/// <summary>
/// Currently used by the image server
/// to get thumbnails that are used in the add page dialog. Since this dialog can show
/// an enlarged version of the page, we generate these at a higher resolution than usual.
/// Also, to make more realistic views of template pages we insert fake text wherever
/// there is an empty edit block.
///
/// The result is cached for possible future use so the caller should not dispose of it.
/// </summary>
/// <param name="book"></param>
/// <param name="page"></param>
/// <param name="isLandscape"></param>
/// <param name="mustRegenerate"></param>
/// <returns></returns>
public Image GetThumbnailForPage(Book.Book book, IPage page, bool isLandscape, bool mustRegenerate = false)
{
var pageDom = book.GetThumbnailXmlDocumentForPage(page);
var thumbnailOptions = new HtmlThumbNailer.ThumbnailOptions()
{
BackgroundColor = Color.White, // matches the hand-made previews.
BorderStyle = HtmlThumbNailer.ThumbnailOptions.BorderStyles.None, // allows the HTML to add its preferred border in the larger preview
CenterImageUsingTransparentPadding = true,
MustRegenerate = mustRegenerate
};
var pageDiv = pageDom.RawDom.SafeSelectNodes("descendant-or-self::div[contains(@class,'bloom-page')]").Cast <XmlElement>().FirstOrDefault();
// The actual page size is rather arbitrary, but we want the right ratio for A4.
// Using the actual A4 sizes in mm makes a big enough image to look good in the larger
// preview box on the right as well as giving exactly the ratio we want.
// We need to make the image the right shape to avoid some sort of shadow/box effects
// that I can't otherwise find a way to get rid of.
if (isLandscape)
{
thumbnailOptions.Width = 297;
thumbnailOptions.Height = 210;
pageDiv.SetAttribute("class", pageDiv.Attributes["class"].Value.Replace("Portrait", "Landscape"));
}
else
{
thumbnailOptions.Width = 210;
thumbnailOptions.Height = 297;
// On the offchance someone makes a template with by-default-landscape pages...
pageDiv.SetAttribute("class", pageDiv.Attributes["class"].Value.Replace("Landscape", "Portrait"));
}
// In different books (or even the same one) in the same session we may have portrait and landscape
// versions of the same template page. So we must use different IDs.
return(_thumbnailProvider.GetThumbnail(page.Id + (isLandscape ? "L" : ""), pageDom, thumbnailOptions));
}
