Develop Reference

Communication between ViewPager's host Fragment and ViewPager's Fragment item

I have a Fragment(InsiraDocumentosFragment) that has a viewpager and in that fragment I initialize an adapter(InsiraDocumentoAdapter) to initialize the viewpager.
The adapter(InsiraDocumentoAdapter) initializes generic fragments (DocumentoFragment) that I update dynamically, I can now update the image that is shown inside it, but I need to get the click on that image to either change it or to remove it, but this needs to be done in the Fragment that contains the viewpager, because is in this fragment(InsiraDocumentosFragment) that I have the viewmodel that communicates with the database.
How can I watch from InsiraDocumentosFragment the click on the imageview of DocumentFragment ?
Here are my code samples.
class InsiraDocumentosFragment : Fragment() {
private lateinit var _view: View
private lateinit var _imgBack: ImageView
private lateinit var _viewpager: ViewPager
private lateinit var _imgCamera: ImageView
private lateinit var _footerTitle: TextView
private lateinit var _titles: List<String>
private lateinit var _files: MutableList<File?>
private lateinit var _viewModel: DocumentoViewModel
private lateinit var _viewModelProposta: PropostaViewModel
private lateinit var _viewModelArquivo: ArquivoViewModel
private lateinit var _adapter: InsiraDocumentoAdapter
private lateinit var _proposta: PropostaEntity
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? = inflater.inflate(R.layout.fragment_insira_documento, container, false)
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
_view = view
_imgBack = _view.findViewById(R.id.imgBack)
_viewpager = _view.findViewById(R.id.viewpager)
_imgCamera = _view.findViewById(R.id.cameraDocumento)
_footerTitle = _view.findViewById(R.id.footerTitle)
_files = mutableListOf(null, null, null)
_titles = listOf(getString(R.string.identidade), getString(R.string.comprovante_renda), getString(R.string.foto))
_adapter = InsiraDocumentoAdapter(_titles, _files, childFragmentManager)
_viewpager.adapter = _adapter
_viewModel = ViewModelProvider(
this,
DocumentoViewModel.DocumentoViewModelFactory(DocumentoRepositorio(AppDatabase.getDatabase(_view.context).documentoDao()))
).get(DocumentoViewModel::class.java)
_viewModelProposta = ViewModelProvider(
this,
PropostaViewModel.PropostaViewModelFactory(PropostaRepositorio(AppDatabase.getDatabase(_view.context).propostaDao()))
).get(PropostaViewModel::class.java)
_viewModelArquivo = ViewModelProvider(
this,
ArquivoViewModel.ArquivoViewModelFactory(ArquivoRepositorio(AppDatabase.getDatabase(_view.context).arquivoDao()))
).get(ArquivoViewModel::class.java)
addViewPagerListener()
onClickImgBack()
onClickImgCamera()
onClickFooterTitle()
val propostaStr = arguments?.getString(PROPOSTA)
if (!propostaStr.isNullOrBlank()) {
_proposta = jsonToObjProposta(propostaStr)
}
}
private fun addViewPagerListener() {
_viewpager.addOnPageChangeListener(object : OnPageChangeListener {
override fun onPageScrollStateChanged(state: Int) {}
override fun onPageScrolled(position: Int, positionOffset: Float, positionOffsetPixels: Int) {}
override fun onPageSelected(position: Int) {
if (position == _viewpager.adapter!!.count - 1) {
_footerTitle.text = getString(R.string.concluir)
} else {
_footerTitle.text = getString(R.string.proximo)
}
updateViewPagerLayout(position)
}
})
}
private fun updateViewPagerLayout(currentPage: Int) {
when (currentPage) {
0 -> {
habilitaIndicadorPagina(_view.findViewById(R.id.primeiraPagina), _view.findViewById(R.id.imgPrimeiraPagina), R.drawable.primeira_pagina_selecionada)
desabilitaIndicadorPagina(_view.findViewById(R.id.segundaPagina), _view.findViewById(R.id.imgSegundaPagina), R.drawable.segunda_pagina_nao_selecionada)
desabilitaIndicadorPagina(_view.findViewById(R.id.terceiraPagina), _view.findViewById(R.id.imgTerceiraPagina), R.drawable.terceira_pagina_nao_selecionada)
}
1 -> {
desabilitaIndicadorPagina(_view.findViewById(R.id.primeiraPagina), _view.findViewById(R.id.imgPrimeiraPagina), R.drawable.primeira_pagina_nao_selecionada)
habilitaIndicadorPagina(_view.findViewById(R.id.segundaPagina), _view.findViewById(R.id.imgSegundaPagina), R.drawable.segunda_pagina_selecionada)
desabilitaIndicadorPagina(_view.findViewById(R.id.terceiraPagina), _view.findViewById(R.id.imgTerceiraPagina), R.drawable.terceira_pagina_nao_selecionada)
}
2 -> {
desabilitaIndicadorPagina(_view.findViewById(R.id.primeiraPagina), _view.findViewById(R.id.imgPrimeiraPagina), R.drawable.primeira_pagina_nao_selecionada)
desabilitaIndicadorPagina(_view.findViewById(R.id.segundaPagina), _view.findViewById(R.id.imgSegundaPagina), R.drawable.segunda_pagina_nao_selecionada)
habilitaIndicadorPagina(_view.findViewById(R.id.terceiraPagina), _view.findViewById(R.id.imgTerceiraPagina), R.drawable.terceira_pagina_selecionada)
}
}
}
private fun desabilitaIndicadorPagina(layout: ConstraintLayout, image: ImageView, imageDrawable: Int) {
layout.setBackgroundResource(R.drawable.not_selected_indicator)
image.setBackgroundResource(imageDrawable)
}
private fun habilitaIndicadorPagina(layout: ConstraintLayout, image: ImageView, imageDrawable: Int, ) {
layout.setBackgroundResource(R.drawable.indicador_selecionado)
image.setBackgroundResource(imageDrawable)
}
private fun onClickFooterTitle() {
_footerTitle.setOnClickListener {
if (_viewpager.currentItem == _viewpager.adapter!!.count - 1) {
var success = true
for (i in 0..2) {
if (_files[i] == null || _files[i]?.path.isNullOrEmpty()) {
Toast.makeText(_view.context, R.string.favor_preencher_todas_as_fotos, Toast.LENGTH_LONG).show()
_viewpager.currentItem = i
success = false
break
}
}
if (success) {
_viewModelProposta.addProposta(_proposta.numeroProposta, _proposta.valorPropasta, _proposta.clienteId).observe(viewLifecycleOwner, { idProposta ->
_proposta.id = idProposta
_viewModel.addDocumento("Nome do Documento", _proposta.id).observe(viewLifecycleOwner, { idDocumento ->
val arquivos = mutableListOf<ArquivoEntity>()
for (i in 0..2) {
arquivos.add(ArquivoEntity(0, _files[i]!!.path, _titles[i], idDocumento))
}
_viewModelArquivo.addArquivos(arquivos).observe(viewLifecycleOwner, {
_view.findNavController().popBackStack(R.id.clienteFragment, false)
})
})
})
}
} else {
_viewpager.currentItem = _viewpager.currentItem + 1
}
}
}
private fun onClickImgBack() {
_imgBack.setOnClickListener {
_view.findNavController().navigateUp()
}
}
private fun onClickImgCamera() {
_imgCamera.setOnClickListener {
val intent = Intent(_view.context, ScannerActivity::class.java)
startActivityForResult(intent, REQUEST_CODE)
}
}
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
super.onActivityResult(requestCode, resultCode, data)
if (requestCode == REQUEST_CODE && resultCode == Activity.RESULT_OK) {
val mediaList = ScannerActivity.getOutputDirectory(_view.context).listFiles()?.toMutableList() ?: mutableListOf()
