Bug 854339 - Stretching the "equal sign"
 Summary: Stretching the "equal sign"
 Status: RESOLVED FIXED dev-doc-complete Core Components MathML (show other bugs) Trunk All All -- normal with 1 vote (vote) mozilla24 Frédéric Wang (:fredw) 687807 mathml-in-mathjax Show dependency tree / graph

Reported: 2013-03-25 03:16 PDT by Frédéric Wang (:fredw)
Modified: 2013-09-30 08:23 PDT (History)
3 users (show)
ryanvm: in‑testsuite+
Crash Signature:
(edit)
QA Whiteboard:
Iteration: ---
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Attachments
testcase (1.77 KB, text/html)
2013-03-25 03:16 PDT, Frédéric Wang (:fredw)
no flags Details
Patch (6.49 KB, patch)
2013-05-31 02:22 PDT, Frédéric Wang (:fredw)
karlt: review+
Details | Diff | Splinter Review
Patch V2 (6.49 KB, patch)
2013-06-03 22:56 PDT, Frédéric Wang (:fredw)
no flags Details | Diff | Splinter Review

 Frédéric Wang (:fredw) 2013-03-25 03:16:37 PDT Created attachment 728897 [details] testcase Using stretchy equal sign is used to implement the AMScd extension by LaTeXML and MathJax. I attach a testcase produced by MathJax. The idea would be to add a direction:horizontal to the equal sign here: http://mxr.mozilla.org/mozilla-central/source/layout/mathml/mathfont.properties#114 and to add a construction for the equal sign (for example by repeating U+2550 BOX DRAWINGS DOUBLE HORIZONTAL, which is in STIX fonts) in the Unicode table: http://mxr.mozilla.org/mozilla-central/source/layout/mathml/mathfontUnicode.properties Here is a minimal testcase $2 BASE =$ The "2" is to workaround bug 687807. Someone willing to work on this could also have a look at bug 687807 comment 4. Then I guess that should be enough to make the attached testcase render correctly. rushikesh 2013-03-25 03:35:12 PDT I have read the above description, and I am interested in working on it. Frédéric Wang (:fredw) 2013-03-25 03:42:27 PDT (In reply to rushikesh from comment #1) > I have read the above description, and I am interested in working on it. Thanks, I guess you already read https://developer.mozilla.org/en-US/docs/Introduction but if you need more information, do not hesitate to ask. Regarding the syntax to use for mathfontUnicode see http://mxr.mozilla.org/mozilla-central/source/layout/mathml/mathfont.properties#1211 Here, I think you could just do as for the double vertical line: http://mxr.mozilla.org/mozilla-central/source/layout/mathml/mathfontUnicode.properties#27 that is only use U+2550 for both the "glue" and "size0" character. Frédéric Wang (:fredw) 2013-03-25 03:43:49 PDT And of course, you'll also need https://developer.mozilla.org/en-US/docs/Mozilla_MathML_Project/Fonts Frédéric Wang (:fredw) 2013-04-06 08:51:33 PDT (In reply to Frédéric Wang (:fredw) from comment #0) > The "2" is to workaround bug 687807. Someone willing to work on this could > also have a look at bug 687807 comment 4. Then I guess that should be enough > to make the attached testcase render correctly. I've uploaded a patch on bug 687807. With that new patch, a minimal test case for the present bug becomes: $BASE =$ rushikesh 2013-04-06 11:31:26 PDT Hi, I am still working ..I will need if any help is required Josh Matthews [:jdm] 2013-04-24 12:14:04 PDT Rushikesh, could you confirm that you're still working on this? rushikesh 2013-04-24 23:30:47 PDT Yes..but I am still finding it hard to get to the root of problem.. can you give me some hint? Frédéric Wang (:fredw) 2013-04-25 02:30:12 PDT Really the most difficult part is to understand the whole process to compile, create a patch, submit it etc: https://developer.mozilla.org/en-US/docs/Introduction You will probably find someone on IRC #introduction to help you. Have you been able to build the source? I also recommend to install the math fonts: https://developer.mozilla.org/en-US/docs/Mozilla_MathML_Project/Fonts/Test Then regarding the bug itself, consider $AVERYLONGBASE$ you should see that the arrow stretches to cover AVERYLONGBASE. The construction is described at this line: http://mxr.mozilla.org/mozilla-central/source/layout/mathml/mathfontUnicode.properties#33 \u2194 = \u2190\uFFFD\u2192\u23AF\u2194\u27F7 where each \u**** is a Unicode code point that can be understood that way (from left to right): 1) \u2194: the character we want to stretch, "LEFT RIGHT ARROW U+2194" 2) The construction is described by various characters that we will put together to form the stretchy arrow: \u2190: the left piece "LEFTWARDS ARROW U+2190" \uFFFD: the middle piece. The character "REPLACEMENT CHARACTER U+FFFD" means that we don't actually use a middle piece (as opposed to e.g. horizontal braces) \u2192: the right piece "RIGHTWARDS ARROW U+2192" \u23AF: the glue "HORIZONTAL LINE EXTENSION U+23AF" that is we repeat several horizontal line characters between the left and right pieces. 3) Alternatively, for small sizes we can use a single character: \u2194: the smallest size "LEFT RIGHT ARROW U+2194" \u27F7: a larger size "LONG LEFT RIGHT ARROW U+27F7" Now, try instead with $AVERYLONGBASE =$ At the moment, the equal sign does not stretch and this is the bug we want to fix. You need to modify http://mxr.mozilla.org/mozilla-central/source/layout/mathml/mathfontUnicode.properties to add a construction for the equal sign. Since its code point is EQUALS SIGN U+003D, that would be a new line \003D = ... I suggest considering U+2550 BOX DRAWINGS DOUBLE HORIZONTAL ═ for the pieces. Hope that helps. Frédéric Wang (:fredw) 2013-05-23 05:32:20 PDT Rushikesh, have you been able to build the source code since the last time? Have you tried asking help on #introduction? Frédéric Wang (:fredw) 2013-05-31 02:22:47 PDT Created attachment 756457 [details] [diff] [review] Patch https://tbpl.mozilla.org/?tree=Try&rev=89f9371c0b90 The test case from AMScd does not work because of other missing features / bugs with our stretchy support. Karl Tomlinson (:karlt) 2013-06-03 18:28:48 PDT Comment on attachment 756457 [details] [diff] [review] Patch >+\u003D = \uFFFD\uFFFD\uFFFD\u2550\u003D # = equal sign Could we use U+003D EQUALS SIGN instead of U+2550 BOX DRAWINGS DOUBLE HORIZONTAL for the repeated glyph here? That should stretch fine I expect? And it would be more consistent with the unstretched glyph. Frédéric Wang (:fredw) 2013-06-03 22:56:23 PDT Created attachment 757813 [details] [diff] [review] Patch V2 Yes, that seems to work too. Ryan VanderMeulen [:RyanVM] 2013-06-04 05:27:39 PDT https://hg.mozilla.org/integration/mozilla-inbound/rev/6a7dd82b2762 Ryan VanderMeulen [:RyanVM] 2013-06-04 12:05:51 PDT https://hg.mozilla.org/mozilla-central/rev/6a7dd82b2762 Florian Scholz [:fscholz] (MDN) 2013-09-30 08:23:23 PDT A note has been added to: https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/24#MathML

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