixtyImages"
android:layout_alignEnd="#+id/priceValue"
android:fontFamily="#font/medium"
android:layout_marginBottom="24dp"
android:text="#string/perPersonLabel"
android:textColor="#color/colorPrimaryLightV2"
android:textSize="12sp" />
</RelativeLayout>
</androidx.cardview.widget.CardView>
Then, here is the adapter giving the card view the values:
class ProductsAdapter(private val products: List<Product>) :
RecyclerView.Adapter<ProductsAdapter.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) : ViewHolder {
val view = LayoutInflater.from(parent.context)
.inflate(R.layout.view_layout_featuredproduct_row, parent, false)
view.layoutParams.height = (parent.measuredWidth - 40)/2 + 30
view.requestLayout()
return ViewHolder(view)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bindProduct(products[position])
}
override fun getItemCount(): Int = products.size
class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
private val image = view.findViewById<ShapeableImageView>(R.id.ivFeaturedProduct)
private val featuredProductTitle = view.findViewById<TextView>(R.id.textViewProductTitle)
private val category = view.findViewById<TextView>(R.id.textViewCategory)
private val featuredProductDuration = view.findViewById<TextView>(R.id.textViewDurationValue)
private val language = view.findViewById<TextView>(R.id.textViewLanguageValue)
private val averageRating = view.findViewById<TextView>(R.id.ratingValue)
private val ratingcount = view.findViewById<TextView>(R.id.ratingCount)
private val pricevalue = view.findViewById<TextView>(R.id.priceValue)
private val context = view.context
private val resources = view.resources
fun bindProduct(product: Product) {
with(product) {
val uri = this.header_image
Picasso.get().load(uri).
placeholder( R.drawable.progress_animation ).
transform(ColorFilterTransformation(ContextCompat.getColor(context, R.color.colorOverlay))).
into(image)
val categoryHelper = this.sku
if (categoryHelper[0].equals('S')){
category.text = resources.getString(R.string.skipTheLineTours)
category.setBackgroundResource(R.drawable.label_skipthelinetour)
category.setTextColor(resources.getColor(R.color.colorSkipTheLineTourTxt))
}
if (categoryHelper[0].equals('A')){
category.text = resources.getString(R.string.audioTours)
category.setBackgroundResource(R.drawable.label_audiotour)
category.setTextColor(resources.getColor(R.color.colorAudioTourTxt))
}
if(categoryHelper[0].equals('V')){
category.text = resources.getString(R.string.virtualTours)
category.setBackgroundResource(R.drawable.label_virtualtour)
category.setTextColor(resources.getColor(R.color.colorVirtualTourTxt))
}
featuredProductTitle.text = this.title
featuredProductDuration.text = this.duration+" minutes"
language.text = languages.size.toString()+" languages"
//category.text = this.sku
averageRating.text = this.average_rating
ratingcount.text = "("+this.rating_count.toString()+")"
pricevalue.text = this.retail_price.toString()+"€"
}
}
}
}
And last but not least, here is the code generating the recycler view:
class ExploreFragment : Fragment() {
private lateinit var viewProductsAdapter: ProductsAdapter
private val model: ProductsViewModel by activityViewModels()
private lateinit var featuredProducts: MutableList<Product>
private lateinit var viewManager : LinearLayoutManager
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_explore, container, false)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
loadFeaturedProducts()
}
private fun loadFeaturedProducts() {
if(!NetworkState().isNetworkAvailable(this#ExploreFragment.context!!.applicationContext)){
return;
}
featuredProducts = mutableListOf()
val recyclerView = rvExploreFragmentFeaturedProducts
viewProductsAdapter = ProductsAdapter(this.featuredProducts)
viewManager = LinearLayoutManager(this.context, LinearLayoutManager.VERTICAL, false)
recyclerView.layoutManager = viewManager
//recyclerView.setHasFixedSize(true)
recyclerView.adapter = viewProductsAdapter
Timber.i("Fragment: load featured products")
model.getProducts().observe(viewLifecycleOwner, { products->
if(products.status == Status.SUCCESS) {
this.featuredProducts.addAll(products.data!!)
viewProductsAdapter.notifyDataSetChanged()
}else {
Timber.i("Featured Products message: "+products.message)
Snackbar.make(view!!, "Cannot load featured products! Error:"+products.message, Snackbar.LENGTH_LONG).show()
}
})
}
}

Thank you for your answers - I figured out my mistake:
I couldn't see anything that was below the ImageView inside my CardView, even though it loaded correctly.
On ProductsListAdapter I forgot to remove an unnecessary calculation:
view.layoutParams.height = (parent.measuredWidth - 40)/2 + 30
view.requestLayout()
which was what caused the problem!

