Develop Reference

How to call a method in adapter from a fragment in kotlin?

I have been trying to call a function from fragment to adapter, but I can't approach it right.
I want to invisible the button present in the fragment from adapter.
**My Adapter Code:**
package com.littleboo.brandlogo.Adapters
import android.R
import android.content.Context
import android.content.Intent
import android.graphics.Color
import android.graphics.drawable.ColorDrawable
import android.net.Uri
import android.os.Build
import android.os.VibrationEffect
import android.os.Vibrator
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.view.animation.Animation
import android.view.animation.AnimationUtils
import android.widget.Button
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import androidx.core.content.ContextCompat.getSystemService
import androidx.recyclerview.widget.RecyclerView
import com.littleboo.brandlogo.Fragments.QuizFragment
import com.littleboo.brandlogo.MainActivity
import com.littleboo.brandlogo.Models.Question
import com.littleboo.brandlogo.databinding.ActivityMainBinding.inflate
import com.littleboo.brandlogo.databinding.FragmentQuizBinding
import kotlinx.coroutines.NonDisposableHandle.parent
class QuestionAdap(val context: Context, val question: Question) :
RecyclerView.Adapter<QuestionAdap.OptionViewHolder>() {
var index = 1
var score = 0
val animShake: Animation = AnimationUtils.loadAnimation(context, com.littleboo.brandlogo.R.anim.shake)
private var options: List<String> = listOf(question.option1, question.option2, question.option3, question.option4)
inner class OptionViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView){
var optionView = itemView.findViewById<TextView>(com.littleboo.brandlogo.R.id.quiz_option)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): OptionViewHolder {
val view = LayoutInflater.from(context).inflate(com.littleboo.brandlogo.R.layout.quizoptions, parent, false)
return OptionViewHolder(view)
}
override fun onBindViewHolder(holder: OptionViewHolder, position: Int) {
holder.optionView.text = options[position]
holder.itemView.setOnClickListener {
question.userAnswer = options[position]
notifyDataSetChanged()
}
if(question.userAnswer == options[position] && question.userAnswer == question.answer){
holder.itemView.setBackgroundResource(com.littleboo.brandlogo.R.drawable.option_item_selected_bg)
score += 10
Toast.makeText(context,"Score is $score", Toast.LENGTH_SHORT).show()
}
else if(question.userAnswer == options[position] && question.userAnswer != question.answer){
holder.itemView.setBackgroundResource(com.littleboo.brandlogo.R.drawable.wrong_option_item_selected_bg)
holder.itemView.startAnimation(animShake)
}
else{
holder.itemView.setBackgroundResource(com.littleboo.brandlogo.R.drawable.non_option_item_selected_bg)
}
}
override fun getItemCount(): Int {
return options.size
}
}
My Quiz Fragment Code:
package com.littleboo.brandlogo.Fragments
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import androidx.fragment.app.Fragment
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import androidx.swiperefreshlayout.widget.CircularProgressDrawable
import com.bumptech.glide.Glide
import com.google.firebase.firestore.FirebaseFirestore
