RegistrationManager.cs

// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

using Microsoft.Windows.Widgets.Providers;
using System;
using System.Threading;

namespace WidgetHelper
{
  public class RegistrationManager<TWidgetProvider> : IDisposable
      where TWidgetProvider : IWidgetProvider, new()
  {
    private bool disposedValue = false;
    private ManualResetEvent disposedEvent = new ManualResetEvent(false);

    private class ClassLifetimeUnregister : IDisposable
    {
      public ClassLifetimeUnregister(uint registrationHandle) { COMRegistrationHandle = registrationHandle; }
      private readonly uint COMRegistrationHandle;

      public void Dispose()
      {
        Com.ClassObject.Revoke(COMRegistrationHandle);
      }
    }

    private IDisposable registeredProvider;

    private RegistrationManager(IDisposable provider)
    {
      registeredProvider = provider;
    }

    public static RegistrationManager<TWidgetProvider> RegisterProvider()
    {
      var registration = RegisterClass(typeof(TWidgetProvider).GUID, new WidgetProviderFactory<TWidgetProvider>());
      return new RegistrationManager<TWidgetProvider>(registration);
    }

    private static IDisposable RegisterClass(Guid clsid, Com.IClassFactory factory)
    {
      uint registrationHandle;
      Com.ClassObject.Register(clsid, factory, out registrationHandle);

      return new ClassLifetimeUnregister(registrationHandle);
    }

    protected virtual void Dispose(bool disposing)
    {
      if (!disposedValue)
      {
        registeredProvider.Dispose();
        disposedValue = true;
        disposedEvent.Set();
      }
    }

    ~RegistrationManager()
    {
      Dispose(disposing: false);
    }

    public ManualResetEvent GetDisposedEvent()
    {
      return disposedEvent;
    }
    public void Dispose()
    {
      // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
      Dispose(disposing: true);
      GC.SuppressFinalize(this);
    }
  }
}