j key activate "activate previously used tab"

j key in normal mode actions is go down line

open my.py file and my.ipynb file
select my.py tab with editor
using vim keymap, press j at last line
I got activate my.ipynb tab

But at the last line of script, pressing j key
"activate previously used tab' which is bound to " ctrl + shift + ' "
Weired behavior

[axelfahy]

I can reproduce, it is indeed a weird behavior.

[ianhi]

oh wacky. This is because the moveByCellOrLines https://github.com/axelfahy/jupyterlab-vim/blob/c4e43f940ef4be4c961608b6192412d2f3a33d1f/src/index.ts#L85
https://github.com/axelfahy/jupyterlab-vim/blob/c4e43f940ef4be4c961608b6192412d2f3a33d1f/src/index.ts#L127-L133
doesn't check if you're in a notebook so these notebook cell switching commands get run. This means you can also get the same behavior by using k at the top of the editor.

The fix for this is to add some sort of check to that function to only run the commands if you're in a notebook, not if in the editor.

[ianhi]

I believe this is fixed by #105

[ianhi]

wait maybe not - I think i was confused. WIll re-open until i can properly check.

[firai]

It seems like this only happens now in the first file editor instance if JL is loaded/reloaded with a URL pointing to a file editor-type document, and it doesn't always reproduce. It does not seem to happen after switching tabs.

I tried to track the modify calls when JL is loaded, but I don't comprehend what's happening. When the behavior exists, the following set of calls are logged when JL is loaded/reloaded:

onActiveEditorChanged()
shell.currentChanged() -> editorTracker -> modifyEditor()
onActiveCellChanged()
shell.currentChanged() -> notebookTracker -> modifyCell()
shell.currentChanged() -> editorTracker -> modifyEditor()
onActiveCellChanged()

When it doesn't happen, the following set of calls happen when JL is loaded/reloaded:

onActiveCellChanged()
shell.currentChanged() -> notebookTracker -> modifyCell()
onActiveEditorChanged()
shell.currentChanged() -> editorTracker -> modifyEditor()
onActiveCellChanged()

I'm not sure why there are so many changed signals fired at initial load, why the matching tracker flips back and forth, why the order of how it flips changes from load to load, or how the extra flip in the former case causes this behavior. Don't know why there's always an onActiveCellChanged() call when loading file editors either.

I wonder if the shell signals should be connected to the onActive... calls to fix some sort of race condition. EDIT: That doesn't fix the issue.

[firai]

The current behavior seems to be caused by notebookTracker.activeCellChanged or editorTracker.currentChanged signals firing as background tabs are initialized, but the resulting onActiveCellChanged() -> modifyCell() or onActiveEditorChanged() -> modifyEditor() operation modifies the editor or cell in the foreground.