* IBuffer

Buffer management is a constant irritation with any editor.  After
having a bit of a performance issue when using [[https://github.com/florommel/bufferlo][bufferlo]] I've decided
to try doing something with emacs's built in IBuffer.

This is *heavily* inspired, and mostly outright copied from this [[https://olddeuteronomy.github.io/post/emacs-ibuffer-config/][post]]
by [[https://olddeuteronomy.github.io][The Emacs Cat]].

Icons can make identifying buffers easy at a glance so I think adding
them is pretty handy.

#+begin_src emacs-lisp
(use-package all-the-icons-ibuffer
  :ensure t
  :after (all-the-icons)
  :hook
  (ibuffer-mode . all-the-icons-ibuffer-mode))
#+end_src

Now for the main part of the configuration.  This provides a nice
logical grouping for buffers.  As I use this more I might change
the grouping to be a bit less file type oriented, and lean more
towards use case.

#+begin_src emacs-lisp
(use-package ibuffer :ensure nil
  :bind
  (("C-x B" . ibuffer))
  :config
  (setq ibuffer-expert t)
  (setq ibuffer-display-summary nil)
  (setq ibuffer-use-other-window nil)
  (setq ibuffer-show-empty-filter-groups nil)
  (setq ibuffer-default-sorting-mode 'filename/process)
  (setq ibuffer-title-face 'font-lock-doc-face)
  (setq ibuffer-use-header-line t)
  (setq ibuffer-default-shrink-to-minimum-size nil)
  (setq ibuffer-formats
        '((mark modified read-only locked " "
                (name 30 30 :left :elide)
                " "
                (size 9 -1 :right)
                " "
                (mode 16 16 :left :elide)
                " " filename-and-process)
          (mark " "
                (name 16 -1)
                " " filename)))
  (setq ibuffer-saved-filter-groups
        '(("Main"
           ("Directories" (mode . dired-mode))
           ("C++" (or
                   (mode . c++-mode)
                   (mode . c++-ts-mode)
                   (mode . c-mode)
                   (mode . c-ts-mode)
                   (mode . c-or-c++-ts-mode)))
           ("Python" (or
                      (mode . python-ts-mode)
                      (mode . c-mode)
                      (mode . python-mode)))
           ("Build" (or
                     (mode . make-mode)
                     (mode . makefile-gmake-mode)
                     (name . "^Makefile$")
                     (mode . change-log-mode)))
           ("Scripts" (or
                       (mode . shell-script-mode)
                       (mode . shell-mode)
                       (mode . sh-mode)
                       (mode . lua-mode)
                       (mode . bat-mode)))
           ("Config" (or
                      (mode . conf-mode)
                      (mode . conf-toml-mode)
                      (mode . toml-ts-mode)
                      (mode . conf-windows-mode)
                      (name . "^\\.clangd$")
                      (name . "^\\.gitignore$")
                      (name . "^Doxyfile$")
                      (name . "^config\\.toml$")
                      (mode . yaml-mode)))
           ("Web" (or
                   (mode . mhtml-mode)
                   (mode . html-mode)
                   (mode . web-mode)
                   (mode . nxml-mode)))
           ("CSS" (or
                   (mode . css-mode)
                   (mode . sass-mode)))
           ("JS" (or
                  (mode . js-mode)
                  (mode . rjsx-mode)))
           ("Markup" (or
                   (mode . markdown-mode)
                   (mode . adoc-mode)))
           ("Org" (mode . org-mode))
           ("LaTeX" (name . "\.tex$"))
           ("Magit" (or
                     (mode . magit-blame-mode)
                     (mode . magit-cherry-mode)
                     (mode . magit-diff-mode)
                     (mode . magit-log-mode)
                     (mode . magit-process-mode)
                     (mode . magit-status-mode)))
           ("Apps" (or
                    (mode . elfeed-search-mode)
                    (mode . elfeed-show-mode)))
           ("Fundamental" (or
                           (mode . fundamental-mode)
                           (mode . text-mode)))
           ("Emacs" (or
                     (mode . emacs-lisp-mode)
                     (name . "^\\*Help\\*$")
                     (name . "^\\*Custom.*")
                     (name . "^\\*Org Agenda\\*$")
                     (name . "^\\*info\\*$")
                     (name . "^\\*scratch\\*$")
                     (name . "^\\*Backtrace\\*$")
                     (name . "^\\*Messages\\*$"))))))
  :hook
  (ibuffer-mode . (lambda ()
                    (ibuffer-switch-to-saved-filter-groups "Main")))
)
#+end_src