I've gotten the request from multiple of my clients to look into the
border display issues caused by anti aliasing in PDF viewers. I'm aware
that printing the PDF documents generated by FOP is never the issue, but
when viewing, there definitely is (I know that anti aliasing can be
disabled in Adobe Acrobat, but I can't control my users environment).
Since viewing PDF files on electric devices is getting more and more
important, I think it's worth to have a new look on this issue. Digging
around in the FOP mailing lists, I've discovered that PDF viewers don't
like that table borders are rendered with shapes instead of lines. I'm
aware that shapes are used for supporting all border styles of the
xsl-fo spec. The thing is that 99% of my clients use only solid lines,
so it is important to improve the display quality here. AFAIK there are
two possible ways to achieve this:
1. Fallback to the old (0.20.5) table border rendering code, if only
solid lines are used inside a table.
2. Algorithm for merging shapes if width, color and style match.
Are you aware of any other ways to improve this? I'll start to
investigate both approaches in the next view days, so I can't say much
about the viability and expected dev time yet. Perhaps some of you has
already started to do some work or research on this issue and wants to
share his experience. Personally I'm more inclined towards approach #2,
but I have a limited time budget to achieve this, so if #2 involves a
lot of work I'd go for #1.