Propagate loc="best" down to AnchoredOffsetbox?

[jklymak]

Folks often want a way to automatically place text, but not use a legend (#4489, #1313), but attempts to implement this have not passed muster (#12841)

As pointed out by @ImportanceofBeeingEarnest one way to make this more constrained is to use AnchoredOffsetbox which legend already uses, and just propagate the legend logic to the parent class. The folks could put their text or other annotations in this box.

@andrzejnovak I think what you're asking for is rather a loc="best" option for AnchoredOffsetbox, such that one could write AnchoredText("my text", loc="best"). This is very different from what this PR suggested, and most concerns raised here would not even apply.

Originally posted by @ImportanceOfBeingErnest in #12841 (comment)

[codeananda]

Could something like this answer by Chipmuenk do the trick?

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.patches as mpl_patches

x = np.linspace(-1,1)
fig, ax = plt.subplots()
ax.plot(x, x*x)

labels = [
    "pi = {0:.4g}".format(np.pi),
    "root(2) = {0:.4g}".format(np.sqrt(2))
]

# create a list with as many empty handles as labels
handles = [mpl_patches.Rectangle((0, 0), 1, 1, fc="white", ec="white", 
                                 lw=0, alpha=0)] * len(labels)

# create the legend, supressing the blank space of the empty line symbol and the
# padding between symbol and label by setting handlelenght and handletextpad
ax.legend(handles, labels, loc='best', fontsize='small', 
          fancybox=True, framealpha=0.7, 
          handlelength=0, handletextpad=0)
plt.show()

[timhoffm]

Could something like this answer by Chipmuenk do the trick?

Abusing legend as a simple list of texts is a hacking workaround. It may solve the problem for a certain subset of cases if users really need this capability in current versions of matplotlib. However, it cannot be an officially recommended way of working.

[codeananda]

Yes it is a hack. But it's the only one that gives you the option to use loc='best', right?

[timhoffm]

But it's the only one that gives you the option to use loc='best', right?

Yes, as long as this issue is not implemented it's the only option. But it's not the general solution needed to implement this issue.