How to get all Recycler View item view position ( x,y ) in nested scrollview

Question

I have to draw a curved line on the left side of recycler view ( which connect all the item in the recyclerview).But i cant get all of the position of recyclerview item to start draw my custom view.I tryed to get the x,y position inside onBindViewHolder but it not work ( i though when inside nestedscrollview it just like a tableview).So how can i get all the position of recyclerview's items after set it adapter

Here is the screen shot of what i have to do: https://imgur.com/a/C1jTNKr

Inside `OnScrollListener` get the first visible item position & last visible item position, if it has a difference more than one then calculate the visible item positions. After you got the visible item positions get its view from layoutManager and calculate the X,Y positions from the view — Rahul Khurana, Sep 13 '19 at 04:15
hi @RahulKhurana,thank for reply.i tryed to get the X,Y even view height but all return to zero.any solution?.my recycler view is inside a nested scrollview btw — shadow, Sep 13 '19 at 04:29
@RahulKhurana how it work.i tryed on recyclerview but it not event jump into onScroll.or maybe u tryed to tell me to add on the nestedScrollview?? — shadow, Sep 13 '19 at 04:36
@RahulKhurana yes,it have alot of text content above and it must have the nestedScrollview. — shadow, Sep 13 '19 at 04:38
@RahulKhurana its only trigger onSrolled one,after that it not.i think it caugh the onScroll of nested scrollview but not recycler view ( i set nestedscrollable = false inside xml for conflig scroll issue) — shadow, Sep 13 '19 at 05:28
Also, can you post the desired output screenshot in the question? — Rahul Khurana, Sep 13 '19 at 06:10
@RahulKhurana look like it what i looking for.checking and upvote later for u.thanks for supporting me!!! — shadow, Sep 13 '19 at 06:12

score 2 · Answer 1 · answered Sep 13 '19 at 06:05

If your RecyclerView has hundreds of items, you shouldn't put it inside NestedScrollView or try to get any measure of all items at once.

The reason is: RecyclerView will have to measure layout for all items at once, which is totally opposite with the purpose of RecyclerView (calculate layout for item when needed) and lead to a very bad performance, very laggy or even freeze your app (if there are about 1000 items)

In your case, I think you should try to draw each path of the line inside each onBindViewHolder() as part of each item. If the logic to calculate how each draw is drawn is not too complex, I think this is an doable solution to consider

thank you.i put the recyclerview inside nested cause it not able to load more and only got 7-10 items.and i'm not able to get the point ( x,y) of all the item because it already load all view in the nested scroll view in the first time ( it not visible yet).but @RahulKhurana gave me a really hopeful solution.thank for your reply!!! — shadow, Sep 13 '19 at 06:17

How to get all Recycler View item view position ( x,y ) in nested scrollview

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