/// <summary>
/// Navigate back in current page modal navigation stack.
/// </summary>
/// <param name="closeModal">Close modal page</param>
/// <param name="parameter">The navigation paremeter</param>
public Task GoBackModalAsync(bool closeModal, object parameter = null)
{
ContentPage backOutPage = m_navigation.NavigationStack.LastOrDefault();
ContentPage backInPage = null;
if (m_navigation.NavigationStack.Count > 2 && closeModal == false)
{
backInPage = m_navigation.NavigationStack.ElementAt(m_navigation.NavigationStack.Count - 2);
}
DissapearEventArgs dissapearArgs = new DissapearEventArgs(NavigationDirection.Out);
AppearEventArgs appearArgs = new AppearEventArgs(NavigationDirection.In, parameter);
NavigationPage.InvokeOnNavigationAwareElement(backOutPage, v => v.OnDissapearing(dissapearArgs));
NavigationPage.InvokeOnNavigationAwareElement(backInPage, v => v.OnAppearing(appearArgs));
return(m_navigation.PopModalAsync(closeModal).ContinueWith((arg) =>
{
NavigationPage.InvokeOnNavigationAwareElement(backOutPage, v => v.OnDissapeared(dissapearArgs));
NavigationPage.InvokeOnNavigationAwareElement(backInPage, v => v.OnAppeared(appearArgs));
TaskCompletionSource <object> tcs = m_modalTaskDictionary[backOutPage];
m_modalTaskDictionary.Remove(backOutPage);
tcs.SetResult(parameter);
}));
}
/// <summary>
/// Page is appeared to screen and animation is finished
/// </summary>
public virtual void OnAppeared(AppearEventArgs args)
{
if (IsDebugEnabled)
{
Debug.WriteLine(NavigationBar.GetTitle(this) + ": OnAppeared");
}
LifecycleState = LifecycleStates.Appeared;
if (ContentCreateEvent == ContentCreateEvents.Appeared && ContentTemplate != null && Content is View == false && _contentElement == null)
{
if (_contentElement != null && Children.Contains(_contentElement))
{
Children.Remove(_contentElement);
}
_contentElement = ContentTemplate.CreateContent() as View;
Children.Insert(0, _contentElement);
if (Content != null)
{
_contentElement.BindingContext = Content;
}
}
}
/// <summary>
/// Page is started to appearing on the screen with animation
/// </summary>
public virtual void OnAppearing(AppearEventArgs args)
{
if (IsDebugEnabled)
{
Debug.WriteLine(NavigationBar.GetTitle(this) + ": OnAppearing");
}
LifecycleState = LifecycleStates.Appearing;
}
/// <summary>
/// Navigate to new modal page. If current page has modal pages visible, then modal pages is closed
/// with current page.
/// </summary>
/// <param name="page">Page class name</param>
/// <param name="parameter">The navigation parameter</param>
public Task <object> NavigateModalAsync(string page, object parameter)
{
ContentPage currentModalPage = m_navigation.ModalNavigationStack.LastOrDefault();
ContentPage nextModalPage = m_createPage(page);
DissapearEventArgs dissapearArgs = new DissapearEventArgs(NavigationDirection.Out);
AppearEventArgs appearArgs = new AppearEventArgs(NavigationDirection.In, parameter);
NavigationPage.InvokeOnNavigationAwareElement(currentModalPage, v => v.OnDissapearing(dissapearArgs));
NavigationPage.InvokeOnNavigationAwareElement(nextModalPage, v => v.OnAppearing(appearArgs));
m_navigation.PushModalAsync(nextModalPage).ContinueWith((arg) =>
{
NavigationPage.InvokeOnNavigationAwareElement(currentModalPage, v => v.OnDissapeared(dissapearArgs));
NavigationPage.InvokeOnNavigationAwareElement(nextModalPage, v => v.OnAppeared(appearArgs));
});
TaskCompletionSource <object> tcs = new TaskCompletionSource <object>();
m_modalTaskDictionary.Add(nextModalPage, tcs);
return(tcs.Task);
}
