TabularEditor's columns change

Hello,

I would like to change the TabularEditor's columns traits.

Here a CME, from Traits UI demos NumPy_array_tabular_editor_demo.py:

from numpy import sqrt
from numpy.random import random

from traits.api import HasTraits, Property, Array, String, Any
from traitsui.api import View, Item, TabularAdapter, TabularEditor, HGroup

class ArrayAdapter(TabularAdapter):

columns = [('i', 'index'), ('x', 0), ('y', 1), ('z', 2)]

font = 'Courier 10'
alignment = 'right'
format = '%.4f'

index_text = Property()
index_image = Property()

def _get_index_text(self):
return str(self.row)

def _get_index_image(self):
x, y, z = self.item
if sqrt((x - 0.5) ** 2 + (y - 0.5) ** 2 + (z - 0.5) ** 2) <= 0.25:
return '@icons:red_ball'

return None

class ShowArray(HasTraits):

data = Array

xlabel, ylabel, zlabel = String, String, String

adapter = Any

def traits_view(self):
view = View(
Item(
'data',
show_label=False,
editor=TabularEditor(
adapter=self.adapter,
auto_resize=True,
# Do not allow any kind of editing of the array:
editable=False,
operations=[],
drag_move=False,
),
),
HGroup(Item('xlabel'),
Item('ylabel'),
Item('zlabel')),
title='Array Viewer',
resizable=True,
)
return (view)

def _adapter_default(self):
return (ArrayAdapter())

def _xlabel_changed(self):
print(self.adapter.columns)
self.adapter.columns[1] = (self.xlabel, 0)
print(self.adapter.columns)

def _ylabel_changed(self):
print(self.adapter.columns)
self.adapter.columns[2] = (self.ylabel, 0)
print(self.adapter.columns)

def _zlabel_changed(self):
print(self.adapter.columns)
self.adapter.columns[3] = (self.zlabel, 0)

demo = ShowArray(data=random((5, 3)))

if __name__ == '__main__':
demo.configure_traits()

If I modify xlabel, self.adapter.columns is modified, ok, but not in the UI.

What am I doing wrong?

Thanks in advance for any help.

Regards.