import com.littleboo.brandlogo.Adapters.QuestionAdap
import com.littleboo.brandlogo.Models.Question
import com.littleboo.brandlogo.Models.quizmodel
import com.littleboo.brandlogo.R
import com.littleboo.brandlogo.databinding.FragmentQuizBinding
class QuizFragment : Fragment(){
lateinit var binding: FragmentQuizBinding
var quizzes: MutableList<quizmodel>? = null
private var questions = mutableMapOf<String, Question>()
private lateinit var mArraylist: ArrayList<Question>
var index = 1
private lateinit var mfirestore: FirebaseFirestore
private lateinit var mrecycler: RecyclerView
lateinit var myadapter: QuestionAdap
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding = FragmentQuizBinding.inflate(layoutInflater)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
mrecycler = binding.optionList
mrecycler.layoutManager
myadapter = QuestionAdap(requireContext(),Question())
mArraylist = arrayListOf()
questions.map { it.key to it.value }.shuffled().toMap()
setUpFirestore()
setUpEventListener()
}
override fun onDestroy() {
super.onDestroy()
mfirestore.terminate()
// finish()
}
private fun setUpEventListener() {
binding.nextbtn.setOnClickListener {
index++
bindViews()
}
// binding.btnSubmit.setOnClickListener {
// Log.d("FINALQUIZ", questions.toString())
// val intent = Intent(this, ResultActivity::class.java)
// val json = Gson().toJson(quizzes!![0])
// intent.putExtra("QUIZ", json)
// startActivity(intent)
// finish()
// }
}
private fun setUpFirestore() {
mfirestore = FirebaseFirestore.getInstance()
val quizTitle = activity?.intent?.getStringExtra("title")
if (quizTitle != null) {
mfirestore.collection("Quizes").whereEqualTo("title", quizTitle)
.get()
.addOnSuccessListener {
if (it != null && !it.isEmpty) {
quizzes = it.toObjects(quizmodel::class.java)
questions = quizzes!![0].questions
shuffle()
bindViews()
}
}
}
}
private fun bindViews() {
// btnPrevious.visibility = View.GONE
// binding.btnSubmit.visibility = View.GONE
// binding.btnNext.visibility = View.GONE
// if (index == 1) { //first question
// binding.btnNext.visibility = View.VISIBLE
// } else if (index == questions!!.size) { // last question
// binding.btnSubmit.visibility = View.VISIBLE
//// btnPrevious.visibility = View.VISIBLE
// } else { // Middle
//// btnPrevious.visibility = View.VISIBLE
// binding.btnNext.visibility = View.VISIBLE
// }
val circularProgressDrawable = CircularProgressDrawable(requireContext())
circularProgressDrawable.strokeWidth = 8f
// circularProgressDrawable.colorFilter = ("#ac5fe1")
circularProgressDrawable.centerRadius = 30f
circularProgressDrawable.start()
val question = questions!!["question$index"]
question?.let {
Glide.with(this).load(it.imagequiz).placeholder(circularProgressDrawable).into(binding.imagequiz)
val optionAdapter = QuestionAdap(requireContext(), it)
mrecycler.layoutManager = LinearLayoutManager(requireContext())
mrecycler.adapter = optionAdapter
mrecycler.setHasFixedSize(true)
}
}
private fun shuffle() {
val keys = questions.keys.toMutableList().shuffled()
val values = questions.values.toMutableList().shuffled()
keys.forEachIndexed { index, key ->
questions[key] = values[index]
}
}
}
I tried calling fragment in adapter like:
QuizFragment().binding.btnxt.visibility = View.Visible
in BindViewHolder function.
Thank You

