fdo#66088 Export some math symbols as <mi> elements.

Change-Id: Ib08717c3d4d41abc7bce4cd6bc2e63bda7db6086
Reviewed-on: https://gerrit.libreoffice.org/4595
Reviewed-by: Fridrich Strba <fridrich@documentfoundation.org>
Tested-by: Fridrich Strba <fridrich@documentfoundation.org>

9 files changed, 64 insertions, 21 deletions

diff --git a/starmath/inc/node.hxx b/starmath/inc/node.hxx
index b1640a338e56..2416d6e9080b 100644
--- a/starmath/inc/node.hxx
+++ b/starmath/inc/node.hxx
@@ -73,7 +73,7 @@ enum SmNodeType
 /*10*/ NBINDIAGONAL,   NSUBSUP,        NMATRIX,        NPLACE,         NTEXT,
 /*15*/ NSPECIAL,       NGLYPH_SPECIAL, NMATH,          NBLANK,         NERROR,
 /*20*/ NLINE,          NEXPRESSION,    NPOLYLINE,      NROOT,          NROOTSYMBOL,
-/*25*/ NRECTANGLE,     NVERTICAL_BRACE
+/*25*/ NRECTANGLE,     NVERTICAL_BRACE, NMATHIDENT
 };
 
 
@@ -579,6 +579,20 @@ public:
     void Accept(SmVisitor* pVisitor);
 };
 
+////////////////////////////////////////////////////////////////////////////////
+
+/** Math Identifier
+ *
+ * This behaves essentially the same as SmMathSymbolNode and is only used to
+ * represent math symbols that should be exported as <mi> elements rather than
+ * <mo> elements.
+ */
+class SmMathIdentifierNode : public SmMathSymbolNode
+{
+public:
+    SmMathIdentifierNode(const SmToken &rNodeToken)
+    :   SmMathSymbolNode(NMATHIDENT, rNodeToken) {}
+};
 
 ////////////////////////////////////////////////////////////////////////////////
 
diff --git a/starmath/source/mathmlexport.cxx b/starmath/source/mathmlexport.cxx
index d23662c47065..fb1e6c365130 100644
--- a/starmath/source/mathmlexport.cxx
+++ b/starmath/source/mathmlexport.cxx
@@ -871,7 +871,26 @@ void SmXMLExport::ExportTable(const SmNode *pNode, int nLevel)
 void SmXMLExport::ExportMath(const SmNode *pNode, int /*nLevel*/)
 {
     const SmMathSymbolNode *pTemp = static_cast<const SmMathSymbolNode *>(pNode);
-    SvXMLElementExport aMath(*this, XML_NAMESPACE_MATH, XML_MO, sal_True, sal_False);
+    SvXMLElementExport *pMath = 0;
+
+    if (pNode->GetType() == NMATH)
+    {
+        // Export NMATH symbols as <mo> elements
+        pMath = new SvXMLElementExport(*this, XML_NAMESPACE_MATH, XML_MO, sal_True, sal_False);
+    }
+    else
+    {
+        // Export NMATHIDENT and NPLACE symbols as <mi> elements:
+        // - These math symbols should not be drawn slanted. Hence we should
+        // attach a mathvariant="normal" attribute to single-char <mi> elements
+        // that are not mathematical alphanumeric symbol. For simplicity and to
+        // work around browser limitations, we always attach such an attribute.
+        // - The MathML specification suggests to use empty <mi> elements as
+        // placeholders but they won't be visible in most MathML rendering
+        // engines so let's use an empty square for NPLACE instead.
+        AddAttribute(XML_NAMESPACE_MATH, XML_MATHVARIANT, XML_NORMAL);
+        pMath = new SvXMLElementExport(*this, XML_NAMESPACE_MATH, XML_MI, sal_True, sal_False);
+    }
     sal_Unicode nArse[2];
     nArse[0] = pTemp->GetText()[0];
     sal_Unicode cTmp = ConvertMathToMathML( nArse[0] );
@@ -880,6 +899,8 @@ void SmXMLExport::ExportMath(const SmNode *pNode, int /*nLevel*/)
     OSL_ENSURE(nArse[0] != 0xffff,"Non existent symbol");
     nArse[1] = 0;
     GetDocHandler()->characters(nArse);
+
+    delete pMath;
 }
 
