knockknock

Unobtrusive notifications with icons and SVG support

knockknock provides beautiful, elegant notifications using posframe and nerd-icons. Display temporary alert messages with custom icons, titles, and messages in a centered, customizable frame that automatically disappears. Features pixel-perfect SVG layout with automatic text wrapping for long messages.

Support

This package is developed and maintained in my free time. If you find it useful and want to support continued development, consider sponsoring:

💝 Sponsor on GitHub

Every contribution, no matter how small, is greatly appreciated and helps keep this project alive!

Features

• Beautiful icon-based notifications with nerd-icons
• Custom SVG icons: Use your own SVG files as notification icons
• Two layout modes:
  • SVG-based (default): Pixel-perfect positioning with automatic text wrapping
  • Text-based: Uses nerd-icons with Emacs text properties
• Two-column layout: icon on left, title and message on right
• Automatic text wrapping for long messages
• New notifications automatically replace current ones
• Clean, centered notification display
• Fully customizable appearance (colors, borders, duration, icon size)
• Auto-dismiss after configurable duration
• Manual dismiss support
• Multiple position handlers available
• Robust error handling: Automatic fallback from SVG to text layout on failure
• XML escaping: Secure SVG rendering prevents crashes from special characters
• Smart image sizing: Temporary max-image-size handling during rendering
• Debug mode: Optional debug logging for troubleshooting
• Backward compatible with simple text alerts

Screenshots

Basic Notifications

Simple alert with icon and message:

Package installation notification:

Layout Variations

Notification without icon:

Long message with automatic text wrapping:

Wide notification for longer content:

Position Options

Center-positioned notification:

Top-right corner notification:

Custom Text Colors

Dark background with red text (error style):

Dark background with blue text (info style):

Requirements

• Emacs 26.1 or later
• posframe
• nerd-icons

Installation

Manual Installation

1. Clone or download this repository to your local packages directory:

cd ~/.emacs.d/localpackages
git clone https://github.com/konrad1977/knockknock.git

2. Add to your Emacs configuration:

(add-to-list 'load-path "~/.emacs.d/localpackages/knockknock")
(require 'knockknock)

Using straight.el

(straight-use-package
 '(knockknock :type git :host github :repo "konrad1977/knockknock"))

Using use-package with straight

(use-package knockknock
  :straight (:host github :repo "konrad1977/knockknock"))

Usage

Modern API (with icons)

Display a notification with title and message:

(knockknock-notify :title "Build Complete"
                   :message "All tests passed!")

Display a notification with custom icon:

(knockknock-notify :title "Error"
                   :message "Build failed"
                   :icon "cod-error"
                   :duration 5)

Display with only a title:

(knockknock-notify :title "Task Complete" :icon "cod-check")

Long messages wrap automatically:

(knockknock-notify :title "Long Message"
                   :message "This is a very long message that will automatically wrap to multiple lines to fit nicely in the notification"
                   :icon "cod-info"
                   :duration 8)

Available icon examples (you can use with or without "nf-" prefix):

• "cod-check" or "nf-cod-check" - Checkmark
• "cod-error" or "nf-cod-error" - Error/X
• "cod-info" or "nf-cod-info" - Information
• "cod-warning" or "nf-cod-warning" - Warning
• "fa-rocket" or "nf-fa-rocket" - Rocket
• "fa-save" or "nf-fa-save" - Save/Disk
• And many more from nerd-icons

Custom SVG Icons

You can use your own SVG files as notification icons with the :icon-file parameter:

(knockknock-notify :title "Custom Icon"
                   :message "Using my own SVG!"
                   :icon-file "~/icons/my-custom-icon.svg")

Notes:

• Custom SVG icons only work in SVG layout mode (knockknock-use-svg-layout t)
• The SVG is automatically scaled to knockknock-svg-icon-size (default 32 pixels)
• If :icon-file is provided along with :icon, the custom file takes precedence
• If the file cannot be loaded, it falls back to the :icon or default icon
• In text layout mode, :icon-file is ignored and falls back to nerd-icons

Legacy API (simple text)

Display a notification with default duration (3 seconds):

(knockknock-alert "Hello, World!")

