languages = {'English': 'en', 'Spanish': 'es', 'Italian': 'it', 'German': 'de', 'French': 'fr'}

padding = {'padx': 1, 'pady': 1}

def __init__(self, *args, **kwargs):

Frame.__init__(self, *args, **kwargs)

self.master.title('Dual Language Convertor')

def select_file_grid_row(row, text, button_text, filedialog):

filename = StringVar() # Variable will update automatically if filename is changed

language = StringVar() # Variable will update automatically if language is changed

language.set("Select")

def callback():

# Do not change filename if dialog was cancelled.

new_filename = filedialog()

if new_filename:

filename.set(new_filename)

# Filename selectors

Label(self, text=text).grid(row=row, column=0, sticky=W, **self.padding)

Entry(self, textvariable=filename).grid(row=row, column=1, sticky=W+E, **self.padding)

Button(self, text=button_text, command=callback).grid(row=row, column=2, sticky=W+E, **self.padding)

# Language selectors

Label(self, text='Language:').grid(row=row, column=3, sticky=W, **self.padding)

OptionMenu(self, language, *self.languages.keys()).grid(row=row, column=4, sticky=W+E, **self.padding)

return filename, language

self.input_file, self.input_language = select_file_grid_row(0, 'Input File:', 'Open...', askopenfilename)

self.output_file, self.output_language = select_file_grid_row(1, 'Output File:', 'Save As...', asksaveasfilename)

Button(self, text='Convert', command=self.convert).grid(row=2, column=1, sticky=W+E, **self.padding)

Button(self, text='Quit', command=self.quit).grid(row=2, column=2, sticky=W+E, **self.padding)

def valid_input(self):

""" Checks the input and displays a warning popup if something is invalid. """

if not os.path.isfile(self.input_file.get()):

showwarning(title='Error', message='Invalid input file.')

return False

elif not self.output_file.get():

showwarning(title='Error', message='Invalid output file.')

return False

elif self.input_language.get() not in self.languages:

showwarning(title='Error', message='Invalid input language.')

return False

elif self.output_language.get() not in self.languages:

showwarning(title='Error', message='Invalid output language.')

return False

else:

return True

def convert(self):

""" Runs the parallel_text converter in a thread with the current input. """

if not self.valid_input():

return

popup = Toplevel(self)

# Disable closing of the popup window

popup.protocol('WM_DELETE_WINDOW', lambda : None)

progress = IntVar()

Label(popup, text='Converting Epub. This cannot be interrupted. Please wait...').grid(row=0, column=0)

progressbar = Progressbar(popup, orient=HORIZONTAL, length=200, mode='determinate', variable=progress)

progressbar.grid(row=1, column=0)

# Run converter in thread

converter = Converter(self.languages[self.input_language.get()], self.languages[self.output_language.get()])

self._error = False

def target():

try:

converter.convert_epub(self.input_file.get(), self.output_file.get())

except Exception as e:

self._error = True

self._message = str(e)

thread = Thread(target=target)

thread.start()

# Keep updating progress bar

def update_progressbar():

progress.set(converter.percent_complete)

if thread.is_alive():

popup.after(500, update_progressbar)

else:

progressbar.stop()

popup.destroy()

if self._error:

showinfo(title="Conversion failed", message=self._message)

else:

showinfo(title="Conversion complete", message="Conversion complete.")

popup.after(500, update_progressbar)

# Disable the main window

popup.transient(self)

popup.grab_set()