Embedding in GTK3 with a navigation toolbar

Demonstrate NavigationToolbar with GTK3 accessed via pygobject.

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk

from matplotlib.backends.backend_gtk3 import (
    NavigationToolbar2GTK3 as NavigationToolbar)
from matplotlib.backends.backend_gtk3agg import (
    FigureCanvasGTK3Agg as FigureCanvas)
from matplotlib.figure import Figure
import numpy as np

win = Gtk.Window()
win.connect("delete-event", Gtk.main_quit)
win.set_default_size(400, 300)
win.set_title("Embedding in GTK3")

fig = Figure(figsize=(5, 4), dpi=100)
ax = fig.add_subplot(1, 1, 1)
t = np.arange(0.0, 3.0, 0.01)
s = np.sin(2*np.pi*t)
ax.plot(t, s)

vbox = Gtk.VBox()
win.add(vbox)

# Add canvas to vbox
canvas = FigureCanvas(fig)  # a Gtk.DrawingArea
vbox.pack_start(canvas, True, True, 0)

# Create toolbar
toolbar = NavigationToolbar(canvas)
vbox.pack_start(toolbar, False, False, 0)

win.show_all()
Gtk.main()