Display a notification with custom duration (5 seconds):

(knockknock-alert "This will show for 5 seconds" 5)

Manual Close

Manually close the current notification:

M-x knockknock-close

Progress Bar Notifications

knockknock supports progress bar notifications for long-running operations:

Percent-based progress

;; Create progress bar
(knockknock-progress-create :id 'download
                            :title "Downloading"
                            :message "package.tar.gz"
                            :icon "cod-cloud-download"
                            :percent 0)

;; Update progress
(knockknock-progress-update 'download :percent 50 :message "Halfway there...")
(knockknock-progress-update 'download :percent 100)  ; Auto-closes when complete

Step-based progress

;; Create with total steps
(knockknock-progress-create :id 'build
                            :title "Building"
                            :message "Compiling..."
                            :total 10)

;; Update current step
(knockknock-progress-update 'build :current 3)
(knockknock-progress-update 'build :current 7 :message "Linking...")
(knockknock-progress-update 'build :current 10)  ; Auto-closes at 100%

Manual close

(knockknock-progress-close 'download)

Customization

All aspects of knockknock can be customized through M-x customize-group RET knockknock RET or by setting variables in your configuration:

;; Duration
(setq knockknock-default-duration 5)

;; Colors (nil = use theme defaults)
(setq knockknock-background-color nil)  ; Use theme background
(setq knockknock-foreground-color nil)  ; Use theme foreground
(setq knockknock-border-color "orange")

;; Background color adjustments (applied to theme background)
(setq knockknock-darken-background-percent 0)   ; Darken background by percentage (0-100)
(setq knockknock-lighten-background-percent 0)  ; Lighten background by percentage (0-100)

;; Border and spacing
(setq knockknock-border-width 2)
(setq knockknock-left-fringe 10)
(setq knockknock-right-fringe 10)

;; Icon settings
(setq knockknock-use-icons t)                ; Enable/disable icons
(setq knockknock-default-icon "fa-bell")     ; Default icon

;; Debug mode
(setq knockknock-debug nil)                  ; Enable debug logging (default: nil)

;; Text wrapping
(setq knockknock-max-message-width 40)       ; Max characters per line

;; Position (see posframe documentation for available handlers)
(setq knockknock-poshandler #'posframe-poshandler-frame-top-center)

Text Layout Settings

For text-based layout:

(setq knockknock-use-svg-layout nil)         ; Switch to text layout
(setq knockknock-icon-size 3.5)              ; Icon size multiplier
(setq knockknock-icon-padding 2)             ; Spaces between icon and text
(setq knockknock-text-column 4)              ; Column position for text

SVG Layout Settings

For SVG-based layout (default):

(setq knockknock-use-svg-layout t)           ; SVG layout (default)
(setq knockknock-svg-icon-size 32)           ; Icon size in pixels
(setq knockknock-svg-min-width 300)          ; Minimum canvas width in pixels
(setq knockknock-svg-max-width 500)          ; Maximum canvas width in pixels
(setq knockknock-svg-padding 12)             ; Padding between icon and text
(setq knockknock-left-padding 12)            ; Left padding from edge to icon (pixels)
(setq knockknock-right-padding 16)           ; Right padding from text to edge (pixels)

Note: Image size limits are handled automatically during rendering. The package temporarily adjusts max-image-size when displaying notifications to ensure SVGs render correctly without affecting other parts of Emacs.

