Android Downsampler

#!/usr/bin/env python
from PIL import Image as PilImage
import sys, os.path, ConfigParser
from Tkinter import *
import ttk
import tkFileDialog, tkMessageBox
import codecs

# Fix for Unicode Filenames ( http://habrahabr.ru/post/119405/ )
class UnicodeConfigParser(ConfigParser.RawConfigParser):

    def __init__(self, *args, **kwargs):
        ConfigParser.RawConfigParser.__init__(self, *args, **kwargs)

    def write(self, fp):
        """Fixed for Unicode output"""
        if self._defaults:
            fp.write("[%s]\n" % DEFAULTSECT)
            for (key, value) in self._defaults.items():
                fp.write("%s = %s\n" % (key, unicode(value).replace('\n', '\n\t')))
            fp.write("\n")
        for section in self._sections:
            fp.write("[%s]\n" % section)
            for (key, value) in self._sections[section].items():
                if key != "__name__":
                    fp.write("%s = %s\n" %
                             (key, unicode(value).replace('\n','\n\t')))
            fp.write("\n")

    # This function is needed to override default lower-case conversion
    # of the parameter's names. They will be saved 'as is'.
    def optionxform(self, strOut):
        return strOut

resolutions = [("mdpi", 1.0), ("hdpi", 1.5), ("xhdpi", 2.0), ("xxhdpi", 3.0), ("xxxhdpi", 4.0)]
configFile = "config.txt"
configSection = "configuration"
configLastDir = "LastDir"

imagePath = u""
imageDir = u""
imageName = u""
image = None
defWidth = defHeight = 1

root = Tk()
root.title("Android Drawable Downsampler")
root.resizable(0, 0)
pyfilepath = ""
if hasattr(sys, 'frozen'):
    pyfilepath = sys.executable
else:
    pyfilepath = os.path.realpath(__file__)
pyfilepath = os.path.dirname(pyfilepath)
iconpath = pyfilepath + "/addownsampler.ico"
if os.path.exists(iconpath):
    root.iconbitmap(iconpath)
widthVar = StringVar()
heightVar = StringVar()
labelFileName = convertButton = buttonCalculateSizes = None

configdir = os.path.expanduser("~") + "/.downsampler/"
if not os.path.exists(configdir):
    os.makedirs(configdir)
configpath = configdir + configFile

def loadParameter(param, defval):
    if os.path.exists(configpath):
        parser = ConfigParser.ConfigParser()
        parser.optionxform = unicode
        parser.readfp(codecs.open(configpath, "rb", "utf8"))
        items = parser.items(configSection)
        itemsDict = dict(items)
        return itemsDict[param]
    else:
        return defval

def storeParameter(param, value):
    parser = UnicodeConfigParser()
    if os.path.exists(configpath):
        parser.read(configpath)
    else:
        parser.add_section(configSection)
    parser.set(configSection, param, value)
    with codecs.open(configpath, "wb", "utf8") as cfile:
        parser.write(cfile)

def onSelectFile():
    global imagePath, imageDir, imageName, image, defHeight, defWidth
    options = dict()
    options['initialdir'] = loadParameter(configLastDir, pyfilepath)
    options['title'] = 'Select original large image'
    options['filetypes'] = [('PNG files', '.png')]
    imagePath = tkFileDialog.askopenfilename(**options)

    if len(imagePath) == 0:
        return

    imageDir = os.path.dirname(imagePath)
    storeParameter(configLastDir, imageDir)
    imageName = os.path.basename(imagePath)

    image = PilImage.open(imagePath)
    defWidth, defHeight = image.size

    labelFileName["text"] = imageName + " (%dx%d)" % (defWidth, defHeight)
    convertButton["state"] = "enabled"
    buttonCalculateSizes["state"] = "enabled"

def calculateSizes():
    if len(widthVar.get()) == 0 and len(heightVar.get()) > 0:
        height = int(heightVar.get())
        width = int(1.0 * defWidth / defHeight * height)
        widthVar.set(str(width))
    if len(widthVar.get()) > 0 and len(heightVar.get()) == 0:
        width = int(widthVar.get())
        height = int(1.0 * defHeight / defWidth * width)
        heightVar.set(str(height))

def convert():
    if len(widthVar.get()) == 0 or len(heightVar.get()) == 0:
        tkMessageBox.showinfo("Error", "Please, specify width and height for MDPI resolution")
        return
    convertButton["state"] = "disabled"

    width = int(widthVar.get())
    height = int(heightVar.get())
    sizes = {resolution[0]: (int(width * resolution[1]), int(height * resolution[1])) for resolution in resolutions}

    for category, (width, height) in sizes.iteritems():
        finaldir = imageDir + "/drawable-" + category
        if not os.path.exists(finaldir):
            os.makedirs(finaldir)
        print("Resizing for %s to %dx%d" % (category, width, height))
        imageResized = image.resize((width, height), PilImage.ANTIALIAS)
        imageResized.save(finaldir + "/" + imageName)

    convertButton["state"] = "enabled"

labelFileName = ttk.Label(root, text = "Please, select original image")
labelFileName.grid(row = 0, column = 0, columnspan = 2)

buttonSelectFile = ttk.Button(root, text="Choose file...", width = 40, command = onSelectFile)
buttonSelectFile.grid(row = 1, column = 0, columnspan = 2)

ttk.Label(root, text = "MDPI Width").grid(row = 2, column = 0)
ttk.Label(root, text = "MDPI Height").grid(row = 2, column = 1)

textWidth = ttk.Entry(root, width = 30, textvariable = widthVar, justify = "center")
textWidth.grid(row = 3, column = 0)
textHeight = ttk.Entry(root, width = 30, textvariable = heightVar, justify = "center")
textHeight.grid(row = 3, column = 1)

buttonCalculateSizes = ttk.Button(root, text = "Width <==> Height", width = 40, command = calculateSizes)
buttonCalculateSizes.grid(row = 4, column = 0, columnspan = 2)
buttonCalculateSizes["state"] = "disabled"

ttk.Label(root,
    text = "If you left width OR height empty, press button above to maintain aspect ratio").\
    grid(row = 5, column = 0, columnspan = 2)

convertButton = ttk.Button(root, text = "_____  DO  IT  _____", width = 40, command = convert)
convertButton.grid(row = 6, column = 0, columnspan = 2)
convertButton["state"] = "disabled"

ttk.Label(root,
    text = "Result files will be placed to appropriate folders in original image directory").\
    grid(row = 7, column = 0, columnspan = 2)

ttk.Label(root,
    text = "Version 0.1 by Egor Aristov (ef@efprojects.com)").\
    grid(row = 8, column = 0, columnspan = 2)

root.mainloop()