Tabs re-ordering hides internal widgets

[DiegoF90]

Description

When re ordering the children of a Tab widget (i.e. the tabs) any internal ipywidget is hidden. This behaviour does not happen in e.g. Jupyter Notebook.

Reproduce

The following is a minimal reproducible example:

from ipywidgets import Label, Output, Tab, Button
o1 = Output()
with o1:
    display(Label("1"))
o2 = Output()
with o2:
    display(Label("2"))
tabs = Tab(children=[o1, o2])
display(tabs)
btn = Button(description='switch')
def switch(_):
    tabs.children = [o2, o1]
btn.on_click(switch)
display(btn)

When clicking on button "switch" it can be seen that the Label "1" and "2" both disappear. This does not happen when doing the same in Jupyter Notebook.

Expected behavior

Labels should not disappear.

Context

• voila version: 0.4.0
• Operating System: Windows
• Browser: Google Chrome

Troubleshoot Output

(env_local) PS C:\dev> jupyter troubleshoot
sys.executable:

~\env_local\scripts\python.exe
sys.version:

3.11.7 (main, Jan 11 2024, 15:05:28) [MSC v.1927 64 bit (AMD64)]
platform.platform():

Windows-10-10.0.19045-SP0
where jupyter:

~\env_local\Scripts\jupyter.exe
pip list:

