public void RequestNavigate(string regionName, string viewName, string stateName)
{
if (_isInTransition) return;
_isInTransition = true;
if (string.IsNullOrEmpty(regionName))
throw new ArgumentNullException("regionName");
if (string.IsNullOrEmpty(viewName))
throw new ArgumentNullException("viewName");
INavigationRegion region = EnsureRegion(regionName);
NavigationDescriptor descriptor = ActivateView(viewName, region);
ViewState viewState = EnsureState(regionName, viewName, stateName, descriptor);
OnNavigationStart(_previousDescriptor, descriptor, viewState);
Presenter.TransitionCompleted -= OnTransitionCompleted;
if (_previousDescriptor != null && _previousDescriptor.ViewName != descriptor.ViewName)
{
_targetDescriptor = descriptor;
_sourceDescriptor = _previousDescriptor;
_targetState = viewState;
Presenter.TransitionCompleted += OnTransitionCompleted;
Presenter.ApplyTransition(_previousDescriptor.ViewResolver(), descriptor.ViewResolver());
}
else
{
PostTransition();
}
_previousDescriptor = descriptor;
}
public StateNavigationViewModel(ViewState viewState, NavigationDescriptor descriptor, string regionName)
{
_viewState = viewState;
_descriptor = descriptor;
_regionName = regionName;
_navigationService = ServiceLocator.Current.GetInstance<INavigationService>();
_navigationService.NavigationStart += OnNavigationStart;
}
public StateChangingEventArgs(ViewState currentState, ViewState targetState)
{
CurrentState = currentState;
TargetState = targetState;
}
public StateChangedEventArgs(ViewState previousState, ViewState currentState)
{
PreviousState = previousState;
CurrentState = currentState;
}
private void OnNavigationStart(NavigationDescriptor sourceDescriptor, NavigationDescriptor targetDescriptor, ViewState targetState)
{
if (NavigationStart != null)
NavigationStart(this,
new NavigationEventArgs(sourceDescriptor, targetDescriptor) { TargetState = targetState });
}
private void NotifyStateChanging(NavigationDescriptor descriptor, ViewState state)
{
if(descriptor.StateChanging != null)
descriptor.StateChanging(state);
}