 void SmXMLExport::ExportText(const SmNode *pNode, int /*nLevel*/)
@@ -1520,6 +1541,7 @@ void SmXMLExport::ExportNodes(const SmNode *pNode, int nLevel)
                 }
             }
             break;
+        case NMATHIDENT :
         case NPLACE:
             ExportMath(pNode, nLevel);
             break;
diff --git a/starmath/source/mathtype.cxx b/starmath/source/mathtype.cxx
index 8b958a144a42..3de5817b5885 100644
--- a/starmath/source/mathtype.cxx
+++ b/starmath/source/mathtype.cxx
@@ -1997,6 +1997,7 @@ sal_uInt8 MathType::HandleNodes(SmNode *pNode,int nLevel)
             }
             break;
         case NMATH:
+        case NMATHIDENT:
             HandleMath(pNode,nLevel);
             break;
         case NSUBSUP:
diff --git a/starmath/source/node.cxx b/starmath/source/node.cxx
index d3ae70573602..ccfc4b07166e 100644
--- a/starmath/source/node.cxx
+++ b/starmath/source/node.cxx
@@ -621,6 +621,7 @@ void SmNode::DumpAsDot(std::ostream &out, OUString* label, int number, int& id,
         case NROOTSYMBOL:      out<<"SmRootSymbolNode"; break;
         case NRECTANGLE:       out<<"SmRectangleNode"; break;
         case NVERTICAL_BRACE:  out<<"SmVerticalBraceNode"; break;
+        case NMATHIDENT:       out<<"SmMathIdentifierNode"; break;
         default:
             out<<"Unknown Node";
     }
diff --git a/starmath/source/ooxmlexport.cxx b/starmath/source/ooxmlexport.cxx
index 3cbdf45f0875..c7ab7ff5bed4 100644
--- a/starmath/source/ooxmlexport.cxx
+++ b/starmath/source/ooxmlexport.cxx
@@ -236,7 +236,7 @@ void SmOoxmlExport::HandleRoot( const SmRootNode* pNode, int nLevel )
 
 static OString mathSymbolToString( const SmNode* node )
 {
-    assert( node->GetType() == NMATH );
+    assert( node->GetType() == NMATH || node->GetType() == NMATHIDENT );
     const SmTextNode* txtnode = static_cast< const SmTextNode* >( node );
     assert( txtnode->GetText().getLength() == 1 );
     sal_Unicode chr = SmTextNode::ConvertSymbolToUnicode( txtnode->GetText()[0] );
@@ -463,7 +463,7 @@ void SmOoxmlExport::HandleBrace( const SmBraceNode* pNode, int nLevel )
         for( int i = 0; i < body->GetNumSubNodes(); ++i )
         {
             const SmNode* subnode = body->GetSubNode( i );
-            if( subnode->GetType() == NMATH )
+            if (subnode->GetType() == NMATH || subnode->GetType() == NMATHIDENT)
             { // do not write, but write what separator it is
                 const SmMathSymbolNode* math = static_cast< const SmMathSymbolNode* >( subnode );
                 if( !separatorWritten )
diff --git a/starmath/source/parse.cxx b/starmath/source/parse.cxx
index cdb6865db623..4477d1006516 100644
--- a/starmath/source/parse.cxx
+++ b/starmath/source/parse.cxx
@@ -1485,24 +1485,10 @@ void SmParser::Term(bool bGroupNumberIdent)
         case TRIGHTARROW :
         case TUPARROW :
         case TDOWNARROW :
-        case TSETN :
-        case TSETZ :
-        case TSETQ :
-        case TSETR :
-        case TSETC :
-        case THBAR :
-        case TLAMBDABAR :
         case TCIRC :
         case TDRARROW :
         case TDLARROW :
         case TDLRARROW :
-        case TBACKEPSILON :
-        case TALEPH :
-        case TIM :
-        case TRE :
-        case TWP :
-        case TEMPTYSET :
-        case TINFINITY :
         case TEXISTS :
         case TNOTEXISTS :
         case TFORALL :
@@ -1519,6 +1505,24 @@ void SmParser::Term(bool bGroupNumberIdent)
             NextToken();
             break;
 
