# -*- coding: utf-8 -*-
"""
Created on Mon Jul  8 12:24:07 2019

@author: finnh

https://matplotlib.org/gallery/widgets/textbox.html#sphx-glr-gallery-widgets-textbox-py

"""

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import TextBox

# Function for updating plot for new value of param a:
def fun_submit_a(dummy_arg):
    a = eval(text_box_a.text)
    b = eval(text_box_b.text)
    y_array = a*x_array + b
    line_1.set_ydata(y_array)
#    ax.set_ylim(np.min(y_array), np.max(y_array))
    plt.draw()

# Function for updating plot for new value of param b:
def fun_submit_b(dummy_arg):
    a = eval(text_box_a.text)
    b = eval(text_box_b.text)
    y_array = a*x_array + b
    line_1.set_ydata(y_array)
#    ax.set_ylim(np.min(y_array), np.max(y_array))
    plt.draw()
    
# Opening new figure with one positioned plot
plt.close('all')
fig_width_inch = 24/2.54
fig_height_inch = 18/2.54
(fig, ax) = plt.subplots(num='Interactive plot',
                       figsize=(fig_width_inch, fig_height_inch))
left=0.125; bottom=0.3; right=0.9; top=0.9
plt.subplots_adjust(left, bottom, right, top)
plt.ylim(-2, 2)

# Generating and plotting y_array using initial values of a and b:
x_array = np.arange(0.0, 2.0, 0.001)
a = 1
b = 0
y_array = a*x_array + b
line_1, = plt.plot(x_array, y_array)
plt.grid(which='both', color='grey')

# Generating textboxes for a and b:
left_a=0.1; bottom_a=0.15; width_a=0.1; height_a=0.05
left_b=0.1; bottom_b=0.05; width_b=0.1; height_b=0.05
axbox_a = plt.axes([left_a, bottom_a, width_a, height_a])
axbox_b = plt.axes([left_b, bottom_b, width_b, height_b])
caption_a = 'a = '
caption_b = 'b = '
initial_text_a = "1.0"
initial_text_b = "0.0"
text_box_a = TextBox(axbox_a, caption_a, initial_text_a)
text_box_b = TextBox(axbox_b, caption_b, initial_text_b)

# Detecting click on Enter button of a or b:
# Invoking function fun_submit_a() on click:
text_box_a.on_submit(fun_submit_a)
# Invoking function fun_submit_b() on click:
text_box_b.on_submit(fun_submit_b)

plt.show()

#a = 1 og b = 0:
#plt.savefig('prog_interaktivt_plott_tekstboks1.pdf')
#a = -1 og b = 1:
#plt.savefig('prog_interaktivt_plott_tekstboks2.pdf')