MusicXML: Recognize \break

Recognize the \break command by adding a <print new-system="yes" />
to the beginning of a bar.

See
http://usermanuals.musicxml.com/MusicXML/MusicXML.htm#EL-MusicXML-print.htm

Author: eoma

ly/musicxml/create_musicxml.py

@@ -115,6 +115,7 @@ def create_part(self, name="unnamed", abbr=False, midi=False):
     def create_measure(self, **bar_attrs):
         """Create new measure """
         self.current_bar = etree.SubElement(self.current_part, "measure", number=str(self.bar_nr))
+        self.current_print = None
         self.bar_nr +=1
         if bar_attrs:
             self.new_bar_attr(**bar_attrs)
@@ -626,6 +627,13 @@ def add_lyric(self, txt, syll, nr, ext=False):
         if ext:
             etree.SubElement(lyricnode, "extend")
 
+    def new_system(self):
+        if not self.current_print:
+            self.create_print()
+        self.current_print.attrib["new-system"] = "yes"
+
+    def create_print(self):
+        self.current_print = etree.SubElement(self.current_bar, "print")
 
     ##
     # Create the XML document

ly/musicxml/ly2xml_mediator.py

@@ -829,6 +829,10 @@ def new_lyrics_item(self, item):
         elif item == '\\skip':
             self.insert_into.barlist.append("skip")
 
+    def line_break(self):
+        if self.bar:
+            self.bar.line_break = True
+
     def duration_from_tokens(self, tokens):
         """Calculate dots and multibar rests from tokens."""
         dots = 0

ly/musicxml/lymus2musxml.py

@@ -497,6 +497,8 @@ def Command(self, command):
             if self.tupl_span:
                 self.mediator.unset_tuplspan_dur()
                 self.tupl_span = False
+        elif command.token == '\\break':
+            self.mediator.line_break()
         else:
             if command.token not in excls:
                 print("Unknown command:", command.token)

ly/musicxml/xml_objs.py

@@ -103,6 +103,10 @@ def iterate_part(self, part):
     def iterate_bar(self, bar):
         """The objects in the bar are output to the xml-file."""
         self.musxml.create_measure()
+
+        if bar.line_break:
+            self.musxml.new_system()
+
         for obj in bar.obj_list:
             if isinstance(obj, BarAttr):
                 self.new_xml_bar_attr(obj)
@@ -433,6 +437,7 @@ class Bar():
     def __init__(self):
         self.obj_list = []
         self.list_full = False
+        self.line_break = False
 
     def __repr__(self):
         return '<{0} {1}>'.format(self.__class__.__name__, self.obj_list)
@@ -478,6 +483,10 @@ def inject_voice(self, new_voice, override=False):
         """ Adding new voice to bar.
         Omitting double or conflicting bar attributes as long as override is false.
         Omitting also bars with only skips."""
+
+        if new_voice.line_break:
+            self.line_break = True
+
         if new_voice.obj_list[0].has_attr():
             if self.obj_list[0].has_attr():
                 self.obj_list[0].merge_attr(new_voice.obj_list[0], override)