+        case TSETN :
+        case TSETZ :
+        case TSETQ :
+        case TSETR :
+        case TSETC :
+        case THBAR :
+        case TLAMBDABAR :
+        case TBACKEPSILON :
+        case TALEPH :
+        case TIM :
+        case TRE :
+        case TWP :
+        case TEMPTYSET :
+        case TINFINITY :
+            m_aNodeStack.push(new SmMathIdentifierNode(m_aCurToken));
+            NextToken();
+            break;
+
         case TPLACE:
             m_aNodeStack.push(new SmPlaceNode(m_aCurToken));
             NextToken();
diff --git a/starmath/source/rtfexport.cxx b/starmath/source/rtfexport.cxx
index fd6f6d03ca26..9dffbcf02b18 100644
--- a/starmath/source/rtfexport.cxx
+++ b/starmath/source/rtfexport.cxx
@@ -179,7 +179,7 @@ void SmRtfExport::HandleRoot(const SmRootNode* pNode, int nLevel)
 namespace {
 OString mathSymbolToString(const SmNode* node, rtl_TextEncoding nEncoding)
 {
-    assert(node->GetType() == NMATH);
+    assert(node->GetType() == NMATH || node->GetType() == NMATHIDENT);
     const SmTextNode* txtnode = static_cast<const SmTextNode*>(node);
     if (txtnode->GetText().isEmpty())
         return OString();
@@ -403,7 +403,7 @@ void SmRtfExport::HandleBrace(const SmBraceNode* pNode, int nLevel)
         for (int i = 0; i < body->GetNumSubNodes(); ++i)
         {
             const SmNode* subnode = body->GetSubNode(i);
-            if (subnode->GetType() == NMATH)
+            if (subnode->GetType() == NMATH || subnode->GetType() == NMATHIDENT)
             { // do not write, but write what separator it is
                 const SmMathSymbolNode* math = static_cast<const SmMathSymbolNode*>(subnode);
                 if(!separatorWritten)
diff --git a/starmath/source/visitors.cxx b/starmath/source/visitors.cxx
index fc0ffc80cc7a..91032b21845c 100644
--- a/starmath/source/visitors.cxx
+++ b/starmath/source/visitors.cxx
@@ -115,7 +115,7 @@ void SmVisitorTest::Visit( SmGlyphSpecialNode* pNode )
 
 void SmVisitorTest::Visit( SmMathSymbolNode* pNode )
 {
-    OSL_ENSURE( pNode->GetType( ) == NMATH, "the visitor-patterns isn't implemented correctly" );
+    OSL_ENSURE( pNode->GetType( ) == NMATH || pNode->GetType( ) == NMATHIDENT, "the visitor-patterns isn't implemented correctly" );
     VisitChildren( pNode );
 }
 
diff --git a/starmath/source/wordexportbase.cxx b/starmath/source/wordexportbase.cxx
index 0a7a6b866c98..f0df05c43b91 100644
--- a/starmath/source/wordexportbase.cxx
+++ b/starmath/source/wordexportbase.cxx
@@ -65,6 +65,7 @@ void SmWordExportBase::HandleNode( const SmNode* pNode, int nLevel )
             break;
         }
         case NMATH:
+        case NMATHIDENT:
             HandleMath(pNode,nLevel);
             break;
         case NSUBSUP: