/// <summary>
/// Constructs the BackgroundTaskManager (and the progress monitor task)
/// </summary>
public BackgroundTaskManager(ViewManager viewManager)
{
if (Instance != null)
{
throw new InvalidOperationException("This class must only be instantiated once.");
}
Instance = this;
Tasks = new Dictionary <string, BackgroundTask>();
_uiContext = SynchronizationContext.Current;
if (_uiContext == null)
{
if (Debugger.IsAttached)
{
Debugger.Break();
}
}
_uiThreadId = Thread.CurrentThread.ManagedThreadId;
_delayedPostActions = new Queue <Func <bool> >();
_viewManager = viewManager;
_discardableTaskKeys = new List <string>();
_taskFactory = new System.Threading.Tasks.TaskFactory(TaskScheduler.Default);
// Create the progress monitor task
_progressMonitor = new Task(ProgressMonitorTask);
_progressMonitor.Start();
}
/// <summary>
/// Creates an BackgroundTask
/// </summary>
/// <param name="source">The manager</param>
/// <param name="loadingProgressViewModel">The progress indicator view model</param>
/// <param name="key">The key for the task (only one parallel task per key may run simultaneously)</param>
/// <param name="ctx">The callers' synchronization context</param>
internal BackgroundTask(BackgroundTaskManager source, LoadingProgressViewModel loadingProgressViewModel, string key, SynchronizationContext ctx)
{
Ctx = ctx;
LoadingProgressViewModels = new List <LoadingProgressViewModel>();
LoadingProgressViewModels.Add(loadingProgressViewModel);
Cancelled = new CancellationTokenSource();
_trackProgress = new TrackProgressImpl();
}
