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RecyclerView update items on scroll only

I think I've read all the answers to all of the similar questions, and none of them seem to be fixing my problem,they're only workaround. I have recycler view with pictures taken by camera and they only update on scroll.
Using a smoothScrollToPosition() is workaround and I want to know the cause of this issue and fix it.
It's really weird because when a open my fragment and have a couple of images in the recycler view which I added earlier, deleting elements works perfect, but when I add new image from camera intent even the notification for deleting stops working, I have to do a scroll to refresh items in the adapter.
This is the part where I set the data:
viewModel.photos.observe(viewLifecycleOwner, Observer {
list->adapter.data = list
}).
Of course data is set in OnUiThread :
I checked with the debugger-- elements in list are updated.
Does anyone know the cause of this issue?

You have to tell recyclerView.adapter what exactly changed by calling notifyItemChanged. There are also other methods for inserted items, moved items, deleted items, etc. You can look at the full documentation here:
There is also another way by implementing a DiffUtil. You can research about it more. But the difference is that by using DiffUtil, you won't have to manually call those notify methods yourself.
Also, the old/unoptimized/unrecomenended way to do this is to simply call notifyDataSetChanged().
P.S. I highly think you found the somewhat the same answer while searching online and might have thought it as simply "a work around". I'm here to tell you that this is how its supposed to be handled.

when does notifydatasetchanged animates list items separately?

I know that notifydatasetchanged updates the whole list and it is recommended to use DiffUtil to only update changed items, what I am not understanding yet after a lot of research is if it's expected that notifydatasetchanged animates list items separately when being used in a RecyclerView. Because I have one RecyclerAdapter where I replace the dataset completely and then call notifyDataSetChanged leading to list items being animated perfectly, only those added get the default added animation, removed ones get the removed animation and so on. At the same time I have another adapter where I also do the same, call notifyDataSetChanged but here the whole list flashes shortly, I am not getting any animations automatically, so I don't know from what does notifydatasetchanged make this dependent? Both adapters are too complex and long to post here.

I found the answer here:
The framework will attempt to animate views if your adapter uses
stable IDs, which provides enough data to guess which views are
removed/added/etc

RecyclerView: Race condition between notify* and scrollToPostion?

Is is possible to have race conditions between the notify* methods of a RecyclerView.Adapter and scrollToPosition (and smoothScrollToPosition) of the RecyclerView itself? If so, how can I force the scroll to happen strictly after the notify has been applied?
In a bit more detail: I have a RecyclerView with an adapter that frequently is updated with new items (which may or may not overlap with the previous items). Also, whenever I set new items I also want to set the scroll position to a specific item. To that end, I first update the items inside my Adapter and then scroll the RecyclerView.
However, more often than not the scroll position will be wrong after this process. Also, if I then issue another smoothScrollToPosition command without changing the data, the scrolling is weird: It sometimes goes in the wrong direction, etc. After this second scrolling, the position is always correct however. So, it seems that something goes wrong the first time and the RecyclerView catches and corrects that error on the second scroll.
Also, the errors are slightly different when I use notifyDataSetChanged from when I use DiffUtil.
Now I've read in this response by Yigit that notify* is basically asynchronous, so I suppose there can be a race condition between them and the subseqent scrollToPosition - is that correct?
Finally what can I do to establish a strict ordering, so that the scroll is only called when all ViewHolder updates triggered by notify are done?

Prevent RecyclerView to change position when loading additional items

I have a RecyclerView with setStackFromEnd(true) representing a chat list. And I want to load older messages when the list is scrolled to the top. I managed to do this using onScrollListener.
But when I add items to the adapter with messages.addAll(0, aListWithNewMessages) (messages is data set for adapter) and call notifyDataSetChanged(), new list items (as expected) appear before the existing ones and shift them down (not the experience a user wants), and I want to add them silently so a user shouldn't see it.
So my guess for how to tackle this issue is to scroll list to somehow previously saved position.
I understand that this is not a bug or an unexpected behavior, so please help to sort it out.
Thanks

Try being more specific. Instead of calling notifyDataSetChanged() use notifyItemRangeInserted or similar RecyclerView methods. That will allow RecyclerView to know what to do and will provide much better UX.

Android ListView scrolling to top

I have a ListView with custom rows. When any of these rows is
clicked, the ListView's data is regenerated. I'd like the list to
scroll back to the top when this happens.
I initially tried using setSelection(0) in each row's OnClickListener
to achieve this but was unsuccessful (I believe because the ListView
loses its scroll position when its data is invalidated - so my call to
setSelection is undone. I still don't understand how the ListView
decides where to scroll to after invalidation, though).
The only working solution I know of was given by Romain Guy here:
http://groups.google.com/group/android-developers/browse_thread/thread/127ca57414035301
It involves (View.post)ing the call to _listView.setSelection(0). I
found this to perform quite poorly.
The newly generated list shows up with its scroll location unchanged
and there is a considerable delay before it scrolls back to the top.
Is there any better way to achieve this functionality?
Any help would be much appreciated.
Thanks!

call listView.setSelectionAfterHeaderView(); to scroll to top

I have tried lot but this one worked for me
list.smoothScrollToPosition(0);

I simply use listview.setSelection(0);
Works fine for me.

If you need instant scroll just after ListView adapter's data was changed, pay attention that it might not be yet populated. In this case you should post() your setSelection() or setSelectionAfterHeaderView() via Handler so it will be called later in the queue.
listView.Handler.post(new Runnable() {
#Override
public void run() {
listView.setSelectionAfterHeaderView();
}
});
This worked for me.

Personally, I recommend you find a different UI pattern. It is possible that users will find your current "click, and the list changes in situ" approach intuitive, but I am skeptical.
You could try subclassing ListView and overriding layoutChildren() to chain to the superclass, then call setSelection(0) in the case where that is needed. If the "considerable delay" is due to just the post() call, this should clear it up.

as a workaround, you can create a new adapter containing the new regenerated data, then call ListView.setAdapter. after that call ListView.setSelection(n).
btw, the solution provided by commonsware is worked.

On some different requirement.
If you want to scroll up just like while chatting.
mListView.smoothScrollToPosition(mAdapter.getCount());

This one worked fine when you want to focus the edittext from listview header
listview.setSelectionFromTop(0,0);
If you want to select the particular index view from listview then
listview.setSelection(index); // o for top