[Python] How to accurately pick/select cells in PyVista with single mouse click?

I'm trying to implement single-click cell selection in PyVista to get the correct cell index when clicking on a mesh.

I've tried using pv.Plotter().enable_cell_picking() but this has two issues: the first is that it seems to allow only rectangle selection and the callback is not returning a single cell, but an UnstructuredGrid object from which I can't extract the cell index.

I've also tried with enable_element_picking which allows for a single cell selection, but still return an UnstructuredGrid object.

Here is a simple example to reproduce the problem

import pyvista as pv
import numpy as np

pl = pv.Plotter()
mesh = pv.Sphere()
mesh.cell_data['colors'] = np.ones(mesh.n_cells) * 0
pl.add_mesh(mesh, show_edges=True, scalars='colors',)

def my_callback(picked_cell):
"""
Callback function to print the cell index.
This function is triggered when a cell is picked.
"""
cell_index = picked_cell.index
mesh.cell_data['colors'][:] = 0
mesh.cell_data['colors'][cell_index] = 1

pl.update()
print(f"You clicked on cell index: {cell_index}")

pl.enable_element_picking(
callback=my_callback,
mode='cell',
picker='cell',
)
pl.show()

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