Append settings to g-code

A serialised version of the settings are now appended to the g-code. It doesn't introduce line breaks yet, so the g-code may be invalid if the firmware doesn't handle lines longer than 80 characters.

Contributes to issue CURA-34.

plugins/GCodeWriter/GCodeWriter.py

@@ -5,6 +5,7 @@ from UM.Mesh.MeshWriter import MeshWriter
 from UM.Logger import Logger
 from UM.Application import Application
 import io
+import re #For escaping characters in the settings.
 
 
 class GCodeWriter(MeshWriter):
@@ -21,6 +22,33 @@ class GCodeWriter(MeshWriter):
         if gcode_list:
             for gcode in gcode_list:
                 stream.write(gcode)
+            profile = self._serialiseProfile(Application.getInstance().getMachineManager().getActiveProfile()) #Serialise the profile and put them at the end of the file.
+            stream.write(profile)
             return True
 
         return False
+
+    ##  Serialises the profile to prepare it for saving in the g-code.
+    #
+    #   The profile are serialised, and special characters (including newline)
+    #   are escaped.
+    #
+    #   \param profile The profile to serialise.
+    #   \return A serialised string of the profile.
+    def _serialiseProfile(self, profile):
+        serialised = profile.serialise()
+        
+        #Escape characters that have a special meaning in g-code comments.
+        escape_characters = { #Which special characters (keys) are replaced by what escape character (values).
+                              #Note: The keys are regex strings. Values are not.
+            "\\": "\\\\", #The escape character.
+            "\n": "\\n",  #Newlines. They break off the comment.
+            "\r": "\\r",  #Carriage return. Windows users may need this for visualisation in their editors.
+        }
+        pattern = re.compile("|".join(escape_characters.keys()))
+        serialised = pattern.sub(lambda m: escape_characters[m.group(0)], serialised) #Perform the replacement with a regular expression.
+        
+        #TODO: Introduce line breaks so that each comment is no longer than 80 characters.
+        #TODO: Prepend a prefix that includes the keyword "SETTING" and a serialised version number.
+        
+        return ";" + serialised