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 (PageUtilities.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);
}
}
protected virtual async Task ProcessNavigationForMasterDetailPage(MasterDetailPage currentPage, string nextSegment, Queue <string> segments, INavigationParameters parameters, bool?useModalNavigation, bool animated)
{
bool isPresented = GetMasterDetailPageIsPresented(currentPage);
var detail = currentPage.Detail;
if (detail == null)
{
var newDetail = CreatePageFromSegment(nextSegment);
await ProcessNavigation(newDetail, segments, parameters, useModalNavigation, animated);
await DoNavigateAction(null, nextSegment, newDetail, parameters, onNavigationActionCompleted : () =>
{
currentPage.IsPresented = isPresented;
currentPage.Detail = newDetail;
});
return;
}
if (useModalNavigation.HasValue && useModalNavigation.Value)
{
var nextPage = CreatePageFromSegment(nextSegment);
await ProcessNavigation(nextPage, segments, parameters, useModalNavigation, animated);
await DoNavigateAction(currentPage, nextSegment, nextPage, parameters, async() =>
{
currentPage.IsPresented = isPresented;
await DoPush(currentPage, nextPage, true, animated);
});
return;
}
var nextSegmentType = PageNavigationRegistry.GetPageType(UriParsingHelper.GetSegmentName(nextSegment));
//we must recreate the NavigationPage everytime or the transitions on iOS will not work properly, unless we meet the two scenarios below
bool detailIsNavPage = false;
bool reuseNavPage = false;
if (detail is NavigationPage navPage)
{
detailIsNavPage = true;
//we only care if we the next segment is also a NavigationPage.
if (PageUtilities.IsSameOrSubclassOf <NavigationPage>(nextSegmentType))
{
//first we check to see if we are being forced to reuse the NavPage by checking the interface
reuseNavPage = !GetClearNavigationPageNavigationStack(navPage);
if (!reuseNavPage)
{
//if we weren't forced to reuse the NavPage, then let's check the NavPage.CurrentPage against the next segment type as we don't want to recreate the entire nav stack
//just in case the user is trying to navigate to the same page which may be nested in a NavPage
var nextPageType = PageNavigationRegistry.GetPageType(UriParsingHelper.GetSegmentName(segments.Peek()));
var currentPageType = navPage.CurrentPage.GetType();
if (nextPageType == currentPageType)
{
reuseNavPage = true;
}
}
}
}
if ((detailIsNavPage && reuseNavPage) || (!detailIsNavPage && detail.GetType() == nextSegmentType))
{
await ProcessNavigation(detail, segments, parameters, useModalNavigation, animated);
await DoNavigateAction(null, nextSegment, detail, parameters, onNavigationActionCompleted : () =>
{
if (detail is TabbedPage && nextSegment.Contains(KnownNavigationParameters.SelectedTab))
{
var segmentParams = UriParsingHelper.GetSegmentParameters(nextSegment);
SelectPageTab(detail, segmentParams);
}
currentPage.IsPresented = isPresented;
});
return;
}
else
{
var newDetail = CreatePageFromSegment(nextSegment);
await ProcessNavigation(newDetail, segments, parameters, newDetail is NavigationPage?false : true, animated);
await DoNavigateAction(detail, nextSegment, newDetail, parameters, onNavigationActionCompleted : () =>
{
if (detailIsNavPage)
{
OnNavigatedFrom(((NavigationPage)detail).CurrentPage, parameters);
}
currentPage.IsPresented = isPresented;
currentPage.Detail = newDetail;
PageUtilities.DestroyPage(detail);
});
return;
}
}
void ConfigureTabbedPage(TabbedPage tabbedPage, string segment)
{
foreach (var child in tabbedPage.Children)
{
PageUtilities.SetAutowireViewModelOnPage(child);
_pageBehaviorFactory.ApplyPageBehaviors(child);
if (child is NavigationPage navPage)
{
PageUtilities.SetAutowireViewModelOnPage(navPage.CurrentPage);
_pageBehaviorFactory.ApplyPageBehaviors(navPage.CurrentPage);
}
}
var parameters = UriParsingHelper.GetSegmentParameters(segment);
var tabsToCreate = parameters.GetValues <string>(KnownNavigationParameters.CreateTab);
if (tabsToCreate.Count() > 0)
{
foreach (var tabToCreate in tabsToCreate)
{
//created tab can be a single view or a view nested in a NavigationPage with the syntax "NavigationPage|ViewToCreate"
var tabSegements = tabToCreate.Split('|');
if (tabSegements.Length > 1)
{
var navigationPage = CreatePageFromSegment(tabSegements[0]) as NavigationPage;
if (navigationPage != null)
{
var navigationPageChild = CreatePageFromSegment(tabSegements[1]);
navigationPage.PushAsync(navigationPageChild);
//when creating a NavigationPage w/ DI, a blank Page object is injected into the ctor. Let's remove it
if (navigationPage.Navigation.NavigationStack.Count > 1)
{
navigationPage.Navigation.RemovePage(navigationPage.Navigation.NavigationStack[0]);
}
//set the title because Xamarin doesn't do this for us.
