PR Summary

TextBox now checks for both return and enter to check for submission. On my system:

Thinkpad T490
PopOs 20.04 
5.8.0-7630-generic #32~1605108853~20.04~8bcf10e-Ubuntu SMP Wed Nov 11 22:42:16 UTC  x86_64 x86_64 x86_64 GNU/Linux

Hitting the key silkscreend as labelled Enter produces a KeyEvent with event.key of return

You can check this on your system with:

import matplotlib.pyplot as plt
fig, ax = plt.subplots()
def _keypress(event):
    print(event)
    print(event.key)
fig.canvas.mpl_connect('key_press_event', _keypress)
plt.show()

PR Checklist

• Has pytest style unit tests (and pytest passes).
• Is Flake 8 compliant (run flake8 on changed files to check).
• [NA ] New features are documented, with examples if plot related.
• [NA ] Documentation is sphinx and numpydoc compliant (the docs should build without error).
• Conforms to Matplotlib style conventions (install flake8-docstrings and run flake8 --docstring-convention=all).
• [NA ] New features have an entry in doc/users/next_whats_new/ (follow instructions in README.rst there).
• [NA ] API changes documented in doc/api/next_api_changes/ (follow instructions in README.rst there).