You can use kotlin lambda function to achieve it. Like this
class QuestionAdap(val context: Context, val question: Question, var onItemClicked: ((boolean) -> Unit))
call onItemClicked in your adapter where you want it
and in fragment
myadapter = QuestionAdap(requireContext(),Question()) { boolean ->
if (boolean) {
//hide/show
} else {
//hide/show
}
}

You can use the Callback functions of kotlin in your fragment, which will be passed into your adapter. So whenever you invoke that callback from your adapter, it will be triggered in your fragment.
Step 1: Create a method like the one below in your fragment.
private fun showHideButtonFromAdapter (
isButtonVisible: Boolean
) {
// set your button visibility according to isButtonVisible value.
}
Step 2: pass a method from your fragment to adapter as argument
val adapter = YourAdapter(::showHideButtonFromAdapter)
// set above adapter in your recycler view.
Step 3: In your adapter invoke that callback function like the one below.
class ColorPickerAdapter constructor(
private val onItemClicked: (Boolean) -> Unit
) : RecyclerView.Adapter<YourAdapter.ViewHolder>() {
// your other adapter methods here
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
onItemClicked.invoke(pass true or false as per your requirement)
// above invocation will trigger an event in the fragment.
}
}

In your adapter there need to be instance of your fragment, so change it like:
class QuestionAdap(val context: Context, val question: Question, fragment: Fragment) :
RecyclerView.Adapter<QuestionAdap.OptionViewHolder>() {
Then you can call your fragment by simply writing fragment in your adapter like:
override fun onBindViewHolder(holder: OptionViewHolder, position: Int) {
holder.optionView.text = options[position]
holder.itemView.setOnClickListener {
question.userAnswer = options[position]
notifyDataSetChanged()
}
//Example
fragment.shuffle()
And you need to send this fragment instance when you create it's adapter, so in your fragment use this:
myadapter = QuestionAdap(requireContext(),Question(), this)

