Re: Rethinking the design of xwidgets

[Eli Zaretskii]

> From: Akira Kyle <ak@akirakyle.com>
> Cc: Eli Zaretskii <eliz@gnu.org>, emacs-devel@gnu.org
> Date: Tue, 13 Oct 2020 12:29:38 -0600
> 
> For example is it possible to have a live updating rectangle
> displayed as one drags the mouse to select a region to inspect?

Can't that be done with a mask on the image?

> Is it possible to display a slider which can be dragged by the mouse
> to update values on the plot or have a drop down menu to select a
> data series?

You'd need to regenerate the plot with the updated values.

> It seems it may also be difficult to find a way to have elisp
> interact with the matplotlib fast enough to not introduce noticable
> delay as such actions update the view.

And doing this via a module that is called by a widget won't bump into
the same problems?  After all, all the interaction with Emacs goes
through the same mechanism, no matter what the callback does.