feature: Implement sidebar

[cmacrae]

Hey again @rougier 👋

Just got this thrown together tonight. It implements sidebar functionality, à la NeoTree (in fact, it's mostly gutted NeoTree code 😅 )

I'm opening this as a draft to start the conversation early - there's clean up to do, rough edges to smooth out, and further functionality to add.

Take it for a spin: (setq mu4e-dashboard-file "~/path/to/your/dashboard.org") and then try out mu4e-dashboard-show, mu4e-dashboard-hide, mu4e-dashboard-toggle-window.

TODO

• [ ] When visiting a link, focus the result buffer
• [ ] Better window handling. It'd be nice if resulting headers (and any associated windows) were the only other window

[cmacrae]

Using a bit config like this, I can M-x mu4e-dashboard-show to start my mail flow.

(use-package mu4e-dashboard
    :ensure nil
    :load-path "~/src/github.com/cmacrae/mu4e-dashboard"
    :custom (mu4e-dashboard-file "~/org/mu4e-dashboard.org")
    :bind
      (:map mu4e-main-mode-map
        ("C-;"     . mu4e-dashboard-show))
      (:map mu4e-headers-mode-map
        ("C-;"     . mu4e-dashboard-show)
        ("C-c C-;" . mu4e-dasboard-toggle-window))
      (:map mu4e-dashboard-mode-map
        ("C-;"     . (lambda () (interactive) (select-window (previous-window))))))

Visiting any links in the dashboard open in another window. You have the C-; binding whilst in the mu4e-headers-mode to focus (or show, if hidden) the sidebar, pressing C-; again whilst in the sidebar will re-focus the last focussed window (the headers view). If you want to toggle the sidebar, you've also got C-c C-;

[rougier]

Nice ! By the way, there's pending PR for making dashboard a minor mode. I don't to what extent your PR will be compatible. Can you have multiple opened dashboards? Would that possible to have that as an option?

[cmacrae]

Ah great, I'll rebase that PR's branch onto mine 👍
As for multiple dashboards, I think that might be possible 🤔 I'll have a play around - what sort of setup were you thinking you'd like with multiple dashboards?

[rougier]

Personally I use a single dashboard, but if we have the option of having multiple dashboards, I wonder to what extent a sidebar would "cancel" that option. If we can still use the minor mode as intended I would be happy.