FOP and fonts

FOP makes me feel dumb because it is great. In a previous post I already mentioned that FOP's font handling was better than I thought first, so I could have been wrong forcing a custom font naming. As a matter of fact, FOP holds a list of fonts inside the FontCache of its FontFactory. Novelang instantiates the FontFactory so it has full hands on it. Using a Java debugger, let's look at what a FontCache contains.

fontMap = {java.util.HashMap}
  [0] = {java.util.HashMap$Entry} 
    key: java.lang.String
        "file:/…/fonts/URWGothicL-BookObli.ttf"
    value: org.apache.fop.fonts.CachedFontInfo
      lastModified = 1042610200000
      metricsFile = {java.lang.String}
          "file:/…/.fop-font-metrics-14045 \
               .temp/URWGothicL-BookObli.xml"
      embedFile = {java.lang.String}
          "file:/…/fonts/URWGothicL-BookObli.ttf"
      kerning = true
      fontTriplets = {java.util.ArrayList} 
        [0] = {org.apache.fop.fonts.FontTriplet} 
          name = {java.lang.String} 
              "URWGothicL-BookObli"
          style = {java.lang.String} "normal"
          weight = 400
          priority = 0
          key = {java.lang.String}
              "URWGothicL-BookObli,normal,400"
        […]
  […]
failedFontMap = {java.util.HashMap}

Sweet! Here is everything I need:

• Font name.
• Font style, "italic" or "normal".
• Weight. Not just "normal" or "bold" but "light" and "extra-bold".
• Priority for dealing with duplicates
• A list of fonts which could not be read (failedFontMap).

The moderately bad news is, fontMap and failedFontMap are private fields but I see no reason to not use dirty reflexion here. The example above is biased as it was created from a Novelang-generated font list, so I'll have to investigate a bit more to see how Fop deals with:

• Failed fonts.
• Font name different from font file name.
• Multiple directories (including nested ones).

To sum up, FOP provides all I need to make Novelang code cleaner and bring following enhancements:

• Multiple directories.
• List of failed fonts.
• Warning in case of duplicates.
• Fonts sorted by font name.
• Throw away temporary .fop-font-metrics directory.
• Cache of font descriptions handled by FOP itself (this is the meaning of the lastModified field in the FontCache).
• Support more font types. By letting FOP do its job we let its FontFileFinder recognize following font files: *.ttf for True Type, *.pfb for Type One. The *.otf suffix also appears and those fonts may be treated as TTF,