fixed STEP import to preserve colors

import time

import pickle

import math

import pprint # pretty print objects

import xml.etree.ElementTree as et

from xml.dom import minidom

from configparser import ConfigParser #In Python 3, ConfigParser has been renamed to configparser for PEP 8 compliance. 

import sys

import traceback

#https://github.com/FreeCAD/FreeCAD/blob/master/src/Mod/Part/App/ImportStep.cpp

CONFIG_PATH= "~/.FreeCAD/x3d_step_assy.ini"

ROOT_DIR = '~/parts/0393/export'

STEP_PARTS='~/parts/0393/export/step_parts'

    progress_bar = Base.ProgressIndicator()

    progress_bar.start("Generating objects%s to export to X3D ..."%(txt), len(freecadObjects))

    FreeCAD.Console.PrintMessage("Generating %d objects%s to export to X3D\n"%( len(freecadObjects), txt));

    print("Generating %d objects%s to export to X3D\n"%( len(freecadObjects), txt));

    objects = []

    pp = pprint.PrettyPrinter(indent=4)

    allSolids=[]

    for o in freecadObjects:

#        FreeCAD.Console.PrintMessage("Generating object # %d\n"%(no));

#        print("Generating object # %d"%(no));

        if hasattr(o, "Shape"):

            shape=o.Shape

            #repairing open shells

                fromShell=False

            # get all colors for faces in this object (normally just one Shell/Solid

            color_set=set()

            if o.ViewObject:

                for clr in o.ViewObject.DiffuseColor: # colors are one per face

            try:

                dc = o.ViewObject.DiffuseColor

            except AttributeError:

                continue 

            for clr in dc: # colors are one per face

                color_set.add(clr)

            col_list = list(color_set)

            col_dict={} # index for each color (reverse to list)

            for i, clr in enumerate(col_list):

                col_dict[clr] = i

            #Calculate per-color centers for each object (normally each object has just one Solid/Shell

            dc=o.ViewObject.DiffuseColor

            if (len(dc) == 1) and (len(o.Shape.Faces)>1):

                dc= dc * len(o.Shape.Faces)

            colorCenters=[[0.0,0.0,0.0,0.0] for c in col_list] # SX,SY,SZ,S0

        info_path = os.path.join(ROOT_DIR,INFO_DIR, name + INFO_EXT)

        info_dict[name] = pickle.load(open(info_path, "rb"))

        progress_bar.next()

        print("Read info for ", name)

        if name == '0393-13-14A':

            print ('info_dict[name]=',info_dict[name])

    progress_bar.stop()

#    FreeCAD.Console.PrintMessage("get_info_files() - loaded"); #Rare FreeCAD crash?

        trans={}

        print ("%d findPartsTransformations:"%(i))

        for cand_name in candidates[i]:

            print("cand_name=",cand_name)

            co = info_dict[cand_name][0] # First solid in the candidate part file 

            print("co=",co)

            print("candidates[i]=",candidates[i])

            print("candidates[i][cand_name]=",candidates[i][cand_name])

            try:

                colorCenters = co['colorCenters']

            except:

                colorCenters = {}

            """

def ppToMatrix(pp,

               center =      (0,0,0),

               colorCenters = {}, # should have all the colors in a colors list "by design"

               colors =       [],

               orient  =      0,

               precision =    PRECISION): 

            """

            matrix_part = ppToMatrix(co['principal'],co['center'], colorCenters, candidates[i][cand_name], 0, precision)

            # Now try 4 orientations (until the first match).

        objects,solids = create_file_info_nogui(shape, aname)

#        shape = assembly

    else:

        print("GUI mode: assembly=",assembly) # [<Part::PartFeature>]

        objects,solids = create_file_info(assembly, aname)

        print("GUI mode: objects=",objects)

        print("GUI mode: solids=",solids)

    show_best = True #FIXME: debugging

#    print (objects)

    progress_bar = Base.ProgressIndicator()

    progress_bar.start("Looking for matching parts for each of the assembly element ...", len(objects))

                                                                                errors[2]/rg_av,

                                                                                errors[3]/rg_av,

                                                                                errors[4]/rg_av))

        print ("this_candidates=",this_candidates)

        # Filter candidates by number of color areas matched

        colored_candidates=colorMatchCandidate(o, this_candidates, info_dict, precision_area)

        try:

        self.setGeometry(100, 100, 300, 200)

        self.setWindowTitle("STEP assembly to X3D converter")

        FreeCAD.Console.PrintMessage("Disabling STEP compound merge in preferences/Import-Export/STEP");

#FIXME - uncomment when done. Merges STEP solid into a single grey object        

        App.ParamGet("User parameter:BaseApp/Preferences/Mod/Import/hSTEP").SetBool('ReadShapeCompoundMode',False)

    #----------------------------------------------------------------------

    def selectLogFile(self):

        prompt_file = self.log_file