get Sibling Page Index
Gets page sibling index (usable in double page mode).
Return
Provided page sibling, or -1
if there is none.
Parameters
page Index
Index of the page for which we look for the sibling.
Gets page sibling index (usable in double page mode).
Provided page sibling, or -1
if there is none.
Index of the page for which we look for the sibling.