getProgressFromCurrentPage method
Returns how many pages are left until the last page. 0 means it's the last page.
getProgressFromCurrentPage() + 1 means push until the last page and then
invoke lastPageCallback
.
Implementation
@override
int getProgressFromCurrentPage(Widget currentPage) {
return _getCurrentPageDLLData(currentPage)
.getTraversalSteps(PageDLLTraversalDirection.right);
}