/// <summary>
/// Given a book, typically one in a temporary folder made just for exporting (or testing),
/// examine the CSS files and determine what fonts should be necessary. (Enhance: we could actually
/// load the book into a DOM and find out what font IS used for each block.)
/// Copy the font file for the normal style of that font family from the system font folder,
/// if permitted; or post a warning in progress if we can't embed it.
/// Create an extra css file (fonts.css) which tells the book to find the font files for those font families
/// in the local folder, and insert a link to it into the book.
/// </summary>
/// <param name="book"></param>
/// <param name="progress"></param>
/// <param name="fontFileFinder">use new FontFinder() for real, or a stub in testing</param>
public static void EmbedFonts(Book book, IWebSocketProgress progress, IFontFinder fontFileFinder)
{
const string defaultFont = "Andika New Basic"; // already in BR, don't need to embed or make rule.
// The 'false' here says to ignore all but the first font face in CSS's ordered lists of desired font faces.
// If someone is publishing an Epub, they should have that font showing. For one thing, this makes it easier
// for us to not embed fonts we don't want/ need.For another, it makes it less likely that an epub will look
// different or have glyph errors when shown on a machine that does have that primary font.
var fontsWanted = EpubMaker.GetFontsUsed(book.FolderPath, false).ToList();
fontsWanted.Remove(defaultFont);
fontFileFinder.NoteFontsWeCantInstall = true;
var filesToEmbed = new List <string>();
foreach (var font in fontsWanted)
{
var fontFiles = fontFileFinder.GetFilesForFont(font);
if (fontFiles.Count() > 0)
{
filesToEmbed.AddRange(fontFiles);
progress.MessageWithParams("CheckFontOK", "{0} is a font name", "Checking {0} font: License OK for embedding.", font);
// Assumes only one font file per font; if we embed multiple ones will need to enhance this.
var size = new FileInfo(fontFiles.First()).Length;
var sizeToReport = (size / 1000000.0).ToString("F1"); // purposely locale-specific; might be e.g. 1,2
progress.MessageWithColorAndParams("Embedding",
"{1} is a number with one decimal place, the number of megabytes the font file takes up",
"blue",
"Embedding font {0} at a cost of {1} megs",
font, sizeToReport);
continue;
}
if (fontFileFinder.FontsWeCantInstall.Contains(font))
{
progress.ErrorWithParams("LicenseForbids", "{0} is a font name", "Checking {0} font: License does not permit embedding.", font);
}
else
{
progress.ErrorWithParams("NoFontFound", "{0} is a font name", "Checking {0} font: No font found to embed.", font);
}
progress.ErrorWithParams("SubstitutingAndika", "{0} and {1} are font names", "Substituting \"{0}\" for \"{1}\"", defaultFont, font);
}
foreach (var file in filesToEmbed)
{
// Enhance: do we need to worry about problem characters in font file names?
var dest = Path.Combine(book.FolderPath, Path.GetFileName(file));
RobustFile.Copy(file, dest);
}
// Create the fonts.css file, which tells the browser where to find the fonts for those families.
var sb = new StringBuilder();
foreach (var font in fontsWanted)
{
var group = fontFileFinder.GetGroupForFont(font);
if (group != null)
{
EpubMaker.AddFontFace(sb, font, "normal", "normal", group.Normal);
}
// We don't need (or want) a rule to use Andika instead.
// The reader typically WILL use Andika, because we have a rule making it the default font
// for the whole body of the document, and BloomReader always has it available.
// However, it's possible that although we aren't allowed to embed the desired font,
// the device actually has it installed. In that case, we want to use it.
}
RobustFile.WriteAllText(Path.Combine(book.FolderPath, "fonts.css"), sb.ToString());
// Tell the document to use the new stylesheet.
book.OurHtmlDom.AddStyleSheet("fonts.css");
}
/// <summary>
/// Checks the wanted fonts for being valid for embedding, both for licensing and for the type of file
/// (based on the filename extension).
/// The list of rejected fonts is returned in badFonts and the list of files to copy for good fonts is
/// returned in filesToEmbed. Messages are written to the progress output as the processing goes along.
/// </summary>
/// <remarks>
/// fontFileFinder must be either a new instance or a stub for testing.
