# plotm1.py3   experiment with  matplotlib lines_text.py3
import numpy as np
from numpy import array
import matplotlib.pyplot as plt
import matplotlib.lines as lines
import matplotlib.transforms as mtransforms
import matplotlib.text as mtext


class MyLine(lines.Line2D):
  def __init__(self, *args, **kwargs):
    # we'll update the position when the line data is set
    self.text = mtext.Text(0, 0, '')
    lines.Line2D.__init__(self, *args, **kwargs)
    # we can't access the label attr until *after* the line is inited
    self.text.set_text(self.get_label())

  def set_figure(self, figure):
    self.text.set_figure(figure)
    lines.Line2D.set_figure(self, figure)

  def set_axes(self, axes):
    self.text.set_axes(axes)
    lines.Line2D.set_axes(self, axes)

  def set_transform(self, transform):
    # 2 pixel offset
    texttrans = transform + mtransforms.Affine2D().translate(2, 2)
    self.text.set_transform(texttrans)
    lines.Line2D.set_transform(self, transform)

  def set_data(self, x, y):
    if len(x):
      self.text.set_position((x[-1], y[-1]))

    lines.Line2D.set_data(self, x, y)

  def draw(self, renderer):
    # draw my label at the end of the line with 2 pixel offset
    lines.Line2D.draw(self, renderer)
    self.text.draw(renderer)


print("plotm1.py3 running")
fig, ax = plt.subplots()
# x, y = np.random.rand(2, 20) # 20 seqments
npts = 10
x = array([(0.0) for j in range(npts)])
y = array([(0.0) for j in range(npts)])
x[0] = 0.1
x[1] = 0.2
x[2] = 0.7
x[3] = 0.8
x[4] = 0.9
x[5] = 0.3
x[6] = 0.4
x[7] = 0.5
x[8] = 0.6
x[9] = 0.6
y[0] = 0.1
y[1] = 0.2
y[2] = 0.3
y[3] = 0.4
y[4] = 0.5
y[5] = 0.9
y[6] = 0.8
y[7] = 0.7
y[8] = 0.6
y[9] = 0.6
print("x=",x)
print("y=",y)
line = MyLine(x, y, mfc='green', ms=12, label='line label')
#line.text.set_text('new label')
line.text.set_color('red')
line.text.set_fontsize(20)
ax.add_line(line)
plt.title('line text plot1.py3')
plt.xlabel('X axis')
plt.ylabel('Y axis')

plt.show()
print("plotm1.py3 finished")