Notebooks - Variables explorer cleared when data-viewer is invoked from it and given focus.

[claudiaregio]

Environment data

• VS Code version: 1.60.0
• Jupyter Extension version: v2021.8.2031173646

Steps to reproduce:

1. Open variable explorer
2. Open dataframe in data viewer

Expected behavior

Variables are remain

Actual behavior

Variables are cleared

I know that this happens because the focus changes to the data viewer which is obviously not a notebook and therefore has no variables to show. However, I found this to be a really strange interaction. When wanting to open two dataframes back to back I thought it broke, took me a second to realize I had to go back to get focus on the notebook to go open the variable again.

[rchiodo]

I assume we're just going to make the variable viewer work when a data viewer is open?

[rchiodo]

Verification steps:

• Open a notebook and a python file
• From the notebook create a list or something that can be opened in the data frame viewer
• Create another list with a different name
• Open the data viewer for the first list
• You should still see variables and you should still be able to open the second list
• Switch back to the python file and verify the variables go away