if (mediaList.size > 0) {
val documentoFile = mediaList[mediaList.size - 1]
_files.removeAt(_viewpager.currentItem)
_files.add(_viewpager.currentItem, documentoFile)
_adapter.notifyDataSetChanged()
}
}
}
private fun jsonToObjProposta(json: String): PropostaEntity {
val gson = Gson()
val arrayTutorialType = object : TypeToken<PropostaEntity>() {}.type
return gson.fromJson(json, arrayTutorialType)
}
override fun onResume() {
super.onResume()
_view = requireView()
}
companion object {
const val REQUEST_CODE = 1
const val IMAGE = "IMAGE"
const val ID_PROPOSTA = "ID_PROPOSTA"
const val PROPOSTA = "PROPOSTA"
}
}
class InsiraDocumentoAdapter(private val titles: List<String>, private var files: List<File?>, manager: FragmentManager): FragmentStatePagerAdapter(manager, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
override fun getCount() = 3
override fun getItem(position: Int): Fragment {
return DocumentoFragment.newInstance(titles[position], files[position])
}
override fun getItemPosition(`object`: Any): Int {
return POSITION_NONE
}
}
class DocumentoFragment : Fragment() {
private lateinit var _view: View
private lateinit var _documento: ImageView
private lateinit var _documentoShape: ImageView
private lateinit var _txtTitle: TextView
private var _file: File? = null
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? = inflater.inflate(R.layout.fragment_documento, container, false)
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
_view = view
}
private fun setUpView() {
_documento = _view.findViewById(R.id.documento)
_documentoShape = _view.findViewById(R.id.documentoShape)
_txtTitle = _view.findViewById(R.id.txtTitle)
_txtTitle.text = arguments?.getString(TITLE)
if (!arguments?.getString(FILE).isNullOrEmpty()) {
_file = File(arguments?.getString(FILE))
}
onImgClick()
insereImagem()
}
private fun onImgClick() {
_documento.setOnClickListener {
if (_documentoShape.visibility == View.GONE && _file != null) {
val intent = Intent(_view.context, FullScreenActivity::class.java)
intent.putExtra(InsiraDocumentosFragment.IMAGE, _file?.path)
intent.putExtra(TITLE, _txtTitle.text)
startActivity(intent)
}
}
}
private fun insereImagem() {
if (_file != null) {
Picasso.get().load(_file!!).into(_view.findViewById<ImageView>(R.id.documento))
_view.findViewById<ImageView>(R.id.documentoShape)?.visibility = View.GONE
} else {
_view.findViewById<ImageView>(R.id.documentoShape)?.visibility = View.VISIBLE
}
}
override fun onResume() {
super.onResume()
setUpView()
}
companion object {
fun newInstance(title: String, file: File?): DocumentoFragment {
val fragmentFirst = DocumentoFragment()
val args = bundleOf(
TITLE to title,
FILE to file?.path
)
fragmentFirst.arguments = args
return fragmentFirst
}
const val TITLE = "TITLE"
const val FILE = "FILE"
}
}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".documento.view.DocumentoFragment">
<TextView
android:id="#+id/txtTitle"
android:layout_width="wrap_content"
android:layout_height="#dimen/dimen_24dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
tools:text="Identidade"
android:textColor="#015669"
android:textSize="#dimen/dimen_20sp"
/>
<ImageView
android:id="#+id/documento"
android:layout_width="match_parent"
android:layout_height="0dp"
android:background="#ffffff"
android:src="#drawable/rectangle_white"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/txtTitle"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:scaleType="fitXY"
android:layout_marginTop="#dimen/dimen_20dp"
android:contentDescription="#string/foto_documento"/>
<ImageView
android:id="#+id/documentoShape"
android:layout_width="88dp"
android:layout_height="101dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:src="#drawable/document_shape"
android:contentDescription="#string/foto_documento"/>
</androidx.constraintlayout.widget.ConstraintLayout>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".documento.view.InsiraDocumentosFragment"
android:background="#f0f0f0">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="#dimen/dimen_56dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:background="#drawable/rectangle_blue_toolbar">
<ImageView
android:id="#+id/imgBack"
android:layout_width="#dimen/dimen_12dp"
android:layout_height="#dimen/dimen_20dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
android:layout_marginStart="#dimen/dimen_20dp"
android:layout_marginTop="18dp"
android:src="#drawable/tint_color"
android:contentDescription="#string/voltar"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:text="#string/insira_os_documentos"
android:textColor="#ffffff"
android:textSize="#dimen/dimen_20sp"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/pagerIndicator"
android:layout_width="wrap_content"
android:layout_height="#dimen/dimen_30dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="#id/toolbar"
android:layout_marginTop="#dimen/dimen_20dp">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/primeiraPagina"
android:layout_width="#dimen/dimen_30dp"
android:layout_height="#dimen/dimen_30dp"
android:background="#drawable/indicador_selecionado"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/segundaPagina"
android:layout_marginHorizontal="#dimen/dimen_10dp"
>
<ImageView
android:id="#+id/imgPrimeiraPagina"
android:layout_width="#dimen/dimen_9dp"
android:layout_height="#dimen/dimen_18dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:background="#drawable/primeira_pagina_selecionada"/>
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/segundaPagina"
android:layout_width="#dimen/dimen_30dp"
android:layout_height="#dimen/dimen_30dp"
android:background="#drawable/not_selected_indicator"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toEndOf="#id/primeiraPagina"
android:layout_marginHorizontal="#dimen/dimen_10dp"
>
<ImageView
android:id="#+id/imgSegundaPagina"
android:layout_width="#dimen/dimen_9dp"
android:layout_height="#dimen/dimen_18dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:background="#drawable/segunda_pagina_nao_selecionada"/>
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/terceiraPagina"
android:layout_width="#dimen/dimen_30dp"
android:layout_height="#dimen/dimen_30dp"
android:background="#drawable/not_selected_indicator"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toEndOf="#id/segundaPagina"
android:layout_marginHorizontal="#dimen/dimen_10dp"
>
<ImageView
android:id="#+id/imgTerceiraPagina"
android:layout_width="#dimen/dimen_9dp"
android:layout_height="#dimen/dimen_18dp"
android:layout_gravity="center"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:background="#drawable/terceira_pagina"/>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewpager"
android:layout_width="#dimen/dimen_280dp"
android:layout_height="0dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/pagerIndicator"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintBottom_toTopOf="#id/footer"
