#Name: Print on Object
#Info: Lets you print an object on an other one. Attention, be sure that the printhead can go to his home position to initialize. Deactivate the skirt (for Cura - 13.06.4 under Expert --> Open expert settings... --> Skirt, set Line count to "0"). Check for the comment about PrintonObject plugin used in gcode on first line.
#Depend: GCode
#Type: postprocess
#Param: objectheight(float:0) Object height (mm)

#version of the plugin
version = 1.1

#import the Library of Regular expressions 
import re

#only lines with this key will be processed
key = "Z"
#comment sign used in gcode files
commentsign = ";"
#compile regular expression to a pattern object and save it
regex = re.compile("Z[0-9]+\\.?[0-9]*")

#search and change the values of the "Z" axis.
#key = only lines with this key will be processed
#line = the current line who will be edited
#objectheight = the value which will be added to the current value of the "Z" axis
#commentsign = commentsign of Gcode files,
#regex = regular expression pattern object which is used to find the substring who have to be edited.
def changeValue(key, line, objectheight, commentsign, regex):
    #sorts out lines who will not be processed
    if key in line and not(commentsign in line and line.find(key) > line.find(commentsign)):
        #saves the result of the search for the regex in the current line in "match"
        match = regex.search(line)
        #if there is a result saved in "match"
        if match != None:
            #saves the matched substring of the line in "substr"
            substr = match.group()
            #so it does'nt change the Home position
            if float(substr[1::1]) != 0:
                #replace the current value with the current value + "objectheight" and returns the whole line
                return line.replace(substr[1::1],str(float(substr[1::1])+objectheight))
    #if one, two or all of the ifs aren't true it returns the line unchanged
    return line

#opens the file with the filename provided by Cura in read mode and create the reference "f"
with open(filename, "r") as f:
    #creates an array "lines", an empty list of lines
    lines = []
    #iterates with "line" through every line in the file referenced by "f"
    for line in f:
        #add every line to the end of the array "lines"
        lines.append(line)

#opens the file with the filename provided by Cura in write mode and create the reference "f"
with open(filename, "w") as f:
    #write comment header - no more supported by UM2
    #f.write("; This Gcode file has been edited with PrintonObject version " + str(version) + "\n")
    #iterates with "line" through every line in the array "lines"
    for line in lines:
        #writes the return value of the function "changeValue" into the file
        f.write(changeValue(key, line, objectheight, commentsign, regex))