Android Recycler View Horizontal Scroll to last item and show the first item

Question

Currently I'm working on a recycler view that has a horizontal scroll.

I have a list that contains these values:

{"2001","2002","2003","2004","2005","2006","2007","2008","2009","2010",...}

and so on, until 2017

My objective here is to select the year on the center

All works good but I have 2 problems here :

I can't scroll to the right edge, it's like the recyclerview has its limit on scrolling. Let's say the 4 last items are "2014", "2015", "2016", "2017". I can only scroll until "2003". For now i fix this issue by adding a dummy years before and after the list. (very hackish, but not so solid)
I want to show the first child when the scrolling reaches the end. For example, when I'm able to scroll until the end 2017 , I want to show the first item of the list right next to 2017 and in this case is "2001". For example: 2013 | 2014 | 2015 | 2016 | 2017 | 2001 | ...

why cant you show 2018,2019... with disabled text in that list? — Lingeshwaran, Oct 12 '17 at 08:52
no the last value is 2017, i dont need to show value beyond it, what i need to show is 2001 after 2017 (show the first item next to 2017) — Webster, Oct 12 '17 at 08:53
See this link https://stackoverflow.com/questions/34909927/recyclerview-how-to-make-cyclic — J Ramesh, Oct 12 '17 at 08:55
you can try https://rubensousa.github.io/2016/08/recyclerviewsnap — Om Infowave Developers, Oct 12 '17 at 09:02

Boukharist · Answer 1 · 2017-10-12T09:18:40.760

1

what you should use here is loop your recyclerview

in your adapter override getItemCount() to return something big like Integer.MAX_VALUE:

@Override
public int getItemCount() {
    return Integer.MAX_VALUE;
}

in onBindViewHolder() modulo divide (%) position by real item number:

 @Override
   public void onBindViewHolder(MyViewHolder holder, int position) {
        int positionInList = position % dataList.size();
        Item item = dataList.get(positionInList);
        //...
    }

at the end, set current item to something in the middle (or else, it would be endless only in downward direction).

// scroll to middle item
recyclerView.getLayoutManager().scrollToPosition(Integer.MAX_VALUE / 2);

edited Oct 12 '17 at 09:18

answered Oct 12 '17 at 08:56

Boukharist

1,219
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19

1

i think it should be dataList.get(positionInList). i ll give it a try tho – Webster Oct 12 '17 at 09:06
Good solution, suggesting to calculate `dataList.size()` outside once onBind for better performance – Reejesh May 11 '22 at 07:15
For anyone looking for a kotlin reference : https://github.com/mdroid23/AutoScrollRecyclerView – Reejesh May 11 '22 at 07:38

score 0 · Answer 2 · answered Oct 12 '17 at 09:22

Try this,

recyclerView.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));
recyclerView.getLayoutManager().scrollToPosition(5);

you can put your item number here in place of 5, can do (list.size()-3) for specific year.

Android Recycler View Horizontal Scroll to last item and show the first item

2 Answers2