/// <inheritdoc />
public async Task PopAsync(INavigationParameters parameters, AnimationOptions animationOptions)
{
if (m_IsBusy)
{
return;
}
if (m_Current == null)
{
throw new InvalidOperationException("Cannot pop if there is no screen current being displayed!");
}
if (!m_Current.CanNavigate(parameters))
{
return;
}
IScreenController previousScreen = null;
if (m_NavigationStack.Count != 0)
{
previousScreen = m_NavigationStack.Pop();
}
try
{
m_IsBusy = true;
if (!animationOptions.enabled)
{
m_Current.OnScreenDestroyed(parameters);
await m_Current.UpdateDisplayAsync(NavigationMode.Removed, false);
if (previousScreen != null)
{
m_Current = previousScreen;
m_Current.OnNavigatingBack(parameters);
await m_Current.UpdateDisplayAsync(NavigationMode.Returning, false);
m_Current.OnNavigatedBack(parameters);
}
else
{
m_Current = null;
}
}
else
{
if (animationOptions.playSynchronously)
{
m_Current.OnScreenDestroyed(parameters);
m_ParallelTasks.Clear();
m_ParallelTasks.Add(m_Current.UpdateDisplayAsync(NavigationMode.Removed));
if (previousScreen != null)
{
previousScreen.OnNavigatingBack(parameters);
m_ParallelTasks.Add(previousScreen.UpdateDisplayAsync(NavigationMode.Returning));
}
await Task.WhenAll(m_ParallelTasks);
if (previousScreen != null)
{
m_Current = previousScreen;
m_Current.OnNavigatedBack(parameters);
}
else
{
m_Current = null;
}
}
else
{
m_Current.OnScreenDestroyed(parameters);
await m_Current.UpdateDisplayAsync(NavigationMode.Removed);
m_Current = previousScreen;
m_Current.OnNavigatingBack(parameters);
await m_Current.UpdateDisplayAsync(NavigationMode.Returning);
m_Current.OnNavigatedBack(parameters);
}
m_EventManager.Invoke(new NavigationCompletedEvent(m_Current.id, m_NavigationStack));
}
}
catch (Exception e)
{
Debug.LogException(e);
}
finally
{
m_IsBusy = false;
}
}