"""
Illustrate the figure and axes enter and leave events by changing the
frame colors on enter and leave
"""
import matplotlib.pyplot as plt


def enter_axes(event):
    print('enter_axes', event.inaxes)
    event.inaxes.patch.set_facecolor('yellow')
    event.canvas.draw()


def leave_axes(event):
    print('leave_axes', event.inaxes)
    event.inaxes.patch.set_facecolor('white')
    event.canvas.draw()


def enter_figure(event):
    print('enter_figure', event.canvas.figure)
    event.canvas.figure.patch.set_facecolor('red')
    event.canvas.draw()


def leave_figure(event):
    print('leave_figure', event.canvas.figure)
    event.canvas.figure.patch.set_facecolor('grey')
    event.canvas.draw()


fig, ax = plt.subplots()
fig.suptitle('mouse hover over figure or axes to trigger events')

ax.set_label('Level 0')
for i in range(4):
    ax = ax.inset_axes([0.2, 0.2, 0.6, 0.6])
    ax.set_label(f'Level {i+1}')

fig.canvas.mpl_connect('figure_enter_event', enter_figure)
fig.canvas.mpl_connect('figure_leave_event', leave_figure)
fig.canvas.mpl_connect('axes_enter_event', enter_axes)
fig.canvas.mpl_connect('axes_leave_event', leave_axes)

plt.show()

from matplotlib import pyplot as plt


def on_motion(event):
    inaxes = event.inaxes  # Depends on the actual inaxes semantics, of course.
    for ax in axs:
        ax.patch.set_facecolor("w")
    if inaxes:
        inaxes.patch.set_facecolor("y")
    event.canvas.draw()  # Could draw only if a change was actually made.


axs = []

fig, ax = plt.subplots()

ax.set_label('Level 0')
axs.append(ax)
for i in range(4):
    ax = ax.inset_axes([0.2, 0.2, 0.6, 0.6])
    ax.set_label(f'Level {i+1}')
    axs.append(ax)

fig.canvas.mpl_connect('motion_notify_event', on_motion)

plt.show()