Instead of using the following code:
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvExploreFragmentFeaturedProducts"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="30dp"
>
</androidx.recyclerview.widget.RecyclerView>
Please update it with
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/rvExploreFragmentFeaturedProducts"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="30dp"
/>
the Reason you are not getting data is tags! You are not closing tag of Recycler View instead you are creating a new scope to add more things in it like we do with Layouts.
So remove : </androidx.recyclerview.widget.RecyclerView> and add "/" to the closing tag of recycler view or just simply copy and paste my code above

Can't setOnItemClickListener ListView Kotlin

I have implemented a custom adapter in a ListView but when i try to use setOnItemClickListener the function does not work. I tried using a toast to notify me if the click respond but it did not work
Here is my activity and the adapter
class PasswordListActivity : AppCompatActivity() {
private lateinit var dataSource: SavedPasswordDB
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_password_list)
user = intent.getSerializableExtra("loggedUser") as User
loadPasswords()
btAddOpt.setOnClickListener {
// ...
}
}
override fun onPause() {
super.onPause()
this.loadPasswords()
}
override fun onResume() {
super.onResume()
this.loadPasswords()
}
internal class CustomAdapter(context: Context, data: List<SavedPassword>): ArrayAdapter<SavedPassword>(context, R.layout.activity_password_list, data) {
#SuppressLint("ViewHolder", "SetTextI18n")
private lateinit var dataSource: SavedPasswordDB
override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
val inflater = LayoutInflater.from(context).inflate(R.layout.custom_row, parent, false)
val pwd = getItem(position)
dataSource = SavedPasswordDB(context)
inflater.tvTitle.text = pwd!!.fromTitle
inflater.tvUser.text = "User: " + pwd.pwdUser
inflater.tvCont.text = "Password: " + pwd.pwdContent
inflater.tvOptLink.text = "Site link: " + pwd.optionalLink
inflater.tvCreated.text = "Created At: " + pwd.createdAt
inflater.btDeleteCurrent.setOnClickListener {
// ...
}
return inflater
}
}
private fun loadPasswords () {
dataSource = SavedPasswordDB(this)
var passwords = mutableListOf<SavedPassword>()
val cursor = dataSource.selectPwdByUser(user.id)
while (cursor.moveToNext()) {
val col = SavedPassword(cursor.getInt(0), cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4), cursor.getString(5), cursor.getInt(6))
passwords.add(col)
}
val adapter = CustomAdapter(this, passwords)
lvPwds.adapter = adapter
lvPwds.setOnItemClickListener { adapterView, view, i, id ->
val intent = Intent(this, PasswordDetailActivity::class.java)
startActivity(intent)
}
}
}
Also, i was thinking that the error could be in the XML files, maybe there is a property that im missging, so here they are:
ListView Activity:
<ListView
android:id="#+id/lvPwds"
android:layout_width="353dp"
android:layout_height="593dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/btAddOpt"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.87"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.90999997"
android:src="#drawable/add_icon"/>
Custom Adapter:
<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:padding="15dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="160dp"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<LinearLayout
android:layout_width="260dp"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:id="#+id/tvTitle"
android:layout_width="35dp"
android:layout_height="wrap_content"
android:text="#string/site"
android:textColor="#000000"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.046"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="#+id/tvUser"
android:layout_width="61dp"
android:layout_height="wrap_content"
android:text="#string/userc"
app:layout_constraintStart_toStartOf="#+id/tvTitle"
app:layout_constraintTop_toBottomOf="#+id/tvTitle" />
<TextView
android:id="#+id/tvCont"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/content"
app:layout_constraintStart_toStartOf="#+id/tvTitle"
app:layout_constraintTop_toBottomOf="#+id/tvTitle" />
<TextView
android:id="#+id/tvOptLink"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/optional_link"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="#+id/tvTitle"
app:layout_constraintTop_toBottomOf="#+id/tvCont"
app:layout_constraintVertical_bias="0.043" />
<TextView
android:id="#+id/tvCreated"
android:layout_width="wrap_content"
android:layout_height="27dp"
android:text="#string/created_at"
app:layout_constraintStart_toStartOf="#+id/tvUser"
app:layout_constraintTop_toBottomOf="#+id/tvUser" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageButton
android:id="#+id/btDeleteCurrent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.952"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#android:drawable/ic_delete" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
</LinearLayout>

Add below line to your ListViewtag in xml -
android:descendantFocusability="blocksDescendants"
It will help you.