android:layout_marginHorizontal="#dimen/dimen_40dp"
android:layout_marginTop="#dimen/dimen_20dp"
android:layout_marginBottom="#dimen/dimen_20dp"/>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/footer"
android:layout_width="match_parent"
android:layout_height="#dimen/dimen_69dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
android:background="#drawable/footer">
<ImageView
android:id="#+id/imgDocumento"
android:layout_width="#dimen/dimen_26dp"
android:layout_height="#dimen/dimen_30dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginStart="#dimen/dimen_20dp"
android:layout_marginVertical="#dimen/dimen_20dp"
android:src="#drawable/combined_shape"
android:backgroundTint="#0179b0"
android:contentDescription="#string/formato_documento"
/>
<TextView
android:id="#+id/footerTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintStart_toEndOf="#id/imgDocumento"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toStartOf="#+id/cameraDocumento"
app:layout_constraintBottom_toBottomOf="parent"
android:textSize="#dimen/dimen_20sp"
android:textColor="#0179b0"
android:gravity="center"
android:text="#string/proximo"/>
<ImageView
android:id="#+id/cameraDocumento"
android:layout_width="#dimen/dimen_33dp"
android:layout_height="#dimen/dimen_30dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginEnd="#dimen/dimen_20dp"
android:layout_marginVertical="#dimen/dimen_20dp"
android:src="#drawable/camera_shape"
android:backgroundTint="#0179b0"
android:contentDescription="#string/capturar_foto"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

I need to get the click on that image to either change it or to remove it, but this needs to be done in the Fragment that contains the viewpager, because is in this fragment(InsiraDocumentosFragment) that I have the viewmodel that communicates with the database.
You have a couple of options to do that:
First one:
Make the ViewModel shared between both fragments (InsiraDocumentosFragment & DocumentoFragment) by instantiating it in both fragments with the activity as the owner using requireActivity() that hosts both fragments:
val viewModel =
ViewModelProvider(requireActivity()).get(MyViewModel::class.java)
And then no need to access the parent fragment for changing the image; because now you've an instance of the ViewModel in the DocumentoFragment.
Second one:
Access the InsiraDocumentosFragment from the DocumentoFragment using requireParentFragment(), but first create a method in parent that you want to call from the page fragment to do your needed job.
Assuming the method that you created in InsiraDocumentosFragment is someMethodInParent()
In DocumentoFragment:
val parentFragment = requireParentFragment() as InsiraDocumentosFragment
parentFragment.someMethodInParent()

RecyclerView Overwrite last element a couple times

I'm using MVVC pattern and I'm populating a recyclerView with data from database using Room. At the Logcat, data return correctly and is looped correctly, but recyclerview display seven elements and in the eighth starts to overwrite it with the nineth and tenth elements e after that create 2 more elements with the first 2 elements from list.
I'm coudn't find what is wrong with my code.
So, I'm asking for some help.
AvaliacaoFragment.kt:
class AvaliacaoFragment : Fragment() {
private lateinit var ctx: Context
private var _binding: FragmentAvaliacaoBinding? = null
// This property is only valid between onCreateView and
// onDestroyView.
private val binding get() = _binding!!
private lateinit var textoSemSecoes: TextView
private lateinit var nomeAvaliacao: TextView
private lateinit var dataAvaliacao: TextView
private val args by navArgs<AvaliacaoFragmentArgs>()
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
// Inflate the layout for this fragment
_binding = FragmentAvaliacaoBinding.inflate(inflater, container, false)
return binding.root
// return inflater.inflate(R.layout.fragment_avaliacoes, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
ctx = view.context
// dialogNovaAvaliacao = MaterialAlertDialogBuilder(ctx, android.R.style.Theme_DeviceDefault_Light_NoActionBar_Fullscreen)
// dialogNovaAvaliacao = MaterialAlertDialogBuilder(ctx,R.style.AlertDialogTheme)
// val builder = MaterialDatePicker.Builder.datePicker()
textoSemSecoes = view.findViewById(R.id.texto_sem_secoes)
nomeAvaliacao = view.findViewById(R.id.nome_avaliacao)
dataAvaliacao = view.findViewById(R.id.data_avaliacao)
nomeAvaliacao.text = args.currentAvaliacao.nome
dataAvaliacao.text = args.currentAvaliacao.dataCriacao
/*
btnAddAvaliacao = view.findViewById(R.id.btn_add_avaliacao)
btnAddAvaliacao.setOnClickListener {
findNavController().navigate(R.id.action_navigation_avaliacoes_to_addAvaliacaoFragment)
}
*/
// Recycler
val recyclerAdapter = SecaoAdapter()
val recyclerView = binding.secaoRecyclerView
recyclerView.adapter = recyclerAdapter
recyclerView.layoutManager = LinearLayoutManager(requireContext())
// ViewModelFactory para passar argumentos para a ViewModel
val factory = object : ViewModelProvider.Factory {
override fun <T : ViewModel?> create(modelClass: Class<T>): T {
return SecaoViewModel(Application(), args.currentAvaliacao.id) as T
}
}
// ViewModel
mSecaoViewModel = ViewModelProvider(this, factory).get(SecaoViewModel::class.java)
mSecaoViewModel.readAllData.observe(viewLifecycleOwner, Observer { secaoList ->
if(secaoList.isNotEmpty()){
Log.d(TAG, "secaoList: ${secaoList.toString()}")
Log.d(TAG, "secaoList.size: ${secaoList.size}")
textoSemSecoes.visibility = View.GONE
recyclerView.visibility = View.VISIBLE
recyclerAdapter.setData(secaoList.sortedBy { it.codigo.toInt() })
} else {
textoSemSecoes.visibility = View.VISIBLE
recyclerView.visibility = View.GONE
}
})
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
companion object {
private val TAG: String = AvaliacaoFragment::class.java.name
lateinit var mSecaoViewModel: SecaoViewModel
private lateinit var btnAddSecao: FloatingActionButton
private lateinit var dialogNovaSecao: MaterialAlertDialogBuilder
}
}
SecaoAdapter.kt:
class SecaoAdapter: RecyclerView.Adapter<SecaoAdapter.SecaoViewHolder>() {
private val TAG: String = SecaoAdapter::class.java.name
private var secaoList = emptyList<Secao>()
private lateinit var binding: ItemSecaoBinding
class SecaoViewHolder(itemBinding: ItemSecaoBinding): RecyclerView.ViewHolder(itemBinding.root) {
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): SecaoViewHolder {
binding = ItemSecaoBinding.inflate(LayoutInflater.from(parent.context), parent, false)
return SecaoViewHolder(binding)
}
override fun getItemCount(): Int {
return secaoList.size
}
override fun onBindViewHolder(holder: SecaoViewHolder, position: Int) {
Log.d(TAG, "position: $position")
val currentItem = secaoList[position]
Log.d(TAG, "currentItem: ${currentItem.toString()}")
binding.secaoCodigo.text = currentItem.codigo
