I have implemented Paging 3 with RemoteMediator. And also have a LoadStateAdapter.
Initially, I was experiencing flickers, glitches and jumps when scrolling pages. This answer worked to resolve the issue - https://stackoverflow.com/a/66713643/15392387
I can see 3 items in my RecyclerView in one screen, so setting the PageSize = 8, as suggested, resolved all flickering issues.
But since I also use PagingDataAdapter.withLoadStateHeaderAndFooter, the initial load when the app is installed, automatically scrolls down to the 8th ListItem.
It does not start from the top of the page.
Can someone help me resolve this issue?
I found an answer that might be talking about the same issue, but solution is still unclear - https://stackoverflow.com/a/66763460/15392387
HomeFragment.kt
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
_binding = FragmentHomeBinding.bind(view) //View Binding
val parentAdapter = PlaylistParentPagingAdapter(this, this)
binding.apply {
playlistParentRecyclerView.setHasFixedSize(true)
playlistParentRecyclerView.adapter = parentAdapter.withLoadStateHeaderAndFooter(
header = PlaylistLoadStateAdapter { parentAdapter.retry() },
footer = PlaylistLoadStateAdapter { parentAdapter.retry() },
)
}
viewModel.playlists.observe(viewLifecycleOwner) {
parentAdapter.submitData(viewLifecycleOwner.lifecycle, it)
}
}
PlaylistLoadStateAdapter.kt
class PlaylistLoadStateAdapter(private val retry: () -> Unit) :
LoadStateAdapter<PlaylistLoadStateAdapter.LoadStateViewHolder>() {
private val TAG = "PlaylistLoadStateAdapte"
override fun onCreateViewHolder(parent: ViewGroup, loadState: LoadState): LoadStateViewHolder {
val binding = PlaylistLoadStateFooterBinding.inflate(
LayoutInflater.from(parent.context),
parent,
false
)
return LoadStateViewHolder(binding)
}
override fun onBindViewHolder(holder: LoadStateViewHolder, loadState: LoadState) {
holder.bind(loadState)
}
inner class LoadStateViewHolder(private val binding: PlaylistLoadStateFooterBinding) :
RecyclerView.ViewHolder(binding.root) {
init {
binding.retryButtonFooter.setOnClickListener {
retry.invoke()
}
}
fun bind(loadState: LoadState) {
binding.apply {
Log.d(TAG, "bind: loadstate = $loadState")
progressBarFooter.isVisible = loadState is LoadState.Loading
retryButtonFooter.isVisible = loadState !is LoadState.Loading
errorTextViewFooter.isVisible = loadState !is LoadState.Loading
}
}
}
