Bug Hunting Session
Bug 66277 - Use columnalign to implement matrix alignment
Summary: Use columnalign to implement matrix alignment
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Formula Editor (show other bugs)
(earliest affected) Master
Hardware: All All
: medium normal
Assignee: Frédéric Wang
Whiteboard: target:4.2.0
Depends on:
Reported: 2013-06-27 21:12 UTC by Frédéric Wang
Modified: 2013-07-09 09:12 UTC (History)
0 users

See Also:
Crash report or crash signature:

Sample output (4.56 KB, text/html)
2013-06-29 20:59 UTC, Frédéric Wang

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Description Frédéric Wang 2013-06-27 21:12:51 UTC
Two examples from the LibreOffice doc:

matrix{ a =b
a # "=" # alignl{b} ## = c +1
{} # "=" # alignl{c+1} 

'phantom') alignl{a} = b # 
           alignl{phantom{a} = c+1} 

The equal signs are supposed to be aligned but this property is lost when exported to MathML. The mtable@columnalign attribute should be used instead. This will work in MathJax and Firefox (but note the following bug: https://bugzilla.mozilla.org/show_bug.cgi?id=491384).
Comment 1 Frédéric Wang 2013-06-27 21:55:32 UTC
Mass changes to assign bugs to myself.
Comment 2 Frédéric Wang 2013-06-29 20:58:09 UTC
I've submitted a patch for review:


Testcases (some are from the user manual):

alignr x+y # {}={} # alignl 2 ##
alignr x
# {}={} # alignl 2-y

{alignl x^2 - 9} over {alignl x} newline
left(binom { alignr 100} {alignr 7} right)

stack{Hello world # 

a # "=" # alignl{b} ## 
{} # "=" # alignl{c+1} 

alignl a^2 + b^2 = c^2 newline
alignc 2 * (1 + 2 + 3 + 4 + 5) = 6 * 5 newline
alignr %gamma = x^2 - y^2

Note that StarMath applies alignment recursively: that is if you align some cells in a matrix the same alignment will apply for example to numerator and denominator of fractions inside the matrix cell. That seems a bit weird to me and I don't think that's what we want in general. The MathML output only applies alignment at the specified level. I think it's better and anyway it's easier to handle.
Comment 3 Frédéric Wang 2013-06-29 20:59:17 UTC
Created attachment 81724 [details]
Sample output

As usual, I attach the new output in a Web page that you can open in Firefox. If you see https://bugzilla.mozilla.org/show_bug.cgi?id=491384 try to zoom in/out the page.
Comment 4 Commit Notification 2013-07-09 09:12:18 UTC
Frederic Wang committed a patch related to this issue.
It has been pushed to "master":


 fdo#66277 - fix alignment for binom and stack too.

The patch should be included in the daily builds available at
http://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.