Bug summary

Using matplotlib backend for a navigation toolbar in tkinter with grid package manager gives the error:

_tkinter.TclError: cannot use geometry manager pack inside .!frame which already has slaves managed by grid

One should be able to use either package managers pack or grid ideally.

Code for reproduction

import tkinter
import tkinter as tk
from mpl_toolkits.mplot3d import Axes3D
from mpl_toolkits.mplot3d import proj3d
from matplotlib.backends.backend_tkagg import (
                                    FigureCanvasTkAgg, NavigationToolbar2Tk)

window = tkinter.Tk()
window.wm_title("MRI in Tk")
frame = ttk.Frame(window)
frame.grid(row=0, column=0, sticky="nsew")
fig = Figure(figsize=(8,8))
pc_label = FigureCanvasTkAgg(fig, master=frame)
pc_label.get_tk_widget().grid(row=0, column=1)
pc_toolbar_label = NavigationToolbar2Tk(pc_label, frame)
pc_toolbar_label.grid(row=0, column=1, sticky="s")

Actual outcome

Traceback (most recent call last):
  File "/home/varora/PythonProjects/gui/tmp.py", line 16, in <module>
    pc_toolbar_label = NavigationToolbar2Tk(pc_label, frame)
  File "/home/varora/anaconda3/envs/nnunet_venv/lib/python3.10/site-packages/matplotlib/backends/_backend_tk.py", line 657, in __init__
    self.pack(side=tk.BOTTOM, fill=tk.X)
  File "/home/varora/anaconda3/envs/nnunet_venv/lib/python3.10/tkinter/__init__.py", line 2425, in pack_configure
    self.tk.call(
_tkinter.TclError: cannot use geometry manager pack inside .!frame which already has slaves managed by grid

Expected outcome

Additional information

This script uses a matplotlib backend for tkinter for displaying the navigation toolbar which natively implements
the package manager pack() for tkinter. Since we use grid() package manager, this creates a conflict and hence
you need to change the Line: 657 in [PYTHON-DIR]/site-packages/matplotlib/backends/_backend_tk.py.

One should be able to use either package managers ideally.

Operating system

Ubuntu

Matplotlib Version

3.7.2

Matplotlib Backend

module://backend_interagg

Python version

3.10

Jupyter version

No response

Installation

pip