Forced Line Breaking
Hello all, I have a question about line breaking. I'm working in an environment where text going off the page should be avoided at all costs. Even when using hyphenation in FOP, it seems like some strings (e.g. only numbers) cannot be broken and therefore can go off the page[1]. This seems especially prevalent when using table cells. One of the common recommendations seems to be introducing zero width spaces into the string. However, I'm more interested in seeing if it's possible for FOP to detect this issue automatically and force a line break. My current understanding of the line breaking algorithm is that each "word" will be a single KnuthInlineBox. If hyphenation is enabled and hyphenation points are found, it will break this KnuthInlineBox into multiple KnuthInlineBoxes that are groups of characters; penalties and glues are then placed between each new KnuthInlineBox (representing each hyphenation point). I'm wondering how realistic it would be to further break these new KnuthInlineBoxes into KnuthInlineBoxes for each character. Then, add glue and even higher penalities between these character KnuthInlineBoxes. The goal would be to prefer the standard hyphenation points, but have even higher penalty places to break just in case. If there are no hyphenation points found, it will just break the original KnuthInlineBox into KnuthInlineBoxes for each character. I have created a simple proof of concept and it "seems" to work. My question is: how reasonable does this strategy sound? Is there a better way to accomplish this that someone could recommend? I suppose it's less efficient since multiple objects will be created for each character. Additionally, since hyphens could be added anywhere in a string, it could be added somewhere that changes the meaning of the string. I consider that a reasonable alternative to text going off the screen though. Thanks! [1] Here is an example where the string of characters will go off of the page since it is only numbers: http://www.w3.org/1999/XSL/Format"; language="en">12 CONFIDENTIALITY NOTICE This message and any included attachments are from Cerner Corporation and are intended only for the addressee. The information contained in this message is confidential and may constitute inside or non-public information under international, federal, or state securities laws. Unauthorized forwarding, printing, copying, distribution, or use of such information is strictly prohibited and may be unlawful. If you are not the addressee, please promptly delete this message and notify the sender of the delivery error by e-mail or you may call Cerner's corporate offices in Kansas City, Missouri, U.S.A at (+1) (816)221-1024.
[jira] [Commented] (FOP-2569) Exception in thread "main" java.lang.StackOverflowError at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244)
[ https://issues.apache.org/jira/browse/FOP-2569?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17134325#comment-17134325 ] Chris Bowditch commented on FOP-2569: - I think I managed to get this working. I generated a .hyp file anyway :) which I attached, but I don't think you can use it as you will need the new code. The hyp file is a serialized version of the Java object and I amended this by changing char[] to int[]. I need to do a bit more testing before I commit my changes > Exception in thread "main" java.lang.StackOverflowError at > org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > -- > > Key: FOP-2569 > URL: https://issues.apache.org/jira/browse/FOP-2569 > Project: FOP > Issue Type: Bug >Affects Versions: 2.0 >Reporter: Mathieu Malaterre >Priority: Major > Fix For: 1.1 > > Attachments: hyph_de_DE.fop, hyph_de_DE.hyp > > > fop + offo is broken since release 2.0 (and 2.1). It used to be possible to > build fop-hyph.jar using fop 1.1. Please resurrect a working hyph building > mechanism. > Here is what it states: > $ /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java -Xss512k -classpath > /home/mathieu/debian/fop/fop-2.1/build/classes > org.apache.fop.hyphenation.SerializeHyphPattern > /home/mathieu/debian/fop/fop-2.1/hyph > /home/mathieu/debian/fop/fop-2.1/build/classes/hyph > Processing /home/mathieu/debian/fop/fop-2.1/hyph/sa.xml > Exception in thread "main" java.lang.StackOverflowError > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > [...] > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > See thread: > http://mail-archives.apache.org/mod_mbox/xmlgraphics-fop-users/201602.mbox/%3CCA%2B7wUszWN2PdZY_t_Kgn0E4eatL7CUQswOWj9XC%3Dg9GDdgsyXw%40mail.gmail.com%3E -- This message was sent by Atlassian Jira (v8.3.4#803005)
