android - Recyclerview make the last added item be the selected item? -

i have horizontal recyclerview displays bitmaps. way implemented have imageview , recyclerview underneath it. selected item displayed on image view. selected image view given blue background indicate selected. can choose images gallery , each time new image selected, want scroll last position , make item selected.

the list of images maintained in array list , each time new image added, add image list , notifydatachanged().

currently when binding view, toggle visibility of blue background in

public void onbindviewholder(final myrecyclerviewholder holder, int position) { }

but problem is, if child off screen, bind view not called , dont scroll new position. read through documentation of recycler view , not figure out how scroll particular child view. not there smoothscrollto method question trigger ?

there 1 solution:

1. in recyclerview adapter, add variable selecteditem , methods setselecteditem():

   private static int selecteditem = -1;   ... ...  public void setselecteditem(int position) {    selecteditem = position; } 

2. in onbindviewholder(...), add:

   @override public void onbindviewholder(viewholder holder, final int position)  {    ... ...     if(selecteditem == position)       holder.itemview.setselected(true); }    

3. now can scroll specific item , set selected programmatically by:

   myrecyclerviewadapter.setselecteditem(position_scrollto); myrecyclerview.scrolltoposition(position_scrollto); 

for example, want scroll last position , make selected, just:

    int last_pos = myrecyclerviewadapter.getitemcount() - 1;     myrecyclerviewadapter.setselecteditem(last_pos);     myrecyclerview.scrolltoposition(last_pos); 

[update]

to add item , make selected, should have additem(...) method in adapter, add item item list. after adding item, refresh list , scroll new added/latest item:

myrecyclerviewadapter.additem(...); myrecyclerviewadapter.notifydatasetchanged(); myrecyclerviewadapter.setselecteditem(myrecyclerviewadapter.getitemcount() - 1);  myrecyclerview.scrolltoposition(myrecyclerviewadapter.getitemcount() - 1); 

hope help!