SortedList

public static final int INVALID_POSITION = -1

Used by indexOf when the item cannot be found in the list.

public SortedList(
    @NonNull Class<T> klass,
    @NonNull SortedList.Callback<T> callback
)

Creates a new SortedList of type T.

public SortedList(
    @NonNull Class<T> klass,
    @NonNull SortedList.Callback<T> callback,
    int initialCapacity
)

Creates a new SortedList of type T.

public int add(T item)

Adds the given item to the list. If this is a new item, SortedList calls onInserted.

If the item already exists in the list and its sorting criteria is not changed, it is replaced with the existing Item. SortedList uses areItemsTheSame to check if two items are the same item and uses areContentsTheSame to decide whether it should call onChanged or not. In both cases, it always removes the reference to the old item and puts the new item into the backing array even if areContentsTheSame returns false.

If the sorting criteria of the item is changed, SortedList won't be able to find its duplicate in the list which will result in having a duplicate of the Item in the list. If you need to update sorting criteria of an item that already exists in the list, use updateItemAt. You can find the index of the item using indexOf before you update the object.

public void addAll(@NonNull T[] items)

Adds the given items to the list. Does not modify or retain the input.

public void addAll(@NonNull Collection<T> items)

Adds the given items to the list. Does not modify or retain the input.

public void addAll(@NonNull T[] items, boolean mayModifyInput)

Adds the given items to the list. Equivalent to calling add in a loop, except the callback events may be in a different order/granularity since addAll can batch them for better performance.

If allowed, will reference the input array during, and possibly after, the operation to avoid extra memory allocation, in which case you should not continue to reference or modify the array yourself.

public void beginBatchedUpdates()

Batches adapter updates that happen after calling this method and before calling endBatchedUpdates. For example, if you add multiple items in a loop and they are placed into consecutive indices, SortedList calls onInserted only once with the proper item count. If an event cannot be merged with the previous event, the previous event is dispatched to the callback instantly.

After running your data updates, you must call endBatchedUpdates which will dispatch any deferred data change event to the current callback.

A sample implementation may look like this:

    mSortedList.beginBatchedUpdates();
    try {
        mSortedList.add(item1)
        mSortedList.add(item2)
        mSortedList.remove(item3)
        ...
    } finally {
        mSortedList.endBatchedUpdates();
    }

Instead of using this method to batch calls, you can use a Callback that extends BatchedCallback. In that case, you must make sure that you are manually calling dispatchLastEvent right after you complete your data changes. Failing to do so may create data inconsistencies with the Callback.

If the current Callback is an instance of BatchedCallback, calling this method has no effect.

public void clear()

Removes all items from the SortedList.

public void endBatchedUpdates()

Ends the update transaction and dispatches any remaining event to the callback.

public T get(int index)

Returns the item at the given index.

public int indexOf(T item)

Returns the position of the provided item.

public void recalculatePositionOfItemAt(int index)

This method can be used to recalculate the position of the item at the given index, without triggering an onChanged callback.

If you are editing objects in the list such that their position in the list may change but you don't want to trigger an onChange animation, you can use this method to re-position it. If the item changes position, SortedList will call onMoved without calling onChanged.

A sample usage may look like:

    final int position = mSortedList.indexOf(item);
    item.incrementPriority(); // assume items are sorted by priority
    mSortedList.recalculatePositionOfItemAt(position);

public boolean remove(T item)

Removes the provided item from the list and calls onRemoved.

public T removeItemAt(int index)

Removes the item at the given index and calls onRemoved.

public void replaceAll(@NonNull T[] items)

Replaces the current items with the new items, dispatching ListUpdateCallback events for each change detected as appropriate. Does not modify or retain the input.

public void replaceAll(@NonNull Collection<T> items)

Replaces the current items with the new items, dispatching ListUpdateCallback events for each change detected as appropriate. Does not modify or retain the input.

public void replaceAll(@NonNull T[] items, boolean mayModifyInput)

Replaces the current items with the new items, dispatching ListUpdateCallback events for each change detected as appropriate.

If allowed, will reference the input array during, and possibly after, the operation to avoid extra memory allocation, in which case you should not continue to reference or modify the array yourself.

Note: this method does not detect moves or dispatch onMoved events. It instead treats moves as a remove followed by an add and therefore dispatches onRemoved and onRemoved events. See DiffUtil if you want your implementation to dispatch move events.

public int size()

The number of items in the list.

public void updateItemAt(int index, T item)

Updates the item at the given index and calls onChanged and/or onMoved if necessary.

You can use this method if you need to change an existing Item such that its position in the list may change.

If the new object is a different object (get(index) != item) and areContentsTheSame returns true, SortedList avoids calling onChanged otherwise it calls onChanged.

If the new position of the item is different than the provided index, SortedList calls onMoved.