androidandroid-recyclerviewsmooth-scrolling

Purpose of RecyclerView.NO_POSITION and smoothScrollToPosition()?

I’m some kind of new working with RecyclerView and I have noticed lately on one of the tutorials that they use RecyclerView.NO_POSITION with smoothScrollToPosition().

Here's the example:

 private RecyclerView mRecyclerView;
 private int mPosition = RecyclerView.NO_POSITION;

 @Override                                                                                             
 public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
    if (mPosition == RecyclerView.NO_POSITION) mPosition = 0;
    mRecyclerView.smoothScrollToPosition(mPosition);
}

But I don’t know exactly what NO_POSITION or this smoothScrollToPosition() actually do? Also I tried to search official doc, other essays or checking other guys questions here. Unfortunately, none helped me.

Can anyone explain what their purpose/why do we need to use them?

Solution

  • NO_POSITION is a constant whose value is -1, it basically means that when don't you find the position of the model in the underlying dataset the return value of this method will be NO_POSITION.

    smoothScrollToPostion(value) tells your view to go to that particular position in the recyclerView.