[jira] [Commented] (FOP-2222) Incorrect page break in cell
[ https://issues.apache.org/jira/browse/FOP-?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13651355#comment-13651355 ] Vincent Hennebert commented on FOP-: This issue indeed corresponds to what is described in that 'Known Problems' section; it has nothing to do with column balancing. Column balancing was about better taking into account the properties of boxes, glues and penalties: mainly, include the height of a penalty when breaking there, and discard glues and penalties that follow a break up to the next box. This problem has to do with Knuth elements not accurately representing the actual content. It is described into more details at the following page: http://wiki.apache.org/xmlgraphics-fop/TableLayout/KnownProblems Fixing it requires an intimate understanding of the box/glue/penalty model and the breaking algorithm. Departing from that algorithm would actually be necessary, as we would have to deal with different sequences of Knuth elements depending on where we break in the table. Given that the algorithm is all about considering several feasible breaks in the same time, those Knuth sequences would have to be dealt with simultaneously, in a compartmented way. Basically that issue shows that while the box/glue/penalty model is great to simulate a paragraph, it is not suited for more complex material like tables, that are made of loosely coupled columns of content. Between the synchronization points that row boundaries represent (more or less —you can also have row-spanning cells), the layouts of the different cells can vary widely. I think I'd rather try and find a way to work around this issue by designing the document differently... > Incorrect page break in cell > > > Key: FOP- > URL: https://issues.apache.org/jira/browse/FOP- > Project: Fop > Issue Type: Bug > Components: page-master/layout >Affects Versions: 1.1, trunk >Reporter: Nico > Attachments: test-two-cells.fo, test-two-cells.pdf > > > In a table with one row and two cells, spanning across multiple pages, the > pages break are not what should be expected. (I don't know if it's by design > or a bug). > Please see the attached .fo and .pdf. > Test case : the first cell has blocks with 120mm height. The second cell has > blocks with 100mm heights. The page height is 266mm > First page : each cell contains his two blocks on the page > second page : after the first page break, the fist cell show only the one > block where two is expected. The second block, which is on page 3, should fit > on page 2. > Is it standard behaviour ? Thanks. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (FOP-2222) Incorrect page break in cell
[ https://issues.apache.org/jira/browse/FOP-?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13646964#comment-13646964 ] Luis Bernardo commented on FOP-: I know the column balancing method is not involved. What I meant to say is that I suspect that the algorithm that is used to decide the cell page breaks is the same or suffers from the same problems that the previous algorithm used for column balancing had. That algorithm was recently changed (see FOP-1840) and I think the new approach used there may also be useful for the cell page break problem you are facing. > Incorrect page break in cell > > > Key: FOP- > URL: https://issues.apache.org/jira/browse/FOP- > Project: Fop > Issue Type: Bug > Components: page-master/layout >Affects Versions: 1.1, trunk >Reporter: Nico > Attachments: test-two-cells.fo, test-two-cells.pdf > > > In a table with one row and two cells, spanning across multiple pages, the > pages break are not what should be expected. (I don't know if it's by design > or a bug). > Please see the attached .fo and .pdf. > Test case : the first cell has blocks with 120mm height. The second cell has > blocks with 100mm heights. The page height is 266mm > First page : each cell contains his two blocks on the page > second page : after the first page break, the fist cell show only the one > block where two is expected. The second block, which is on page 3, should fit > on page 2. > Is it standard behaviour ? Thanks. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (FOP-2222) Incorrect page break in cell
[ https://issues.apache.org/jira/browse/FOP-?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13646581#comment-13646581 ] Nico commented on FOP-: --- Thanks Luis for the link. However, the problem is different (BalancingColumnBreakingAlgorithm is not involved). My test case is just a table with 2 cells. Fop can't set up the right page breaks on this simple example. You are right, getCombinedKnuthElementsForRowGroup seems to be the problem, but I can't figure out how it works (what are the purpose of the box and penalties ?). The element list it sends to PageBreakingAlgorithm::computeDifference is only ok for the first page : it simply need to be recomputed on each page break. Does the fop code structure allow this ? > Incorrect page break in cell > > > Key: FOP- > URL: https://issues.apache.org/jira/browse/FOP- > Project: Fop > Issue Type: Bug > Components: page-master/layout >Affects Versions: 1.1, trunk >Reporter: Nico > Attachments: test-two-cells.fo, test-two-cells.pdf > > > In a table with one row and two cells, spanning across multiple pages, the > pages break are not what should be expected. (I don't know if it's by design > or a bug). > Please see the attached .fo and .pdf. > Test case : the first cell has blocks with 120mm height. The second cell has > blocks with 100mm heights. The page height is 266mm > First page : each cell contains his two blocks on the page > second page : after the first page break, the fist cell show only the one > block where two is expected. The second block, which is on page 3, should fit > on page 2. > Is it standard behaviour ? Thanks. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (FOP-2222) Incorrect page break in cell
