Develop Reference

convert myAdapter synthetic to viewbinding

i'm confused, how can i update my adapter views from synthetic to viewbinding!
here is my code, how define viewbinding to viewHolder?
class PlayersListAdapter(
var items: ArrayList<MatchPlayer>
) :
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
val inflate: View =
LayoutInflater.from(parent.context)
.inflate(R.layout.item_team_player, parent, false)
return MatchSubstitutionHolder(inflate)
}
override fun onBindViewHolder(viewHolder: RecyclerView.ViewHolder, position: Int) {
viewHolder.itemView.lblPlayerName.text = "name"
}
class MatchSubstitutionHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
var view = itemView
}
override fun getItemCount(): Int {
return items.size
}
}

it's so easy like define viewbinding in fragment or activity
class PlayersListAdapter(
var items: ArrayList<MatchPlayer>
) :
RecyclerView.Adapter<TeamPlayersListAdapter.MatchSubstitutionHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MatchSubstitutionHolder {
val binding= ItemTeamPlayerBinding.inflate(LayoutInflater.from(parent.context),parent,false)
return MatchSubstitutionHolder(binding)
}
override fun onBindViewHolder(viewHolder: MatchSubstitutionHolder, position: Int) {
viewHolder.binding.lblPlayerName.text = "name"
}
class MatchSubstitutionHolder(val binding: ItemTeamPlayerBinding) : RecyclerView.ViewHolder(binding.root)
override fun getItemCount(): Int {
return items.size
}}

I think this is best for you
class PlayersListAdapter(var items: ArrayList<MatchPlayer>) :
RecyclerView.Adapter<TeamPlayersListAdapter.MatchSubstitutionHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MatchSubstitutionHolder {
val binding = ItemTeamPlayerBinding.inflate(LayoutInflater.from(parent.context), parent, false)
return MatchSubstitutionHolder(binding)
}
override fun getItemCount(): Int {
return items.size
}
override fun onBindViewHolder(viewHolder: MatchSubstitutionHolder, position: Int) {
viewHolder.bind(position)
}
class MatchSubstitutionHolder(val binding: ItemTeamPlayerBinding) : RecyclerView.ViewHolder(binding.root) {
fun bind(position: Int) {
val matchPlayer = items[position]
binding.lblPlayerName.text = "name"
}
}
}

Android: Values are not assigned when using data binding in my custom adapter

I'm trying to pass my binding variable for the adapter to the ViewHolder to assing values to the textviews in my adapter but the values are not assigned and the click listeners dont do anything.
Here's my adapter class:
class DoneAppointmentsAdapter(var context: DoneAppointmentsFragment, listener: ContentListener, var arrayList: List<Appointment>) :
RecyclerView.Adapter<DoneAppointmentsAdapter.ItemHolder>() {
private val listener: ContentListener = listener
private var binding: DoneAppointmentsAdapterBinding? = null
var activity = context
override fun onCreateViewHolder(
parent: ViewGroup,
viewType: Int
): ItemHolder {
val viewHolder = LayoutInflater.from(parent.context)
.inflate(R.layout.done_appointments_adapter, parent, false)
binding = DoneAppointmentsAdapterBinding.inflate(LayoutInflater.from(parent.context))
return ItemHolder(viewHolder,binding, parent.context)
}
override fun onBindViewHolder(holder: ItemHolder, position: Int) {
holder.bind(arrayList, listener)
}
override fun getItemCount(): Int {
return arrayList.size
}
class ItemHolder(view: View, var binding: DoneAppointmentsAdapterBinding?, val context: Context) : RecyclerView.ViewHolder(view) {
fun bind(listOfData: List<Appointment>, listener: ContentListener) {
val dataListItem = listOfData[adapterPosition]
binding?.donePatientItemName?.text = "${dataListItem.patientName}"
binding?.donePatientItemTime?.text = "Some date"
binding?.donePatientItemPatientInfo?.setOnClickListener {
tempAppointmentId = dataListItem.id
listener.onPatientHistoryViewClicked(dataListItem.requestedBy)
}
binding?.donePatientItemReviewCase?.setOnClickListener {
amendPrescriptionWarning(dataListItem,context)
}
binding.donePatientItemViewCase.setOnClickListener {
startPreview(dataListItem)
}
}
}
}

