[Libreoffice] new comer

Michael Meeks michael.meeks at novell.com
Tue Feb 22 03:41:08 PST 2011

Hi Zonbo Zhang,

On Tue, 2011-02-22 at 10:06 +0100, Zongbo Zhang wrote:
> I am interested in the development of Libre office, mostly the writer
> part. I assume my interest reside in changing the source code of
> Writer to form some new functions, for instance, if I want to change
> or enhance the track change function of Writer, where should I start
> my work?

	Track changes is an 'exciting' part of writer to work on ;-) I strongly
suggest that you start by writing some unit tests that we can use at
run-time to check that nothing broke in this area.

	The right place for that is sw/qa/core/swdoc-test.cxx - and you
probably want to read through sw/inc/redline.hxx and associated
implementations; I also attach some rough notes of mine on the writer
core from a previous bout of digging there ( from build/doc/sw.txt for
corrections ;-).

	Thanks !


 michael.meeks at novell.com  <><, Pseudo Engineer, itinerant idiot

-------------- next part --------------
Notes on debugging redlining: from caolan.

Delphic utterances:

    "redlining sort of busted in the core for many things, but on the
     basic ww8 side, it's fairly easy:  in ww8par4.cxx"
	-> ww8par4.cxx (Read_CRevisionMark)
	    -> ww8par6.cxx (NewAttr) -> redlinestack::open
		+ filter/inc/fltshell.hxx (SwFltRedLine) attr ...
		+ filter/inc/msfilter.hxx (RedLineStack)

    "perhaps adding some prints to the ReadPlainChars and then
     to sw:util::RedlineStack open & close might throw the
     problem out"
	+ ww8par.cxx (SwWW8ImplReader::ReadPlainChars)
	+ writerhelper.cxx (RedlineStack::open) etc.

    "could be a corrupt, or reading corrupt srpms property,
     sometimes there are places where we get the length of
     properties wrong, and so lose one"
	"if the dates are whacked, then there might be some
	 buggery along those lines"

    "though writer's redlining is foul, word's is simply an
     attribute like bold/italic. writer's is a sort of
     bag-on-the-side et of indexes into places, and doesn't
     work well with graphics and tables
    "so we have to cut up the word span into little mini
     "acceptable to writer" spans when the redline range
     encompases eg. text table text so someting might have
     gone wrong in a place like that too"

    "in *theory* in *theory*, though I don't think it ever happens
     those redline properties could appear in styles and not as
     hard-attributes during text. No idea if we ever handled that
     case, but that's unlikely. It'll be a more prosaic out by one or

    "the 'redline' problem is sort of the same as the 'delete a table
     in a document if there's no content before it' problem. ie. there
     is no place for the cursor to go so as to be able to get the
     range over which to put redlining, same as putting the cursor
     into eg. the last cell of a table and select as far as *outside*
     the table into the following paragraph"
	 "eg. new writer doc->insert table, try & delete - foo !
			    ->return, insert table, easy to delete - baa!"

** sw/inc/redlenum.hxx:

enum SwRedlineType
	// die RedlineTypen gehen von 0 bis 127
	REDLINE_INSERT, 			// Inhalt wurde eingefuegt
	REDLINE_DELETE, 			// Inhalt wurde geloescht
	REDLINE_FORMAT,				// Attributierung wurde angewendet
	REDLINE_TABLE,				// TabellenStruktur wurde veraendert
	REDLINE_FMTCOLL,			// FormatVorlage wurde veraendert (Autoformat!)

	// ab 128 koennen Flags hineinverodert werden
	REDLINE_FORM_AUTOFMT	= 0x0080	// kann als Flag im RedlineType stehen

*** Helpful debugging patch ***

--- sw/source/filter/ww8/writerhelper.cxx
+++ sw/source/filter/ww8/writerhelper.cxx
@@ -833,6 +833,10 @@ namespace sw
         void RedlineStack::open(const SwPosition& rPos, const SfxPoolItem& rAttr)
+                       const SwFltRedline *pRl = static_cast<const SwFltRedline *> (&rAttr);
+                       fprintf (stderr, "RedlineStack::open type %d (%d) Auth %d (%d)\n",
+                                        pRl->eType, pRl->eTypePrev, pRl->nAutorNo, pRl->nAutorNoPrev);
             ASSERT(rAttr.Which() == RES_FLTR_REDLINE, "not a redline");
             maStack.push_back(new SwFltStackEntry(rPos,rAttr.Clone()));
@@ -858,7 +862,12 @@ namespace sw
             ASSERT(aResult != maStack.rend(), "close without open!");
             if (aResult != maStack.rend())
+                       {
+                               const SwFltRedline *pRl = static_cast<const SwFltRedline *> ((*aResult)->pAttr);
+                               fprintf (stderr, "RedlineStack::close intype %d type %d (%d) Auth %d (%d)\n",
+                                                eType, pRl->eType, pRl->eTypePrev, pRl->nAutorNo, pRl->nAutorNoPrev);
+                       }
diff -u -p -u -r1.168 ww8par.cxx
--- sw/source/filter/ww8/ww8par.cxx
+++ sw/source/filter/ww8/ww8par.cxx
@@ -2609,6 +2609,8 @@ bool SwWW8ImplReader::ReadPlainChars(WW8
     if (nL2)
+               fprintf (stderr, "Text: '%s'\n",
+                                rtl::OUStringToOString (sPlainCharsBuf, RTL_TEXTENCODING_UTF8 ).getStr() );
         rPos += nL2;
         if (!maApos.back()) //a para end in apo doesn't count

*** Sample output ***

RedlineStack::open type 1 (0) Auth 1 (65535) /DELETE
RedlineStack::open type 0 (0) Auth 2 (65535) /INSERT 
Text: 'such'
RedlineStack::close intype 0 type 0 (0) Auth 2 (65535) /INSERT
RedlineStack::close intype 1 type 1 (0) Auth 1 (65535) /DELETE

* During RedlineStack destruction:

            std::sort(maStack.begin(), maStack.end(), CompareRedlines());
            std::for_each(maStack.begin(), maStack.end(), SetInDocAndDelete(mrDoc));

void SetInDocAndDelete::operator()(SwFltStackEntry *pEntry)
     + presumably where the entries actually are inserted

before sort
type delete auth# 1 time 2006-06-21 10:42:00.00
type insert auth# 2 time 2029-06-00 00:02:00.00
after sort
type delete auth# 1 time 2006-06-21 10:42:00.00
type insert auth# 2 time 2029-06-00 00:02:00.00

** Core redlining support:

    + sw/source/core/doc/docredln.cxx

** Most likely:
    + date/time support broken ...

** Good trick:

    + Export to Office Open XML & poke:

      <w:ins w:id="0" w:author="Author">
        <w:del w:id="1" w:author="Travis Tom" w:date="2006-06-21T10:42:00Z">
          <w:r w:rsidR="0075694B" w:rsidDel="0056141D">
              <w:color w:val="000000"/>
              <w:sz w:val="20"/>
              <w:szCs w:val="20"/>

** code: ww8par4.cxx

    pPlcxMan->HasCharSprm( bIns ? 0x6805 : 0x6864, aResult);
    pSprmCDttmRMark = aResult.empty() ? 0 : aResult.front();

-> ww8scan.cxx::HasCharSprm -> HasSprm
    -> ww8scan.hxx: WW8SprmIter::GetAktParams
        const BYTE* GetAktParams() const { return pAktParams; }


struct SprmInfo
    sal_uInt16 nId;         //A ww8 sprm is hardcoded as 16bits
    unsigned int nLen : 6;
    unsigned int nVari : 2;

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