ENG-59: Fix missing secondary beam breaks

Previously, only the first beam was taken into account when importing
Beam::Mode. This commit adds a mechanism to collect the beam type
for all beams and make a more correct choice about Beam::Mode (including
BEGIN32 and BEGIN64). Additionally, it adds handling of these modes to
the export code. Now the round trip from .mscx -> .xml -> .mscx is
correct and complete *when beam modes are specified explicitly in the
.mscx*; however, more thorough handling of Beam::Mode::AUTO (where it
results in the equivalent of BEGIN32 or BEGIN64) on export needs to be
done.

Duplicate of musescore#8492, plus fixing 4 compiler warnings, see musescore#8554

importexport/musicxml/exportxml.cpp

@@ -2928,30 +2928,43 @@ static void writeBeam(XmlWriter& xml, ChordRest* const cr, Beam* const b)
       int blp = -1; // beam level previous chord
       int blc = -1; // beam level current chord
       int bln = -1; // beam level next chord
+      Beam::Mode bmc = Beam::Mode::AUTO; // beam mode current chord
+      Beam::Mode bmn = Beam::Mode::AUTO; // beam mode next chord
       // find beam level previous chord
       for (int i = idx - 1; blp == -1 && i >= 0; --i) {
             const auto crst = elements[i];
             if (crst->isChord())
                   blp = toChord(crst)->beams();
             }
       // find beam level current chord
-      if (cr->isChord())
+      if (cr->isChord()) {
             blc = toChord(cr)->beams();
+            bmc = toChord(cr)->beamMode();
+            }
       // find beam level next chord
       for (int i = idx + 1; bln == -1 && i < elements.size(); ++i) {
             const auto crst = elements[i];
-            if (crst->isChord())
+            if (crst->isChord()) {
                   bln = toChord(crst)->beams();
+                  bmn = toChord(crst)->beamMode();
+                  }
             }
       // find beam type and write
       for (int i = 1; i <= blc; ++i) {
             QString text;
-            if (blp < i && bln >= i) text = "begin";
+            // TODO: correctly handle Beam::Mode::AUTO
+            // when equivalent to BEGIN32 or BEGIN64
+            if ((blp < i && bln >= i)
+             || (bmc == Beam::Mode::BEGIN32 && i > 1)
+             || (bmc == Beam::Mode::BEGIN64 && i > 2))
+                  text = "begin";
             else if (blp < i && bln < i) {
                   if (bln > 0) text = "forward hook";
                   else if (blp > 0) text = "backward hook";
                   }
-            else if (blp >= i && bln < i)
+            else if ((blp >= i && bln < i)
+                  || (bmn == Beam::Mode::BEGIN32 && i > 1)
+                  || (bmn == Beam::Mode::BEGIN64 && i > 2))
                   text = "end";
             else if (blp >= i && bln >= i)
                   text = "continue";

importexport/musicxml/importmxmlpass2.cpp

@@ -1836,7 +1836,7 @@ static void handleBeamAndStemDir(ChordRest* cr, const Beam::Mode bm, const Direc
                   // reset beam mode for all elements and remove the beam
                   removeBeam(beam);
                   }
-            else if (!(bm == Beam::Mode::BEGIN || bm == Beam::Mode::MID || bm == Beam::Mode::END)) {
+            else if (!(bm == Beam::Mode::BEGIN || bm == Beam::Mode::MID || bm == Beam::Mode::END || bm == Beam::Mode::BEGIN32 || bm == Beam::Mode::BEGIN64)) {
                   qDebug("handleBeamAndStemDir() in beam, bm %d -> abort beam", static_cast<int>(bm));
                   // reset beam mode for all elements and remove the beam
                   removeBeam(beam);
@@ -4497,6 +4497,36 @@ static void setNoteHead(Note* note, const QColor noteheadColor, const bool noteh
             note->setHeadType(NoteHead::Type::HEAD_QUARTER);
       }
 
