pagination
private int previousTotal = 0;
private final int visibleThreshold = 5;
private RecyclerView postRecyclerView;
private boolean loading = true;
private int firstVisibleItem, visibleItemCount, totalItemCount;
@SuppressLint("SourceLockedOrientationActivity")
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_home, container, false);
StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(1, StaggeredGridLayoutManager.VERTICAL);
postRecyclerView.setLayoutManager(
staggeredGridLayoutManager
);
postRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
visibleItemCount = staggeredGridLayoutManager.getChildCount();
totalItemCount = staggeredGridLayoutManager.getItemCount();
int[] firstVisibleItems = null;
firstVisibleItems = staggeredGridLayoutManager.findFirstVisibleItemPositions(firstVisibleItems);
if (loading) {
if (totalItemCount > previousTotal) {
loading = false;
previousTotal = totalItemCount;
}
}
if (!loading && (totalItemCount - visibleItemCount)
<= (firstVisibleItem + visibleThreshold)) {
getData();
loading = true;
}
}
});
return view;
}
private void getData() {
databaseReference.addValueEventListener(new ValueEventListener() {
@SuppressLint("NotifyDataSetChanged")
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
if (snapshot.exists()) {
shimmerFrameLayout.stopShimmer();
shimmerFrameLayout.setVisibility(View.GONE);
postRecyclerView.setVisibility(View.VISIBLE);
mUploads.clear();
for (DataSnapshot dataSnapshot : snapshot.getChildren()) {
Upload upload = dataSnapshot.getValue(Upload.class);
assert upload != null;
upload.setmKey(dataSnapshot.getKey());
mUploads.add(upload);
}
}
postsAdapter.setUploads(mUploads);
//notify the adapter
postsAdapter.notifyDataSetChanged();
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
}
});
}