You have messed up inside onCreateViewHolder . you have created view twice once with the LayoutInflater.from(parent.context) and once with DoneAppointmentsAdapterBinding.inflate . There should be only one in this case onlyDoneAppointmentsAdapterBinding .
class DoneAppointmentsAdapter(var context: DoneAppointmentsFragment, listener: ContentListener, var arrayList: List<Appointment>) :
RecyclerView.Adapter<DoneAppointmentsAdapter.ItemHolder>() {
private val listener: ContentListener = listener
override fun onCreateViewHolder(
parent: ViewGroup,
viewType: Int
): ItemHolder {
val binding = DoneAppointmentsAdapterBinding.inflate(LayoutInflater.from(parent.context))
return ItemHolder(binding)
}
override fun onBindViewHolder(holder: ItemHolder, position: Int) {
holder.bind(arrayList, listener)
}
override fun getItemCount(): Int {
return arrayList.size
}
class ItemHolder (var binding: DoneAppointmentsAdapterBinding) : RecyclerView.ViewHolder(binding.root) {
fun bind(listOfData: List<Appointment>, listener: ContentListener) {
val dataListItem = listOfData[adapterPosition]
binding.donePatientItemName.text = "${dataListItem.patientName}"
binding.donePatientItemTime.text = "Some date"
binding.donePatientItemPatientInfo.setOnClickListener {
tempAppointmentId = dataListItem.id
listener.onPatientHistoryViewClicked(dataListItem.requestedBy)
}
binding.donePatientItemReviewCase.setOnClickListener {
amendPrescriptionWarning(dataListItem,binding.donePatientItemReviewCase.context)
}
binding.donePatientItemViewCase.setOnClickListener {
startPreview(dataListItem)
}
}
}
}
It should be like this . I have also removed extra useless arguments from ItemHolder .
To make it clear the problem with your code was RecyclerView.ViewHolder(view) you were passing view while you were doing all action and stuff on binding those holds are two different instances of View . Which should be fixed with above code.

Sharing recyclerview item ID with another fragment

Currently I have a recyclerview adapter that gets data from the database and displays it in the dashboard fragment. Once the item is clicked, I want to pass the item id to the details fragment to get the correct items information on the detailed view. How can I pass this ID to the detailed fragment?
Dashboard Fragment
class DashboardFragment : Fragment() {
private lateinit var viewModel: DashboardViewModel
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Get a reference to the binding object and inflate the fragment views.
val binding: DashboardFragmentBinding = DataBindingUtil.inflate(
inflater, R.layout.dashboard_fragment, container, false)
val application = requireNotNull(this.activity).application
val dataSource = NumberDatabase.getInstance(application).numberDatabaseDao
val viewModelFactory = DashboardViewModelFactory(dataSource, application)
// Get a reference to the ViewModel associated with this fragment.
val dashboardViewModel =
ViewModelProviders.of(
this, viewModelFactory).get(DashboardViewModel::class.java)
// To use the View Model with data binding, you have to explicitly
// give the binding object a reference to it.
binding.dashboardViewModel = dashboardViewModel
val adapter = CounterAdapter(CounterListener { nightId ->
dashboardViewModel.onCountClicked(nightId)
})
binding.counterList.adapter = adapter
dashboardViewModel.counts.observe(viewLifecycleOwner, Observer {
it?.let {
adapter.submitList(it)
}
})
}
Adapter
class CounterAdapter (val clickListener: CounterListener): ListAdapter<Number, CounterAdapter.ViewHolder>(NightDiffCallback()) {
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bind(getItem(position)!!, clickListener)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
return ViewHolder.from(parent)
}
class ViewHolder private constructor(val binding: ListItemCounterBinding) : RecyclerView.ViewHolder(binding.root){
fun bind(item: Number, clickListener: CounterListener) {
binding.night = item
binding.clickListener = clickListener
binding.executePendingBindings()
}
companion object {
fun from(parent: ViewGroup): ViewHolder {
val layoutInflater = LayoutInflater.from(parent.context)
val binding = ListItemCounterBinding.inflate(layoutInflater, parent, false)
return ViewHolder(binding)
}
}
}
}
class CounterListener(val clickListener: (nightId: Long) -> Unit) {
fun onClick(night: Number) = clickListener(night.nightId)
}

