"""
legend - Plot a legend.
"""
import io
from pygmt._typing import PathLike
from pygmt.clib import Session
from pygmt.exceptions import GMTInvalidInput
from pygmt.helpers import (
build_arg_list,
data_kind,
fmt_docstring,
is_nonstr_iter,
kwargs_to_strings,
use_alias,
)
@fmt_docstring
@use_alias(
R="region",
J="projection",
D="position",
F="box",
V="verbose",
c="panel",
p="perspective",
t="transparency",
)
@kwargs_to_strings(R="sequence", c="sequence_comma", p="sequence")
def legend(
self,
spec: PathLike | io.StringIO | None = None,
position="JTR+jTR+o0.2c",
box="+gwhite+p1p",
**kwargs,
):
r"""
Plot a legend.
Makes legends that can be overlaid on maps. Reads specific
legend-related information from an input file, or automatically creates
legend entries from plotted symbols that have labels. Unless otherwise
noted, annotations will be made using the primary annotation font and
size in effect (i.e., :gmt-term:`FONT_ANNOT_PRIMARY`).
Full option list at :gmt-docs:`legend.html`
{aliases}
Parameters
----------
spec
The legend specification. It can be:
- ``None`` which means using the automatically generated legend specification
file
- Path to the legend specification file
- A :class:`io.StringIO` object containing the legend specification
See :gmt-docs:`legend.html` for the definition of the legend specification.
{projection}
{region}
position : str
[**g**\|\ **j**\|\ **J**\|\ **n**\|\ **x**]\ *refpoint*\
**+w**\ *width*\ [/*height*]\ [**+j**\ *justify*]\ [**+l**\ *spacing*]\
[**+o**\ *dx*\ [/*dy*]].
Define the reference point on the map for the
legend. By default, uses **JTR**\ **+jTR**\ **+o**\ 0.2c which
places the legend at the top-right corner inside the map frame, with a
0.2 cm offset.
box : bool or str
[**+c**\ *clearances*][**+g**\ *fill*][**+i**\ [[*gap*/]\ *pen*]]\
[**+p**\ [*pen*]][**+r**\ [*radius*]][**+s**\ [[*dx*/*dy*/][*shade*]]].
If set to ``True``, draw a rectangular border around the legend
using :gmt-term:`MAP_FRAME_PEN`. By default, uses
**+g**\ white\ **+p**\ 1p which draws a box around the legend using a
1p black pen and adds a white background.
{verbose}
{panel}
{perspective}
{transparency}
"""
self._activate_figure()
if kwargs.get("D") is None:
kwargs["D"] = position
if kwargs.get("F") is None:
kwargs["F"] = box
kind = data_kind(spec)
if kind not in {"empty", "file", "stringio"}:
msg = f"Unrecognized data type: {type(spec)}"
raise GMTInvalidInput(msg)
if kind == "file" and is_nonstr_iter(spec):
msg = "Only one legend specification file is allowed."
raise GMTInvalidInput(msg)
with Session() as lib:
with lib.virtualfile_in(data=spec, required=False) as vintbl:
lib.call_module(module="legend", args=build_arg_list(kwargs, infile=vintbl))