[Feature Request] Add a mode for "speedbar".

[shamefulCake1]

May I ask that mu4e-overview supply a "speedbar minor mode" wrapping it?

Seemingly the data model would map very well to the tree widged "supported" by speedbar, and although speedbar is not the best example of code, it is shipped with Emacs, and can be exploited.

There already is a prototype of the code in the stock mu4e, called mu4e-speedbar, but it is also not a "speedbar mode".

https://github.com/djcb/mu/blob/master/mu4e/mu4e-speedbar.el

[mkcms]

Thanks for the feature request.

I don't use speedbar myself, but I will try it out and see if it can be extended to support our mu4e hierarchy.
At the very least, I could provide a more higher-level function that yields our maildir hierarchy, to make it easier to write your own speedbar wrapper.

I will look into speedbar to see if this makes sense.

[mkcms]

I just pushed 673fe69 which adds a public function to get the folder hierarchy and the total/unread counts. That makes it possible for users to implement alternative views for the hierarchy. I still haven't delved into speedbar though.