from tkinter import * from functools import partial # To prevent unwanted windows import all_constants as c import conversion_rounding_v2 as cr class Converter: """ Weight conversion tool (lb to kg or kg to lb) """ def __init__(self): """ Weight conversion GUI """ self.all_calculations_list = [] self.main_frame = Frame(padx=10, pady=10) self.main_frame.grid() self.main_heading = Label(self.main_frame, text="Weight Convertor", font=("Arial", "16", "bold") ) self.main_heading.grid(row=0) instructions = ("Please enter a weight below and then press " "one of the buttons to convert it from kilograms " "to pounds.") self.main_instructions = Label(self.main_frame, text=instructions, wraplength=250, width=40, justify="left") self.main_instructions.grid(row=1) self.main_entry = Entry(self.main_frame, font=("Arial", "14") ) self.main_entry.grid(row=2, padx=10, pady=10) error = "Please enter a number" self.answer_error = Label(self.main_frame, text=error, fg="#004C99", font=("Arial", "12", "bold")) self.answer_error.grid(row=3) # Conversion, help and history / export buttons self.button_frame = Frame(self.main_frame) self.button_frame.grid(row=4) # button list (button text | bg colour | command | row | column) button_details_list = [ ["To Kilograms", "#990099", lambda: self.check_weight(c.LB_TO_KG), 0, 0], ["To Pounds", "#009900", lambda: self.check_weight(c.KG_TO_LB), 0, 1], ["Help / Info", "#CC6600", self.to_help, 1, 0], ["History / Export", "#004C99", "", 1, 1] ] # List to hold buttons once they have been made self.button_ref_list = [] for item in button_details_list: self.make_button = Button(self.button_frame, text=item[0], bg=item[1], fg="#FFFFFF", font=("Arial", "12", "bold"), width=12, command=item[2]) self.make_button.grid(row=item[3], column=item[4], padx=5, pady=5) self.button_ref_list.append(self.make_button) # retrieve to_help button self.to_help_button = self.button_ref_list[2] # retrieve 'history / export' button and disable it at the start self.to_history_button = self.button_ref_list[3] self.to_history_button.config(state=DISABLED) def check_weight(self, min_weight): """ Checks weight is valid and either invokes calculation function or shows a custom error """ # Retrieve weight to be converted to_convert = self.main_entry.get() # Reset label and entry box (if we had an error) self.answer_error.config(fg="#004C99", font=("Arial", "13", "bold")) self.main_entry.config(bg="#FFFFFF") error = f"Enter a number between {c.MIN_WEIGHT} and {c.MAX_WEIGHT}" has_errors = "no" # checks that amount to be converted is a number above absolute zero try: to_convert = float(to_convert) if c.MIN_WEIGHT <= to_convert <= c.MAX_WEIGHT: self.convert(min_weight, to_convert) else: has_errors = "yes" except ValueError: has_errors = "yes" # display the error if necessary if has_errors == "yes": self.answer_error.config(text=error, fg="#9C0000", font=("Arial", "10", "bold")) self.main_entry.config(bg="#F4CCCC") self.main_entry.delete(0, END) def convert(self, min_weight, to_convert): """ Converts weight and updates answer label. Also stores calculations for Export / History feature """ if min_weight == c.KG_TO_LB: answer = cr.to_pounds(to_convert) answer_statement = f"{to_convert}kg is {answer}lb" else: answer = cr.to_kilogram(to_convert) answer_statement = f"{to_convert} lb is {answer} kg" # enable history export button as soon as we have a valid calculation self.to_history_button.config(state=NORMAL) self.answer_error.config(text=answer_statement) self.all_calculations_list.append(answer_statement) print(self.all_calculations_list) def to_help(self): """ Opens help dialogue box and disables help button (so that users can't create multiple help boxes). """ DisplayHelp(self) class DisplayHelp: """ Displays help dialogue box """ def __init__(self, partner): # setup dialogue box and background colour background = "#ffe6cc" self.help_box = Toplevel() # disable help button partner.to_help_button.config(state=DISABLED) # If users press cross at top, closes help and # 'releases' help button self.help_box.protocol('WM_DELETE_WINDOW', partial(self.close_help, partner)) self.help_frame = Frame(self.help_box, width=300, height=200) self.help_frame.grid() self.help_heading_label = Label(self.help_frame, text="Help / Info", font=("Arial", "14", "bold")) self.help_heading_label.grid(row=0) help_text = "To use the program, simply enter the weight " \ "you wish to convert and then choose to convert " \ "to either kilograms (kg) or " \ "pounds (lb).. \n\n" \ " Note that if you try to convert a " \ "weight that is less than or equal to 0, " \ "you will get an error message. \n\n " \ "To see your " \ "calculation history and export it to a text " \ "file, please click the 'History / Export' button." self.help_text_label = Label(self.help_frame, text=help_text, wraplength=350, justify="left") self.help_text_label.grid(row=1, padx=10) self.dismiss_button = Button(self.help_frame, font=("Arial", "12", "bold"), text="Dismiss", bg="#CC6600", fg="#FFFFFF", command=partial(self.close_help, partner)) self.dismiss_button.grid(row=2, padx=10, pady=10) # List and loop to set background colour on # everything except the buttons. recolour_list = [self.help_frame, self.help_heading_label, self.help_text_label] for item in recolour_list: item.config(bg=background) def close_help(self, partner): """ Closes help dialogue box (and enables help button) """ # Put help button back to normal... partner.to_help_button.config(state=NORMAL) self.help_box.destroy() # main routine if __name__ == "__main__": root = Tk() root.title("Temperature Converter") Converter() root.mainloop()