/// <summary>
/// Creates a thumbnail of just the cover image (no title, language name, etc.)
/// </summary>
/// <returns>Returns true if successful; false otherwise. </returns>
internal static bool CreateThumbnailOfCoverImage(Book.Book book, HtmlThumbNailer.ThumbnailOptions options, Action <Image> callback = null)
{
var imageSrc = book.GetCoverImagePath();
if (!IsCoverImageSrcValid(imageSrc, options))
{
Debug.WriteLine(book.StoragePageFolder + " does not have a cover image.");
return(false);
}
var size = Math.Max(options.Width, options.Height);
var destFilePath = Path.Combine(book.StoragePageFolder, options.FileName);
// Writing a transparent image to a file, then reading it in again appears to be the only
// way to get the thumbnail image to draw with the book's cover color background reliably.
var transparentImageFile = Path.Combine(Path.GetTempPath(), "Bloom", "Transparent", Path.GetFileName(imageSrc));
Directory.CreateDirectory(Path.GetDirectoryName(transparentImageFile));
try
{
if (RuntimeImageProcessor.MakePngBackgroundTransparent(imageSrc, transparentImageFile))
{
imageSrc = transparentImageFile;
}
using (var coverImage = PalasoImage.FromFile(imageSrc))
{
if (imageSrc == transparentImageFile)
{
coverImage.Image = MakeImageOpaque(coverImage.Image, book.GetCoverColor());
}
var shouldAddDashedBorder = options.BorderStyle == HtmlThumbNailer.ThumbnailOptions.BorderStyles.Dashed;
coverImage.Image = options.CenterImageUsingTransparentPadding ?
ImageUtils.CenterImageIfNecessary(new Size(size, size), coverImage.Image, shouldAddDashedBorder) :
ImageUtils.ResizeImageIfNecessary(new Size(size, size), coverImage.Image, shouldAddDashedBorder);
switch (Path.GetExtension(destFilePath).ToLowerInvariant())
{
case ".jpg":
case ".jpeg":
ImageUtils.SaveAsTopQualityJpeg(coverImage.Image, destFilePath);
break;
default:
PalasoImage.SaveImageRobustly(coverImage, destFilePath);
break;
}
if (callback != null)
{
callback(coverImage.Image.Clone() as Image); // don't leave GC to chance
}
}
}
finally
{
if (File.Exists(transparentImageFile))
{
SIL.IO.RobustFile.Delete(transparentImageFile);
}
}
return(true);
}
// We are trying our best to end up with a thumbnail whose height/width ratio
// is the same as the original image. This allows the Uploading and Already in Bloom Library
// thumbs to top-align.
private string ChooseBestUploadingThumbnailPath(Book.Book book)
{
// If this exists, it will have the original image's ratio of height to width.
var thumb70Path = Path.Combine(book.FolderPath, "thumbnail-70.png");
if (RobustFile.Exists(thumb70Path))
{
return(thumb70Path);
}
var coverImagePath = book.GetCoverImagePath();
if (coverImagePath == null)
{
return(book.ThumbnailPath);
}
else
{
RuntimeImageProcessor.GenerateThumbnail(book.GetCoverImagePath(),
book.NonPaddedThumbnailPath, 70, ColorTranslator.FromHtml(book.GetCoverColor()));
return(book.NonPaddedThumbnailPath);
}
}
