ENG-6: Add partial default-y support

Due to inconsistencies in the MusicXML spec and its implementation
with regards to default-y and relative-y, precise implementation is
not currently reasonable. Instead, this commit adds two essential
functions which provide a sufficient amount of support for the vertical
layout of direction elements:

- In the case that the placement (above/below) isn't specified,
this is inferred by the value of default-y + relative-y (here called
totalY).
- Rather than being added to their Segment upon read, direction elements
with a default-y or relative-y specified are collected, sorted by
totalY, then added to their Segment in ascending order. Autoplace places
elements in the order they are added, so this allows at least the
ordering of default-y and relative-y to be respected

importexport/musicxml/exportxml.cpp

@@ -6085,6 +6085,7 @@ static void annotationsWithoutNote(ExportMusicXml* exp, const int strack, const
                         if (!element->isFiguredBass() && !element->isHarmony()) {       // handled elsewhere
                               const auto wtrack = findTrackForAnnotations(element->track(), segment); // track to write annotation
                               if (strack <= element->track() && element->track() < (strack + VOICES * staves) && wtrack < 0)
+                                    // TODO: the logic for staves here appears to be incorrect.
                                     commonAnnotations(exp, element, staves > 1 ? 1 : 0);
                               }
                         }

importexport/musicxml/importmxmlpass2.cpp

@@ -1995,6 +1995,8 @@ void MusicXMLParserPass2::measure(const QString& partId,
       FiguredBassList fbl;               // List of figured bass elements under a single note
       MxmlTupletStates tupletStates;       // Tuplet state for each voice in the current part
       Tuplets tuplets;       // Current tuplet for each voice in the current part
+      DelayedDirectionsList delayedDirections; // Directions to be added to score *after* collecting all and sorting
+
 
       // collect candidates for courtesy accidentals to work out at measure end
       QMap<Note*, int> alterMap;
@@ -2004,7 +2006,7 @@ void MusicXMLParserPass2::measure(const QString& partId,
                   attributes(partId, measure, time + mTime);
             else if (_e.name() == "direction") {
                   MusicXMLParserDirection dir(_e, _score, _pass1, *this, _logger);
-                  dir.direction(partId, measure, time + mTime, _divs, _spanners);
+                  dir.direction(partId, measure, time + mTime, _divs, _spanners, delayedDirections);
                   }
             else if (_e.name() == "figured-bass") {
                   FiguredBass* fb = figuredBass();
@@ -2127,6 +2129,18 @@ void MusicXMLParserPass2::measure(const QString& partId,
                   removeBeam(beam);
       }
 
+      // Sort and add delayed directions
+      std::sort(delayedDirections.begin(), delayedDirections.end(),
+            // Lambda: sort by absolute value of totalY
+            [](const MusicXMLDelayedDirectionElement* a, const MusicXMLDelayedDirectionElement* b) -> bool {
+                  return std::abs(a->totalY()) < std::abs(b->totalY());
+                  }
+            );
+      for (auto direction : delayedDirections) {
+            direction->addElem();
+            delete direction;
+      }
+
       // TODO:
       // - how to handle _timeSigDura.isZero (shouldn't happen ?)
       // - how to handle unmetered music
@@ -2376,6 +2390,12 @@ static Fraction calcTicks(const QString& text, int divs, MxmlLogger* logger, con
       return dura;
       }
 
+
+void MusicXMLDelayedDirectionElement::addElem()
+      {
+      addElemOffset(_element, _track, _placement, _measure, _tick);
+      }
+
 //---------------------------------------------------------
 //   direction
 //---------------------------------------------------------
@@ -2388,7 +2408,8 @@ void MusicXMLParserDirection::direction(const QString& partId,
                                         Measure* measure,
                                         const Fraction& tick,
                                         const int divisions,
-                                        MusicXmlSpannerMap& spanners)
+                                        MusicXmlSpannerMap& spanners,
+                                        DelayedDirectionsList& delayedDirections)
       {
       Q_ASSERT(_e.isStartElement() && _e.name() == "direction");
       //qDebug("direction tick %s", qPrintable(tick.print()));
@@ -2486,8 +2507,17 @@ void MusicXMLParserDirection::direction(const QString& partId,
                         t->setFrameRound(0);
                         }
 