Getting first index of each list in a nested list in Kotlin

I'm retrieving a list of lists from an API in JSON. This is how the response looks like.
{
"result":"success",
"documentation":"https://www.exchangerate-api.com/docs",
"terms_of_use":"https://www.exchangerate-api.com/terms"
"supported_codes":[
["AED","UAE Dirham"],
["AFN","Afghan Afghani"],
["ALL","Albanian Lek"],
["AMD","Armenian Dram"],
["ANG","Netherlands Antillian Guilder"],
["AOA","Angolan Kwanza"],
["ARS","Argentine Peso"],
["AUD","Australian Dollar"],
["AWG","Aruban Florin"],
["AZN","Azerbaijani Manat"],
["BAM","Bosnia and Herzegovina Convertible Mark"],
["BBD","Barbados Dollar"] etc. etc.
]
}
And this is the data class
data class CurrencyResponse(
#Json(name="documentation") val documentation: String,
#Json(name="result") val result: String,
#Json(name="supported_codes") val supported_codes: List<List<String>>,
#Json(name="terms_of_use") val terms_of_use: String
)
I managed to get the list of lists(supported_codes) but what I want now is to get the first index of each list(AED,AFN,ALL,etc.) and store them in a list, convert it to an array, then use that array to populate my spinners. Can anyone help me out with that?
Below is the relevant code.
Thank you.
CurrencyRepository.kt
package com.example.currencyconverter.data
import com.example.currencyconverter.BuildConfig
import javax.inject.Inject
import javax.inject.Singleton
#Singleton
class CurrencyRepository #Inject constructor(private val currencyApi: CurrencyApi) {
suspend fun getConversionRate(baseCurrency: String, toCurrency: String, amount: Double?): ConversionResponse {
return currencyApi.convert(BuildConfig.API_KEY, baseCurrency, toCurrency, amount)
}
suspend fun getCurrencies(): List<String> {
return currencyApi.getCurrencies(BuildConfig.API_KEY).supported_codes
}
}
CurrencyViewModel.kt
package com.example.currencyconverter.ui
import androidx.lifecycle.LiveData
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.ViewModel
import androidx.lifecycle.viewModelScope
import com.example.currencyconverter.data.CurrencyRepository
import dagger.hilt.android.lifecycle.HiltViewModel
import kotlinx.coroutines.launch
import javax.inject.Inject
#HiltViewModel
class CurrencyViewModel #Inject constructor(private val repository: CurrencyRepository): ViewModel() {
private val _conversionResult = MutableLiveData<String>()
val conversionResult: LiveData<String> = _conversionResult
private val _currencies = MutableLiveData<List<String>>()
val currencies: LiveData<List<String>> = _currencies
init {
getCurrencies()
}
fun getConversionRate(baseCurrency: String, toCurrency: String, amount: Double?) {
viewModelScope.launch {
_conversionResult.value = repository.getConversionRate(baseCurrency, toCurrency, amount).conversion_result
}
}
fun getCurrencies() {
viewModelScope.launch {
_currencies.value = repository.getCurrencies()
}
}
}
HomeFragment.kt
package com.example.currencyconverter.ui
import android.content.Context
import android.os.Bundle
import android.view.LayoutInflater
import android.view.MotionEvent
import android.view.View
import android.view.ViewGroup
import android.view.inputmethod.InputMethodManager
import android.widget.AdapterView
import android.widget.ArrayAdapter
import androidx.fragment.app.Fragment
import androidx.fragment.app.viewModels
import com.example.currencyconverter.R
import com.example.currencyconverter.databinding.FragmentHomeBinding
import dagger.hilt.android.AndroidEntryPoint
#AndroidEntryPoint
class HomeFragment : Fragment(R.layout.fragment_home) {
private val viewModel by viewModels<CurrencyViewModel>()
private var _binding: FragmentHomeBinding? = null
private val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_home, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
_binding = FragmentHomeBinding.bind(view)
lateinit var firstCurrency: String
lateinit var secondCurrency: String
viewModel.currencies.observe(viewLifecycleOwner) {
binding.list.text = " ${it[0]} , ${it[1]} "
}
var currenciesFormat = arrayOf(viewModel.currencies.value?.get(0),
viewModel.currencies.value?.get(1)
)
binding.apply {
spinnerFirst.adapter = ArrayAdapter(requireContext(), android.R.layout.simple_spinner_item, currenciesFormat)
spinnerFirst.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
override fun onItemSelected(
adapterView: AdapterView<*>?,
view: View?,
position: Int,
id: Long
) {
firstCurrency = adapterView?.getItemAtPosition(position).toString()
}
override fun onNothingSelected(p0: AdapterView<*>?) {
}
}
spinnerSecond.onItemSelectedListener = object : AdapterView.OnItemSelectedListener {
override fun onItemSelected(
adapterView: AdapterView<*>?,
view: View?,
position: Int,
id: Long
) {
secondCurrency = adapterView?.getItemAtPosition(position).toString()
}
override fun onNothingSelected(p0: AdapterView<*>?) {
}
}
}
binding.constraintLayout.setOnTouchListener(object : View.OnTouchListener {
override fun onTouch(p0: View?, p1: MotionEvent?): Boolean {
closeKeyboard(p0)
return true
}
})
binding.button.setOnClickListener {
val stringInTextField = binding.amountText.text.toString()
val amount = stringInTextField.toDoubleOrNull()
if (amount == null) {
binding.resultText.text = " "
}
closeKeyboard(binding.amountText)
viewModel.getConversionRate(firstCurrency, secondCurrency, amount)
viewModel.conversionResult.observe(viewLifecycleOwner) {
binding.resultText.text = it
}
}
}
private fun closeKeyboard(view: View?) {
val imm =
view?.context?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
if (view != null) {
imm.hideSoftInputFromWindow(view.windowToken, 0)
}
}
}