[ https://issues.apache.org/jira/browse/FOP-?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13639759#comment-13639759 ] Luis Bernardo commented on FOP-: Assuming the issue is the one described in the above link then I think the algorithm may suffer from the same problem that was causing FOP-1840, i.e., an algorithm that makes decisions too soon based on wrong (incomplete) information. In that case the approach used to fix FOP-1840 may also work. > Incorrect page break in cell > > > Key: FOP- > URL: https://issues.apache.org/jira/browse/FOP- > Project: Fop > Issue Type: Bug > Components: page-master/layout >Affects Versions: 1.1, trunk >Reporter: Nico > Attachments: test-two-cells.fo, test-two-cells.pdf > > > In a table with one row and two cells, spanning across multiple pages, the > pages break are not what should be expected. (I don't know if it's by design > or a bug). > Please see the attached .fo and .pdf. > Test case : the first cell has blocks with 120mm height. The second cell has > blocks with 100mm heights. The page height is 266mm > First page : each cell contains his two blocks on the page > second page : after the first page break, the fist cell show only the one > block where two is expected. The second block, which is on page 3, should fit > on page 2. > Is it standard behaviour ? Thanks. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (FOP-2222) Incorrect page break in cell
[ https://issues.apache.org/jira/browse/FOP-?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13618016#comment-13618016 ] Nico commented on FOP-: --- Thanks Luis. I believe this is the behaviour described in http://wiki.apache.org/xmlgraphics-fop/TableLayout/KnuthElementsForTables (in "Knowns problems"), but the algo is failing as soon as the second page. So it is great for finding the first page break, but not the others. The element list must be recomputed on each new page. Is it possible to do ? > Incorrect page break in cell > > > Key: FOP- > URL: https://issues.apache.org/jira/browse/FOP- > Project: Fop > Issue Type: Bug > Components: page-master/layout >Affects Versions: 1.1, trunk >Reporter: Nico > Attachments: test-two-cells.fo, test-two-cells.pdf > > > In a table with one row and two cells, spanning across multiple pages, the > pages break are not what should be expected. (I don't know if it's by design > or a bug). > Please see the attached .fo and .pdf. > Test case : the first cell has blocks with 120mm height. The second cell has > blocks with 100mm heights. The page height is 266mm > First page : each cell contains his two blocks on the page > second page : after the first page break, the fist cell show only the one > block where two is expected. The second block, which is on page 3, should fit > on page 2. > Is it standard behaviour ? Thanks. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (FOP-2222) Incorrect page break in cell
[ https://issues.apache.org/jira/browse/FOP-?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13614739#comment-13614739 ] Luis Bernardo commented on FOP-: I may be mistaken, but probably o.a.f.layoutmgr.table.TableStepper is the class to look at. In particular the getCombinedKnuthElementsForRowGroup() method may be involved. > Incorrect page break in cell > > > Key: FOP- > URL: https://issues.apache.org/jira/browse/FOP- > Project: Fop > Issue Type: Bug > Components: page-master/layout >Affects Versions: 1.1, trunk >Reporter: Nico > Attachments: test-two-cells.fo, test-two-cells.pdf > > > In a table with one row and two cells, spanning across multiple pages, the > pages break are not what should be expected. (I don't know if it's by design > or a bug). > Please see the attached .fo and .pdf. > Test case : the first cell has blocks with 120mm height. The second cell has > blocks with 100mm heights. The page height is 266mm > First page : each cell contains his two blocks on the page > second page : after the first page break, the fist cell show only the one > block where two is expected. The second block, which is on page 3, should fit > on page 2. > Is it standard behaviour ? Thanks. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
[jira] [Commented] (FOP-2222) Incorrect page break in cell
[ https://issues.apache.org/jira/browse/FOP-?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13609980#comment-13609980 ] Nico commented on FOP-: --- Hello, I would be willing to take a look at it and try to provide a patch. Could someone tell me where to look at ? I'm not familiar with the source code. Any insight would be appreciated ! thanks! > Incorrect page break in cell > > > Key: FOP- > URL: https://issues.apache.org/jira/browse/FOP- > Project: Fop > Issue Type: Bug > Components: page-master/layout >Affects Versions: 1.1, trunk >Reporter: Nico > Attachments: test-two-cells.fo, test-two-cells.pdf > > > In a table with one row and two cells, spanning across multiple pages, the > pages break are not what should be expected. (I don't know if it's by design > or a bug). > Please see the attached .fo and .pdf. > Test case : the first cell has blocks with 120mm height. The second cell has > blocks with 100mm heights. The page height is 266mm > First page : each cell contains his two blocks on the page > second page : after the first page break, the fist cell show only the one > block where two is expected. The second block, which is on page 3, should fit > on page 2. > Is it standard behaviour ? Thanks. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