Recyclerview missing item when element's width and height is enlarged

I've been scratching my head about this problem. I have a recyclerview inside a recyclerview that shows a grid layout where you can scroll both vertically and horizontally.
I decided to enlarge the width and height of each item. Previously, width and height were: 80 x 100
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/book_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/inner_dropshadow"
android:layout_width="80dp"
android:layout_height="100dp"
android:scaleType="fitXY"
app:layout_constraintBottom_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#drawable/bookdropshadow" />
</android.support.constraint.ConstraintLayout>
And then I enlarged it to 150x 180. And then Level 4-6 row completely disappeared no matter how much I scroll up. I only expected the recyclerview to display larger images. Why does this happen?
[EDIT] I ran a debug and it seems only 3 positions are bound in the outer adapter when the app is run on a phone but there are 4 positions when run on a tablet.
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/book_container"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="#+id/inner_dropshadow"
android:layout_width="150dp"
android:layout_height="180dp"
android:scaleType="fitXY"
app:layout_constraintBottom_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="#drawable/bookdropshadow" />
</android.support.constraint.ConstraintLayout>
Please note that this also happens when I run the app on a device. In a tablet, it shows all the Levels, while on a phone, it only shows Levels 1-3.
Outer recyclerview layout
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/mainlayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/color_white">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.v4.widget.SwipeRefreshLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:id="#+id/swiperefresh"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toTopOf="#+id/toolbar">
<ScrollView
android:id="#+id/scrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:overScrollMode="always">
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<include layout="#layout/browsebooksheader_layout"
android:id="#+id/bb_header"
app:layout_constraintBottom_toTopOf="#+id/guidelinetop"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="parent"/>
<android.support.constraint.Guideline
android:id="#+id/guidelinetop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.30"/>
<Button
android:id="#+id/btn_search"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal"
android:background="#drawable/search_btn_border"
android:padding="8dp"
android:text="Search"
android:textSize="#dimen/browse_search_textsize"
android:textColor="#android:color/darker_gray"
app:layout_constraintBottom_toTopOf="#+id/recyclerview_main"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/bb_header" />
<ProgressBar
android:id="#+id/main_progressbar"
style="?android:attr/progressBarStyleSmall"
android:layout_marginTop="16dp"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_gravity="center"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:indeterminateTint="#color/color_grey"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/btn_search"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/recyclerview_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:nestedScrollingEnabled="false"
android:background="#color/color_white"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/btn_search"
app:layout_constraintBottom_toBottomOf="parent"/>
</android.support.constraint.ConstraintLayout>
</ScrollView>
</android.support.v4.widget.SwipeRefreshLayout>
<android.support.constraint.ConstraintLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:id="#+id/toolbar"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#id/swiperefresh"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent">
<include layout="#layout/toolbar_layout_wo_learn"/>
</android.support.constraint.ConstraintLayout>
</android.support.constraint.ConstraintLayout>
</android.support.constraint.ConstraintLayout>
Inner recyclerview layout
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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="wrap_content">
<TextView
android:id="#+id/book_category"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:text="Category Title"
android:textColor="#color/defaultdark_color"
android:textSize="#dimen/browse_category_textsize"
android:fontFamily="#font/vagroundedstd_bold"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:layout_width="#dimen/browse_seeall_imagesize"
android:layout_height="#dimen/browse_seeall_imagesize"
android:layout_marginBottom="2dp"
android:layout_marginTop="2dp"
android:layout_marginEnd="8dp"
android:id="#+id/see_all_btn"
android:src="#drawable/seeall"
