"shared" interactive legend outside of plots

I built on a suggestion from Bryan to make a small example on how to make an interactive legend outside of the figure that can trigger visibility of lines in different plots, and can also handle new lines being added.

from bokeh.io import curdoc

from bokeh.plotting import figure

from bokeh.models import Button,Legend

from bokeh.layouts import gridplot, Column

from bokeh.palettes import Category20_20

from functools import partial

from random import random,choice

import numpy as np

doc = curdoc()


fig1 = figure(plot_width=250,plot_height=250)

fig1.renderers =

fig2 = figure(plot_width=250,plot_height=250)

fig2.renderers =

dum_fig = figure(plot_width=250,plot_height=500,outline_line_alpha=0)

legend = Legend(click_policy=‘hide’,border_line_alpha=0,location=‘top_left’)

dum_fig.renderers = [legend]

set a range of values that will not include any data

dum_fig.x_range.end = 1005

dum_fig.x_range.start = 1000

button = Button(label=“add a line”,width=100)

def add_line():

colo = choice(Category20_20)

randname = str(random())

line1 = fig1.line(x,[random() for i in x],color=colo,line_width=3,legend=randname)

line2 = fig2.line(x,[random() for i in x],color=colo,line_width=3)




def share_visible(attr,old,new,line1,line2):

line2.visible = line1.visible

def update_legend(line1):

leg1 = fig1.legend[0]

legend.items += leg1.items

dum_fig.renderers += [line1]

leg1.visible = False

fig1.renderers = [i for i in fig1.renderers if i!=leg1]

grid = gridplot([[button],[Column(fig1,fig2),dum_fig]],toolbar_location=None)