/// <summary>
/// Craetes a new FamFrame and adds the resulting NavigationService to the
/// WindowWrapper collection. In addition, it optionally will setup the
/// shell back button to react to the nav of the Frame.
/// A developer should call this when creating a new/secondary frame.
/// The shell back button should only be setup one time.
/// </summary>
public Services.NavigationService.NavigationService NavigationServiceFactory(BackButton backButton, ExistingContent existingContent)
{
var frame = new Frame
{
Language = Windows.Globalization.ApplicationLanguages.Languages[0],
Content = (existingContent == ExistingContent.Include) ? Window.Current.Content : null,
};
var navigationService = new Services.NavigationService.NavigationService(frame);
WindowWrapper.Current().NavigationServices.Add(navigationService);
if (backButton == BackButton.Attach)
{
// TODO: unattach others
// update shell back when backstack changes
// only the default frame in this case because secondary should not dismiss the app
frame.RegisterPropertyChangedCallback(Frame.BackStackDepthProperty, (s, args) => UpdateShellBackButton());
// update shell back when navigation occurs
// only the default frame in this case because secondary should not dismiss the app
frame.Navigated += (s, args) => UpdateShellBackButton();
}
// this is always okay to check, default or not
// expire any state (based on expiry)
DateTime cacheDate;
// default the cache age to very fresh if not known
var otherwise = DateTime.MinValue.ToString();
if (DateTime.TryParse(navigationService.FrameFacade.GetFrameState(CacheDateKey, otherwise), out cacheDate))
{
var cacheAge = DateTime.Now.Subtract(cacheDate);
if (cacheAge >= CacheMaxDuration)
{
// clear state in every nav service in every view
foreach (var service in WindowWrapper.ActiveWrappers.SelectMany(x => x.NavigationServices))
{
service.FrameFacade.ClearFrameState();
}
}
}
else
{
// no date, that's okay
}
return navigationService;
}
private static void AttachFrameEvents(NavButtonBehavior behavior, Frame frame)
{
if (behavior == null || frame == null)
{
return;
}
FrameEventRegistration eventReg;
if (behavior._eventRegistrationInfo.TryGetValue(frame, out eventReg))
{
// events already attached
return;
}
eventReg = new FrameEventRegistration();
behavior._eventRegistrationInfo.Add(frame, eventReg);
eventReg.GoBackReg = frame.RegisterPropertyChangedCallback(Frame.CanGoBackProperty, (s, e) => behavior.CalculateThrottled());
eventReg.GoForwardReg = frame.RegisterPropertyChangedCallback(Frame.CanGoForwardProperty, (s, e) => behavior.CalculateThrottled());
frame.Navigated += behavior.OnNavigated;
frame.Loaded += behavior.FrameOnLoaded;
}
// this is private because there's no reason for the developer to call this
private Frame InitializeFrame(ILaunchActivatedEventArgs e)
{
// do not recreate the frame
if (Window.Current.Content is Frame)
return Window.Current.Content as Frame;
// first show the splash
var splashScreen = default(UIElement);
if (SplashFactory != null)
{
splashScreen = SplashFactory(e.SplashScreen);
Window.Current.Content = splashScreen;
Window.Current.Activate();
}
else
{
// if there is no SplashScreen then the default/static splash will show.
}
// in any case, next create a new, default frame
var defaultFrame = new Frame
{
Language = Windows.Globalization.ApplicationLanguages.Languages[0]
};
// set default frame as primary, default visual
Window.Current.Content = defaultFrame;
// next setup the default view
var navigationService = new Services.NavigationService.NavigationService(defaultFrame);
WindowWrapper.Current().NavigationServices.Add(navigationService);
// this anon method will be used to refresh the shell back button
Action updateShellBack = () =>
{
// show the shell back only if there is anywhere to go in the default frame
SystemNavigationManager.GetForCurrentView().AppViewBackButtonVisibility =
(ShowShellBackButton && NavigationService.Frame.CanGoBack)
? AppViewBackButtonVisibility.Visible
: AppViewBackButtonVisibility.Collapsed;
};
// update shell back when backstack changes
// only the default frame in this case because secondary should not dismiss the app
defaultFrame.RegisterPropertyChangedCallback(Frame.BackStackDepthProperty, (s, args) => updateShellBack());
// update shell back when navigation occurs
// only the default frame in this case because secondary should not dismiss the app
defaultFrame.Navigated += (s, args) => updateShellBack();
// expire any state (based on expiry)
DateTime cacheDate;
// default the cache age to very fresh if not known
var otherwise = DateTime.MinValue.ToString();
if (DateTime.TryParse(navigationService.FrameFacade.GetFrameState(CacheDateKey, otherwise), out cacheDate))
{
var cacheAge = DateTime.Now.Subtract(cacheDate);
if (cacheAge >= CacheMaxDuration)
{
// clear state in every nav service in every view
foreach (var service in WindowWrapper.ActiveWrappers.SelectMany(x => x.NavigationServices))
{
service.FrameFacade.ClearFrameState();
}
}
}
else
{
// no date, that's okay
}
// finally return our new frame
return defaultFrame;
}