You can use kotlin.collections's map function. https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/map.html
fun main(){
val supportedCodes = listOf(
listOf("AED","UAE Dirham"),
listOf("AFN","Afghan Afghani"),
listOf("ALL","Albanian Lek")
)
val codes = supportedCodes.map { it[0] }
println(codes)
}
The output is a list containing just the first element from each nested list.
[AED, AFN, ALL]

App closes after intent activity change - Kotlin

I have an image gallery on a Fragment and I want to create a program that, once the user clicks on a certain image, the program redirects the user to an Activity where more details are presented. However, after implementing the Intent, the program just crashes when the Activity opens.
I don't know what I might be doing wrong as I do not have much experience with fragments (I believe it is something I'm doing wrong in the fragment intent)
Here's the code:
Fragment
package cm.a12872_a18797.favlist.fragments
import android.content.Context
import android.content.Intent
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.*
import androidx.fragment.app.Fragment
import cm.a12872_a18797.favlist.ImageDetailActivity
import cm.a12872_a18797.favlist.Modal
import cm.a12872_a18797.favlist.R
class HomeFragment : Fragment() {
lateinit var rootView: View
public val modalList = ArrayList<Modal>()
lateinit var gridView: GridView
private var descriptions = arrayOf(
"Golden Bridge", "Tampa Bay Buccaneers", "Chevrolet Camaro",
"Vegetable Casserole", "Sweet and Sour Chicken", "Design Vector",
"Pork Loin", "Sidney's Opera House", "Pasta Dish",
"Dope Setup", "Singapore", "Tacos Dish",
"Toquio", "Warm Salad Dish"
)
private var images = intArrayOf(
R.drawable.bridge, R.drawable.buccaneers, R.drawable.camaro,
R.drawable.casserole, R.drawable.chicken, R.drawable.design,
R.drawable.lombo, R.drawable.operahouse, R.drawable.pasta,
R.drawable.setup, R.drawable.singapore, R.drawable.tacos,
R.drawable.toquio, R.drawable.warmsalad
)
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
rootView = inflater.inflate(R.layout.fragment_home, container, false)
gridView = rootView.findViewById(R.id.home_grid)
for (i in descriptions.indices){
modalList.add(Modal(descriptions[i], images[i]))
}
var customAdapter = GridAdapter(modalList, this#HomeFragment.requireContext())
gridView.adapter = customAdapter
gridView.setOnItemClickListener() { adapterView, view, position, l ->
var intent = Intent(this#HomeFragment.requireContext(), ImageDetailActivity::class.java)
intent.putExtra("data", modalList[position])
startActivity(intent)
}
return rootView
}
class GridAdapter(var itemModel : ArrayList<Modal>, var context: Context): BaseAdapter(){
var layoutInflater = context.getSystemService(Context.LAYOUT_INFLATER_SERVICE) as LayoutInflater
override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {
var view = convertView
if (view == null){
view = layoutInflater.inflate(R.layout.home_grid_row, parent, false)
}
var imageViewName = view?.findViewById<ImageView>(R.id.grid_image)
imageViewName?.setImageResource(itemModel[position].image!!)
return view!!
}
override fun getItem(position: Int): Any {
return itemModel[position]
}
override fun getItemId(position: Int): Long {
return position.toLong()
}
override fun getCount(): Int {
return itemModel.size
}
}
}
Activity:
package cm.a12872_a18797.favlist
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.ImageView
import android.widget.TextView
import androidx.fragment.app.Fragment
import cm.a12872_a18797.favlist.fragments.HomeFragment
import cm.a12872_a18797.favlist.fragments.ListsFragment
import cm.a12872_a18797.favlist.fragments.SearchFragment
import com.google.android.material.bottomnavigation.BottomNavigationView
class ImageDetailActivity : AppCompatActivity() {
val TAG = "ImageDetailActivity"
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_image_detail)
//region Bottom Navigation Menu =====================================
val bottomNavigation: BottomNavigationView = findViewById(R.id.bottom_navigation)
val homeFragment = HomeFragment()
val listsFragment = ListsFragment()
val searchFragment = SearchFragment()
bottomNavigation.setOnNavigationItemSelectedListener {
when (it.itemId) {
R.id.nav_home -> {
setCurrentFragment(homeFragment)
Log.i(TAG, "Home Selected")
}
R.id.nav_lists -> {
setCurrentFragment(listsFragment)
Log.i(TAG, "My Lists Selected")
}
R.id.nav_search -> {
setCurrentFragment(searchFragment)
Log.i(TAG, "Search Selected")
}
}
true
}
//endregion ==
val detailText = findViewById<TextView>(R.id.detailText)
val detailImage = findViewById<ImageView>(R.id.detailImage)
var modalItems: Modal = intent.getSerializableExtra("data") as Modal
detailText.text = modalItems.name
detailImage.setImageResource(modalItems.image!!)
}
private fun setCurrentFragment(fragment : Fragment) =
supportFragmentManager.beginTransaction().apply {
replace(R.id.fl_wrapper, fragment)
commit()
}
}
Modal Class:
package cm.a12872_a18797.favlist
import java.io.Serializable
class Modal : Serializable {
var name:String? = null
var image:Int? = null
constructor(name:String, image:Int){
this.name = name
this.image = image
}
}

Android Paging library, Recyclerview, Retrofit, MVVM

I'm trying to build an app with Android Architecture Components. I'm using TMDB API in my app. In my app, a user searches for a movie or series and gets the result. I've achieved this but I want to get all the pages from API with Paging library. (Endless Recyclerview) I've looked at several tutorials but I didn't get what I wanted. Please help me, I'm new with this Android Architecture Components. Thank you in advance.
The API result:
RecyclerViewMovieAdapter
import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.bumptech.glide.Glide
import com.martiandeveloper.muuvi.R
import com.martiandeveloper.muuvi.model.Movie
import kotlinx.android.synthetic.main.recyclerview_movie_item.view.*
class RecyclerViewMovieAdapter(private val movieList: ArrayList<Movie>) :
RecyclerView.Adapter<RecyclerViewMovieAdapter.RecyclerViewMovieViewHolder>() {
lateinit var context: Context
class RecyclerViewMovieViewHolder(var view: View) : RecyclerView.ViewHolder(view)
override fun onCreateViewHolder(
parent: ViewGroup,
viewType: Int
): RecyclerViewMovieViewHolder {
context = parent.context
val view = LayoutInflater.from(context)
.inflate(R.layout.recyclerview_movie_item, parent, false)
return RecyclerViewMovieViewHolder(view)
}
override fun getItemCount(): Int {
return movieList.size
}
override fun onBindViewHolder(holder: RecyclerViewMovieViewHolder, position: Int) {
if (movieList[position].mediaType != "person") {
if (movieList[position].mediaType == "tv") {
val title =
movieList[position].originalName + " (" + movieList[position].firstAirDate?.split(
"-"
)?.get(0) + ")"
holder.view.recyclerview_movie_item_titleMTV.text = title
} else {
val title =
movieList[position].title + " (" + movieList[position].releaseDate?.split("-")
?.get(0) + ")"
holder.view.recyclerview_movie_item_titleMTV.text = title
}
holder.view.recyclerview_movie_item_voteAverageMTV.text =
movieList[position].voteAverage.toString()
Glide.with(context)
.load("https://image.tmdb.org/t/p/w300${movieList[position].posterPath}")
.placeholder(R.drawable.logo1)
.centerCrop()
.into(holder.view.recyclerview_movie_item_posterIV)
}
}
fun updateMovieList(newMovieList: List<Movie>) {
movieList.clear()
movieList.addAll(newMovieList)
notifyDataSetChanged()
}
}
Movie.kt
import com.google.gson.annotations.SerializedName
data class Movie(
#SerializedName("original_name")
val originalName: String?,
#SerializedName("genre_ids")
val genreIds: List<Int>?,
#SerializedName("media_type")
val mediaType: String?,
#SerializedName("name")
val name: String?,
#SerializedName("origin_country")
val originCountry: List<String>?,
#SerializedName("first_air_date")
val firstAirDate: String?,
#SerializedName("original_language")
val originalLanguage: String?,
#SerializedName("id")
val id: Int?,
#SerializedName("vote_average")
val voteAverage: Float?,
#SerializedName("overview")
val overview: String?,
#SerializedName("poster_path")
val posterPath: String?,
#SerializedName("title")
val title: String?,
#SerializedName("release_date")
val releaseDate: String?,
#SerializedName("original_title")
val originalTitle: String?)
MovieResult.kt
import com.google.gson.annotations.SerializedName
data class MovieResult(
#SerializedName("page")
val page: Int?,
#SerializedName("total_results")
val totalResults: Int?,
#SerializedName("total_pages")
val totalPages: Int?,
#SerializedName("results")
val results: ArrayList<Movie>?
)
MovieApi.kt
import com.martiandeveloper.muuvi.model.MovieResult
import io.reactivex.Single
import retrofit2.http.GET
import retrofit2.http.Query
interface MovieApi {
#GET("search/multi")
fun getMovie(
#Query("api_key") apiKey: String,
#Query("query") movie: String,
#Query("page") page: Int
): Single<MovieResult>
}
MovieService.kt
import com.martiandeveloper.muuvi.model.MovieResult
import io.reactivex.Single
import retrofit2.Retrofit
import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory
import retrofit2.converter.gson.GsonConverterFactory
const val API_KEY = "fb640042b4bc08f6f7f65fbd8573f2a9"
const val BASE_URL = "https://api.themoviedb.org/3/"
// https://api.themoviedb.org/3/search/multi?api_key=my_api_key&query=break&page=1
// https://image.tmdb.org/t/p/w342/or06FN3Dka5tukK1e9sl16pB3iy.jpg
class MovieService {
private val api =
Retrofit.Builder().baseUrl(BASE_URL).addConverterFactory(GsonConverterFactory.create())
.addCallAdapterFactory(RxJava2CallAdapterFactory.create()).build()
.create(MovieApi::class.java)
fun getData(movie: String, page: Int): Single<MovieResult> {
return api.getMovie(API_KEY, movie, page)
}
}