Progress Bar Settings

;; Bar appearance
(setq knockknock-progress-bar-height 12)        ; Height in pixels (SVG mode)
(setq knockknock-progress-bar-corner-radius 0)  ; 0 for square corners
(setq knockknock-progress-bar-width 30)         ; Width in characters (text mode)
(setq knockknock-progress-bar-margin-top 8)     ; Space above bar

;; Colors
(setq knockknock-progress-color "#2196F3")      ; Fill color (blue)
(setq knockknock-progress-background-color "#3a3a3a")  ; Track color

;; Style: 'modern (default), 'terminal, or 'ascii
(setq knockknock-progress-style 'modern)
;; modern:   ███████████░░░░░░░░░ 55%
;; terminal: ###########---------- 55%
;; ascii:    [===========          ] 55%

Customizing Faces

You can customize the appearance of titles, messages, and icons:

;; Make titles larger and bolder
(set-face-attribute 'knockknock-title-face nil
                    :weight 'bold
                    :height 1.3
                    :foreground "#ff6347")

;; Style the message text
(set-face-attribute 'knockknock-message-face nil
                    :slant 'italic
                    :foreground "#555555")

;; Change icon color
(set-face-attribute 'knockknock-icon-face nil
                    :foreground "#4169e1")

SVG Layout vs Text Layout

Feature	SVG Layout (default)	Text Layout
Positioning	Pixel-perfect	Text-flow based
Theme integration	Automatic	Automatic
Text wrapping	Multi-line support	Multi-line support
Icon scaling	Exact pixels	Text properties
Custom SVG icons	Supported	Not supported
Implementation	Sophisticated	Simple
Performance	Slightly slower	Fast
Error handling	Automatic fallback	N/A
XML safety	Built-in escaping	N/A
Crash prevention	Yes	N/A

When to use SVG layout (default):

• You want pixel-perfect control over positioning
• You're building a UI similar to agent-shell
• You need exact icon and text placement
• You want consistent rendering across different themes
• You benefit from automatic error handling and safety features

When to use text layout:

• You want simpler, faster rendering
• Text-based layout is sufficient
• You prefer Emacs-native text properties
• Maximum performance is critical

Available Position Handlers

• posframe-poshandler-window-bottom-right-corner (default)
• posframe-poshandler-frame-center
• posframe-poshandler-frame-top-center
• posframe-poshandler-frame-bottom-center
• posframe-poshandler-point-bottom-left-corner
• And many more from posframe

Example Integration

With compilation

(add-hook 'compilation-finish-functions
          (lambda (buf status)
            (if (string-match "^finished" status)
                (knockknock-notify :title "Build Complete"
                                   :message "Compilation successful!"
                                   :icon "cod-check"
                                   :duration 3)
              (knockknock-notify :title "Build Failed"
                                 :message "Compilation failed"
                                 :icon "cod-error"
                                 :duration 5))))

With org-pomodoro

(add-hook 'org-pomodoro-finished-hook
          (lambda ()
            (knockknock-notify :title "Pomodoro Complete"
                               :message "Time for a break!"
                               :icon "fa-coffee"
                               :duration 5)))

(add-hook 'org-pomodoro-break-finished-hook
          (lambda ()
            (knockknock-notify :title "Break Over"
                               :message "Back to work!"
                               :icon "fa-clock_o"
                               :duration 5)))

With save notifications

(defun my-save-notification ()
  (knockknock-notify :title "File Saved"
                     :message (buffer-name)
                     :icon "fa-save"
                     :duration 2))

(add-hook 'after-save-hook #'my-save-notification)

With Git operations

(defun my-git-push-notification ()
  (knockknock-notify :title "Git Push"
                     :message "Successfully pushed to remote"
                     :icon "dev-git"
                     :duration 3))

With long messages (automatic wrapping)

(knockknock-notify
  :title "Test Results"
  :message "All 127 tests passed successfully. Code coverage is at 94%. No critical issues found."
  :icon "cod-check"
  :duration 6)

Custom notification functions

(defun my-notify-success (msg)
  (knockknock-notify :title "Success"
                     :message msg
                     :icon "cod-check"
                     :duration 3))

(defun my-notify-error (msg)
  (knockknock-notify :title "Error"
                     :message msg
                     :icon "cod-error"
                     :duration 5))

(defun my-notify-info (msg)
  (knockknock-notify :title "Information"
                     :message msg
                     :icon "cod-info"
                     :duration 4))

;; Usage
(my-notify-success "Operation completed!")
(my-notify-error "Something went wrong!")
(my-notify-info "Please review the changes")

Adjusting notification background brightness

Make notifications slightly darker or lighter than your theme:

;; Make notifications 5% darker than theme background
(setq knockknock-darken-background-percent 5)

;; Or make them 10% lighter
(setq knockknock-lighten-background-percent 10)

;; Reset to use exact theme color
(setq knockknock-darken-background-percent 0)
(setq knockknock-lighten-background-percent 0)

This is useful for making notifications visually distinct from regular buffers while still maintaining theme consistency. Note: If both are set, darken takes precedence.

