hi, i have a little problem, i try to use a viewPa...

# android

[Tsafack Dagha cedrick]

hi, i have a little problem, i try to use a viewPager with a tabLaout to display an infinite list of data grouped by date so that the title each tab is a date (a month). I know how to use the FragmentPagerAdapter to display a limited number of fragments, but for an infinite list, I learned that we must use the FragmentStatePagerAdapter but I do not know how to use it. Can someone help me please?

[Dominaezzz]

Hmm, isn't it a drop-in replacement? At least source-code wise.

[Dominaezzz]

Also, check out the link in the channel description to get better help.

[Tsafack Dagha cedrick]

what link?

[Dominaezzz]

http://android-united.community/

[Tsafack Dagha cedrick]

thank you

[zhuinden]

FragmentPagerAdapter also works fine for infinite items afaik, because it detaches the fragment meaning the views are not kept beyond the off-screen page limit 🤔 i should probably look into the big difference in FragmentStatePagerAdapter so i'm not wrong tho

[zhuinden]

so FragmentStatePagerAdapter juggles a bunch of fragments and only retains their SavedState but not the Fragment itself, interesting

[Tsafack Dagha cedrick]

ok how to use it? do you have a little example or link?

[Priyankkumar Patel]

for this adapter you can refer this file, as we are building to store data of artist name and genre.

[Priyankkumar Patel]

return ArtistViewHolder(view)
}
}
}

[Priyankkumar Patel]

package com.infrontofthenet.firemusic

import android.content.Intent
import android.net.Uri
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import android.widget.TextView
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.firebase.ui.firestore.FirestoreRecyclerAdapter
import com.firebase.ui.firestore.FirestoreRecyclerOptions
import com.google.firebase.firestore.FirebaseFirestore
import com.google.firebase.firestore.Query
import kotlinx.android.synthetic.main.activity_artist_list.*

class ArtistList : AppCompatActivity() {

// connect to firestore
var db = FirebaseFirestore.getInstance()

// classes to store and pass query data
private var adapter: ArtistAdapter? = null

// Kotlin equivalent of Java ArrayList class. We decided we don't need this after all
//private var artistList = mutableListOf<Artist>()

override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_artist_list)

// recycler will have linear layout
recyclerViewArtists.setLayoutManager(LinearLayoutManager(this))

// query
val query = db.collection("artists").orderBy("artistName", Query.Direction.ASCENDING)

// pass the query results to the recycler adapter for display
val options = FirestoreRecyclerOptions.Builder<Artist>().setQuery(query, Artist::class.java).build()
adapter = ArtistAdapter(options)

// bind the adapter to the recyclerview (adapter means the datasource)
recyclerViewArtists.adapter = adapter
}

// start listening for changes if the the activity starts / restarts
override fun onStart() {
super.onStart()
adapter!!.startListening()
}

// stop listening for data changes if the activity gets stopped
override fun onStop() {
super.onStop()
adapter!!.stopListening()
}

// inner classes needed to read and bind the data
private inner class ArtistViewHolder internal constructor(private val view: View) :
RecyclerView.ViewHolder(view) {

// not needed if we bind to the item template directly on the onBindViewHolder method below
// internal fun displayArtist(artistName: String, artistGenre: String) {
// // populate the corresponding textViews in the layout template inflated when adapter created below
// val textViewName = view.findViewById<TextView>(R.id.textViewName)
// val textViewGenre = view.findViewById<TextView>(R.id.textViewGenre)
//
// textViewName.text = artistName
// textViewGenre.text = artistGenre
// }
}

private inner class ArtistAdapter internal constructor(options: FirestoreRecyclerOptions<Artist>) :
FirestoreRecyclerAdapter<Artist,
ArtistViewHolder>(options) {

override fun onBindViewHolder(p0: ArtistViewHolder, p1: Int, p2: Artist) {
// pass current Artist values to the display function above
//p0.displayArtist(p2.artistName.toString(), p2.artistGenre.toString()) - replaced by 2 lines below
p0.itemView.findViewById<TextView>(R.id.textViewName).text = p2.artistName
p0.itemView.findViewById<TextView>(R.id.textViewGenre).text = p2.artistGenre

p0.itemView.setOnClickListener {
val url = p2.url.toString()
val i = Intent(Intent.ACTION_VIEW)
i.data = Uri.parse(url)
startActivity(i)
}
}

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ArtistViewHolder {
val view = LayoutInflater.from(parent.context).inflate(R.layout.item_artist, parent, false)