binding.secaoNome.text = currentItem.nome
binding.secaoMediaTotal.text = currentItem.mediaPositivo.toString()
binding.secaoPerguntasNaoAplicaveis.text = currentItem.qdePerguntasNaoAplicaveis.toString()
binding.secaoPerguntasRespondidas.text = currentItem.qdePerguntasRespondidas.toString()
binding.secaoPerguntasTotais.text = currentItem.qdePerguntas.toString()
binding.cardSecao.setOnClickListener {
val action = AvaliacaoFragmentDirections.actionAvaliacaoFragmentToSecaoFragment(currentItem)
holder.itemView.findNavController().navigate(action)
}
}
fun setData(secao: List<Secao>){
this.secaoList = secao
notifyDataSetChanged()
}
}
fragment_avaliacao.xml:
<?xml version="1.0" encoding="utf-8"?><androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorPrimaryDark"
tools:context=".ui.secoes.AvaliacaoFragment">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="#+id/container_titulo_avaliacao"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="8dp"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
>
<TextView
android:id="#+id/nome_avaliacao"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
android:text="#string/padrao_avaliacao_sem_nome"
android:textSize="24sp"
android:textColor="#color/colorIcons"
android:textAlignment="center"
/>
<TextView
android:id="#+id/data_avaliacao"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="16dp"
android:text="#string/padrao_formato_data_hora"
android:textSize="14sp"
android:textColor="#color/colorPrimaryLight"
android:textAlignment="center"
/>
</LinearLayout>
<TextView
android:id="#+id/texto_sem_secoes"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#+id/container_titulo_avaliacao"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:layout_marginStart="8dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="8dp"
android:textAlignment="center"
android:textSize="16sp"
android:text="#string/nenhuma_secao_criada"
android:textColor="#color/colorPrimaryLight"
/>
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/secaoRecyclerView"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintTop_toBottomOf="#+id/container_titulo_avaliacao"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.coordinatorlayout.widget.CoordinatorLayout></androidx.constraintlayout.widget.ConstraintLayout>
Logcat loop from secaoList at the SecaoAdapter (is looping correctly to all elements):
I create a gif to show what is happening with the elements on recyclerView:
Here you can see that it displays seventh element then eighth is replaced by nineth and subsequently replaced by tenth. And final two elements (that should be ninth and tenth) is constructed with first and second list elements.
Thanks for the help in advance.

So the mistake here is that you are referencing only one binding in your adapter which is getting overwritten. Every time you call onCreateViewHolder you are changing the binding reference. The reason this looks okay to start with is that the onCreateViewHolder calls are followed by the onBindViewHolder calls for items visible on the screen. However as you scroll, just onBindViewHolder is called in order to rebind the recycled views.
What you should be doing is using your ViewHolder to store the individual bindings and then obtaining a reference in onBindViewHolder with something like holder.binding.
I would recommend you have a read into the view holder pattern and how to implement it!

Android Jetpack Navigation Disable Scroll Position

I have a single activity with many fragments (Using jetpack navigation). On my first fragment, i have a recyclerview. If i scroll on the first fragment and then navigate to the other fragment, the fragment retains the scroll position and i don't want that. An example is as follows:
i.e. Suppose i have two fragments A and B, When my app starts it starts on A. Suppose i start scrolling on A and then navigate to B. My app retains the scroll position on B which is not what i want. I want fragment B to start on top. And then when it returns to fragment A, i want it to retain the scroll position it previously scrolled.
Fragment A.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"
xmlns:tools="http://schemas.android.com/tools">
<data>
<import type="android.view.View" />
<variable
name="ViewModel"
type="....AccountViewModel" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/Layout_Fragment_Account"
android:layout_width="match_parent"
android:layout_height="match_parent">
<!--
Recyclerview
-->
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/RecyclerView_Account"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="#{ViewModel.accountListVisibility? View.VISIBLE : View.GONE}"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:visibility="gone" />
<!--
Empty Views and group
-->
<androidx.constraintlayout.widget.Group
android:id="#+id/Empty_View"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="#{ViewModel.accountEmptyViewVisibility?
View.VISIBLE : View.GONE}"
app:constraint_referenced_ids="Empty_View_Illustration,Empty_View_Title,Empty_View_Subtitle" />
<ImageView
android:id="#+id/Empty_View_Illustration"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:scaleType="centerCrop"
app:layout_constraintBottom_toTopOf="#+id/Empty_View_Title"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_chainStyle="packed"
app:srcCompat="#drawable/il_account" />
<TextView
android:id="#+id/Empty_View_Title"
style="#style/Locky.Text.Title6"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginEnd="32dp"
android:text="#string/text_title_emptyView_accounts"
android:textAlignment="center"
app:layout_constraintBottom_toTopOf="#id/Empty_View_Subtitle"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/Empty_View_Illustration"
app:layout_constraintVertical_chainStyle="packed"
app:layout_constraintWidth_default="percent"
app:layout_constraintWidth_percent=".8" />
<TextView
android:id="#+id/Empty_View_Subtitle"
style="#style/Locky.Text.Subtitle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginStart="32dp"
android:layout_marginEnd="32dp"
android:layout_marginBottom="?attr/actionBarSize"
android:text="#string/text_subtitle_emptyView_accounts"
android:textAlignment="center"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.6"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/Empty_View_Title"
app:layout_constraintWidth_default="percent"
app:layout_constraintWidth_percent=".8" />
<!--
Progress Bar
-->
<include
android:id="#+id/Progress_Bar"
layout="#layout/custom_view_list_loading"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:visibility="#{ViewModel.loadingStatus? View.VISIBLE : View.GONE}"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
Fragment A.kt:
class AccountFragment : Fragment() {
private var _binding: FragmentAccountBinding? = null
private var _viewModel: AccountViewModel? = null
private var _lastClickTime: Long = 0
private val binding get() = _binding!!
