Bug summary

_BackendTk.new_figure_manager_given_figure calls _c_internal_utils.Win32_SetProcessDpiAwareness_max, which affects the entire process attached to the script, and all windows part of it, rather than just the matplotlib output window.

Ideally, the DPI awareness context should only be changed for the current thread before a matplotlib window is drawn and returned to the previous value afterwards, or at the very least there should be an option to disable the DPI change.

Code for reproduction

# reproduces the bug when run on a high DPI display on Windows

import tkinter as tk
from tkinter import ttk

import matplotlib
matplotlib.use('TkAgg')  # in case other GUI libraries are installed
import matplotlib.pyplot as plt

root = tk.Tk()

button = ttk.Button(root, text="Run matplotlib.pyplot.subplots",
                    command=plt.subplots)
button.pack(padx=30, pady=30)

root.wait_window()  #root.mainloop seems to prevent DPI updates

Actual outcome

The scaling of the window changes.

Expected outcome

The scaling of the window shouldn't change just because subplots was called.

Additional information

Introduced in #19167

Operating system

Windows 10

Matplotlib Version

3.5.0

Matplotlib Backend

TkAgg

Python version

3.9.6

Jupyter version

No response

Installation

pip