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Exception not handled in widgetlock()

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#471 2 comments 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
jupyter-notebook, python
Domain
frontend

Research direction

Reproduce the issue with the minimal Jupyter example, then inspect ipympl/backend_nbagg.py and matplotlib/widgets.py around the widget lock handling shown in the traceback. Confirm the expected behavior when zoom or pan attempts to acquire an occupied lock, and add coverage showing that the interaction no longer produces an uncaught ValueError.

Written by the indexing model from the issue text.

Description

Describe the issue

I want to use a selector matplotlib.widgets.RectangleSelector , it is incompatible with zoom and pan
So I try to call widget lock to prevent user from using zoom in the same time.

minimum code:

%matplotlib ipympl
import matplotlib.pyplot as plt
fig,ax = plt.subplots()
ax.plot([0,1],[0,1])
fig.canvas.widgetlock(ax)   # get the widget lock

if you then hit the zoom or pan matplotlib button, which also try to get the lock, you get

ValueError                                Traceback (most recent call last)
File ~/spike/venvOW/lib/python3.9/site-packages/ipympl/backend_nbagg.py:279, in Canvas._handle_message(self, object, content, buffers)
    276     self.manager.handle_json(content)
    278 else:
--> 279     self.manager.handle_json(content)

...

File ~/spike/venvOW/lib/python3.9/site-packages/matplotlib/widgets.py:42, in LockDraw.__call__(self, o)
     40 """Reserve the lock for *o*."""
     41 if not self.available(o):
---> 42     raise ValueError('already locked')
     43 self._owner = o

ValueError: already locked

Alternatively, I could use the right click for the selector, but I have not found a way to restrict zoom and pan to left click only.

Versions

 3.9.7 (default, Sep 16 2021, 13:09:58) 
[GCC 7.5.0]
ipympl version: 0.8.8
Selected Jupyter core packages...
IPython          : 8.0.1
ipykernel        : 6.9.1
ipywidgets       : 7.6.5
jupyter_client   : 7.1.2
jupyter_core     : 4.9.2
jupyter_server   : 1.13.5
jupyterlab       : not installed
nbclient         : 0.5.11
nbconvert        : 6.4.2
nbformat         : 5.1.3
notebook         : 6.4.8
qtconsole        : 5.2.2
traitlets        : 5.1.1
Dominant language
Jupyter Notebook
Stars
1.7k
Forks
234
PR merge metrics
No merged PRs in 30d

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