In your recyclerview
class RecipeRecyclerAdapter(
mFragmentCommunication: FragmentCommunication
) :
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
private var mFragmentCommunication: FragmentCommunication? = null
init {
this.mFragmentCommunication =mFragmentCommunication
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int):
RecyclerView.ViewHolder {
view = LayoutInflater.from(parent.context)
.inflate(
com.broadcast.recipeslistapp.R.layout.layout_recipe_list_item,
parent,
false
)
return RecipeViewHolder(view)
}
}
override fun getItemCount(): Int {
if (mRecipes.isNullOrEmpty()) {
return 0
} else {
return mRecipes!!.size
}
}
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
holder.itemView.setOnClickListener {
mFragmentCommunication!!.PassNightId(nightId = 1) //value of nightId
}
}
interface FragmentCommunication {
fun PassNightId(nightId: Int)
}
Fragment A from where you want to send data :
class RecipeListActivity : BaseActivity(),
RecipeRecyclerAdapter.FragmentCommunication {
private lateinit var layoutManager: LinearLayoutManager
}
private fun initRecyclerView() {
mAdapter = RecipeRecyclerAdapter( this)
val itemDecorator = VerticalSpacingItemDecorator(30);
recipe_list.addItemDecoration(itemDecorator);
recipe_list.adapter = mAdapter
layoutManager = LinearLayoutManager(this);
recipe_list.layoutManager = layoutManager
}
override fun PassNightId(nightId: Int) {
val testFragment = TestFragment()
val bundle = Bundle()
bundle.putString("nightId", "$nightId")
testFragment.arguments = bundle
supportFragmentManager.beginTransaction().replace(R.id.containerId,testFragment).commit()
}
}
Fragment B where you want to getData :
class TestFragment : Fragment()
{
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val nightId =arguments?.getString("nightId")
}
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.test_fragment,container,false)
}
}
This is how you can send data from on fragment to another fragment.

imageView is null in recyclerview viewholder

I want to set an onClick Listener to the imageView present in the recycler view. But whenever I pass the imageview from onViewCreated() method from the fragment, it is still null and throws a NullPointerException when I invoke setOnClickListener.
These are kotlin classes.
class ShowDuesFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? =
inflater.inflate(R.layout.fragment_show, container, false)
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
val adapter = Adapter(mutableListOf(..), fragmentmanager!!, imageView)
recycler_view.apply {
layoutManager = LinearLayoutManager(activity!!.applicationContext)
setHasFixedSize(true)
this.adapter = adapter
}
}
}
class Adapter(private val list: List<Due>, private val manager: FragmentManager, private val imageView: ImageView?) : RecyclerView.Adapter<ViewHolder> {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder =
ViewHolder(
LayoutInflater.from(parent.context).inflate(
R.layout.card_view,
parent,
false
),
parent.context,
manager,
imageView
)
override fun getItemCount() = list.size
override fun onBindViewHolder(holder: ViewHolder, position: Int) = holder.putData(list[position])
}
class ViewHolder(itemView: View, context: Context, manager: FragmentManager, imageView: ImageView? = null) :
RecyclerView.ViewHolder(itemView), DatePickerDialog.OnDateSetListener {
lateinit var item: Due
init {
Log.i("ViewHolder", (imageView == null).toString()) //log prints 'true'
imageView?.setOnClickListener {
val popup = PopupMenu(context, it)
popup.menuInflater.inflate(R.menu.menu_popup, popup.menu)
popup.setOnMenuItemClickListener { menuItem ->
when (menuItem.itemId) {
R.id.notify -> {
val datePicker = DatePickerFragment()
datePicker.show(manager, "DatePickerFragment")
}
}
context.toast((item as Due).name)
true
}
popup.show()
}
}
fun putData(due: Due) {
…
item = due
}
…
}
The log message I get is true and when I click on the imageView, it does not respond to my clicks. How do I successfully implement an onClickListener to my imageView?

You are never initializing the imageView. As you are using ( ?.) while setting onClickListner to ImageView, you are not getting any crash due to safe call. One better way to do this is:
class ShowDuesFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? =
inflater.inflate(R.layout.fragment_show, container, false)
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
val adapter = Adapter(mutableListOf(..), fragmentmanager!!)
recycler_view.apply {
layoutManager = LinearLayoutManager(activity!!.applicationContext)
setHasFixedSize(true)
this.adapter = adapter
}
}
}
class Adapter(private val list: List, private val manager: FragmentManager, private val imageView: ImageView?) : RecyclerView.Adapter {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder =
ViewHolder(
LayoutInflater.from(parent.context).inflate(
R.layout.card_view,
parent,
false
),
parent.context,
manager
)
override fun getItemCount() = list.size
override fun onBindViewHolder(holder: ViewHolder, position: Int) = holder.putData(list[position])
}
class ViewHolder(itemView: View, context: Context, manager: FragmentManager) :
RecyclerView.ViewHolder(itemView), DatePickerDialog.OnDateSetListener {
lateinit var item: Due
init {
val imageView = itemView //Cast this to image view if required you can use itemView.findViewById for other //views.
Log.i("ViewHolder", (imageView == null).toString()) //log prints 'true'
imageView?.setOnClickListener {
val popup = PopupMenu(context, it)
popup.menuInflater.inflate(R.menu.menu_popup, popup.menu)
popup.setOnMenuItemClickListener { menuItem ->
when (menuItem.itemId) {
R.id.notify -> {
val datePicker = DatePickerFragment()
datePicker.show(manager, "DatePickerFragment")
}
}
context.toast((item as Due).name)
true
}
popup.show()
}
}
fun putData(due: Due) {
…
item = due
}
…
}

