Bug report

The following code example uses the RectangleSelector widget, so that we should see a continuously updated rectangular patch over the plot. However, nothing can be seen, unless we set useblit=False.

Code for reproduction

#!/usr/bin/env python3

import matplotlib
from matplotlib.widgets import RectangleSelector

if __name__ == '__main__':
    matplotlib.use('wxagg')
    import matplotlib.pyplot as plt
    figure = plt.figure()
    rect = RectangleSelector(figure.gca(), (lambda e1, e2: print(e1, e2)), useblit=True)
    plt.show()

Matplotlib version

• Operating system: ubuntu 17.10
• Matplotlib version: 2.2.2
• Matplotlib backend: wxagg
• Python version: 3.6.3
• Other libraries: wxpython 4.0.1

Everything was installed from virtualenv + pip.