Hi Marc > On 06 May 2015, at 13:40, Marc Wiest <marc.wi...@getabstract.com> wrote: > > I have the requirements of > 1. allow adding hyphenation exceptions at runtime (web container) > 2. don't hyphenate more than two successive lines in a paragraph > > For 1. the only solution I found is to use a third-party library to add the > actual soft-hyphens in the text, instead. > This has other benefits for me, including that I can use hyphenation in other > places than PDF generation, so I prefer this separation. > But if anyone knows a way to add exceptions for words at runtime, I would be > highly interested how to do that. > > Since I solved 1. Using a new library for adding soft-hyphens into the text, > 2. doesn't work anymore. My XSL contains hyphenation-ladder-count="2" > attributes on all relevant blocks, which does the trick when passing text > without soft-hyphens and relying on FOP hyphenation entirely. But it does > nothing if I don't use FOP to hyphenate the words. In general, hyphenation > works, though, like the soft-hyphens in the text are taken into account. But > it happens that 6 or more successive lines are hyphenated, which is deemed > bad style.
The effect you see in FOP is just very basic Unicode line breaking at work. An explicit SHY is obviously a legal breaking point, but is not recognised as a true hyphenation point by FOP. Internally, what FOP tries to hyphenate are only the word fragments in between the spaces and SHYs, but those cannot be broken up further themselves. As strange as it sounds, a SHY is treated as a word boundary here, similar to a zero-width space. The SHY is recognised as a special character, however, that only needs to be taken into account and rendered in case the effective line-break occurs at that point, but that is as far as it goes, currently. Not sure how difficult it would be to make FOP recognise that the text in a paragraph has already been hyphenated and then register the SHY as a precomputed hyphenation point. If that can be done, then hyphenation-ladder-count would 'automagically' come into play here. At any rate, something like the above would be a prerequisite for adding hyphenation exceptions. As long as FOP does not see a SHY as a hyphenation point, it is almost useless to add exceptions on this end. KR Andreas --------------------------------------------------------------------- To unsubscribe, e-mail: fop-users-unsubscr...@xmlgraphics.apache.org For additional commands, e-mail: fop-users-h...@xmlgraphics.apache.org
