Problem with split panel on Mac

[kolibril13]

In JLab Version 4.1.8, on Mac I get a bug when running the below script:

from ipylab import JupyterFrontEnd, SplitPanel
from ipywidgets import IntSlider

app = JupyterFrontEnd()

split_panel = SplitPanel()

slider_ctrl = IntSlider(min=0, max=100, step=1, description='Slider Control:',)


# add the widgets to the split panel
split_panel.children = [
    slider_ctrl
]

app.shell.add(split_panel, 'main', { 'mode': 'split-right' })
split_panel

split_panel.title.label = 'A SplitPanel'
split_panel.title.icon_class = 'jp-PythonIcon'
split_panel.title.closable = True
split_panel.orientation = 'vertical'

The panel just stays grey when I run the script.
Only when I move the panel to the left or when I zoom in and out the widget appears.

That happens both in google chrome and in safari on local jupyter.

Screen.Recording.2024-06-06.at.22.48.33.mov

Interestingly, this bug does not occur when running this script on https://ipylab.readthedocs.io/en/latest/lite/lab/?path=widgets.ipynb

[shb84]

Just echoing the same experience on Mac (widget only appears after zooming in/out). In addition, there seems to be an inconsistency with where the first widget in children is displayed. With split-bottom the widget is displayed where one would expect but, with split-right, it is incorrectly displayed (see below).

[psychemedia]

In Chrome on a Mac, JL 4.1.8, trying to render the simple slider widget in a panel of its own as per the demo fails for me:

The "render into the top bar" seems to work okay.

[jtpio]

We looked at this issue with @kolibril13 today during the PyData Paris 2024 sprints.

I can also reproduce it locally with JupyterLab 4 on Ubuntu in Chrome:

ipylab-splitpanel-issue.webm

But it seems to be working fine with JupyterLab 3. So it's likely caused by a change in JupyterLab 4, or in Lumino 2 (since JupyterLab 4 uses Lumino 2), that we would need to handle here in ipylab.