使用RecyclerView进行平滑滚动，将项目放在列表底部

Question

I want the user to be able to navigate to certain positions within a RecyclerView . I can determine the position of the items and when I use recycleView.smoothScrollToPosition() it scrolls to the correct item.
The problem is this item is at the bottom of the screen. How can I scroll so that the item appears at the top (it must be the first visible item).

Here is the code I use to setup the RecyclerView :

recyclerView = (RecyclerView)findViewById(R.id.recyclerview);
recyclerView.setHasFixedSize(false);
recyclerView.setAdapter(actionAdapter);
final LinearLayoutManager layoutManager = new LinearLayoutManager(InteractionTimelineActivity.this, LinearLayoutManager.VERTICAL, false);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setOnScrollListener(new RecyclerScrollListner());

And this is how I scroll:

if (recycleView != null) {               
    recycleView.smoothScrollToPosition(position + 1);
}

Answer 1

You have to calculate how many items fit on one screen and use that as offset when you scroll! You can use the methods findFirstCompletelyVisibleItemPosition() and findLastCompletelyVisibleItemPosition() of the LayoutManager to calculate the offset like this:

int offset = getLayoutManager()).findLastCompletelyVisibleItemPosition() 
           - getLayoutManager()).findFirstCompletelyVisibleItemPosition();

And once you have the offset you can scroll like this:

recycleView.smoothScrollToPosition(Math.min(position + offset + 1, adapter.getItemCount()));