No good way to disable SpanSelector

[LindyBalboa]

1.5.1 Python3.5

So it seems SpanSelector has no built in method to shut down. The docs say "For the selector to remain responsive you must keep a reference to it." but even without a reference, the behavior persists. I attempted doing a del spanSelector but the behavior persisted.

The docs suggest doing spanSelector.set_visible(False) but in order to turn it back on again, one must use spanSelector.set_visible(True). This automatically shows the last selected span, which is probably not a desirable default behavior.

from matplotlib import pyplot as plt
import matpltotlib

ax = plt.subplot(111)
def onSelect(m,n):
    print(m,n)
s = matplotlib.widgets.SpanSelector(ax, onSelect, 'horizontal')
s.set_visible(False)
s.set_visible(True)

[LindyBalboa]

It seems it inherits through _SelectorWidget and AxesWidget an active attribute which when set to False will completely turn off the widget through the ignore method. Should a setter method be added or only make mention of the attribute in the docs?

Otherwise, I still don't understand why the operates if the widget is deleted.

[tacaswell]

Just document that setting w.active = False is enough to disable it.

We are (long term) planning to move away from all the get_ and set_ methods to properties/traitlets.

Are you sure something else does not keep a reference to it? It only goes away if it gets garbage collected (as the callbacks only hold a weakref to it). It is also possible that SpanSelector (unlike the other widgets) inserts a reference to it's self. If so, that should be tracked down an fixed.

The widgets are sorely under documented.

Also see #5786