public Task InitializeViewAsync(IViewModel viewModel, object view, IDataContext context = null)
{
var tcs = new TaskCompletionSource <object>();
ThreadManager.InvokeOnUiThreadAsync(() =>
{
if (context == null)
{
context = DataContext.Empty;
}
view = ToolkitExtensions.GetUnderlyingView <object>(view);
var oldView = viewModel.GetCurrentView <object>(false);
if (ReferenceEquals(oldView, view))
{
tcs.SetResult(null);
return;
}
if (oldView != null)
{
CleanupViewInternal(viewModel, oldView, context);
}
InitializeView(viewModel, view, context);
ViewInitialized?.Invoke(this, new ViewInitializedEventArgs(view, viewModel, context));
tcs.SetResult(null);
});
return(tcs.Task);
}
public Task InitializeViewAsync(IViewModel viewModel, object view, IDataContext context = null)
{
var tcs = new TaskCompletionSource <object>();
ThreadManager.InvokeOnUiThreadAsync(() =>
{
if (context == null)
{
context = DataContext.Empty;
}
view = ToolkitExtensions.GetUnderlyingView <object>(view);
var oldView = viewModel.Settings.Metadata.GetData(ViewModelConstants.View);
if (ReferenceEquals(oldView, view))
{
tcs.SetResult(null);
return;
}
if (oldView != null)
{
CleanupViewInternal(viewModel, oldView, context);
}
InitializeView(viewModel, view, context);
Action <IViewManager, IViewModel, object, IDataContext> handler = ViewInitialized;
if (handler != null)
{
handler(this, viewModel, view, context);
}
tcs.SetResult(null);
});
return(tcs.Task);
}
public Task <bool> GoToStateAsync(object view, string stateName, bool useTransitions, IDataContext context)
{
Should.NotBeNull(view, "view");
#if WPF
var control = ToolkitExtensions.GetUnderlyingView <object>(view) as FrameworkElement;
#else
var control = ToolkitExtensions.GetUnderlyingView <object>(view) as Control;
#endif
if (control == null)
{
return(Empty.FalseTask);
}
var tcs = new TaskCompletionSource <bool>();
_threadManager.InvokeOnUiThreadAsync(() =>
{
#if WPF
var result = System.Windows.VisualStateManager.GoToState(control, stateName, useTransitions);
#elif !WINDOWSCOMMON
var result = System.Windows.VisualStateManager.GoToState(control, stateName, useTransitions);
#else
var result = Windows.UI.Xaml.VisualStateManager.GoToState(control, stateName, useTransitions);
#endif
tcs.SetResult(result);
});
return(tcs.Task);
}
public virtual IViewModel TryTakeViewModelFromCache(INavigationContext context, object view)
{
view = ToolkitExtensions.GetUnderlyingView <object>(view);
var type = view.GetType();
List <IViewModel> list;
if (!_cachedViewModels.TryGetValue(type, out list) || list == null || list.Count == 0)
{
if (Tracer.TraceInformation)
{
Tracer.Info("Navigation cache - the view model for the view {0} is not found in the cache, navigation mode: {1}", type, context.NavigationMode);
}
return(null);
}
IViewModel vm = list[0];
list.RemoveAt(0);
if (list.Count == 0)
{
_cachedViewModels.Remove(type);
}
if (Tracer.TraceInformation)
{
Tracer.Info("Navigation cache - the view model {0} for the view {1} was taken from the cache, navigation mode: {2}",
vm.GetType(), type, context.NavigationMode);
}
return(vm);
}
public static TView GetCurrentView <TView>([NotNull] this IViewModel viewModel, bool underlyingView = true)
where TView : class
{
Should.NotBeNull(viewModel, nameof(viewModel));
var view = viewModel.Settings.Metadata.GetData(ViewModelConstants.View);
if (view == null || !underlyingView)
{
return((TView)view);
}
return(ToolkitExtensions.GetUnderlyingView <TView>(view));
}
protected virtual void CleanupView([NotNull] IViewModel viewModel, [NotNull] object view,
[NotNull] IDataContext context)
{
InitializeViewInternal(null, view, context);
viewModel.Settings.Metadata.Remove(ViewModelConstants.View);
