sideline

Show informations on the side

This library provides the frontend UI to display information either on the left/right side of the buffer window.

P.S. The implementation is extracted and modified from lsp-ui-sideline

Table of Contents

• sideline
  • ❓ Why?
  • 🔨 Quickstart
    • 👥 Configure backends
  • 📌 Define your own backend
  • 📂 Example projects
  • Contribute

❓ Why?

Instead of hard-coded information, we extracted it to multiple different backends. It allows us to customize the displayed information we want, which is more flexible and configurable.

🔨 Quickstart

(use-package sideline
  :init
  (setq sideline-backends-skip-current-line t  ; don't display on current line
        sideline-order-left 'down              ; or 'up
        sideline-order-right 'up               ; or 'down
        sideline-format-left "%s   "           ; format for left aligment
        sideline-format-right "   %s"          ; format for right aligment
        sideline-priority 100                  ; overlays' priority
        sideline-display-backend-name t))      ; display the backend name

👥 Configure backends

The most basic way to set up the backends for sideline.

(use-package sideline
  :init
  (setq sideline-backends-left '(sideline-flycheck)
        sideline-backends-right '(sideline-lsp)))

Alternatively, you could set it to cons cell with the search order.

(use-package sideline
  :init
  (setq sideline-backends-right '((sideline-lsp      . up)
                                  (sideline-flycheck . down))))

📌 Define your own backend

Following is an example code to define your own sideline backend:

(defun my-backend (command)
  "Example backend."
  (cl-case command
    (`candidates '("info 1" "info 2" "info 3"))  ; required
    (`action (lambda (candidate &rest _)   ; optional
               (message "Execute command for `%s`!" candidate)))))

or define it asynchronously:

(defun my-backend-async (command)
  "Example async backend."
  (cl-case command
    (`candidates (cons :async (lambda (callback &rest _)
                                (funcall callback '("info 1" "info 2" "info 3")))))
    (`action ...)))

then you can tell your user to...

(setq sideline-backends-left '(my-backend))  ; use `sideline-backends-right' for right alignment

Here is a list of supported commands:

• candidates - list of strings to display; accept async function
• action - (optional) callback function after the mouse click
• face - (optional) face overrides the default sideline face
• name - (optional) backend name to display

📂 Example projects

• sideline-blame
• sideline-flycheck
• sideline-flymake
• sideline-lsp
• sideline-eldoc

Contribute

If you would like to contribute to this project, you may either clone and make pull requests to this repository. Or you can clone the project and establish your own branch of this tool. Any methods are welcome!