+//---------------------------------------------------------
+//   computeBeamMode
+//---------------------------------------------------------
+
+/**
+ Calculate the beam mode based on the collected beamTypes.
+ */
+
+static Beam::Mode computeBeamMode(const QMap<int, QString>& beamTypes)
+      {
+      // Start with uniquely-handled beam modes
+      if (beamTypes.value(1) == "continue"
+       && beamTypes.value(2) == "begin") 
+            return Beam::Mode::BEGIN32;
+      else if (beamTypes.value(1) == "continue"
+            && beamTypes.value(2) == "continue"
+            && beamTypes.value(3) == "begin")
+            return Beam::Mode::BEGIN64;
+      // Generic beam modes are naive to all except the first beam
+      else if (beamTypes.value(1) == "begin")
+            return Beam::Mode::BEGIN;
+      else if (beamTypes.value(1) == "continue")
+            return Beam::Mode::MID;
+      else if (beamTypes.value(1) == "end")
+            return Beam::Mode::END;
+      else
+            // backward-hook, forward-hook, and other unknown combinations
+            return Beam::Mode::AUTO;
+      }
+
 //---------------------------------------------------------
 //   addFiguredBassElemens
 //---------------------------------------------------------
@@ -4707,7 +4737,8 @@ Note* MusicXMLParserPass2::note(const QString& partId,
       int velocity = round(_e.attributes().value("dynamics").toDouble() * 0.9);
       bool graceSlash = false;
       bool printObject = _e.attributes().value("print-object") != "no";
-      Beam::Mode bm  = Beam::Mode::AUTO;
+      Beam::Mode bm;
+      QMap<int, QString> beamTypes;
       QString instrumentId;
       MusicXMLParserLyric lyric { _pass1.getMusicXmlPart(partId).lyricNumberHandler(), _e, _score, _logger };
       MusicXMLParserNotations notations { _e, _score, _logger };
@@ -4723,7 +4754,7 @@ Note* MusicXMLParserPass2::note(const QString& partId,
                   // element handled
                   }
             else if (_e.name() == "beam")
-                  beam(bm);
+                  beam(beamTypes);
             else if (_e.name() == "chord") {
                   chord = true;
                   _e.readNext();
@@ -4805,6 +4836,8 @@ Note* MusicXMLParserPass2::note(const QString& partId,
             currBeams.insert(currentVoice, (Beam *)nullptr);
       Beam* &currBeam = currBeams[currentVoice];
 
+      bm = computeBeamMode(beamTypes);
+
       // check for timing error(s) and set dura
       // keep in this order as checkTiming() might change dura
       auto errorStr = mnd.checkTiming(type, rest, grace);
@@ -5630,32 +5663,17 @@ void MusicXMLParserPass2::harmony(const QString& partId, Measure* measure, const
 
 /**
  Parse the /score-partwise/part/measure/note/beam node.
- Sets beamMode in case of begin, continue or end beam number 1.
+ Collects beamTypes, used in computeBeamMode.
  */
 
-void MusicXMLParserPass2::beam(Beam::Mode& beamMode)
-      {
+void MusicXMLParserPass2::beam(QMap<int, QString>& beamTypes) {
       Q_ASSERT(_e.isStartElement() && _e.name() == "beam");
 
-      int beamNo = _e.attributes().value("number").toInt();
-
-      if (beamNo == 1) {
-            QString s = _e.readElementText();
-            if (s == "begin")
-                  beamMode = Beam::Mode::BEGIN;
-            else if (s == "end")
-                  beamMode = Beam::Mode::END;
-            else if (s == "continue")
-                  beamMode = Beam::Mode::MID;
-            else if (s == "backward hook")
-                  ;
-            else if (s == "forward hook")
-                  ;
-            else
-                  _logger->logError(QString("unknown beam keyword '%1'").arg(s), &_e);
-            }
-      else
-            _e.skipCurrentElement();
+      bool hasBeamNo;
+      int beamNo = _e.attributes().value("number").toInt(&hasBeamNo);
+      QString s = _e.readElementText();
+
+      beamTypes.insert(hasBeamNo ? beamNo : 1, s);
       }
 
 //---------------------------------------------------------

importexport/musicxml/importmxmlpass2.h

@@ -288,7 +288,7 @@ class MusicXMLParserPass2 {
       FretDiagram* frame(qreal& defaultY, qreal& relativeY, bool& hasTotalY);
       void harmony(const QString& partId, Measure* measure, const Fraction sTime, DelayedDirectionsList& delayedDirections);
       Accidental* accidental();
-      void beam(Beam::Mode& beamMode);
+      void beam(QMap<int, QString>& beamTypes);
       void duration(Fraction& dura);
       void forward(Fraction& dura);
       void backup(Fraction& dura);