AddFragment.kt
import android.content.Context
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.view.inputmethod.InputMethodManager
import android.widget.Toast
import androidx.databinding.DataBindingUtil
import androidx.fragment.app.Fragment
import androidx.lifecycle.Observer
import androidx.lifecycle.ViewModelProviders
import androidx.recyclerview.widget.LinearLayoutManager
import com.martiandeveloper.muuvi.R
import com.martiandeveloper.muuvi.adapter.RecyclerViewMovieAdapter
import com.martiandeveloper.muuvi.databinding.FragmentAddBinding
import com.martiandeveloper.muuvi.viewmodel.AddViewModel
import kotlinx.android.synthetic.main.fragment_add.*
class AddFragment : Fragment(), View.OnClickListener {
private lateinit var vm: AddViewModel
private val adapter = RecyclerViewMovieAdapter(arrayListOf())
private lateinit var binding: FragmentAddBinding
private lateinit var layoutManager: LinearLayoutManager
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
vm = activity?.run {
ViewModelProviders.of(this)[AddViewModel::class.java]
} ?: throw Exception("Invalid activity")
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
binding =
DataBindingUtil.inflate(inflater, R.layout.fragment_add, container, false)
binding.addViewModel = vm
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
initUI()
}
private fun initUI() {
setRecyclerView()
observe()
setProgress(isRecyclerViewGone = false, isProgressLLViewGone = true)
binding.isClearIVGone = true
setListeners()
fragment_add_movieSeriesET.requestFocus()
val imm = context?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
imm.showSoftInput(fragment_add_movieSeriesET, InputMethodManager.SHOW_IMPLICIT)
}
private fun setRecyclerView() {
layoutManager = LinearLayoutManager(context)
fragment_add_mainRV.layoutManager = layoutManager
fragment_add_mainRV.adapter = adapter
}
private fun observe() {
vm.movieList.observe(viewLifecycleOwner, Observer { movieList ->
movieList?.let {
adapter.updateMovieList(it)
}
})
vm.isError.observe(viewLifecycleOwner, Observer { isError ->
isError?.let {
setProgress(isRecyclerViewGone = false, isProgressLLViewGone = true)
if (it) {
setToast(resources.getString(R.string.something_went_wrong_please_try_again_later))
}
}
})
vm.isLoading.observe(viewLifecycleOwner, Observer { isLoading ->
isLoading?.let {
if (it) {
setProgress(isRecyclerViewGone = true, isProgressLLViewGone = false)
} else {
setProgress(isRecyclerViewGone = false, isProgressLLViewGone = true)
}
}
})
vm.movieSeriesETContent.observe(viewLifecycleOwner, Observer {
if (it.isNotEmpty()) {
vm.refreshData(it, 1)
binding.isClearIVGone = false
} else {
adapter.updateMovieList(arrayListOf())
binding.isClearIVGone = true
}
})
}
private fun setProgress(isRecyclerViewGone: Boolean, isProgressLLViewGone: Boolean) {
if (vm.movieSeriesETContent.value != null) {
val text =
"${resources.getString(R.string.searching_for)} \"${vm.movieSeriesETContent.value}\"..."
binding.searchingFor = text
}
binding.isMainRVGone = isRecyclerViewGone
binding.isProgressLLGone = isProgressLLViewGone
}
private fun setToast(text: String) {
Toast.makeText(context, text, Toast.LENGTH_SHORT).show()
}
private fun setListeners() {
fragment_add_clearIV.setOnClickListener(this)
}
override fun onClick(v: View?) {
if (v != null) {
when (v.id) {
R.id.fragment_add_clearIV -> fragment_add_movieSeriesET.text.clear()
}
}
}
}
AddViewModel.kt
import androidx.lifecycle.MutableLiveData
import androidx.lifecycle.ViewModel
import com.martiandeveloper.muuvi.model.MovieResult
import com.martiandeveloper.muuvi.model.Movie
import com.martiandeveloper.muuvi.service.MovieService
import io.reactivex.android.schedulers.AndroidSchedulers
import io.reactivex.disposables.CompositeDisposable
import io.reactivex.observers.DisposableSingleObserver
import io.reactivex.schedulers.Schedulers
class AddViewModel : ViewModel() {
private val movieService = MovieService()
private val disposable = CompositeDisposable()
val movieList = MutableLiveData<ArrayList<Movie>>()
val isError = MutableLiveData<Boolean>()
val isLoading = MutableLiveData<Boolean>()
val movieSeriesETContent = MutableLiveData<String>()
fun refreshData(movie: String, page: Int) {
isLoading.value = true
disposable.add(
movieService.getData(movie, page).subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribeWith(object : DisposableSingleObserver<MovieResult>() {
override fun onSuccess(t: MovieResult) {
movieList.value = t.results
isError.value = false
isLoading.value = false
}
override fun onError(e: Throwable) {
isError.value = true
isLoading.value = false
}
})
)
}
}