Package                       Version

----------------------------- --------------

accessible-pygments           0.0.4

aiosqlite                     0.19.0

alabaster                     0.7.13

alembic                       1.13.1

annotated-types               0.6.0

ansi2html                     1.8.0

anyio                         3.6.2

appdirs                       1.4.4

argon2-cffi                   21.3.0

argon2-cffi-bindings          21.2.0

astroid                       3.1.0

asyncpg                       0.28.0

attrs                         23.1.0

Babel                         2.12.1

backcall                      0.2.0

backoff                       2.2.1

beautifulsoup4                4.12.2

bleach                        6.0.0

blinker                       1.6.2

cachelib                      0.9.0

cachetools                    5.3.0

caf                           1.1.4

caf-version                   999.0

certifi                       2023.5.7

cffi                          1.16.0

cfgv                          3.4.0

chardet                       3.0.4

charset-normalizer            3.1.0

click                         8.1.3

clr-loader                    0.2.5

colorama                      0.4.6

comtypes                      1.1.14

ConfigArgParse                1.5.3

contourpy                     1.0.7

coverage                      7.4.4

cryptography                  42.0.5

cssselect                     1.2.0

cvxpy                         1.3.1

cycler                        0.11.0

dash                          2.9.3

dash-ag-grid                  2.3.0

dash-bootstrap-components     1.3.1

dash-core-components          2.0.0

dash-extensions               1.0.0

dash-html-components          2.0.0

dash-mantine-components       0.12.1

dash-table                    5.0.0

databases                     0.8.0

DateTime                      5.1

debugpy                       1.6.7

decorator                     5.1.1

defusedxml                    0.7.1

deprecation                   2.1.0

dill                          0.3.8

diskcache                     5.6.1

distlib                       0.3.6

docutils                      0.20.1

ecos                          2.0.12

EditorConfig                  0.12.3

eikon                         1.1.16

entrypoints                   0.4

et-xmlfile                    1.1.0

fastapi                       0.103.0

fastjsonschema                2.16.3

filelock                      3.12.0

Flask                         2.3.2

Flask-Caching                 2.0.2

Flask-Cors                    3.0.10

fonttools                     4.39.4

freetype-py                   2.3.0

freezegun                     1.2.2

graypy                        2.1.0

greenlet                      2.0.2

grpcio                        1.54.2

grpcio-tools                  1.54.2

h11                           0.14.0

h2                            3.2.0

hpack                         3.0.0

httpcore                      0.17.1

httpx                         0.24.0

hyperframe                    5.2.0

identify                      2.5.35

idna                          2.10

imagesize                     1.4.1

importlib-metadata            6.6.0

importlib-resources           5.12.0

iniconfig                     2.0.0

ipyaggrid                     0.5.1

ipykernel                     6.2.0

ipysheet                      0.7.0

ipython                       7.34.0

ipython-genutils              0.2.0

ipytree                       0.2.2

ipywidgets                    8.0.2

isort                         5.13.2

itsdangerous                  2.1.2

jedi                          0.18.2

Jinja2                        3.1.2

joblib                        1.2.0

jsbeautifier                  1.14.7

json5                         0.9.14

jsonschema                    4.17.3

jupyter                       1.0.0

jupyter_client                7.4.1

jupyter-console               6.4.4

jupyter_core                  5.3.0

jupyter-dash                  0.4.2

jupyter-server                1.24.0

jupyterlab-pygments           0.2.2

jupyterlab_server             2.22.1

jupyterlab-widgets            3.0.7

jupytext                      1.14.5

kaleido                       0.2.1

kiwisolver                    1.4.4

llvmlite                      0.40.0

lxml                          4.9.2

Mako                          1.2.4

markdown-it-py                2.2.0

MarkupSafe                    2.1.2

matplotlib                    3.6.3

matplotlib-inline             0.1.6

mccabe                        0.7.0

mdit-py-plugins               0.3.5

mdurl                         0.1.2

mistune                       2.0.5

mock                          5.0.2

more-itertools                9.1.0

multidict                     6.0.5

multiprocess                  0.70.15

mypy                          1.9.0

mypy-extensions               1.0.0

nbclassic                     1.0.0

nbclient                      0.7.4

nbconvert                     7.4.0

nbformat                      5.8.0

nest-asyncio                  1.5.6

nodeenv                       1.8.0

nose                          1.3.7

notebook                      6.5.4

notebook_shim                 0.2.3

numba                         0.57.0

numexpr                       2.8.4

numpy                         1.23.5

openpyxl                      3.1.2

ordered-set                   4.1.0

osqp                          0.6.2.post9

packaging                     24.0

pandas                        1.5.3

pandocfilters                 1.5.0

parameterized                 0.9.0

parso                         0.8.3

patsy                         0.5.3

pdfrw                         0.4

pickleshare                   0.7.5

Pillow                        9.5.0

pip                           24.0

pip-system-certs              4.0

platformdirs                  3.2.0

plotly                        5.14.1

pluggy                        1.4.0

pre-commit                    3.6.2

pretty-html-table             0.9.16

prometheus-client             0.16.0

prompt-toolkit                3.0.38

protobuf                      4.23.1

psutil                        5.9.5

psycopg2-binary               2.9.6

pyasn1                        0.5.0

pycairo                       1.23.0

pycountry                     22.3.5

pycparser                     2.21

pydantic                      2.5.3

pydantic_core                 2.14.6

pydantic-settings             2.0.3

pydata-sphinx-theme           0.13.3

pydocstyle                    6.3.0

pyee                          11.1.0

Pygments                      2.15.1

pyhumps                       3.8.0

pyjnius                       1.5.0

PyLaTeX                       1.4.1

pylint                        3.1.0

PyMySQL                       1.1.0

pyparsing                     3.0.9

pyrsistent                    0.19.3

pysmb                         1.2.9.1

pytest                        8.1.1

pytest-asyncio                0.23.6

pytest-mock                   3.14.0

pytest-recording              0.13.1

python-dateutil               2.8.2

python-dotenv                 1.0.0

pythonnet                     3.0.1

pytz                          2023.3

pyvar                         1.1.0

pywin32                       306

pywinpty                      2.0.10

PyYAML                        6.0.1

pyzmq                         25.0.2

qdldl                         0.1.7

qPython3                      1.0.1

qtconsole                     5.4.3

QtPy                          2.3.1

redis                         4.5.5

refinitiv-data                1.6.1

reportlab                     4.0.0

requests                      2.30.0

retrying                      1.3.4

rfc3986                       1.5.0

rlPyCairo                     0.2.0

schedule                      1.2.0

scikit-learn                  1.2.2

scipy                         1.9.3

scs                           3.2.3

seaborn                       0.12.2

Send2Trash                    1.8.2

setuptools                    65.5.0

simplejson                    3.19.1

six                           1.16.0

sniffio                       1.3.0

snowballstemmer               2.2.0

sobol-seq                     0.2.0

soupsieve                     2.4.1

Sphinx                        7.0.1

sphinxcontrib-applehelp       1.0.4

sphinxcontrib-devhelp         1.0.2

sphinxcontrib-htmlhelp        2.0.1

sphinxcontrib-jsmath          1.0.1

sphinxcontrib-qthelp          1.0.3

sphinxcontrib-serializinghtml 1.1.5

SQLAlchemy                    1.4.49

starlette                     0.27.0

statsmodels                   0.14.0

suds                          1.1.2

svn                           1.0.1

teamcity-messages             1.31

tenacity                      8.2.2

terminado                     0.17.1

threadpoolctl                 3.1.0

tinycss2                      1.2.1

toml                          0.10.2

tomlkit                       0.12.4

tornado                       6.3.2

tqdm                          4.65.0

traitlets                     5.9.0

typeguard                     4.2.1

types-beautifulsoup4          4.12.0.20240229

types-cachetools              5.3.0.7

types-decorator               5.1.8.20240310

types-html5lib                1.1.11.20240228

types-lxml                    2024.4.14

types-protobuf                4.24.0.20240311

types-pyOpenSSL               24.0.0.20240311

types-python-dateutil         2.9.0.20240316

types-pytz                    2024.1.0.20240203

types-PyYAML                  6.0.12.20240311

types-redis                   4.6.0.20240311

types-requests                2.31.0.6

types-setuptools              69.2.0.20240317

types-simplejson              3.19.0.20240310

types-urllib3                 1.26.25.14

typing_extensions             4.10.0

tzdata                        2024.1

urllib3                       1.26.18

vcrpy                         6.0.1

virtualenv                    20.22.0

voila                         0.4.0

watchdog                      2.3.1

wcwidth                       0.2.6

webencodings                  0.5.1

websocket-client              1.5.1

websockets                    11.0.3

Werkzeug                      2.3.4

wheel                         0.43.0

wheel-filename                1.4.1

widgetsnbextension            4.0.7

winshares                     1.0.2

wrapt                         1.16.0

xlrd                          2.0.1

XlsxWriter                    3.1.0

xlwings                       0.11.5

yarl                          1.9.4

zipp                          3.15.0

zope.interface                6.0