Hello world!

I'm trying to create an handler for retreiving thumbnails for pdf files. This is what i've got so far:

  public class PdfThumbnailProvider : AbstractThumbnailProvider
  {
    protected override IEnumerable<string> SupportedExtensions
    {
      get { return new List<string> { ".pdf" }; }
    }

    protected override bool TryGetThumbnailUrl(string fileUrl, out string thumbUrl)
    {
      // Set thumbnail url to empty strin initially
      thumbUrl = string.Empty;

      // Make sure file has an extension
      var ext = Path.GetExtension( fileUrl );
      if( string.IsNullOrEmpty( ext ) )
        return false;

      // Make sure it has a supported file extension
      if( !IsSupportedExtension( ext ) )
        return false;

      // Make sure the thumbnail exists
      var tmpThumbUrl = fileUrl.Replace( ext, "_thumb.jpg" );

      try
      {
        var fs = FileSystemProviderManager.Current.GetFileSystemProvider<MediaFileSystem>();
        var relativeThumbPath = fs.GetRelativePath( tmpThumbUrl );
        if( !fs.FileExists( relativeThumbPath ) )
          return false;
      }
      catch( Exception )
      {
        // If something odd happens, just return false and move on
        return false;
      }

      // We've got this far, so thumbnail must exist
      thumbUrl = tmpThumbUrl;
      return true;
    }
  }

But this isn't working, what am i missing?

I've based in on this source: https://github.com/umbraco/Umbraco-CMS/blob/dev-v7/src/Umbraco.Web/Media/ThumbnailProviders/ImageThumbnailProvider.cs

Best regards Rasmus E.

-- UPDATE:

Found the following ThumbnailProvidersResolver, but it turns out this is internal sealed and not public sealed like the ContentFinderResolver

I've created a pull-request here: https://github.com/umbraco/Umbraco-CMS/pull/751

And issue here: http://issues.umbraco.org/issue/U4-6902?query=ThumbnailProvider