should work if you change onViewCreated to:
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
val adapter = Adapter(mutableListOf(..), fragmentmanager!!, view.imageView) // Specify which imageView you mean, as there might be a bunch of these fragments or none, system doesn't know.
or, do the whole view.findViewById() thingy if you're not using the kotlinx thingies

The ViewHolder class should be inside the Adapter as an inner class. By doing so, imageView is not null.
Something like this:-
class Adapter (
private val list: List<Due>,
private val manager: FragmentManager
) : RecyclerView.Adapter<Adapter.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder =
ViewHolder(
LayoutInflater.from(parent.context).inflate(
R.layout.card_view,
parent,
false
),
parent.context
)
override fun getItemCount() = list.size
override fun onBindViewHolder(holder: ViewHolder, position: Int) = holder.putData(list[position])
inner class ViewHolder(itemView: View, context: Context) :
RecyclerView.ViewHolder(itemView) {
private lateinit var item: Due
init {
Log.i("ViewHolder", (imageView == null).toString()) //log prints 'false'
itemView.dropdown_menu.setOnClickListener {
val popup = PopupMenu(context, it)
popup.menuInflater.inflate(R.menu.menu_popup, popup.menu)
popup.setOnMenuItemClickListener { menuItem ->
when (menuItem.itemId) {
R.id.notify -> {
val datePickerFragment = DatePickerFragment()
datePickerFragment.show(manager, "date picker")
}
}
true
}
popup.show()
}
}
fun putData(due: Due) {
…
}
}
}
And we instantiate the Adapter like:-
val adapter = Adapter(mutableListOf(…), fragmentmanager!!)

ViewPager2 | View.ClickListener not called

I use new android widget ViewPager2 version 1.0.0-alpha03 and when I set click listener on it method onClick() not called.
My Actvity class:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
supportFragmentManager.beginTransaction()
.add(R.id.fragmentContent, SecondFragment.newInstance(), SecondFragment.TAG)
.addToBackStack(SecondFragment.TAG)
.commit()
}
}
My Fragment:
class SecondFragment : Fragment() {
companion object {
val TAG = SecondFragment::class.java.canonicalName
fun newInstance(): SecondFragment = SecondFragment()
}
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
return inflater.inflate(R.layout.fragment_second, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
viewPager2.setOnClickListener {
Log.d("logi", "click : ")
}
}
}
My layout xml file:
<androidx.coordinatorlayout.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.viewpager2.widget.ViewPager2
android:id="#+id/viewPager2"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Any assumption or workaround?

I found a solution! ViewPager2 contains RecyclerView and we must work with it as RecyclerView. I created RecyclerView.Adapter and set the ClickListener on itemView into the constructor RecyclerView.ViewHolder and VOILA!!!
in Fragment:
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
viewPager2.adapter = ViewPager2Adapter {
Log.d("logi", "clicked at : $it")
}
}
RecyclerView adapter:
class ViewPager2Adapter(private val itemClickListener: (Int) -> (Unit)) :
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
val items = mutableListOf<Any>()
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder =
ItemViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.item, parent, false))
override fun getItemCount(): Int = items.size
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
// bind your items
}
private inner class ItemViewHolder(itemView: View): RecyclerView.ViewHolder(itemView) {
init {
itemView.setOnClickListener {
Log.d("logi", "Click!") // WORKS!!!
itemClickListener(adapterPosition)
}
}
}
}

Another approach can be like below:
class MyAdapter(
private val items: List<Any>,
private val onItemClickListener: OnItemClickListener
) : RecyclerView.Adapter<MyAdapter.MyViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
val itemView = parent.inflate(R.layout.item_details_view_pager)
return MyViewHolder(itemView)
}
override fun getItemCount(): Int = items.size
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.imageView.apply {
setOnClickListener {
onItemClickListener.onItemClick(position)
}
...
}
}
inner class MyViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val imageView: ImageView = itemView.findViewById(R.id.some_image_view)
}
}
The constructor parameter onItemClickListener could be a lambda as well, but it's a simple interface for me:
interface OnItemClickListener {
fun onItemClick(position: Int)
}