Method Detail

• convertOldPositionToNew

   int convertOldPositionToNew(int oldListPosition)

  Given a position in the old list, returns the position in the new list, or {@code NO_POSITION} if it was removed.

  Parameters:

  oldListPosition - Position of item in old list

• convertNewPositionToOld

   int convertNewPositionToOld(int newListPosition)

  Given a position in the new list, returns the position in the old list, or {@code NO_POSITION} if it was removed.

  Parameters:

  newListPosition - Position of item in new list

• dispatchUpdatesTo

   void dispatchUpdatesTo(@NonNull() RecyclerView.Adapter adapter)

  Dispatches the update events to the given adapter.

  For example, if you have an Adapter that is backed by a List, you can swap the list with the new one then call thismethod to dispatch all updates to the RecyclerView.

      List oldList = mAdapter.getData();
      DiffResult result = DiffUtil.calculateDiff(new MyCallback(oldList, newList));
      mAdapter.setData(newList);
      result.dispatchUpdatesTo(mAdapter);
  

  Note that the RecyclerView requires you to dispatch adapter updates immediately when youchange the data (you cannot defer {@code notify*} calls). The usage above adheres to thisrule because updates are sent to the adapter right after the backing data is changed,before RecyclerView tries to read it.

  On the other hand, if you have another AdapterDataObserver that tries to process events synchronously, this may confuse that observer because thelist is instantly moved to its final state while the adapter updates are dispatched lateron, one by one. If you have such an AdapterDataObserver,you can use dispatchUpdatesTo to handle each modificationmanually.

  Parameters:

  adapter - A RecyclerView adapter which was displaying the old list and will startdisplaying the new list.

• dispatchUpdatesTo

   void dispatchUpdatesTo(@NonNull() ListUpdateCallback updateCallback)

  Dispatches update operations to the given Callback.

  These updates are atomic such that the first update call affects every update call thatcomes after it (the same as RecyclerView).

  Parameters:

  updateCallback - The callback to receive the update operations.