app:layout_constraintBottom_toTopOf="#+id/inner_recyclerview"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<android.support.v7.widget.RecyclerView
android:id="#+id/inner_recyclerview"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:nestedScrollingEnabled="false"
android:background="#color/color_white"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#+id/book_category"/>
<TextView
android:id="#+id/h_line"
android:layout_width="match_parent"
android:layout_height="0.8dp"
android:background="#color/color_grey"
android:gravity="center"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
android:alpha="0.5"
app:layout_constraintTop_toBottomOf="#id/inner_recyclerview"/>
</android.support.constraint.ConstraintLayout>
Outer Adapter
class BrowseBooksAdapter : RecyclerView.Adapter<BrowseBooksAdapter.SimpleViewHolder>() {
private var sortedList : SortedMap<String, List<ResourcesList>> = emptyMap<String, List<ResourcesList>>().toSortedMap()
fun setData(sortedList : SortedMap<String, List<ResourcesList>>) {
if (this.sortedList != sortedList) {
this.sortedList = sortedList
notifyDataSetChanged()
}
}
override fun getItemCount(): Int {
return sortedList.count()
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): SimpleViewHolder {
val view = LayoutInflater.from(parent.context).inflate(R.layout.browsebooks_layout, parent, false)
return SimpleViewHolder(view)
}
override fun onBindViewHolder(holder: SimpleViewHolder, position: Int) {
val dataList = ArrayList(sortedList.values)[position]
holder.category_text.text = ArrayList(sortedList.keys)[position]
holder.booksByCategory = dataList
holder.horizontalAdapter.setData(dataList)
}
class SimpleViewHolder(v: View, var booksByCategory : List<ResourcesList>? = null) : RecyclerView.ViewHolder(v) {
var recyclerView : RecyclerView = v.findViewById(R.id.inner_recyclerview)
var category_text : TextView = v.findViewById(R.id.book_category)
var fragmentCallback: FragmentCallback? = null
val horizontalAdapter: BooksByCategoryAdapter
init {
recyclerView.layoutManager = object : LinearLayoutManager(v.context, LinearLayoutManager.HORIZONTAL, false) {
override fun canScrollHorizontally(): Boolean {
return true
}
override fun canScrollVertically(): Boolean {
return false
}
}
horizontalAdapter = BooksByCategoryAdapter()
recyclerView.adapter = horizontalAdapter
fragmentCallback = v.context as FragmentCallback
var mLastClickTime : Long = 0
v.see_all_btn.setOnClickListener {
val category = v.book_category.text.toString()
// double-clicking prevention, using threshold of 1000 ms
if (!(SystemClock.elapsedRealtime() - mLastClickTime < 1000)){
mLastClickTime = SystemClock.elapsedRealtime()
if(fragmentCallback != null){
fragmentCallback!!.callBackSeeAllFragment(booksByCategory!!, category)
}
}
}
}
}
}
Inner Adapter
class BooksByCategoryAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
private var booksByCategory: List<ResourcesList> = emptyList()
fun setData(data: List<ResourcesList>) {
if (this.booksByCategory != data) {
this.booksByCategory = data
notifyDataSetChanged()
}
}
override fun getItemCount(): Int {
return booksByCategory.size
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
val layoutInflater = LayoutInflater.from(parent.context)
val cellForRow = layoutInflater.inflate(R.layout.bookcontainer_layout, parent, false)
return CustomVH(cellForRow)
}
override fun onBindViewHolder(rawHolder: RecyclerView.ViewHolder, position: Int) {
val holder = rawHolder as CustomVH
val booksProcessModel = BooksProcessModel()
booksProcessModel.setItem(booksByCategory[position])
holder.booksByCategory = booksByCategory[position]
Picasso.get().load(booksByCategory[position].coverURI).into(holder.inner_bookcover)
}
private inner class CustomVH(v: View, var booksByCategory : ResourcesList? = null): RecyclerView.ViewHolder(v) {
var inner_bookcover : ImageView = v.findViewById(R.id.inner_bookcover)
var fragmentCallback: FragmentCallback? = null
var ctx : Context = v.context
var mLastClickTime : Long = 0
init {
fragmentCallback = ctx as FragmentCallback
v.setOnClickListener {
// double-clicking prevention, using threshold of 1000 ms
if (!(SystemClock.elapsedRealtime() - mLastClickTime < 1000)){
mLastClickTime = SystemClock.elapsedRealtime()
if(fragmentCallback != null){
fragmentCallback!!.callBackDownloadBookFragment(booksByCategory!!)
}
}
}
}
}
class BooksProcessModel {
private var processBooks : ResourcesList? = null
fun setItem(books: ResourcesList) {
this.processBooks = books
}
fun setVisibility(ctx: Context) : Int {
val sp = PreferenceManager.getDefaultSharedPreferences(ctx)
val page = sp.getString(processBooks!!.id.toString(), "")
if (page != "") {
return View.VISIBLE
}
return View.INVISIBLE
}
}
}

You need to change the layout_height of the outer recycler view to wrap_content.