/// Setting fontFileFinder.NoteFontsWeCantInstall ensures that fontFileFinder.GetFilesForFont(font)
/// will not return any files for fonts that we know cannot be embedded without reference to the
/// license details.
/// </remarks>
public static void CheckFontsForEmbedding(IWebSocketProgress progress, HashSet <string> fontsWanted, IFontFinder fontFileFinder,
out List <string> filesToEmbed, out HashSet <string> badFonts)
{
filesToEmbed = new List <string>();
badFonts = new HashSet <string>();
const string defaultFont = "Andika New Basic";
fontFileFinder.NoteFontsWeCantInstall = true;
if (_fontMetadataMap == null)
{
_fontMetadataMap = new Dictionary <string, FontMetadata>();
foreach (var meta in FontsApi.AvailableFontMetadata)
{
_fontMetadataMap.Add(meta.name, meta);
}
}
foreach (var font in fontsWanted)
{
var fontFiles = fontFileFinder.GetFilesForFont(font);
var filesFound = fontFiles.Any(); // unembeddable fonts determined don't have any files recorded
var badLicense = false;
var missingLicense = false;
var badFileType = false;
var fileExtension = "";
if (_fontMetadataMap.TryGetValue(font, out var meta))
{
fileExtension = meta.fileExtension;
switch (meta.determinedSuitability)
{
case FontMetadata.kUnsuitable:
badLicense = true;
missingLicense = false;
break;
case FontMetadata.kInvalid:
// We don't really know the values for badLicense and missingLicense, but they don't matter.
badFileType = true;
break;
case FontMetadata.kUnknown: // same as not finding the metadata for the font.
badLicense = false;
missingLicense = true;
break;
case FontMetadata.kOK:
badLicense = false;
missingLicense = false;
break;
}
}
else
{
missingLicense = true;
// This is usually covered by the case kInvalid above, but needed if no metadata at all.
if (filesFound)
{
fileExtension = Path.GetExtension(fontFiles.First()).ToLowerInvariant();
badFileType = !FontMetadata.fontFileTypesBloomKnows.Contains(fileExtension);
}
}
if (filesFound && !badFileType && !badLicense)
{
filesToEmbed.AddRange(fontFiles);
if (missingLicense)
{
progress.MessageWithParams("PublishTab.Android.File.Progress.UnknownLicense", "{0} is a font name", "Checking {0} font: Unknown license", ProgressKind.Progress, font);
}
else
{
progress.MessageWithParams("PublishTab.Android.File.Progress.CheckFontOK", "{0} is a font name", "Checking {0} font: License OK for embedding.", ProgressKind.Progress, font);
}
// Assumes only one font file per font; if we embed multiple ones will need to enhance this.
var size = new FileInfo(fontFiles.First()).Length;
var sizeToReport = (size / 1000000.0).ToString("F1"); // purposely locale-specific; might be e.g. 1,2
progress.MessageWithParams("PublishTab.Android.File.Progress.Embedding",
"{1} is a number with one decimal place, the number of megabytes the font file takes up",
"Embedding font {0} at a cost of {1} megs",
ProgressKind.Note,
font, sizeToReport);
continue;
}
if (badFileType)
{
progress.MessageWithParams("PublishTab.Android.File.Progress.IncompatibleFontFileFormat", "{0} is a font name, {1} is a file extension (for example: .ttc)", "This book has text in a font named \"{0}\". Bloom cannot publish this font's format ({1}).", ProgressKind.Error, font, fileExtension);
}
else if (fontFileFinder.FontsWeCantInstall.Contains(font) || badLicense)
{
progress.MessageWithParams("PublishTab.Android.File.Progress.LicenseForbids", "{0} is a font name", "This book has text in a font named \"{0}\". The license for \"{0}\" does not permit Bloom to embed the font in the book.", ProgressKind.Error, font);
}
else
{
progress.MessageWithParams("PublishTab.Android.File.Progress.NoFontFound", "{0} is a font name", "This book has text in a font named \"{0}\", but Bloom could not find that font on this computer.", ProgressKind.Error, font);
}
progress.MessageWithParams("PublishTab.Android.File.Progress.SubstitutingAndika", "{0} is a font name", "Bloom will substitute \"{0}\" instead.", ProgressKind.Error, defaultFont, font);
badFonts.Add(font); // need to prevent the bad/missing font from showing up in fonts.css and elsewhere
}
}