public Task<bool> HandleNavigation( NavigationContext context )
{
//Contract.Requires<ArgumentNullException>( context != null );
return null;
}
/// <summary>
/// Navigates to the specified view with parameters.
/// </summary>
/// <param name="viewName">Name of the view.</param>
/// <param name="parameters">The parameters.</param>
/// <exception cref="System.ArgumentNullException">viewName</exception>
/// <exception cref="System.ArgumentException">viewName</exception>
public async void Navigate( string viewName, XParameters parameters, bool openInSubFrame = false)
{
var context = new NavigationContext { ViewName = viewName, Parameters = parameters };
foreach( var handler in _navigationHandlers )
{
if( await handler.HandleNavigation( context ) )
{
break;
}
}
if( context.Cancel )
{
return;
}
ViewDescriptor descriptor;
if( !_views.TryGetValue( context.ViewName, out descriptor ) )
{
throw new ArgumentException( String.Format( "View with name '{0}' is not registered.", context.ViewName ), "viewName" );
}
if (openInSubFrame)
{
var subFrame = ((WindowsRTApplication) Application.Current).RootSubFrame;
subFrame.Navigate(descriptor.Type, context.Parameters);
((UIElement)subFrame.Parent).Visibility = Visibility.Visible;
//FlyoutBase.ShowAttachedFlyout(((WindowsRTApplication)Application.Current).RootFrame);
}
else
{
((WindowsRTApplication)Application.Current).RootFrame.Navigate(descriptor.Type, context.Parameters);
}
//if (openInSubFrame) ((WindowsRTApplication)Application.Current).RootSubFrame.Navigate(descriptor.Type, context.Parameters);
//else ((WindowsRTApplication)Application.Current).RootFrame.Navigate(descriptor.Type, context.Parameters);
}
public Frame NavigateWithFrame(string viewName, XParameters parameters)
{
var context = new NavigationContext {ViewName = viewName, Parameters = parameters};
if (context.Cancel)
{
return null;
}
ViewDescriptor descriptor;
if (!_views.TryGetValue(context.ViewName, out descriptor))
{
throw new ArgumentException(String.Format("View with name '{0}' is not registered.", context.ViewName),
"viewName");
}
Frame subFrame = ((WindowsRTApplication) Application.Current).RootSubFrame;
subFrame.Navigate(descriptor.Type, context.Parameters);
((UIElement) subFrame.Parent).Visibility = Visibility.Visible;
return subFrame;
}
private void CancelAuthenticationAndRollbackHistory()
{
if( _snapshotId != null )
{
var snapshotId = _snapshotId;
_snapshotId = null;
_targetContext = null;
_navigationService.RollbackSnapshot( snapshotId );
}
}
private async Task StartAuthentication( string initialViewName, XParameters parameters, Action performWhenAuthenticated )
{
if( _authenticationServiceContext != null )
{
var authenticated = await _authenticationServiceContext.IsAuthenticated();
if( !authenticated )
{
Action<object> guard = NavigationGuard;
if( performWhenAuthenticated != null )
{
guard = async o =>
{
NavigationGuard( o );
if( await _authenticationServiceContext.IsAuthenticated() )
{
performWhenAuthenticated();
}
};
}
_targetContext = null;
_snapshotId = _navigationService.CreateSnapshot( guard );
if( string.IsNullOrEmpty( initialViewName ) )
{
initialViewName = _authenticationServiceContext.AuthenticationViewName;
parameters = _authenticationServiceContext.AuthenticationViewParameters;
}
_navigationService.Navigate( initialViewName, parameters );
}
else
{
if( performWhenAuthenticated != null )
{
performWhenAuthenticated();
}
}
}
}
/// <summary>
/// Completes the authentication.
/// </summary>
public void CompleteAuthentication()
{
if( _snapshotId != null )
{
var snapshotId = _snapshotId;
var targetContext = _targetContext;
_snapshotId = null;
_targetContext = null;
if( targetContext != null )
{
_navigationService.RollbackSnapshot( snapshotId, targetContext.ViewName, targetContext.Parameters );
}
else
{
_navigationService.RollbackSnapshot( snapshotId );
}
}
}
public async Task<bool> HandleNavigation( NavigationContext context )
{
ViewDescriptor descriptor;
var result = false;
if( _authenticationServiceContext == null || !_views.TryGetValue( context.ViewName, out descriptor ) )
{
return false;
}
if( AuthenticationInProgress )
{
if( !descriptor.PartOfAuthentication )
{
context.Cancel = true;
CancelAuthenticationAndRollbackHistory();
result = true;
}
}
else
{
if( descriptor.RequiresAuthentication )
{
var authenticated = await _authenticationServiceContext.IsAuthenticated();
if( !authenticated )
{
_targetContext = new NavigationContext { ViewName = context.ViewName, Parameters = context.Parameters };
_snapshotId = _navigationService.CreateSnapshot( NavigationGuard );
context.ViewName = _authenticationServiceContext.AuthenticationViewName;
context.Parameters = _authenticationServiceContext.AuthenticationViewParameters;
result = true;
}
}
}
return result;
}
private void NavigationGuard( object tag )
{
_snapshotId = null;
_targetContext = null;
}
