Better integrate with the JupyterLab toolbar registry machinery

[jtpio]

Problem

Currently, the Jupyter chat toolbar (next to the input text area) feels a bit different compared to every other toolbar in JupyterLab.

One of the differences is that the toolbar is directly next to the input chat area, which means that when the toolbar has many items, the chat area becomes cramped and the UX is degraded.

Another difference is that the chat toolbar is not configurable via the setting system, unlike the other toolbars, like the Notebook toolbar, or even the top area.

It would be great to check if we could integrate better with the base JupyterLab toolbar registry and factory mechanism? https://jupyterlab.readthedocs.io/en/latest/user/interface_customization.html#toolbars

At the same time, we could also add the ability to move the toolbar to the bottom to give the chat typing area a bit more space.

Proposed Solution

Use the IToolbarWidgetRegistry to configure the chat toolbar.

And also take the opportunity to put the toolbar below the text area:

Additional context

The jupyterlab-chat package makes use of the toolbar registry, but only for the toolbar at the top of the widget. So maybe we will need to move that logic to the main Jupyter chat package so it becomes available more generally.

And in JupyterLab, many toolbars use the toolbar registry, such as the browser, notebook, and cell toolbars:

[brichet]

Use the IToolbarWidgetRegistry to configure the chat toolbar.

For reference, there was a brief discussion on this topic when adding the input toolbar registry #198 (comment)

[jtpio]

Technically, if the whole chat widget is a ReactWidget, we could imagine having a Panel wrapper to add this new chat toolbar as a Lumino widget below.

[brichet]

Technically, if the whole chat widget is a ReactWidget, we could imagine having a Panel wrapper to add this new chat toolbar as a Lumino widget below.

Yes, but the toolbar is also added when editing a message, and the messages are react components embedded in the chat.

An other approach could be to try (again) using the Jupyterlab toolbar registry with the MUI toolbar.

[jtpio]

Yes, but the toolbar is also added when editing a message

Ah right, just double checked:

[jtpio]

And also take the opportunity to put the toolbar below the text area:

Otherwise could a first step be to move the toolbar below the input, to free some space in the typing area?

Before looking into making this compatible with Lumino and the settings?