private val viewModel get() = _viewModel!!
companion object {
const val TAG = "ACCOUNT_FRAGMENT_DEBUG"
}
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
_binding = FragmentAccountBinding.inflate(inflater, container, false)
// Fetch view model
_viewModel = ViewModelProvider(this).get(AccountViewModel::class.java)
//Bind view model to layout
binding.viewModel = _viewModel
// Bind lifecycle owner
binding.lifecycleOwner = this
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
/* Hides the soft keyboard */
hideSoftKeyboard(binding.root)
/* Observe snack bar events */
observeSnackBarEvent()
/* Observe the account list changes */
observeAccounts()
/* Observe back stack entry result after navigating from sort sheet */
observeBackStackEntryForSortSheet()
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setHasOptionsMenu(true)
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.menu_toolbar_filter, menu)
super.onCreateOptionsMenu(menu, inflater)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
return when (item.itemId) {
R.id.Toolbar_Filter -> {
navigateToSort()
true
}
else -> false
}
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
/*
* My Functions
*/
private fun observeBackStackEntryForSortSheet() {
val navController = findNavController()
// After a configuration change or process death, the currentBackStackEntry
// points to the dialog destination, so you must use getBackStackEntry()
// with the specific ID of your destination to ensure we always
// get the right NavBackStackEntry
val navBackStackEntry = navController.getBackStackEntry(R.id.Fragment_Account)
// Create our observer and add it to the NavBackStackEntry's lifecycle
val observer = LifecycleEventObserver { _, event ->
if (event == Lifecycle.Event.ON_RESUME
&& navBackStackEntry.savedStateHandle.contains(KEY_ACCOUNTS_SORT)
) {
viewModel.sortChange(
navBackStackEntry.savedStateHandle.get<AccountSort>(
KEY_ACCOUNTS_SORT
)!!
)
navBackStackEntry.savedStateHandle.remove<AccountSort>(KEY_ACCOUNTS_SORT)
}
}
navBackStackEntry.lifecycle.addObserver(observer)
// As addObserver() does not automatically remove the observer, we
// call removeObserver() manually when the view lifecycle is destroyed
viewLifecycleOwner.lifecycle.addObserver(LifecycleEventObserver { _, event ->
if (event == Lifecycle.Event.ON_DESTROY) {
navBackStackEntry.lifecycle.removeObserver(observer)
}
})
}
private fun observeSnackBarEvent() {
viewModel.showSnackBarEvent.observe(viewLifecycleOwner, Observer {
if (it != null) {
snackBarAction(it)
}
})
}
private fun observeAccounts() {
with(viewModel) {
accounts.observe(viewLifecycleOwner, Observer {
if (it != null) {
//set loading flag to hide loading animation
doneLoading()
//Alternate visibility for account list and empty view
alternateAccountListVisibility(it.size)
//Submit the cards
initiateAccounts().submitList(it)
}
})
}
}
private fun initiateAccounts(): AccountAdapter {
val adapter = AccountAdapter(
AccountClickListener {
navigateToSelectedAccount(it)
},
AccountOptionsClickListener { view, card ->
view.apply {
isEnabled = false
}
createPopupMenu(view, card)
})
binding.RecyclerViewAccount.apply {
this.adapter = adapter
setHasFixedSize(true)
}
return adapter
}
private fun createPopupMenu(view: View, account: Account) {
requireContext().createPopUpMenu(
view,
R.menu.menu_moreoptions_account,
PopupMenu.OnMenuItemClickListener {
when (it.itemId) {
R.id.Menu_CopyUsername -> copyToClipboardAndToast(account.username)
R.id.Menu_CopyPass -> copyToClipboardAndToast(account.password)
R.id.Menu_ShowPass -> triggerSnackBarEvent(account.password)
else -> false
}
}, PopupMenu.OnDismissListener {
view.apply {
isEnabled = true
}
})
}
private fun navigateToSort() {
if (SystemClock.elapsedRealtime() - _lastClickTime >= 800) {
_lastClickTime = SystemClock.elapsedRealtime()
navigateTo(AccountFragmentDirections.actionFragmentAccountToBottomSheetFragmentAccountFilter())
}
}
private fun navigateToSelectedAccount(account: Account) {
navigateTo(
AccountFragmentDirections.actionFragmentAccountToFragmentViewAccount(
account
)
)
}
private fun snackBarAction(message: String) {
binding.LayoutFragmentAccount.snackbar(message) {
action(getString(R.string.button_snack_action_close)) { dismiss() }
}
viewModel.doneShowingSnackBar()
}
private fun triggerSnackBarEvent(message: String): Boolean {
viewModel.setSnackBarMessage(message)
return true
}
private fun copyToClipboardAndToast(message: String): Boolean {
copyToClipboard(message)
toast(getString(R.string.message_copy_successful))
return true
}
Fragment B.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"
xmlns:tools="http://schemas.android.com/tools">
<data>
<variable
name="Account"
type="....Account" />
</data>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/Layout_Credential_View"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="#+id/Account_Logo"
imageUrl="#{Account.logoUrl}"
loadingResource="#{#drawable/ic_image_loading}"
errorResource="#{#drawable/ic_account_placeholder}"
android:layout_width="100dp"
android:layout_height="100dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:src="#drawable/ic_account_placeholder" />
<TextView
android:id="#+id/Account_Name"
style="#style/Locky.Text.Title5.Name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="32dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="32dp"
android:textAlignment="center"
android:text="#{Account.accountName}"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/Account_Logo"
tools:text="This can be a very very very long title toooooo" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/RecyclerView_Credentials_Field"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="24dp"
android:layout_marginEnd="8dp"
android:nestedScrollingEnabled="true"
app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/Account_Name" />
</androidx.constraintlayout.widget.ConstraintLayout>
</layout>
Fragment B.kt
class ViewAccountFragment : Fragment() {
private var _binding: FragmentViewAccountBinding? = null
private var _viewModel: ViewAccountViewModel? = null
private lateinit var _account: Account
private val binding get() = _binding!!
