Positron can't render progress bar powered by `ipywidgets`

[ZhimingYe]

System details:

Positron and OS details:

Positron Version: 2025.08.0 build 130
Code - OSS Version: 1.102.0
Commit: 76ddce5
Date: 2025-08-01T20:08:51.894Z
Electron: 35.6.0
Chromium: 134.0.6998.205
Node.js: 22.15.1
V8: 13.4.114.21-electron.0
OS: Darwin arm64 24.6.0

Session details:

-----
ipywidgets          8.1.7
positron            NA
session_info        v1.0.1
-----
-----
IPython             8.18.1
jupyter_client      8.6.3
jupyter_core        5.8.1
-----
Python 3.11.13 (main, Jun  5 2025, 13:12:00) [GCC 11.2.0]
Linux-6.8.0-51-generic-x86_64-with-glibc2.39
-----
Session information updated at 2025-08-28 12:43

Describe the issue:

Some Python packages, when developed, default to using the progress bars provided by ipywidgets if ipywidgets is present (some analysis package developers mainly use jupyter notebook previously in our research field (bioinformatics) seem rather obsessed with these kinds of progress bars). In such cases, Positron does not render these progress bars well. Normally, these progress bars should appear in the console rather than the plotting pane. At the same time, the plotting pane throws errors.

Although this is not an important issue, it can potentially lead to a poor user experience.

Steps to reproduce the issue:

import time
import ipywidgets as widgets
from IPython.display import display
import session_info
session_info.show()

progress = widgets.IntProgress(value=0, min=0, max=100, description='Progress:')
display(progress)

for i in range(101):
    progress.value = i
    time.sleep(5)

You can see the progress bar is rendered in FIGUREs rather than Console. In Figure window, Positron throw an error.

Expected or desired behavior:

[isabelizimm]

Thanks for letting us know about this! It looks like we have a similar issue at #284. Are you able to take a look to see if you agree and add a 👍 or additional info on your use case?

[ZhimingYe]

@isabelizimm

If you think this is a duplicate issue, please feel free to close it! Whether it should exist depends on what you engineers think is better (beneficial for you to solve the problem), because we users cannot know what's good for you, and we don't want to add trouble to your busy schedule.

Actually, I don't see many similarities between the two issues. From an implementation perspective, the issue you provided is about progressive ANSI control characters buffering output in ipykernel. This issue, however, is about the trade-offs in ipywidgets rendering (implement in #1934). Most ipywidgets are primarily used for outputting interactive objects, which should appear in the plot pane. But progress bars are not. They are more likely to be displayed in a console.

However, the display location is not really important (it's a secondary issue!). What's worse than this experience is that the plot pane throws an error message saying it doesn't support this type of ipywidget. Only the completed progress bar mysteriously appears in the plot pane afterwards. Actually, this issue could be retitled as "Plot pane doesn't support progressive display of progress bars."

It would be great if the error shown in the image below could be avoided.

There may have been some unclear explanations in the initial issue. Thank you for your patience and understanding.

[isabelizimm]

Ah, I appreciate that extra clarity! I do believe both issues are about rendering things in the console, but you're right that this is specific in that the widget is throwing an error in the plots pane we don't want. I'm seeing the same behavior on:

Positron Version: 2025.09.0 build 126
Code - OSS Version: 1.103.0
Commit: a078619a799a55f1797669e30515c995c8dd24f7
Date: 2025-08-27T15:43:27.408Z
Electron: 37.2.3
Chromium: 138.0.7204.100
Node.js: 22.17.0
V8: 13.8.500258-electron.0
OS: Darwin arm64 24.6.0

Thank you for reporting this!