Nevermind, figured it out. I should be using a NestedScrollView instead of a ScrollView. The missing items were still there. It's just that I couldn't scroll the nested recyclerview.

In my case it was because I had the RecyclerView directly and even though it scrolled (horizontally), the same thing happened to me if for example the keyboard appeared.
Solution: Put the RecyclerView inside a NestedScrollView and delegate the scroll to it, like this:
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:listitem="#layout/item"/>
</androidx.core.widget.NestedScrollView>

Data List isn't showing up in the Recycler View in the main activity in android app , using kotlin for development.

activity_main.xml code:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.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"
tools:context="sampleex_recycleview.himanshu.recycleview.MainActivity">
<android.support.v7.widget.RecyclerView
android:id="#+id/RecViewId"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
Data List for RecyclerView in main activity, list_row.xml code:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:background="#color/cardview_shadow_end_color"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.CardView
android:layout_width="375dp"
android:layout_height="140dp"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="4dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/imageViewPhoto"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_centerVertical="true"
android:layout_marginStart="13dp"
android:padding="25dp"
app:srcCompat="#mipmap/ic_launcher_round" />
<TextView
android:id="#+id/AgeTextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_below="#+id/NameTextView"
android:layout_marginTop="14dp"
android:layout_toRightOf="#id/imageViewPhoto"
android:hint="age"
android:padding="5dp" />
<TextView
android:id="#+id/NameTextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignTop="#+id/imageViewPhoto"
android:layout_marginTop="22dp"
android:layout_toEndOf="#+id/imageViewPhoto"
android:hint="name"
android:padding="5dp" />
</RelativeLayout>
</android.support.v7.widget.CardView>
Main Activity code here :
class MainActivity : AppCompatActivity() {
private var adapter : PersonListAdapter? = null
private var layoutManager : RecyclerView.LayoutManager? = null
private var personList : ArrayList<Person>? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
personList = ArrayList<Person>()
layoutManager = LinearLayoutManager(this)
adapter = PersonListAdapter(personList!!, this)
//set up recycle view
RecViewId.layoutManager = layoutManager
RecViewId.adapter = adapter
// loading data
for(i in 1..15){
var person = Person()
person.name = "Person " + i
person.age = 21 + i
}
adapter!!.notifyDataSetChanged()
}
}
Adapter Class' code (exists in package name 'Data') :
// adapter class for the inflating layout for list in the recycler view and parsing data into the feild components of the layout
class PersonListAdapter(private var list : ArrayList<Person>, var context: Context) :
RecyclerView.Adapter<PersonListAdapter.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup?, viewType: Int): ViewHolder {
val view = LayoutInflater.from(context).inflate(R.layout.list_row, parent, false)
return ViewHolder(view)
}
override fun onBindViewHolder(holder: ViewHolder?, position: Int) {
holder?.bindItem(list[position])
}
override fun getItemCount(): Int {
return list.size
}
class ViewHolder(itemView : View) : RecyclerView.ViewHolder(itemView) {
fun bindItem(person: Person){
var Name : TextView = itemView.findViewById(R.id.NameTextView) as TextView
var Age : TextView = itemView.findViewById(R.id.AgeTextView) as TextView
Name.text = person.name
Age.text = person.age.toString()
}
}
}
Person Class' code (exists in different package name 'Model'):
// class for the layout of the data to be shown in the data list in the Recycler view in the main activity
class Person{
var name : String? = null
var age : Int? = null
}

Your just creating person object. Those objects need to be added to the personList.
for(i in 1..15){
var person = Person()
person.name = "Person " + i
person.age = 21 + i
personList.add(person) // Add person object to the list
}
Also you aren't correctly initializing the RecyclerView in the above code.
//set up recycle view
val recView = findViewById<RecyclerView>(R.id.RecViewId)
recView.layoutManager = layoutManager
recView.adapter = adapter

Let's try this code:
<android.support.v7.widget.RecyclerView
android:id="#+id/RecViewId"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginBottom="8dp"
android:layout_marginEnd="8dp"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
and set fixed size for RecyclerView