How to position a topside relative to another widget with and without titlebar

topside_position.py

import tkinter as tk
from tkinter import ttk

"""
    The demo shows how to position a topside window relative to a button widget from multiple directions. The purpose
    is to show that one could theoretically create a custom menu from a toplevel that could be positioned correctly
    aligned to the parent widget with and without a titlebar.

    The problem with positioning a topside relative to another widget is due to the fact that, normally, window
    decorations are added to the window. This adds additional horizontal a vertical space that is not accounted for in
    the screen coordinates calculated by `winfo_rootx` and `winfo_x`. However, using these two measurements together,
    you can calculate the amount of space allocated to the borders and titlebar and adjust your screen position
    accordingly with these offsets.

    The calculate the offset of the x and y position by taking `winfo_x/y` - `winfo_rootx/y`. This difference is then
    added to the x or y position to adjust for the border and titlebar depending on how you want the topside aligned to
    the parent.
"""

class Application(tk.Tk):

    def __init__(self, show_menu_titlebar=False):
        super().__init__()
        self.title('Custom Menu Demo')
        self.geometry('+500+500')
        self.style = ttk.Style()
        self.style.theme_use('clam')
        self.style.configure('menu.TFrame', relief='raised')
        self.frame = ttk.Frame(self, padding=20)
        self.frame.pack()

        ttk.Label(self.frame, text='Choose a direction and push the button').pack()

        values = ['wn','ws','sw','se','es','en','ne','nw']
        self.cbo = ttk.Combobox(self.frame, values=values, foreground='black')
        self.cbo.current(0)
        self.cbo.pack(fill=tk.X, padx=10, pady=10)

        self.titlevar = tk.BooleanVar(value=show_menu_titlebar)
        self.show_titlebar = ttk.Checkbutton(self.frame, text="Show titlebar", variable=self.titlevar)
        self.show_titlebar.pack(padx=10, pady=10)
        
        self.mb = ttk.Button(self.frame, text='Show Menu', command=self.show_menu)
        self.mb.pack(fill=tk.X, padx=10, pady=30)

        self.top = tk.Toplevel()
        self.top.protocol('WM_DELETE_WINDOW', self.hide_menu)

        self.top.state('withdrawn')
        self.topframe = ttk.Frame(self.top, padding=5, style='menu.TFrame')
        self.topframe.pack(fill=tk.BOTH)

        self.option_var = tk.Variable(value=1)
        for x in range(5):
            b = ttk.Radiobutton(self.topframe, text=f'Option {x+1}', value=x, variable=self.option_var)
            b.configure(command=self.hide_menu)
            b.grid(row=x, sticky=tk.EW)

    def hide_menu(self):
        self.top.state('withdrawn')                        

    def show_menu(self):
        """Update the toplevel position and display"""
        # calculate offset for window decorations if not overrideredirect
        show_titlebar = bool(self.titlevar.get())
        if show_titlebar:
            self.top.overrideredirect(0)
            self.offset_x = self.winfo_x() - self.winfo_rootx()
            self.offset_y = self.winfo_y() - self.winfo_rooty()
        else:
            self.top.overrideredirect(1)
            self.offset_x = 0
            self.offset_y = 0

        self.top.state('normal') 
        direction = self.cbo.get()
        parent_x = self.mb.winfo_rootx()
        parent_y = self.mb.winfo_rooty()
        parent_height = self.mb.winfo_height()
        parent_width = self.mb.winfo_width()

        self.update_idletasks()
        top_width = self.top.winfo_width()
        top_height = self.top.winfo_height()
        self.top.focus()
        self.top.lift()

        if direction == 'wn':
            # West-North
            xpos = parent_x - top_width
            ypos = parent_y

        elif direction == 'ws':
            # West-South
            xpos = parent_x - top_width
            ypos = parent_y + parent_height - top_height + self.offset_y

        elif direction == 'sw':  # this is likely what is needed for option menu
            # South-West
            xpos = parent_x + self.offset_x
            ypos = parent_y + parent_height

        elif direction == 'se':
            # South-East
            xpos = parent_x + parent_width - top_width + self.offset_x
            ypos = parent_y + parent_height

        elif direction == 'es':
            # West-South
            xpos = parent_x + parent_width + self.offset_x
            ypos = parent_y + parent_height - top_height + self.offset_y

        elif direction == 'en':
            # East-North
            xpos = parent_x + parent_width + self.offset_x
            ypos = parent_y

        elif direction == 'ne':
            # North-East
            xpos = parent_x + parent_width - top_width + self.offset_x
            ypos = parent_y - top_height + self.offset_y
            
        elif direction == 'nw':
            # North-West
            xpos = parent_x + self.offset_x
            ypos = parent_y - top_height + self.offset_y

        self.top.geometry(f'+{xpos}+{ypos}')
        


if __name__ == '__main__':

    app = Application(show_menu_titlebar=False)
    app.mainloop()