add Slurs to lilypond output

engine/items.py

@@ -1757,7 +1757,7 @@ class Chord(Item):
                     pass
             return pre
 
-        #Do we have a dynamic signature waiting? (convert laborejo prefix to lilypond postfix)
+        #Do we have a dynamic \f signature waiting? (convert laborejo prefix to lilypond postfix)
         #They belong after the duration.
         if "DynamicSignature" in carryLilypondRanges:
             dynsig = carryLilypondRanges["DynamicSignature"]
@@ -1765,7 +1765,12 @@ class Chord(Item):
         else:
             dynsig = ""
 
-        #Do we have a slur signature waiting? (convert laborejo prefix to lilypond postfix)
+        #Do we have a slur ( or ) signature waiting? (convert laborejo prefix to lilypond postfix)
+        if "LegatoSlur" in carryLilypondRanges:
+            slur = carryLilypondRanges["LegatoSlur"]
+            del carryLilypondRanges["LegatoSlur"]
+        else:
+            slur = ""
 
 
         #Create lilypond durations
@@ -1776,10 +1781,10 @@ class Chord(Item):
             tupletSubstring = _createLilypondTuplet(self.notelist[0].duration, carryLilypondRanges)
             if len(pitches) == 1:
                 # The most common case:  Just a single note
-                return tupletSubstring +  pitches[0] + durations[0] + dynsig  #this is a string.
+                return tupletSubstring +  pitches[0] + durations[0] + dynsig  + slur #this is a string.
             else:
                 # A simple chord with mulitple pitches but just one duration
-                return tupletSubstring +  "<" + " ".join(pitches) + ">" + durations[0] + dynsig
+                return tupletSubstring +  "<" + " ".join(pitches) + ">" + durations[0] + dynsig + slur
         else:
             #TODO: Cache this
 
@@ -1787,6 +1792,7 @@ class Chord(Item):
             #Here is how it's done: We group the same duration together and create normal chords which are placed each in its own automatic voice through the lilypond syntax << { <chord> } \\ { <chord> } \\ etc. >>
             #Lilypond default is to take the longest note as overall duration. However, Laborejo uses the shortest duration as logical duration. So we scale all other to logical shortest duration
             #See http://lilypond.org/doc/v2.18/Documentation/notation/writing-rhythms#scaling-durations
+
             table = {}
             for note in self.notelist:
                 pitch, duration = note.lilypond(carryLilypondRanges)
@@ -1810,6 +1816,10 @@ class Chord(Item):
 
             tupletSubstring = _createLilypondTuplet(self.durationGroup, carryLilypondRanges)
             result = tupletSubstring + "<<" + " ".join(substrings) + dynsig + ">>"
+
+            if slur:
+                logging.error("Slurs in single-track polyphonic chords are not supported. Please use multiple tracks for real polyphony. This is the problematic Chord: " + result)
+
             return result
 
 class Rest(Item):
@@ -2750,6 +2760,9 @@ class LegatoSlur(Item):
 
 
     def _exportObject(self, trackState):
+        #We export so many times, the chances are > 99.9% that this cache for lilypond export will be correct
+        self._cacheKeywordForLilypond = self.asText(trackState)
+
         return {
             "type" : "LegatoSlur",
             "slur" : self.openOrClose(trackState),
@@ -2759,6 +2772,15 @@ class LegatoSlur(Item):
             "UIstring" : self.asText(trackState),
         }
 
+    def _lilypond(self, carryLilypondRanges):
+        """
+        Lilypond Slurs are postfix.
+
+        Don't export anything directly, but add the keyword to the lilypond ranges dict
+        so the next chord can use it as postfix. """
+        carryLilypondRanges["LegatoSlur"] = self._cacheKeywordForLilypond
+        return ""
+
 class InstrumentChange(Item):
     """Includes program change, both bank changes and the lilypond short name change.
     Lilypond does not support a full name change, so we don't offer that here."""