Emacs: control where buffers are displayed (the 'display-buffer-alist')

Raw link: https://www.youtube.com/watch?v=1-UIzYPn38s

In this ~30 minute video I show how to tell Emacs where to place specific buffers. The idea is to have a set of rules that specify how you want Emacs to make use of the available space in the frame and which windows to use. Below I show some basic code samples. For more advanced uses, refer to my relevant section in Emacs configuration: https://protesilaos.com/emacs/dotemacs#h:50f8b1e4-b14e-453f-a37e-1c0e495ab80f.

Sample code with basic rules

(setq display-buffer-alist

        ;; The added space is for didactic purposes

        ;; Each entry in this list has this anatomy:


        ;; Match a buffer whose name is "*Occur*".  We have to escape
        ;; the asterisks to match them literally and not as a special
        ;; regular expression character.
         ;; If a buffer with the matching major-mode exists in some
         ;; window, then use that one.  Otherwise, display the buffer
         ;; below the current window.
         (display-buffer-reuse-mode-window display-buffer-below-selected)
         ;; Then we have the parameters...
         (dedicated . t)
         (window-height . fit-window-to-buffer))


;; If you want `switch-to-buffer' and related to respect those rules
;; (I personally do not want this, because if I am switching to a
;; specific buffer in the current window, I probably have a good
;; reason for it):
(setq switch-to-buffer-obey-display-actions t)

;; If you are in a window that is dedicated to its buffer and try to
;; `switch-to-buffer' there, tell Emacs to pop a new window instead of
;; using the current one:
(setq switch-to-buffer-in-dedicated-window 'pop)

;; Other relevant variables which control when Emacs splits the frame
;; vertically or horizontally, with some sample values (do `M-x
;; describe-variable' and search for those variables to learn more
;; about them):
(setq split-height-threshold 80)
(setq split-width-threshold 125)

;; Evaluate these to get to the relevant entries in the manual (NOTE
;; that this is advanced stuff):
(info "(elisp) Displaying Buffers")
(info "(elisp) Buffer Display Action Functions")
(info "(elisp) Buffer Display Action Alists")
(info "(elisp) Window Parameters")

More links to my Emacs configuration

My personal Emacs configuration. It is comprehensive, both in terms of the [custom] code it contains as well as the documentation on what each piece of functionality does.