private val viewModel get() = _viewModel!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
//Fetch the layout and do the binding
_binding = FragmentViewAccountBinding.inflate(inflater, container, false)
//Instantiate view model
_viewModel = ViewModelProvider(this).get(ViewAccountViewModel::class.java)
binding.lifecycleOwner = this
//Fetch the account clicked on the previous screen
_account = ViewAccountFragmentArgs.fromBundle(requireArguments()).parcelcredaccount
with(_account) {
//Bind the account to the layout for displaying
binding.account = this
//Submit the account details to the recyclerview
initiateCredentialsFieldList().submitList(viewModel.fieldList(this))
}
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
/* Hides the soft keyboard */
hideSoftKeyboard(binding.root)
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setHasOptionsMenu(true)
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.menu_credentials_actions, menu)
super.onCreateOptionsMenu(menu, inflater)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
return when (item.itemId) {
R.id.Action_Duplicate -> {
/*
* We set the account id to empty here
* When the add screen receives it, it wil perceive it as a new account that needs to be
* added to the database
*/
navigateToEditScreen(_account.copy(accountID = generateUniqueID()))
true
}
R.id.Action_Edit -> {
navigateToEditScreen(_account)
true
}
R.id.Action_Delete -> {
deleteConfirmationDialog(_account.accountName)
true
}
else -> false
}
}
private fun initiateCredentialsFieldList(): CredentialsViewAdapter {
val credentialsAdapter =
CredentialsViewAdapter(
CopyClickListener { data ->
copyToClipboardAndToast(data)
},
ViewClickListener { data ->
snackBarAction(data)
})
binding.RecyclerViewCredentialsField.apply {
adapter = credentialsAdapter
setHasFixedSize(true)
}
return credentialsAdapter
}
private fun deleteAndNavigateBackToAccountList() {
with(_account) {
viewModel.delete(accountID)
toast(getString(R.string.message_credentials_deleted, accountName))
findNavController().popBackStack()
}
}
navigation.xml
<fragment
android:id="#+id/Fragment_Account"
android:name="....AccountFragment"
android:label="Accounts"
tools:layout="#layout/fragment_account">
<action
android:id="#+id/action_Fragment_Account_to_Fragment_View_Account"
app:destination="#id/Fragment_View_Account" />
<action
android:id="#+id/action_Fragment_Account_to_BottomSheet_Fragment_Account_Filter"
app:destination="#id/BottomSheet_Fragment_Account_Filter" />
</fragment>
MainActivity.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"
xmlns:tools="http://schemas.android.com/tools">
<androidx.drawerlayout.widget.DrawerLayout
android:id="#+id/Drawer_Main"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.main.main.MainActivity">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:id="#+id/Layout_Coordinator_Main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true">
<com.google.android.material.appbar.MaterialToolbar
android:id="#+id/Toolbar_Main"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="#color/colorOnSurface"
android:outlineAmbientShadowColor="#color/colorShadowColor"
android:outlineSpotShadowColor="#color/colorShadowColor">
<TextView
android:id="#+id/Toolbar_Main_Title"
style="#style/Locky.Text.Title6.Toolbar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:text="#string/app_name" />
</com.google.android.material.appbar.MaterialToolbar>
<androidx.core.widget.NestedScrollView
android:id="#+id/Nested_Scroll"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="?attr/actionBarSize"
android:fillViewport="true">
<fragment
android:id="#+id/Navigation_Host"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:defaultNavHost="true"
app:navGraph="#navigation/navigation_drawer_main" />
</androidx.core.widget.NestedScrollView>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/FAB_Search"
style="#style/Locky.FloatingActionButton.Mini"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="0dp"
android:layout_marginBottom="85dp"
app:layout_anchor="#id/FAB_Add"
app:layout_anchorGravity="top|center_horizontal"
app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"
app:srcCompat="#drawable/ic_search" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/FAB_Add"
style="#style/Locky.FloatingActionButton.Normal"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
app:layout_behavior="com.google.android.material.behavior.HideBottomViewOnScrollBehavior"
app:srcCompat="#drawable/ic_add" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
<com.google.android.material.navigation.NavigationView
android:id="#+id/Navigation_View"
style="#style/Locky.Widget.Custom.NavigationView"
android:layout_width="280dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:clipToPadding="false"
android:paddingStart="0dp"
android:paddingEnd="16dp"
app:headerLayout="#layout/drawer_header"
app:itemTextAppearance="#style/Locky.Text.Body.Drawer"
app:menu="#menu/menu_drawer_main" />
</androidx.drawerlayout.widget.DrawerLayout>
MainActivity.kt
class MainActivity : AppCompatActivity() {
private lateinit var _binding: ActivityMainBinding
private lateinit var _viewModel: MainActivityViewModel
private lateinit var _appBarConfiguration: AppBarConfiguration
//Fragments that can navigate with the drawer
private val _navigationFragments = setOf(
R.id.Fragment_Card,
R.id.Fragment_Account,
R.id.Fragment_Device
)
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
_binding = DataBindingUtil.setContentView(this, R.layout.activity_main)
_viewModel = ViewModelProvider(this).get(MainActivityViewModel::class.java)
_binding.lifecycleOwner = this
//Set the support action bar to the toolbar
setSupportActionBar(_binding.ToolbarMain)
//Remove the default actionbar title
supportActionBar?.setDisplayShowTitleEnabled(false)
/* Updates the app settings*/
updateAppSettings()
//Setup the navigation components
navigationUISetup()
//Load FABs
listenerForAddFab()
listenerForSearchFab()
//Scroll changes to adjust toolbar elevation accordingly
setUpNestedScrollChangeListener()
}
override fun onOptionsItemSelected(item: MenuItem) =
item.onNavDestinationSelected(findNavController(R.id.Navigation_Host)) || super.onOptionsItemSelected(
item
)
override fun onSupportNavigateUp() =
findNavController(R.id.Navigation_Host).navigateUp(_appBarConfiguration)
override fun finish() {
super.finish()
ActivityNavigator.applyPopAnimationsToPendingTransition(this)
}
private fun navigationUISetup() {
//Fetch the Nav Controller
val navController = findNavController(R.id.Navigation_Host)
//Setup the App Bar Configuration
_appBarConfiguration = AppBarConfiguration(_navigationFragments, _binding.DrawerMain)
//Use Navigation UI to setup the app bar config and navigation view
NavigationUI.setupActionBarWithNavController(this, navController, _appBarConfiguration)
NavigationUI.setupWithNavController(_binding.NavigationView, navController)
//Set the mini FABs with navigation to navigate to fragments accordingly.
