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How to solve problem with recylerView that is not detecting scrolling of this, if I load exactly 10 items while pagination or when it covers screen

If I load more than 10 items it works fine. e.g. I select 25 or 50 limits from spinner pagination works fine, but when I select limit 10, then scrolling is not detected inside onScrolled of addOnScrollListener method.
Or if I load the amount of elements that cover the screen, then we need to scroll further items of recyclerView.
RecyclerView creation method
VulnerabilityScanAdapter vulnerabilityScanAdapter = new VulnerabilityScanAdapter(
getActivity(), callback, vulnerabilityScanPojoList
);
vulnerabilityScanAdapter.notifyDataSetChanged();
final LinearLayoutManager mLayoutManager = new LinearLayoutManager(getContext(),
LinearLayoutManager.VERTICAL, false);
vulnerabilityScanRv.setLayoutManager(mLayoutManager);
vulnerabilityScanRv.setItemAnimator(new DefaultItemAnimator());
vulnerabilityScanRv.setAdapter(vulnerabilityScanAdapter);
// This is the code for pagination of this recyclerView
vulnerabilityScanRv.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(#NonNull RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
#Override
public void onScrolled(#NonNull RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if(dy > 0){
// Scrolling Down
if (totalCount > currentPageCount) {
LinearLayoutManager linearLayoutManager =
(LinearLayoutManager) recyclerView.getLayoutManager();
if (linearLayoutManager != null &&
linearLayoutManager.findLastCompletelyVisibleItemPosition() ==
vulnerabilityScanPojoList.size() - 1) {
//bottom of list!
loadMore();
}
} else {
//showSnackForAttributes(true,"No more data avaiable.");
}
}else if(dy < 0){
// Scrolling Up
}
}
});
I have done debugging to know whether the control is going inside onScrolled method while scrolling or not. It goes inside onScrollStateChanged when it reaches to the bottom of the list.

How to split large json array into pages in Android

I'm fetching json data from https://jsonplaceholder.typicode.com/photos, and want to split this data into pages so that I can implement the Android Paging Library in my app. Does anyone know how I can achieve this?

Page 1 (returns photos for id 1 to 10):
https://jsonplaceholder.typicode.com/photos?_start=0&_limit=10
Page 2 (returns photos for id 11 to 20)
https://jsonplaceholder.typicode.com/photos?_start=10&_limit=10

For paginatio you will use android jetpack
https://developer.android.com/topic/libraries/architecture/paging
Another method
get specific number of data from api and add into recyleview after that do something like below after loading your specific data again you will call further remaining specific data make a counter for counting loaded data.
getalltemlist() is a method from where u get ur json.
Reference https://www.youtube.com/watch?v=2-vZ1g_G1Zo
boolean isScrolling=false;
rView.setAdapter(adapter);
rView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(#NonNull RecyclerView recyclerView, int
newState) {
super.onScrollStateChanged(recyclerView, newState);
if(newState == AbsListView.OnScrollListener.SCROLL_STATE_TOUCH_SCROLL)
{
isScrolling=true;
}
}
#Override
public void onScrolled(#NonNull RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
currentitems=layoutManager.getChildCount();
totaliitems=layoutManager.getItemCount();
scrolloutitems=layoutManager.findFirstVisibleItemPosition();
if(isScrolling && (currentitems + scrolloutitems == totaliitems))
{
isScrolling=false;
getAllItemList();
}
}
});
adapter.notifyDataSetChanged();
getAllItemList();

Implement Load More in RecyclerView with PairList using MVP pattern

I'm looking for best practices. I want to implement load more [progressbar] after every 10 items (Using RecyclerView).
In past, I did this by simply creating Loader class item and just added into the specific position in my List. Well, this time, I'm using PairList and it's impossible to add Loader class item (even tho I personally think, that's a pretty clean way to do it).
I found a few solutions on SO, which are almost the same: How to implement load more recyclerview in android
Is there any other way I could implement this load more progressbar after every 10th element (First load 10 items from API, then, when user reaches 10th item, we show progress bar [meanwhile we fetch the next 10 items], remove progress bar, add 10 items and so on).

