Afterglow is an Emacs package designed to enhance your editing experience by providing temporary highlighting for regions, lines, or custom-defined regions after specific function calls. This visual feedback tool is perfect for tracking code evaluations, cursor movements, or any changes within your buffer. It offers full control over the highlighting behavior without relying on hooks, using function advices for flexibility and performance. With Afterglow, navigating and understanding code becomes more intuitive and efficient.
The default face for highlighting is `hl-line`, which offers seamless integration with Emacs’ native appearance. Each trigger has its own highlight duration, face, and other properties.
Emacs 26.1 or greater.
The package is available on MELPA.
Install `afterglow` using the following commands:
(package-refresh-contents)
(package-install 'afterglow)Add the following to your Emacs configuration:
(require 'afterglow)
(afterglow-mode 1)
;; Optional
(setq afterglow-default-duration 0.5)
(setq afterglow-default-face 'hl-line)
;; Example 1:
(afterglow-add-triggers
'((evil-previous-visual-line :thing line :width 5 :duration 0.2)
(evil-next-visual-line :thing line :width 5 :duration 0.2)
(previous-line :thing line :duration 0.2)
(next-line :thing line :duration 0.2)
(eval-buffer :thing window :duration 0.2)
(eval-defun :thing defun :duration 0.2)
(eval-expression :thing sexp :duration 1)
(eval-last-sexp :thing sexp :duration 1)
(my-function :thing my-region-function :duration 0.5
:face 'highlight)))
;; Example 2: use let binding instead
(let ((width 5)
(duration 0.3))
(afterglow-add-triggers
`((evil-previous-visual-line :thing line :width ,width
:duration ,duration)
(evil-next-visual-line :thing line :width ,width
:duration ,duration)
(previous-line :thing line :duration ,duration)
(next-line :thing line :duration ,duration)
(eval-buffer :thing window :duration ,duration)
(eval-defun :thing defun :duration ,duration)
(eval-region :thing region :duration ,duration
:face (:background "green"))
(eval-last-sexp :thing sexp :duration ,duration))))To install using `straight.el`, add this to your Emacs configuration:
(straight-use-package 'afterglow)
(require 'afterglow)
(afterglow-mode t)For those who prefer `use-package.el`, here is how you can set up afterglow:
(use-package afterglow
:ensure t
:config
(afterglow-mode t)
;; Optional customizations
(setq afterglow-default-duration 0.5)
(setq afterglow-default-face 'hl-line)
;; Add triggers as needed
(afterglow-add-triggers
'((evil-previous-visual-line :thing line :width 5 :duration 0.2)
(evil-next-visual-line :thing line :width 5 :duration 0.2)
(previous-line :thing line :duration 0.2)
(next-line :thing line :duration 0.2)
(eval-buffer :thing window :duration 0.2)
(eval-defun :thing defun :duration 0.2)
(eval-expression :thing sexp :duration 1)
(eval-last-sexp :thing sexp :duration 1)
(my-function :thing my-region-function :duration 0.5
:face 'highlight))))Clone the `afterglow` repo:
git clone https://github.com/ernstvanderlinden/emacs-afterglow.git add this to your init.el:
;; Replace `"/path/to/emacs-afterglow"` with the actual path to where
;; you've cloned or downloaded this package.
(add-to-list 'load-path "/path/to/emacs-afterglow")
(require 'afterglow)
;; Rest of your custom `afterglow` config settingsAfterglow is designed to be highly customizable. Here are some ways you can tailor it to fit your workflow:
Afterglow allows highlighting based on different ‘things’, including:
| Thing | Description |
|---|---|
| Function | Implement your own function which returns a cons cell containing the beginning and end of a region, e.g., (234 . 543). |
| Region | If a region is active, that region will be highlighted. |
| Line | Add a property `:width` to control the length of the line. |
| Window | Highlights the current window. |
| Other | Defined in the `thingatpt` package: symbol, list, sexp, defun, number, filename, url, email, uuid, word, sentence, whitespace, and page. |
By default, highlights disappear after 1 second. Adjust this duration to your preference:
(setq afterglow-default-duration 0.5) ; Highlight disappears after 0.5 seconds.Change the appearance of the highlight by specifying a different face:
(setq afterglow-default-face 'your-custom-face) ; Use your custom face for highlighting.Refer to Emacs’ documentation `M-x describe-face` for details on creating or modifying faces.
Triggers define when the highlighting should occur, based on function calls. You can add a trigger for any Emacs function, including custom ones, like so:
(afterglow-add-trigger 'previous-line :thing 'line :duration 0.2)This flexibility allows Afterglow to cater to a wide variety of use cases, enhancing your Emacs experience by providing meaningful visual cues based on your interactions.
| Public Functions |
|---|
| afterglow-add-trigger |
| afterglow-add-triggers |
| afterglow-mode |
| afterglow-remove-trigger |
| afterglow-remove-triggers |
| Public Vars |
| afterglow-duration |
| afterglow-face |
| afterglow-mode-hook |
Designed to work seamlessly with Emacs, enhancing your editing experience without disrupting your workflow.
Control how long the highlight remains visible.
Supports highlighting lines, windows, regions, custom region functions, and `things`.
Does not use hooks and only uses advice-add on functions.
| Package | Description |
|---|---|
| beacon-mode | Highlights the current line when the window scrolls. |
| hl-line-mode | Provides permanent line highlighting. |
Contributions to Afterglow are welcome. Whether it’s bug reports, feature suggestions, or code contributions, please feel free to reach out or submit a pull request.
Afterglow is available under the MIT License. See the LICENSE file for more details.
Nicholas Vollmer and Chris Rayner, both of Melpa, who triggered me to add more features and not solely focus on evil-mode users.