"""
==============
BboxImage Demo
==============

A `~matplotlib.image.BboxImage` can be used to position an image according to
a bounding box. This demo shows how to show an image inside a `.text.Text`'s
bounding box as well as how to manually create a bounding box for the image.
"""
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.image import BboxImage
from matplotlib.transforms import Bbox, TransformedBbox


fig, (ax1, ax2) = plt.subplots(ncols=2)

# ----------------------------
# Create a BboxImage with Text
# ----------------------------
txt = ax1.text(0.5, 0.5, "test", size=30, ha="center", color="w")
kwargs = dict()

bbox_image = BboxImage(txt.get_window_extent,
                       norm=None,
                       origin=None,
                       clip_on=False,
                       **kwargs
                       )
a = np.arange(256).reshape(1, 256)/256.
bbox_image.set_data(a)
ax1.add_artist(bbox_image)

# ------------------------------------
# Create a BboxImage for each colormap
# ------------------------------------
a = np.linspace(0, 1, 256).reshape(1, -1)
a = np.vstack((a, a))

# List of all colormaps; skip reversed colormaps.
cmap_names = sorted(m for m in plt.colormaps if not m.endswith("_r"))

ncol = 2
nrow = len(cmap_names) // ncol + 1

xpad_fraction = 0.3
dx = 1 / (ncol + xpad_fraction * (ncol - 1))

ypad_fraction = 0.3
dy = 1 / (nrow + ypad_fraction * (nrow - 1))

for i, cmap_name in enumerate(cmap_names):
    ix, iy = divmod(i, nrow)

    bbox0 = Bbox.from_bounds(ix*dx*(1 + xpad_fraction),
                             1. - iy*dy*(1 + ypad_fraction) - dy,
                             dx, dy)
    bbox = TransformedBbox(bbox0, ax2.transAxes)

    bbox_image = BboxImage(bbox,
                           cmap=cmap_name,
                           norm=None,
                           origin=None,
                           **kwargs
                           )

    bbox_image.set_data(a)
    ax2.add_artist(bbox_image)

plt.show()

#############################################################################
#
# .. admonition:: References
#
#    The use of the following functions, methods, classes and modules is shown
#    in this example:
#
#    - `matplotlib.image.BboxImage`
#    - `matplotlib.transforms.Bbox`
#    - `matplotlib.transforms.TransformedBbox`
#    - `matplotlib.text.Text`