ReflectionExtensions.GetViewProperty(viewModel.GetType())?.SetValue <object>(viewModel, null);
viewModel.Unsubscribe(ToolkitExtensions.GetUnderlyingView <object>(view));
if (ServiceProvider.AttachedValueProvider.Contains(view, ViewManagerCreatorPath))
{
ServiceProvider.AttachedValueProvider.Clear(view, ViewManagerCreatorPath);
(view as IDisposable)?.Dispose();
}
}
public Task CleanupViewAsync(IViewModel viewModel, IDataContext context = null)
{
Should.NotBeNull(viewModel, nameof(viewModel));
object view = viewModel.GetCurrentView <object>(false);
if (view == null)
{
return(Empty.Task);
}
var tcs = new TaskCompletionSource <object>();
ThreadManager.InvokeOnUiThreadAsync(() =>
{
if (context == null)
{
context = DataContext.Empty;
}
CleanupViewInternal(viewModel, ToolkitExtensions.GetUnderlyingView <object>(view), context);
tcs.SetResult(null);
}, OperationPriority.Low);
return(tcs.Task);
}
public virtual void TryCacheViewModel(INavigationContext context, object view, IViewModel viewModel)
{
if (context.NavigationMode == NavigationMode.Back)
{
return;
}
view = ToolkitExtensions.GetUnderlyingView <object>(view);
Type type = view.GetType();
List <IViewModel> list;
if (!_cachedViewModels.TryGetValue(type, out list))
{
list = new List <IViewModel>();
_cachedViewModels[type] = list;
}
list.Insert(0, viewModel);
if (Tracer.TraceInformation)
{
Tracer.Info("Navigation cache - the view model {0} was cached, navigation mode: {1}, view: {2}",
viewModel.GetType(), context.NavigationMode, type);
}
}
public virtual bool Navigate(IViewMappingItem source, string parameter, IDataContext dataContext)
{
Should.NotBeNull(source, nameof(source));
if (dataContext == null)
{
dataContext = DataContext.Empty;
}
bool bringToFront;
dataContext.TryGetData(NavigationProviderConstants.BringToFront, out bringToFront);
if (!RaiseNavigating(new NavigatingCancelEventArgs(source, bringToFront ? NavigationMode.Refresh : NavigationMode.New, parameter)))
{
return(false);
}
var activity = PlatformExtensions.CurrentActivity ?? SplashScreenActivityBase.Current;
var context = activity ?? Application.Context;
var intent = new Intent(context, source.ViewType);
if (activity == null)
{
intent.AddFlags(ActivityFlags.NewTask);
}
else if (dataContext.GetData(NavigationConstants.ClearBackStack))
{
if (PlatformExtensions.IsApiLessThanOrEqualTo10)
{
intent.AddFlags(ActivityFlags.NewTask | ActivityFlags.ClearTop);
}
else
{
intent.AddFlags(ActivityFlags.NewTask | ActivityFlags.ClearTask);
}
ServiceProvider.EventAggregator.Publish(this, MvvmActivityMediator.FinishActivityMessage.Instance);
dataContext.AddOrUpdate(NavigationProviderConstants.InvalidateAllCache, true);
}
if (parameter != null)
{
intent.PutExtra(ParameterString, parameter);
}
if (bringToFront)
{
_isReorder = true;
//http://stackoverflow.com/questions/20695522/puzzling-behavior-with-reorder-to-front
//http://code.google.com/p/android/issues/detail?id=63570#c2
bool closed = false;
if (PlatformExtensions.IsApiGreaterThanOrEqualTo19)
{
var viewModel = dataContext.GetData(NavigationConstants.ViewModel);
if (viewModel != null)
{
var view = viewModel.Settings.Metadata.GetData(ViewModelConstants.View);
var activityView = ToolkitExtensions.GetUnderlyingView <object>(view) as Activity;
if (activityView != null && activityView.IsTaskRoot)
{
var message = new MvvmActivityMediator.FinishActivityMessage(viewModel);
ServiceProvider.EventAggregator.Publish(this, message);
closed = message.Finished;
}
}
}
if (!closed)
{
intent.AddFlags(ActivityFlags.ReorderToFront);
}
dataContext.AddOrUpdate(NavigationProviderConstants.InvalidateCache, true);
}
_isNew = true;
_parameter = parameter;
StartActivity(context, intent, source, dataContext);
return(true);
}