private async Task TransitionBackward(
AlternativePage currentPage,
AlternativePage newPage,
ContentPresenter previousPagePresenter,
ContentPresenter newPagePresenter)
{
var transition = currentPage != null ? (currentPage.PageTransition ?? this.PageTransition) : this.PageTransition;
if (transition != null)
{
if (currentPage != null)
{
await currentPage.OnTransitioningFromInternalAsync();
}
if (newPage != null)
{
await newPage.OnTransitioningToInternalAsync();
}
await transition.TransitionBackward(previousPagePresenter, newPagePresenter);
if (currentPage != null)
{
await currentPage.OnTransitionedFromInternalAsync();
}
if (newPage != null)
{
await newPage.OnTransitionedToInternalAsync();
}
}
}