PR Summary

SpanSelector with the option span_stay will leave the span on the plot. However, when a button is pressed without moving the min max value is equal but the span stays the same. This PR reset the span coordinates in onpress event.

from pylab import *
from matplotlib.widgets import SpanSelector

x = arange(100)/(99.0)
y = sin(x)
fig = figure
ax = subplot(111)
ax.plot(x,y)

span = SpanSelector(ax, print, useblit=True,
                    direction="horizontal", span_stays=True)
show()

PR Checklist

• Has Pytest style unit tests
• Code is PEP 8 compliant
• New features are documented, with examples if plot related
• Documentation is sphinx and numpydoc compliant
• Added an entry to doc/users/next_whats_new/ if major new feature (follow instructions in README.rst there)
• Documented in doc/api/api_changes.rst if API changed in a backward-incompatible way