import tkinter
from tkinter import ttk

class Adder(ttk.Frame):
    def __init__(self, parent, *args, **kwargs):
        ttk.Frame.__init__(self, parent, *args, **kwargs)
        self.root = parent
        self.init_gui()

    def on_quit(self):
        self.root.destroy()
        

    def calculate(self):
        num1 = int(self.num1_entry.get())
        num2 = int(self.num2_entry.get())
        num3 = num1 + num2
        self.answer_label['text'] = num3

    def init_gui(self):
        self.root.title("Number Adder")

        self.grid(column=0, row=0, sticky='nsew')
        

        self.num1_entry = ttk.Entry(self, width=5)
        self.num1_entry.grid(column=1, row=2)
        
        self.num2_entry = ttk.Entry(self, width=5)
        self.num2_entry.grid(column=3, row=2)

        self.calc_button = ttk.Button(self, text='Calculate', command=self.calculate)
        self.calc_button.grid(column=0, row=3, columnspan=2)
        
        self.quit_button = ttk.Button(self, text='Quit', command=self.on_quit)
        self.quit_button.grid(column=2, row=3, columnspan=2)

        self.answer_frame = ttk.LabelFrame(self, text='Answer', height=100)
        self.answer_frame.grid(column=0, row=4, columnspan=4, sticky='nesw')
            
        self.answer_label = ttk.Label(self.answer_frame, text='')
        self.answer_label.grid(column=0, row=0)

        ttk.Label(self, text='Number Adder').grid(column=0, row=0, columnspan=4)
        ttk.Label(self, text='Number One:').grid(column=0, row=2, sticky='w')
        ttk.Label(self, text='Number Two:').grid(column=2, row=2, sticky='w')

        ttk.Separator(self, orient='horizontal').grid(column=0, row=1, columnspan=4, sticky='ew')
        for child in self.winfo_children():
            child.grid_configure(padx=5, pady=5)

#if this is the main script
if __name__ == '__main__':
    root = tkinter.Tk()
    Adder(root)
    root.mainloop()