Maximize figures before saving - python-3.x

Question

The question about how to do maximize a window before saving has been asked several times and has several questions (still no one is portable, though), How to maximize a plt.show() window using Python
and How do you change the size of figures drawn with matplotlib?
I created a small function to maximize a figure window before saving the plots. It works with QT5Agg backend.
import matplotlib.pyplot as plt
def maximize_figure_window(figures=None, tight=True):
"""
Maximize all the open figure windows or the ones indicated in figures
Parameters
----------
figures: (list) figure numbers
tight : (bool) if True, applies the tight_layout option
:return:
"""
if figures is None:
figures = plt.get_fignums()
for fig in figures:
plt.figure(fig)
manager = plt.get_current_fig_manager()
manager.window.showMaximized()
if tight is True:
plt.tight_layout()
Problems:
I have to wait for the windows to be actually maximized before using the plt.savefig() command, otherwise it is saved with as not maximized. This is a problem if I simply want to use the above function in a script
(minor problems:)
2. I have to use the above function twice in order to get the tight_layout option working, i.e. the first time tight=True has no effect.
The solution is not portable. Of course I can add all the possible backend I might use, but that's kind of ugly.
Questions:
how to make the script wait for the windows to be maximized? I don't want to use time.sleep(tot_seconds) because tot_seconds would be kind of arbitrary and makes the function even less portable
how to solve problem 2 ? I guess it is related to problem 1.
is there a portable solution to "maximize all the open windows" problem?
-- Edit --
For problem 3. #DavidG suggestion sounds good. I use tkinter to automatically get width and height, convert them to inches, and use them in fig.set_size_inches or directly during the figure creation via fig = plt.figure(figsize=(width, height)).
So a more portable solution is, for example.
import tkinter as tk
import matplotlib.pyplot as plt
def maximize_figure(figure=None):
root = tk.Tk()
width = root.winfo_screenmmwidth() / 25.4
height = root.winfo_screenmmheight() / 25.4
if figure is not None:
plt.figure(figure).set_size_inches(width, height)
return width, height
where I allow the figure to be None so that I can use the function to just retrieve width and height and use them later.
Problem 1 is still there, though.
I use maximize_figure() in a plot function that I created (let's say my_plot_func()) but still the saved figure doesn't have the right dimensions when saved on file.
I also tried with time.sleep(5) in my_plot_func() right after the figure creation. Not working.
It works only if a manually run in the console maximize_figure() and then run my_plot_func(figure=maximized_figure) with the figure already maximized. Which means that dimension calculation and saving parameters are correct.
It does not work if I run in the console maximize_figure() and my_plot_func(figure=maximized_figure) altogether, i.e. with one call the the console! I really don't get why.
I also tried with a non-interactive backend like 'Agg', so that the figure doesn't get actually created on screen. Not working (wrong dimensions) no matter if I call the functions altogether or one after the other.
To summarize and clarify (problem 1):
by running these two pieces of code in console, figure gets saved correctly.
plt.close('all')
plt.switch_backend('Qt5Agg')
fig = plt.figure()
w, h = maximize_figure(fig.number)
followed by:
my_plot_func(out_file='filename.eps', figure=fig.number)
by running them together (like it would be in a script) figure is not saved correctly.
plt.close('all')
plt.switch_backend('Qt5Agg')
fig = plt.figure()
w, h = maximize_figure(fig.number)
my_plot_func(out_file='filename.eps', figure=fig.number)
Using
plt.switch_backend('Agg')
instead of
plt.switch_backend('Qt5Agg')
it does not work in both cases.