Navigation.setViewNavController(_binding.FABAdd, navController)
Navigation.setViewNavController(_binding.FABSearch, navController)
//Add on change destination listener to navigation controller to handle fab visibility
navigationDestinationChangeListener_FAB(navController)
//Add on change destination listener to navigation controller to handle screen title visibility
navigationDestinationChangeListener_ToolbarTitle(navController)
}
private fun setUpNestedScrollChangeListener() =
_binding.NestedScroll.setOnScrollChangeListener { _, _, scrollY, _, _ ->
if (scrollY > 0) {
_binding.ToolbarMain.elevation = 12F
} else {
_binding.ToolbarMain.elevation = 0F
}
}
private fun navigationDestinationChangeListener_ToolbarTitle(navController: NavController) {
navController.addOnDestinationChangedListener { _, nd, _ ->
when (nd.id) {
R.id.Fragment_Account -> updateToolbar(getString(R.string.text_title_screen_accounts))
R.id.Fragment_Card -> updateToolbar(getString(R.string.text_title_screen_cards))
R.id.Fragment_Device -> updateToolbar(getString(R.string.text_title_screen_devices))
R.id.Fragment_Settings -> updateToolbar(getString(R.string.text_title_screen_settings))
R.id.Fragment_Profile -> updateToolbar(getString(R.string.text_title_screen_profile))
R.id.Fragment_About -> updateToolbar(getString(R.string.text_title_screen_about))
R.id.Fragment_Donate -> updateToolbar(getString(R.string.text_title_screen_donate))
else -> {
//Show the toolbar
updateToolbar(null)
}
}
}
}
private fun navigationDestinationChangeListener_FAB(navController: NavController) {
navController.addOnDestinationChangedListener { nc, nd, _ ->
when (nd.id) {
nc.graph.startDestination,
R.id.Fragment_Card,
R.id.Fragment_Device -> {
_binding.DrawerMain.setDrawerLockMode(DrawerLayout.LOCK_MODE_UNLOCKED)
//Show all the FABs
showFABs()
}
else -> {
_binding.DrawerMain.setDrawerLockMode(DrawerLayout.LOCK_MODE_LOCKED_CLOSED)
//Hide all the FABs
hideFABs()
}
}
}
}
private fun getFadeNavOptions(): NavOptions? {
return NavOptions.Builder()
.setEnterAnim(R.anim.anim_fade_in)
.setExitAnim(R.anim.anim_fade_out)
.build()
}
private fun hideFABs() {
_binding.FABSearch.hide()
_binding.FABAdd.hide()
}
private fun showFABs() {
_binding.FABSearch.show()
_binding.FABAdd.show()
showFABFromSlidingBehavior(_binding.FABSearch, _binding.FABSearch.isVisible)
showFABFromSlidingBehavior(_binding.FABAdd, _binding.FABAdd.isVisible)
}
private fun showFABFromSlidingBehavior(fab: FloatingActionButton, isVisible: Boolean) {
val layoutParams: ViewGroup.LayoutParams = fab.layoutParams
if (layoutParams is CoordinatorLayout.LayoutParams) {
val behavior = layoutParams.behavior
if (behavior is HideBottomViewOnScrollBehavior) {
if (isVisible) {
behavior.slideUp(fab)
} else {
behavior.slideDown(fab)
}
}
}
}
I have attached a gif to demontstrate the issue here:
In the GIF i navigate from 3 fragments (Fragment A > Fragment B > Fragment C)
Is there anything i am doing wrong here ?

you have the same layoutmanager for both fragments, when you populate your different fragments; the same layoutmanager is called. Which then tries to restore the same position thinking its the same recyclerview, which is kind of a feature when you think about it.
from the docs:
Called when the RecyclerView is ready to restore the state based on a
previous RecyclerView. Notice that this might happen after an actual
layout, based on how Adapter prefers to restore State. See
RecyclerView.Adapter.getStateRestorationPolicy()
which means what we need is not to restore the state which can be done by passing
PREVENT to RecyclerView.Adapter.StateRestorationPolicy
solution1: in your fragment B adapter just call adapter.stateRestorationPolicy = PREVENT
solution2: create a different layoutmanager for fragment B in case you want to restore position for something else.
EDIT :: QA :: how can i set the view to be on top (Near Status Bar) :
Well, since you are populating your fragments inside a NestedScrollView you should call NestedScrollView.scrollTo(0, 0); when you navigate to the required fragment probably by waiting on a callback from addOnDestinationChangedListener inside your MainActivity.kt

RecyclerView doesn't appear when back pressed

I see the problem with a RecyclerView in viewpager fragment and I use bottom naviagation bar. When I tab on the navigation bar to change a screen and then pressed on back button it will go to the first screen which have the viewpager but the recyclerview doesn't appear and when I tab the naviagtion bar to reselect this screen it appear.
The recyclerview is show the list from firestore database and using ViewModel.
I try to set retainInstance to true but it doesn't work. And try to setup the recyclerview in onCreate and onCreateView it doesn't work too.
Edit: this is my code.
MainActivity.kt
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val navView: BottomNavigationView = findViewById(R.id.nav_view)
val navController = findNavController(R.id.nav_host_fragment)
navView.setupWithNavController(navController)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
when (item.itemId){
android.R.id.home -> {
onBackPressed()
return true
}
}
return super.onOptionsItemSelected(item)
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.google.android.material.bottomnavigation.BottomNavigationView
android:id="#+id/nav_view"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginStart="0dp"
android:layout_marginEnd="0dp"
android:background="#drawable/bg_nav"
app:itemIconTint="#color/navbar_color"
app:itemTextColor="#color/navbar_color"
app:itemTextAppearanceActive="#style/navbar_font"
app:itemTextAppearanceInactive="#style/navbar_font"
app:itemBackground="#drawable/nav_ripple"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:menu="#menu/bottom_nav_menu"/>
<fragment
android:id="#+id/nav_host_fragment"
android:name="androidx.navigation.fragment.NavHostFragment"
android:layout_width="0dp"
android:layout_height="0dp"
app:defaultNavHost="true"
app:layout_constraintBottom_toTopOf="#id/nav_view"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:navGraph="#navigation/mobile_navigation" />
</androidx.constraintlayout.widget.ConstraintLayout>
HomeFragement.kt (it contain tablayout and viewpager)
class HomeFragment : Fragment() {
private lateinit var homeViewModel: HomeViewModel
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
homeViewModel =
ViewModelProviders.of(this).get(HomeViewModel::class.java)
val root = inflater.inflate(R.layout.fragment_home, container, false)
return root
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
setupTab()
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
}
private fun setupTab(){
Log.d("SET UP TAB", "SETTING UP")
val pageTabAdapter = PageTabAdapter(activity!!.supportFragmentManager, activity_tab.tabCount)
view_activity.adapter = pageTabAdapter
view_activity.addOnPageChangeListener(TabLayout.TabLayoutOnPageChangeListener(activity_tab))
activity_tab.setOnTabSelectedListener(object : TabLayout.OnTabSelectedListener{
override fun onTabReselected(p0: TabLayout.Tab?) {
}
override fun onTabUnselected(p0: TabLayout.Tab?) {
}
override fun onTabSelected(p0: TabLayout.Tab?) {
view_activity.currentItem = p0!!.position
}
})
}
}
fragment_home.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white"
android:orientation="vertical">
<TextView
android:id="#+id/home_header"
style="#style/page_header"
android:text="#string/title_home"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
<Button
android:id="#+id/calendar_btn"
android:layout_width="60dp"
android:layout_height="40dp"
android:background="#drawable/btn_calendar"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="#id/home_header"
app:layout_constraintBottom_toBottomOf="#id/home_header"
android:layout_marginEnd="10dp"/>
<com.google.android.material.tabs.TabLayout
android:id="#+id/activity_tab"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabRippleColor="#color/colorPrimary"
app:tabTextAppearance="#style/tab_font"
app:tabIndicatorHeight="2.5dp"
app:tabGravity="fill"
app:layout_constraintTop_toBottomOf="#id/home_header"
app:layout_constraintStart_toStartOf="parent"
android:background="#android:color/white">
<com.google.android.material.tabs.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="กิจกรรมในเดือนนี้" />
<com.google.android.material.tabs.TabItem
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="กิจกรรมที่ผ่านไปแล้ว" />
</com.google.android.material.tabs.TabLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/view_activity"
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintTop_toBottomOf="#id/activity_tab"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>
PageAdapter.kt
class PageTabAdapter(private val fragmentManager: FragmentManager, private val anInt: Int) :
FragmentStatePagerAdapter(fragmentManager) {
override fun getItem(position: Int): Fragment {
return when (position) {
0 -> {
NewActivity.newInstance()
}
1 -> {
PastActivity.newInstance()
}
else -> {
null!!
