Develop Reference

RecyclerView onScrollListener -on Reverse Layout-

I'm using RecyclerView on my Android App. I want to show firstly bottom and scroll from bottom to top. I can did it but I want to add Scroll Listener and when the scroll position on top I call a function.
chatRecycler = (RecyclerView) findViewById(R.id.chatRecycler);
LinearLayoutManager layoutManager = new LinearLayoutManager(this);
layoutManager.setReverseLayout(true);
layoutManager.setStackFromEnd(true);
chatRecycler.setLayoutManager(layoutManager);
chatRecycler.setItemAnimator(new DefaultItemAnimator());
And I try that but it's not working. This code call the function to bottom:
chatRecycler.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(#NonNull RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
if (!recyclerView.canScrollVertically(1) && newState==RecyclerView.SCROLL_STATE_IDLE) {
pageId++;
chatDuoPresenter.getChatData(pageId);
}
}
});
Edit:
I'm still searching solution.

Solution:
#Override
public void initScrollListener() {
chatRecycler.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(#NonNull RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
int visibleItemCount = layoutManager.getChildCount();
int totalItemCount = layoutManager.getItemCount();
int firstVisibleItemPosition = layoutManager.findFirstVisibleItemPosition();
if ((visibleItemCount + firstVisibleItemPosition) >= totalItemCount && firstVisibleItemPosition >= 0) {
pageId++;
chatDuoPresenter.getChatData(pageId);
}
}
});
}

Pagination in recycler list view

How to implement pagination in recycler listview. I have to show 10 items per page. Can any one tell me how to deal with this?

You can add a scroll listener on recycler view and call the next paginated api on following condition:
recyclerList.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
int visibleItemCount = mLayoutManager.getChildCount();
int totalItemCount = mLayoutManager.getItemCount();
int pastVisibleItems = mLayoutManager
.findFirstVisibleItemPosition();
int currentPos = pastVisibleItems + visibleItemCount;
if (currentPos >= totalItemCount) {
callNextApi();
}
}
}
});

error: cannot find symbol method findFirstVisibleItemPosition()

I think my code is ok, but for some reason I have this error. This is my code:
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener()
{
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy)
{
if(dy > 0) //check for scroll down
{
visibleItemCount = mLayoutManager.getChildCount();
totalItemCount = mLayoutManager.getItemCount();
pastVisiblesItems = mLayoutManager.findFirstVisibleItemPosition();
if (loading)
{
if ( (visibleItemCount + pastVisiblesItems) >= totalItemCount)
{
loading = false;
Log.v("...", "Last Item Wow !");
//Do pagination.. i.e. fetch new data
}
}
}
}
});
I have already imported android.support.v7.widget.LinearLayoutManager and decleared
private RecyclerView recyclerView;
private RecyclerView.LayoutManager mLayoutManager;

Because there is no method like findFirstVisibleItemPosition in RecyclerView.LayoutManager (See documentation). You need to use LinearLayoutManager to use findFirstVisibleItemPosition
Change your declaration from this
private RecyclerView.LayoutManager mLayoutManager
to this
private LinearLayoutManager mLayoutManager

RecyclerView with load more progressbar at bottom

I tried implementing addOnScrollListener() but this thing fetch data and loading the recycler view from the beginning every time.i want to load the data after the current position.Here is my sample code
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_load, null);
progressBar = (ProgressBar) view.findViewById(R.id.progressBar);
progressBar.setVisibility(View.VISIBLE);
myClickHandler();
business_rv = (RecyclerView) view.findViewById(R.id.business_rv);
business = new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL,false);
business_rv.setHasFixedSize(true);
business_rv.setLayoutManager(business);
if (business_rv.getLayoutManager() instanceof LinearLayoutManager) {
business = (LinearLayoutManager) business_rv.getLayoutManager();
business_rv.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
UpdateRecyclerView(url);
}
});
}
return view;
}

what you need is endless recycler view ,which will load the data while scrolling . Here I have attached link for that implementation.
Follow this link

use this as
_recycler.addOnScrollListener(_recyclerViewOnScrollListener);
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(++currentPage);
}
}
}
};

How programmatically know that recyclerview is scrolled position is bottom of recyclerview to execute following function

Which statement should i put in "Recyclerview_position_is_bottem" to satisfy condition that now recyclerview position is bottem to execute function
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
if (Recyclerview_position_is_bottem){
isScrolled=0;
skip = skip + 5;
remove = 1;
feedItems.add(null);
eventsRecyclerView.notifyItemInserted(feedItems.size());
handler.postDelayed(new Runnable() {
#Override
public void run() {
Loadmore(eventsRecyclerView,1);
}
}, 500);
}
}
});

first / last visible child depends on the LayoutManager.
If you are using LinearLayoutManager or GridLayoutManager, you can use
int findFirstVisibleItemPosition();
int findFirstCompletelyVisibleItemPosition();
int findLastVisibleItemPosition();
int findLastCompletelyVisibleItemPosition();
For example:
GridLayoutManager layoutManager = ((GridLayoutManager)mRecyclerView.getLayoutManager());
int firstVisiblePosition = layoutManager.findLastCompletelyVisibleItemPosition();
For LinearLayoutManager, first/last depends on the adapter ordering. Don't query children from RecyclerView; LayoutManager may be prefered to layout more items than visible for caching.

You can use LayoutManager's object which you set on your recyclerView like this:
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
int totalItems = layoutManager.getItemCount();
int lastVisibleItem = layoutManager.findLastVisibleItemPosition();
if (totalItems - 1 == lastVisibleItem){
isScrolled=0;
skip = skip + 5;
remove = 1;
feedItems.add(null);
eventsRecyclerView.notifyItemInserted(feedItems.size());
handler.postDelayed(new Runnable() {
#Override
public void run() {
Loadmore(eventsRecyclerView,1);
}
}, 500);
}
}
});