protected virtual async Task UseReverseNavigation(Page currentPage, string nextSegment, Queue <string> segments, INavigationParameters parameters, bool?useModalNavigation, bool animated)
{
var navigationStack = new Stack <string>();
if (!String.IsNullOrWhiteSpace(nextSegment))
{
navigationStack.Push(nextSegment);
}
var illegalSegments = new Queue <string>();
bool illegalPageFound = false;
foreach (var item in segments)
{
//if we run into an illegal page, we need to create new navigation segments to properly handle the deep link
if (illegalPageFound)
{
illegalSegments.Enqueue(item);
continue;
}
//if any page decide to go modal, we need to consider it and all pages after it an illegal page
var pageParameters = UriParsingHelper.GetSegmentParameters(item);
if (pageParameters.ContainsKey(KnownNavigationParameters.UseModalNavigation))
{
if (pageParameters.GetValue <bool>(KnownNavigationParameters.UseModalNavigation))
{
illegalSegments.Enqueue(item);
illegalPageFound = true;
}
else
{
navigationStack.Push(item);
}
}
else
{
var pageType = PageNavigationRegistry.GetPageType(UriParsingHelper.GetSegmentName(item));
if (PageUtilitiesExtended.IsSameOrSubclassOf <MasterDetailPage>(pageType))
{
illegalSegments.Enqueue(item);
illegalPageFound = true;
}
else
{
navigationStack.Push(item);
}
}
}
var pageOffset = currentPage.Navigation.NavigationStack.Count;
if (currentPage.Navigation.NavigationStack.Count > 2)
{
pageOffset = currentPage.Navigation.NavigationStack.Count - 1;
}
var onNavigatedFromTarget = currentPage;
if (currentPage is NavigationPage navPage && navPage.CurrentPage != null)
{
onNavigatedFromTarget = navPage.CurrentPage;
}
bool insertBefore = false;
while (navigationStack.Count > 0)
{
var segment = navigationStack.Pop();
var nextPage = CreatePageFromSegment(segment);
await DoNavigateAction(onNavigatedFromTarget, segment, nextPage, parameters, async() =>
{
await DoPush(currentPage, nextPage, useModalNavigation, animated, insertBefore, pageOffset);
});
insertBefore = true;
}
//if an illegal page is found, we force a Modal navigation
if (illegalSegments.Count > 0)
{
await ProcessNavigation(currentPage.Navigation.NavigationStack.Last(), illegalSegments, parameters, true, animated);
}
}
internal static bool UseReverseNavigation(Page currentPage, Type nextPageType)
{
return(PageUtilitiesExtended.HasNavigationPageParent(currentPage) && PageUtilitiesExtended.IsSameOrSubclassOf <ContentPage>(nextPageType));
}