navigationPage.Title = navigationPageChild.Title;
navigationPage.Icon = navigationPageChild.Icon;
tabbedPage.Children.Add(navigationPage);
}
}
else
{
var tab = CreatePageFromSegment(tabToCreate);
tabbedPage.Children.Add(tab);
}
}
}
var selectedTab = parameters.GetValue <string>(KnownNavigationParameters.SelectedTab);
if (!string.IsNullOrWhiteSpace(selectedTab))
{
var selectedTabType = PageNavigationRegistry.GetPageType(UriParsingHelper.GetSegmentName(selectedTab));
var childFound = false;
foreach (var child in tabbedPage.Children)
{
if (!childFound && child.GetType() == selectedTabType)
{
tabbedPage.CurrentPage = child;
childFound = true;
}
if (child is NavigationPage)
{
if (!childFound && ((NavigationPage)child).CurrentPage.GetType() == selectedTabType)
{
tabbedPage.CurrentPage = child;
childFound = true;
}
}
}
}
}
protected virtual async Task ProcessNavigationForNavigationPage(NavigationPage currentPage, string nextSegment, Queue <string> segments, INavigationParameters parameters, bool?useModalNavigation, bool animated)
{
if (currentPage.Navigation.NavigationStack.Count == 0)
{
await UseReverseNavigation(currentPage, nextSegment, segments, parameters, false, animated);
return;
}
var clearNavigationStack = GetClearNavigationPageNavigationStack(currentPage);
var isEmptyOfNavigationStack = currentPage.Navigation.NavigationStack.Count == 0;
List <Page> destroyPages;
if (clearNavigationStack && !isEmptyOfNavigationStack)
{
destroyPages = currentPage.Navigation.NavigationStack.ToList();
destroyPages.Reverse();
await currentPage.Navigation.PopToRootAsync(false);
}
else
{
destroyPages = new List <Page>();
}
var topPage = currentPage.Navigation.NavigationStack.LastOrDefault();
var nextPageType = PageNavigationRegistry.GetPageType(UriParsingHelper.GetSegmentName(nextSegment));
if (topPage?.GetType() == nextPageType)
{
if (clearNavigationStack)
{
destroyPages.Remove(destroyPages.Last());
}
if (segments.Count > 0)
{
await UseReverseNavigation(topPage, segments.Dequeue(), segments, parameters, false, animated);
}
await DoNavigateAction(topPage, nextSegment, topPage, parameters, onNavigationActionCompleted : () =>
{
if (nextSegment.Contains(KnownNavigationParameters.SelectedTab))
{
var segmentParams = UriParsingHelper.GetSegmentParameters(nextSegment);
SelectPageTab(topPage, segmentParams);
}
});
}
else
{
await UseReverseNavigation(currentPage, nextSegment, segments, parameters, false, animated);
if (clearNavigationStack && !isEmptyOfNavigationStack)
{
currentPage.Navigation.RemovePage(topPage);
}
}
foreach (var destroyPage in destroyPages)
{
PageUtilities.DestroyPage(destroyPage);
}
}
protected virtual async Task ProcessNavigationForNavigationPage(NavigationPage currentPage, string nextSegment, Queue <string> segments, NavigationParameters parameters, bool?useModalNavigation, bool animated)
{
if (currentPage.Navigation.NavigationStack.Count == 0)
{
await UseReverseNavigation(currentPage, nextSegment, segments, parameters, false, animated);
return;
}
var clearNavigationStack = GetClearNavigationPageNavigationStack(currentPage);
var isEmptyOfNavigationStack = currentPage.Navigation.NavigationStack.Count == 0;
List <Page> destroyPages;
if (clearNavigationStack && !isEmptyOfNavigationStack)
{
destroyPages = currentPage.Navigation.NavigationStack.ToList();
destroyPages.Reverse();
await currentPage.Navigation.PopToRootAsync(false);
}
else
{
destroyPages = new List <Page>();
}
var topPage = currentPage.Navigation.NavigationStack.LastOrDefault();
var nextPageType = PageNavigationRegistry.GetPageType(UriParsingHelper.GetSegmentName(nextSegment));
if (topPage?.GetType() == nextPageType)
{
if (clearNavigationStack)
{
destroyPages.Remove(destroyPages.Last());
}
await ProcessNavigation(topPage, segments, parameters, false, animated);
await DoNavigateAction(topPage, nextSegment, topPage, parameters);
}
else
{
// Replace RootPage of NavigationStack
var nextPage = CreatePageFromSegment(nextSegment);
await ProcessNavigation(nextPage, segments, parameters, false, animated);
await DoNavigateAction(topPage ?? currentPage, nextSegment, nextPage, parameters, async() =>
{
var push = DoPush(currentPage, nextPage, false, animated);
if (clearNavigationStack && !isEmptyOfNavigationStack)
{
currentPage.Navigation.RemovePage(topPage);
}
await push;
});
}
foreach (var destroyPage in destroyPages)
{
PageUtilities.DestroyPage(destroyPage);
}
}
