@return Must return inner item ViewGroup, that contains inner items.

@param adapter must be instance of TailAdapter class

Return current center view or null. @return current center view or null.

@return Must return main item layout

@param lm must be instance of TailLayoutManager class

@return Must return header main layout

@return Must return header alpha-layout. Alpha-layout is the layout which will hide header's views, when item will be scrolled to left or right.

Return item start offset. @return item start offset in pixels.

@return Must return inner item scroll state - is it scrolling now or not.

Set page transformer, @param transformer new page transformer or null. @return current instance of TailLayoutManager.

Creates TailLayoutManager with default values @param context Current context, will be used to access resources.

@return first visible item position.