/// <summary>
/// Generates the cover image for a book, e.g. the thumbnail used on Bloom Library
/// </summary>
/// <param name="book"></param>
/// <param name="requestedSize">The maximum size of either dimension</param>
public static string GenerateCoverImageOfRequestedMaxSize(Book.Book book, int requestedSize)
{
HtmlThumbNailer.ThumbnailOptions thumbnailOptions = BookThumbNailer.GetCoverThumbnailOptions(requestedSize, new Guid());
BookThumbNailer.CreateThumbnailOfCoverImage(book, thumbnailOptions, null);
string thumbnailDestination = Path.Combine(book.FolderPath, thumbnailOptions.FileName);
return(thumbnailDestination);
}
/// <summary>
/// Generates a thumbnail suitable for sharing on Facebook
/// </summary>
/// <param name="book"></param>
/// <returns></returns>
public static string GenerateSocialMediaSharingThumbnail(Book.Book book)
{
// 300 x 300 is picked so that FB will consistently generate a thumbnail that is:
// * to the left of the link
// * a fixed aspect ratio (happens to be square)
// * has enough pixels to work with high res screens with devicePixelRatio up to 4. (FB Mobile App was showing it as 75 CSS pixels)
// See BL-8406
int size = 300;
var options = new HtmlThumbNailer.ThumbnailOptions
{
CenterImageUsingTransparentPadding = true,
RequestId = new Guid(),
Height = size,
Width = size,
};
options.FileName = $"thumbnail-{options.Width}x{options.Height}.png";
BookThumbNailer.CreateThumbnailOfCoverImage(book, options, null);
string thumbnailDestination = Path.Combine(book.FolderPath, options.FileName);
return(thumbnailDestination);
}