Use this InfiniteScrollListener in your recycler scrollListener:
public abstract class InfiniteScrollListener extends RecyclerView.OnScrollListener {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (dy > 0) {
LinearLayoutManager linearLayoutManager = (LinearLayoutManager)recyclerView.getLayoutManager();
int visibleItemCount = linearLayoutManager.getChildCount();
int totalItemCount = linearLayoutManager.getItemCount();
int pastVisiblesItems = linearLayoutManager.findFirstVisibleItemPosition();
if ((visibleItemCount + pastVisiblesItems) >= totalItemCount) {
loadMore();
}
}
}
protected abstract void loadMore();}
recyclerView Listener:
recyclerView.addOnScrollListener(new InfiniteScrollListener() {
#Override
protected void loadMore() {
boolean willLoad = //get your last api call data. if empty set false
int offset = recyclerView.getAdapter().getItemCount();
if(willLoad){
willLoad=false;
onCallApi(offset,10);
}
}
});
your api:
private void onCallApi(int offset,int limit){
//your api
}

ListView scroll up for refresh, scroll down to add new items to the list

Right now I have a Listview that stores 25 items, which are retrieved from an API. What I want is that the ListView refreshes on scroll up (retreive data from api call again). And add another 25 items on scroll down.
What could I use for this?
I found SwipeRefreshLayout, However, I can't find a way to distinguish scroll up and scroll down.

Use RecyclerView instead of ListVIew. Initialize the RecyclerView as follows :
RecyclerView Initialization :
layoutManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(layoutManager);
videosAdapter = new VideosAdapter();
recyclerView.setItemAnimator(new SlideInUpAnimator());
recyclerView.setAdapter(videosAdapter);
// Pagination
recyclerView.addOnScrollListener(recyclerViewOnScrollListener);
Now setup OnScrollListener :
private RecyclerView.OnScrollListener recyclerViewOnScrollListener = new
RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
int visibleItemCount = layoutManager.getChildCount();
int totalItemCount = layoutManager.getItemCount();
int firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition();
if (!isLoading && !isLastPage) {
if ((visibleItemCount + firstVisibleItemPosition) >= totalItemCount
&& firstVisibleItemPosition >= 0
&& totalItemCount >= PAGE_SIZE) {
loadMoreItems();
}
}
}
};
Once you get the response you need to add the received data to the list again.

I think your question is little bit misleading.If i am not wrong, here can be to thing.
Reload List on Over Scroll Down :- This functionality can be achieve by using SwipeRefreshLayout. Follow the android tutorial for Adding Swipe-to-Refresh To Your App.
Load more items on Over Scroll Up:- This is the part of Lay loading(Pagination) . If you are using ListViewthen you can use OnScrollListener and setFooterView() to make it done . Have a look at This thread.
Suggestion:- A simple suggestion Use RecyclerView instead of ListView to make better use of ViewHolder pattern.

How to perform pagination with the Litho framework?

I am implementing a Retrofit APi for getting data from the server and showing this in a RecyclerView using the Litho framework, and it's doing well. As all of us know when we have infinite data to show in recyclerview we have to implement the pagination pattern. And I know this, but I am confused how to implement this in the Litho framework. Litho the provides onScrollListener() method:
final Component component = Recycler.create(context)
.binder(recyclerBinder)
.onScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
//
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
//
})
.build();
I don't know: how to use a customized EndlessRecyclerViewScrollListener for endless scrolling in Litho?

I have had success implementing the "infinite" scroll pattern leveraging the recyclerBinder within the onScrolled method of a OnScrollListener. A trivial example would be the following:
//Initialize the RecyclerBinder
recyclerBinder = new RecyclerBinder(c, new LinearLayoutInfo(getContext(), OrientationHelper.VERTICAL, false));
//Initialize a recycler component
Component component = Recycler.create(c)
.onScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
// use the recyclerBinder to determine what items at what position are visible -
// (you could also use the findLastVisibleItemPosition() method depending on your implementation)
int firstVisibleItemPosition = recyclerBinder.findFirstVisibleItemPosition();
//check if it is within range relative to the current available items and is not loading (room to improve/modify logic pending use case)
if((recyclerBinder.getItemCount() - 5) <= firstVisibleItemPosition && !isLoading) {
//if so - use your service to get the next page
service.getNextPage();
}
}
})
.build();
Then in a call back method - you can insert your items starting at the item count
public void callback(List<T> results) {
int position = recyclerBinder.getItemCount();
for(T result: results) {
Component component = //assemble your component(s) ...
ComponentInfo.Builder info = ComponentInfo.create().component(component);
recyclerBinder.insertItemAt(position, info.build());
position++;
}
}