-//TODO:ws            if (_hasDefaultY) t->textStyle().setYoff(_defaultY);
-                  addElemOffset(t, track, placement, measure, tick + _offset);
+                  if (placement == "" && hasTotalY())
+                        placement = totalY() < 0 ? "above" : "below";
+                  if (hasTotalY()) {
+                        // Add element to score later, after collecting all the others and sorting by default-y
+                        // This allows default-y to be at least respected by the order of elements
+                        MusicXMLDelayedDirectionElement* delayedDirection = new MusicXMLDelayedDirectionElement(totalY(), t, track, placement, measure, tick + _offset);
+                        delayedDirections.push_back(delayedDirection);
+                        }
+                  else {
+                        addElemOffset(t, track, placement, measure, tick + _offset);
+                        }
                   }
             }
       else if (_tpoSound > 0) {
@@ -2504,7 +2534,7 @@ void MusicXMLParserDirection::direction(const QString& partId,
                   t->setTempo(tpo);
                   t->setFollowText(true);
 
-                  // TBD may want ro use tick + _offset if sound is affected
+                  // TBD may want to use tick + _offset if sound is affected
                   _score->setTempo(tick, tpo);
 
                   addElemOffset(t, track, placement, measure, tick + _offset);
@@ -2598,6 +2628,7 @@ void MusicXMLParserDirection::directionType(QList<MusicXmlSpannerDesc>& starts,
 
       while (_e.readNextStartElement()) {
             _defaultY = _e.attributes().value("default-y").toDouble(&_hasDefaultY) * -0.1;
+            _relativeY = _e.attributes().value("relative-y").toDouble(&_hasRelativeY) * -0.1;
             QString number = _e.attributes().value("number").toString();
             int n = 0;
             if (number != "") {
@@ -6515,7 +6546,7 @@ MusicXMLParserDirection::MusicXMLParserDirection(QXmlStreamReader& e,
                                                  MusicXMLParserPass2& pass2,
                                                  MxmlLogger* logger)
       : _e(e), _score(score), _pass1(pass1), _pass2(pass2), _logger(logger),
-      _hasDefaultY(false), _defaultY(0.0), _coda(false), _segno(false),
+      _hasDefaultY(false), _defaultY(0.0), _hasRelativeY(false), _relativeY(0.0), _coda(false), _segno(false),
       _tpoMetro(0), _tpoSound(0), _offset(0, 1)
       {
       // nothing

importexport/musicxml/importmxmlpass2.h

@@ -179,7 +179,9 @@ class Glissando;
 class Pedal;
 class Trill;
 class MxmlLogger;
+class MusicXMLDelayedDirectionElement;
 
+using DelayedDirectionsList = QList<MusicXMLDelayedDirectionElement*>;
 using SlurStack = std::array<SlurDesc, MAX_NUMBER_LEVEL>;
 using TrillStack = std::array<Trill*, MAX_NUMBER_LEVEL>;
 using BracketsStack = std::array<MusicXmlExtendedSpannerDesc, MAX_NUMBER_LEVEL>;
@@ -340,7 +342,8 @@ class MusicXMLParserPass2 {
 class MusicXMLParserDirection {
 public:
       MusicXMLParserDirection(QXmlStreamReader& e, Score* score, const MusicXMLParserPass1& pass1, MusicXMLParserPass2& pass2, MxmlLogger* logger);
-      void direction(const QString& partId, Measure* measure, const Fraction& tick, const int divisions, MusicXmlSpannerMap& spanners);
+      void direction(const QString& partId, Measure* measure, const Fraction& tick, const int divisions, MusicXmlSpannerMap& spanners, DelayedDirectionsList& delayedDirections);
+      qreal totalY() const { return _defaultY + _relativeY; }
 
 private:
       QXmlStreamReader& _e;
@@ -364,6 +367,9 @@ class MusicXMLParserDirection {
       QString _sndFine;
       bool _hasDefaultY;
       qreal _defaultY;
+      bool _hasRelativeY;
+      qreal _relativeY;
+      bool hasTotalY() { return _hasRelativeY || _hasDefaultY; }
       bool _coda;
       bool _segno;
       double _tpoMetro;                 // tempo according to metronome
@@ -384,5 +390,31 @@ class MusicXMLParserDirection {
       void skipLogCurrElem();
       };
 
+//---------------------------------------------------------
+//   MusicXMLDelayedDirectionElement
+//---------------------------------------------------------
+/**
+ Helper class to allow Direction elements to be sorted by _totalY
+ before being added to the score.
+ */
+
+class MusicXMLDelayedDirectionElement {
+public:
+      MusicXMLDelayedDirectionElement(qreal totalY, Element* element, int track,
+                                    QString placement, Measure* measure, Fraction tick) :
+                                     _totalY(totalY),  _element(element), _track(track), _placement(placement),
+                                      _measure(measure), _tick(tick) {}
+      void addElem();
+      qreal totalY() const { return _totalY; }
+
+private:
+      qreal _totalY;
+      Element* _element;
+      int _track;
+      QString _placement;
+      Measure* _measure;
+      Fraction _tick;
+      };
+
 } // namespace Ms
 #endif