}
}
}
override fun getCount(): Int {
return anInt
}
}
ActivityAdapter.kt (this is a recyclerview adapter)
class ActivityAdapter(
private val mContext: Context, private val mItems: List<ActivityModel>
): RecyclerView.Adapter<ActivityAdapter.Holder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): Holder {
val inflater = LayoutInflater.from(this.mContext)
val view = inflater.inflate(R.layout.activity_list, parent, false)
return Holder(view)
}
override fun getItemCount(): Int {
return this.mItems.size
}
override fun onBindViewHolder(holder: Holder, position: Int) {
val item = this.mItems[position]
holder.setName(item.name)
val date = item.date?.toDate()
val dateFormat: DateFormat = SimpleDateFormat("dd-MMM-yyyy")
val newDate = dateFormat.format(date).toString()
holder.setDate(newDate)
val period = item.start + " - " +item.end
holder.setPeriod(period)
holder.setButton(item)
}
inner class Holder(view: View): RecyclerView.ViewHolder(view){
private var activityName: TextView = view.activity_list_name
private var activityDate: TextView = view.activity_list_date
private var activityPeriod: TextView = view.activity_list_period
private var activityPicture: ImageView = view.activity_list_pic
private var activityButton: Button = view.activity_list_btn
fun setName(name: String?){
this.activityName.text = name
}
fun setDate(date: String?){
this.activityDate.text = date
}
fun setPeriod(period: String?){
this.activityPeriod.text = period
}
fun setPicture(picpath: String?){
}
fun setButton(data: ActivityModel){
}
}
}
}
PS.: I'm using Kotlin in my project
Thank you

How can I combine a bottom navigation view, a Tablayout and a Viewpager in Android Kotlin?

I've been trying to combine a bottom navigation view, a tablayout and a viewpager. I already have the tableyout working with the viewpager, but when selecting another item (different from the one containing the tableyout) from the bottom navigation view nothing happens and it seems that they were disabled. I do not know what I'm doing wrong. I am a novice on Android.
I want something like this:
MainActivity.kt
class MainActivity : AppCompatActivity() {
private val onNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
when (item.itemId) {
R.id.navigation_data_sheet -> {
replaceFragment(DataSheetFragment())
return#OnNavigationItemSelectedListener true
}
R.id.navigation_search -> {
replaceFragment(SearchFragment())
return#OnNavigationItemSelectedListener true
}
R.id.navigation_notifications -> {
replaceFragment(NotificationsFragment())
return#OnNavigationItemSelectedListener true
}
R.id.navigation_profile -> {
val intent = Intent(this#MainActivity, NoLoginActivity::class.java)
startActivity(intent)
finish()
return#OnNavigationItemSelectedListener true
}
}
false
}
private fun replaceFragment(fragment: Fragment) {
val fragmentTransition = supportFragmentManager.beginTransaction()
fragmentTransition.replace(R.id.fragmentContainer, fragment)
fragmentTransition.commit()
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
replaceFragment(DataSheetFragment())
val navView: BottomNavigationView = findViewById(R.id.bottom_navigation)
navView.setOnNavigationItemSelectedListener(onNavigationItemSelectedListener)
}}
PagerAdapter.kt
class PagerAdapter(fm: FragmentManager) : FragmentPagerAdapter(fm) {
override fun getItem(position: Int): Fragment {
return when (position) {
0 -> {
SpecimensFragment()
}
else -> {
return FungiFragment()
}
}
}
override fun getCount(): Int {
return 2
}
override fun getPageTitle(position: Int): CharSequence {
return when (position) {
0 -> "Especímenes"
else -> {
return "Hongos"
}
}
}}
DataSheetFragment.kt: Fragment que contiene el tablayout
class DataSheetFragment : Fragment() {
private lateinit var viewPager: ViewPager
private lateinit var tabs: TabLayout
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view: View = inflater.inflate(R.layout.fragment_data_sheet, container, false)
viewPager = view.findViewById(R.id.viewPager)
tabs = view.findViewById(R.id.data_sheet_tabs)
val fragmentAdapter = PagerAdapter(childFragmentManager)
viewPager.adapter = fragmentAdapter
tabs.setupWithViewPager(viewPager)
return view
}}
fragment_data_sheet.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".Fragments.DataSheetFragment"
>
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:title="#string/data_sheet"
app:titleTextColor="#color/white"
android:background="#color/colorPrimary"
>
</androidx.appcompat.widget.Toolbar>
<com.google.android.material.tabs.TabLayout
android:id="#+id/data_sheet_tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#id/toolbar"
android:background="#color/background_color"
app:tabTextAppearance="#style/TabLayoutTextAppearance"
>
<com.google.android.material.tabs.TabItem
android:id="#+id/specimens_tab"
android:text="#string/specimens"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
<com.google.android.material.tabs.TabItem
android:id="#+id/fungi_tab"
android:text="#string/fungi"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</com.google.android.material.tabs.TabLayout>
<androidx.viewpager.widget.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toBottomOf="#id/data_sheet_tabs"
/>
</androidx.constraintlayout.widget.ConstraintLayout>