Getting mouse coordinates from click on heatmap

[JohnMrziglod]

Hi,

I try to get the clicked coordinate on a HeatMap. Unfortunately, neither does on_click, on_element_click or on_background_click seem to work (see example below).

import numpy as np
from bqplot import (Figure, LinearScale, ColorScale, 
                    Color, Axis, HeatMap, ColorAxis)
from ipywidgets import Label, Layout

def print_event(*args, **kwargs):
    print("test!")

x = np.linspace(-5, 5, 200)
y = np.linspace(-5, 5, 200)
X, Y = np.meshgrid(x, y)
color = np.cos(X**2 + Y**2)

x_sc, y_sc, col_sc = LinearScale(), LinearScale(), ColorScale(scheme='RdYlBu')
heat = HeatMap(x=x, y=y, color=color,
               scales={'x': x_sc, 'y': y_sc, 'color': col_sc})

# It doesn't matter which event to catch, none of them fires print_event
heat.on_hover(print_event)
heat.on_element_click(print_event)
heat.on_click(print_event)
heat.on_background_click(print_event)

ax_x = Axis(scale=x_sc)
ax_y = Axis(scale=y_sc, orientation='vertical')
ax_c = ColorAxis(scale=col_sc)
fig = Figure(marks=[heat], axes=[ax_x, ax_y, ax_c],
             title='Cosine',
             layout=Layout(width='650px', height='650px'),
             min_aspect_ratio=1, max_aspect_ratio=1, padding_y=0)

Do I miss something? Or is there another way to get the mouse position when a user clicks on a point in my heatmap?
I tried the solution from #973 but without success, no events were triggered.

[gerazov]

Also stuck ...

Found this for GridHeatMap but it doesn't work, i.e. the callback is not triggered ...
https://uiuc-ischool-dataviz.github.io/is445_spring2021/nbv.html?notebook_name=%2Fis445_spring2021%2Fweek05%2Fprep_notebook_week05.ipynb

# 4. Marks -- lets now re-do our heat map & add in some interactivity:
heat_map = bqplot.GridHeatMap(color = data,
                              scales = {'color': col_sc,
                                        'row': y_sc,
                                        'column': x_sc},
                              interactions = {'click': 'select'}, # make interactive on click of each box
                              anchor_style = {'fill':'blue'}, # to make our selection blue
                              selected_style = {'opacity': 1.0}, # make 100% opaque if box is selected
                              unselected_style = {'opacity': 0.8}) # make a little see-through if not

heat_map.observe(on_selected, 'selected')
def on_selected(change):
    print(change['owner'].selected)