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 NavigationItemViewModel(NavigationDescriptor descriptor, string regionName)
{
_navigationDescriptor = descriptor;
RegionName = regionName;
_navigationService = ServiceLocator.Current.GetInstance<INavigationService>();
_navigationService.NavigationStart += OnNavigationStart;
}
private void NotifyStateChanging(NavigationDescriptor descriptor, ViewState state)
{
if (descriptor.StateChanging != null)
{
descriptor.StateChanging(state);
}
}
public StateNavigationViewModel(ViewState viewState, NavigationDescriptor descriptor, string regionName)
{
_viewState = viewState;
_descriptor = descriptor;
_regionName = regionName;
_navigationService = ServiceLocator.Current.GetInstance<INavigationService>();
_navigationService.NavigationStart += OnNavigationStart;
}
public void Add(NavigationDescriptor descriptor)
{
_navigationViews.Add(descriptor);
if (!descriptor.DelayLoad)
{
_activeNavigationViews.Add(descriptor);
}
}
private NavigationDescriptor ActivateView(string viewName, INavigationRegion region)
{
NavigationDescriptor descriptor = region.ActiveNavigationViews[viewName];
if (descriptor == null)
{
descriptor = region.Activate(viewName);
}
return(descriptor);
}
private void OnNavigationCompleted(NavigationDescriptor sourceDescriptor, NavigationDescriptor targetDescriptor, ViewState targetState)
{
if (NavigationCompleted != null)
{
NavigationCompleted(this,
new NavigationEventArgs(sourceDescriptor, targetDescriptor)
{
TargetState = targetState
});
}
}
public NavigationDescriptor Activate(string viewName)
{
NavigationDescriptor descriptor = _navigationViews[viewName];
if (descriptor == null)
{
throw new InvalidOperationException("View missing: " + viewName);
}
_activeNavigationViews.Add(descriptor);
return(descriptor);
}
private ViewState EnsureState(
string regionName, string viewName, string stateName, NavigationDescriptor descriptor)
{
ViewState viewState = null;
if (!string.IsNullOrEmpty(stateName))
{
if (descriptor.States == null ||
(viewState = descriptor.States.SingleOrDefault(x => x.Name == stateName)) == null)
{
throw new InvalidOperationException(
string.Format("{0}_{1}_{2} does not exist", regionName, viewName, stateName));
}
}
return(viewState);
}
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 NavigationEventArgs(
NavigationDescriptor sourceDescriptor, NavigationDescriptor targetDescriptor)
{
SourceDescriptor = sourceDescriptor;
TargetDescriptor = targetDescriptor;
}
public NavigationEventArgs(
NavigationDescriptor sourceDescriptor, NavigationDescriptor targetDescriptor)
{
SourceDescriptor = sourceDescriptor;
TargetDescriptor = targetDescriptor;
}
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);
}
private ViewState EnsureState(
string regionName, string viewName, string stateName, NavigationDescriptor descriptor)
{
ViewState viewState = null;
if (!string.IsNullOrEmpty(stateName))
{
if (descriptor.States == null ||
(viewState = descriptor.States.SingleOrDefault(x => x.Name == stateName)) == null)
{
throw new InvalidOperationException(
string.Format("{0}_{1}_{2} does not exist", regionName, viewName, stateName));
}
}
return viewState;
}