[jira] [Updated] (FOP-2569) Exception in thread "main" java.lang.StackOverflowError at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244)
[ https://issues.apache.org/jira/browse/FOP-2569?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Chris Bowditch updated FOP-2569: Attachment: hyph_de_DE.hyp > Exception in thread "main" java.lang.StackOverflowError at > org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > -- > > Key: FOP-2569 > URL: https://issues.apache.org/jira/browse/FOP-2569 > Project: FOP > Issue Type: Bug >Affects Versions: 2.0 >Reporter: Mathieu Malaterre >Priority: Major > Fix For: 1.1 > > Attachments: hyph_de_DE.fop, hyph_de_DE.hyp > > > fop + offo is broken since release 2.0 (and 2.1). It used to be possible to > build fop-hyph.jar using fop 1.1. Please resurrect a working hyph building > mechanism. > Here is what it states: > $ /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java -Xss512k -classpath > /home/mathieu/debian/fop/fop-2.1/build/classes > org.apache.fop.hyphenation.SerializeHyphPattern > /home/mathieu/debian/fop/fop-2.1/hyph > /home/mathieu/debian/fop/fop-2.1/build/classes/hyph > Processing /home/mathieu/debian/fop/fop-2.1/hyph/sa.xml > Exception in thread "main" java.lang.StackOverflowError > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > [...] > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > See thread: > http://mail-archives.apache.org/mod_mbox/xmlgraphics-fop-users/201602.mbox/%3CCA%2B7wUszWN2PdZY_t_Kgn0E4eatL7CUQswOWj9XC%3Dg9GDdgsyXw%40mail.gmail.com%3E -- This message was sent by Atlassian Jira (v8.3.4#803005)
[jira] [Commented] (FOP-2569) Exception in thread "main" java.lang.StackOverflowError at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244)
[ https://issues.apache.org/jira/browse/FOP-2569?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17134250#comment-17134250 ] Chris Bowditch commented on FOP-2569: - Thanks for sharing the XML. Looking at the code I think its designed for a maximum number of hyphenation patterns of around 65535. This is backed up by the comments at the top of the class: Using java's char type as pointer (yes, I know pointer * it is a forbidden word in java) we can keep the size of the node * to be just 8 bytes (3 pointers and the data char). This gives * room for about 65000 nodes. In my tests the english patterns * took 7694 nodes and the german patterns 10055 nodes, * so I think we are safe. I'll have a go at changing the char[] to int[] to see if that resolves the issue > Exception in thread "main" java.lang.StackOverflowError at > org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > -- > > Key: FOP-2569 > URL: https://issues.apache.org/jira/browse/FOP-2569 > Project: FOP > Issue Type: Bug >Affects Versions: 2.0 >Reporter: Mathieu Malaterre >Priority: Major > Fix For: 1.1 > > Attachments: hyph_de_DE.fop > > > fop + offo is broken since release 2.0 (and 2.1). It used to be possible to > build fop-hyph.jar using fop 1.1. Please resurrect a working hyph building > mechanism. > Here is what it states: > $ /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java -Xss512k -classpath > /home/mathieu/debian/fop/fop-2.1/build/classes > org.apache.fop.hyphenation.SerializeHyphPattern > /home/mathieu/debian/fop/fop-2.1/hyph > /home/mathieu/debian/fop/fop-2.1/build/classes/hyph > Processing /home/mathieu/debian/fop/fop-2.1/hyph/sa.xml > Exception in thread "main" java.lang.StackOverflowError > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > [...] > at org.apache.fop.hyphenation.TernaryTree.insert(TernaryTree.java:244) > See thread: > http://mail-archives.apache.org/mod_mbox/xmlgraphics-fop-users/201602.mbox/%3CCA%2B7wUszWN2PdZY_t_Kgn0E4eatL7CUQswOWj9XC%3Dg9GDdgsyXw%40mail.gmail.com%3E -- This message was sent by Atlassian Jira (v8.3.4#803005)