loadAfter method of Android Paging library calls itself continuously

Just after calling loadInitial method it automatically starts calling loadAfter method until and unless all pages are loaded and it gets an empty array from response. I am attaching my DataSource and DataSourceFactory code along with ViewModel function and PagedListAdapter.
PassbookDataSource.kt
package co.indiagold.gold.buy.loan.home
import androidx.paging.PageKeyedDataSource
import co.indiagold.gold.buy.loan.helper.GenericMethods.handleServerError
import co.indiagold.gold.buy.loan.helper.GenericResponse
import co.indiagold.gold.buy.loan.network.Repository
import co.indiagold.gold.buy.loan.network.ResultWrapper
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.launch
class PassbookDataSource(private val accessToken: String, private val assetName:String,private val viewModelScope: CoroutineScope) : PageKeyedDataSource<Int, PassbookResponseModel>() {
private val PAGE_SIZE = 20
override fun loadInitial(params: LoadInitialParams<Int>, callback: LoadInitialCallback<Int, PassbookResponseModel>) {
var result: ResultWrapper<GenericResponse<ArrayList<PassbookResponseModel>?>?>? = null
viewModelScope.launch {
result = Repository.getPassbookDetail(accessToken, assetName,1, PAGE_SIZE)
}.invokeOnCompletion {
if (result is ResultWrapper.Success) {
val successResult = result as ResultWrapper.Success
callback.onResult(successResult.value!!.result as MutableList<PassbookResponseModel>, null, 2)
} else {
it.handleServerError("vault/passbook")
}
}
}
override fun loadBefore(params: LoadParams<Int>, callback: LoadCallback<Int, PassbookResponseModel>) {
}
override fun loadAfter(params: LoadParams<Int>, callback: LoadCallback<Int, PassbookResponseModel>) {
var result: ResultWrapper<GenericResponse<ArrayList<PassbookResponseModel>?>?>? = null
viewModelScope.launch {
result = Repository.getPassbookDetail(accessToken,assetName, params.key, PAGE_SIZE)
}.invokeOnCompletion {
if (result is ResultWrapper.Success) {
val successResult = result as ResultWrapper.Success
callback.onResult(successResult.value!!.result as MutableList<PassbookResponseModel>, params.key+1)
} else {
it.handleServerError("vault/passbook")
}
}
}
}
PassbookDataSourceFactory.kt
class PassbookDataSourceFactory(private val accessToken:String,private val assetName:String,private val viewModelScope:CoroutineScope) : DataSource.Factory<Int,PassbookResponseModel>(){
val orderListMLD = MutableLiveData<PassbookDataSource>(null)
var orderDataSource : PassbookDataSource? = null
override fun create(): DataSource<Int, PassbookResponseModel> {
orderDataSource = PassbookDataSource(accessToken,assetName,viewModelScope)
orderListMLD.postValue(orderDataSource)
return orderDataSource!!
}
}
Viewmodel Function
fun getPassbookDetail(assetName: String) {
val accessToken = GenericMethods.getDataFromPreferences(Constants.SHARED_PREFS.LOGIN_PREFERENCES, Constants.SHARED_PREFS.ACCESS_TOKEN)
if (accessToken.isNullOrEmpty()) {
handleNullAccessTokenCase()
} else {
val factory = PassbookDataSourceFactory(accessToken, assetName, viewModelScope)
val config = PagedList.Config.Builder()
.setEnablePlaceholders(true)
.setInitialLoadSizeHint(10)
.setPrefetchDistance(4)
.build()
val executor = Executors.newFixedThreadPool(5)
passbookResponseMLD = LivePagedListBuilder(factory, config)
.setFetchExecutor(executor)
.build()
}
}
PassbookAdapter.kt
package co.indiagold.gold.buy.loan.home
import android.app.Activity
import android.content.Intent
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.paging.PagedList
import androidx.paging.PagedListAdapter
import androidx.recyclerview.widget.DiffUtil
import androidx.recyclerview.widget.RecyclerView
import co.indiagold.gold.buy.loan.databinding.CardPassbookBinding
import co.indiagold.gold.buy.loan.helper.Constants
import co.indiagold.gold.buy.loan.orders.OrdersActivity
import kotlinx.android.synthetic.main.card_passbook.view.*
class PassbookAdapter(private val activity: Activity,private val emptyListListener: EmptyListListener) : PagedListAdapter<PassbookResponseModel,PassbookAdapter.MyHolder>(PASSBOOK_DIFF_CALLBACK) {
private lateinit var binding: CardPassbookBinding
class MyHolder(itemView : View) : RecyclerView.ViewHolder(itemView)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyHolder {
binding = CardPassbookBinding.inflate(LayoutInflater.from(parent.context))
emptyListListener.onListLoad(currentList?.size)
return MyHolder(binding.root)
}
override fun onCurrentListChanged(previousList: PagedList<PassbookResponseModel>?, currentList: PagedList<PassbookResponseModel>?) {
super.onCurrentListChanged(previousList, currentList)
emptyListListener.onListLoad(currentList?.size)
}
override fun onBindViewHolder(holder: MyHolder, position: Int) {
binding.passbookEntry = getItem(position)
holder.itemView.passbookRootLayout.setOnClickListener {
val intent = Intent(activity,OrdersActivity::class.java)
intent.putExtra(Constants.BUNDLE_STRINGS.ORDER_ID,getItem(position)?.referenceId)
activity.startActivity(intent)
}
}
override fun getItemId(position: Int): Long {
return getItem(position)!!.createdAt
}
/*override fun getItemViewType(position: Int): Int {
return position
}*/
}
private val PASSBOOK_DIFF_CALLBACK = object : DiffUtil.ItemCallback<PassbookResponseModel>(){
override fun areItemsTheSame(oldItem: PassbookResponseModel, newItem: PassbookResponseModel): Boolean {
return oldItem.createdAt == newItem.createdAt
}
override fun areContentsTheSame(oldItem: PassbookResponseModel, newItem: PassbookResponseModel): Boolean {
return oldItem == newItem
}
}

The issue is, that you may put recycler view inside NextedScrollview or ScrollView, by removing scrollview it will work fine