Advanced Features

Automatic Notification Replacement

New notifications automatically replace any currently displayed notification:

;; First notification
(knockknock-notify :title "Building..." :icon "cod-loading")

;; This immediately replaces the first one
(knockknock-notify :title "Build Complete" :icon "cod-check")

Text Wrapping Customization

Control how long messages are wrapped:

;; Shorter lines (30 characters)
(setq knockknock-max-message-width 30)

;; Longer lines (50 characters)
(setq knockknock-max-message-width 50)

Disabling Icons

Show notifications without icons:

(setq knockknock-use-icons nil)
(knockknock-notify :title "No Icon" :message "Just text")

Reliability & Safety

knockknock v0.2.2 includes several improvements for stability and crash prevention:

Automatic Error Handling

If SVG rendering fails for any reason, the package automatically falls back to text-based layout without user intervention. You'll see a message in *Messages* if this happens, but your notification will still display.

XML Escaping

All text (titles, messages, and icons) is automatically XML-escaped before being inserted into SVG. This prevents crashes from special characters like <, >, &, quotes, etc.

Smart Image Sizing

The package temporarily adjusts max-image-size only during notification display, then immediately restores it. This ensures:

• SVG notifications render correctly
• Other parts of Emacs are not affected
• No global state pollution

Memory Safety

Image size calculations are kept minimal (default max 500x100 pixels) to avoid memory issues, while still providing beautiful notifications.

Troubleshooting

Icons not showing in SVG layout

Make sure you have nerd-icons installed and the font is available system-wide:

M-x nerd-icons-install-fonts

The font family used is "Symbols Nerd Font Mono". Verify it's installed correctly on your system.

SVG not rendering or showing blank notifications

The package handles image size limits automatically. If you still have issues:

1. Enable debug mode to see what's happening:

   (setq knockknock-debug t)

   Check the *Messages* buffer for debug output.

2. Try switching to text layout temporarily:

   (setq knockknock-use-svg-layout nil)

3. Check for SVG support in your Emacs build:

   (image-type-available-p 'svg)  ; Should return t

Emacs crashes or memory issues

If you experience crashes:

1. The package now includes automatic error handling that falls back to text layout if SVG fails
2. XML escaping prevents crashes from special characters in notifications
3. Image size limits are handled automatically and temporarily - they don't affect other parts of Emacs

If crashes persist, disable SVG layout:

(setq knockknock-use-svg-layout nil)

Theme colors not working

Set background and foreground to nil to use theme defaults:

(setq knockknock-background-color nil)
(setq knockknock-foreground-color nil)

Debug Mode

Enable detailed logging to troubleshoot issues:

(setq knockknock-debug t)

Debug messages appear in the *Messages* buffer and include:

• Layout mode selection (SVG vs text)
• SVG rendering progress
• Image creation status
• Error messages with automatic fallback notifications

Changelog

v0.3.0 (2025)

New Features:

• Progress bar notifications with knockknock-progress-create, knockknock-progress-update, knockknock-progress-close
• Support for both percent-based and step-based progress
• Auto-close when progress reaches 100%
• Progress bar stays visible until completion (not interrupted by regular notifications)
• Customizable progress bar appearance:
  • knockknock-progress-color - Fill color
  • knockknock-progress-background-color - Track color
  • knockknock-progress-bar-height - Height in pixels
  • knockknock-progress-bar-corner-radius - Corner radius (0 for square)
  • knockknock-progress-style - Visual style (modern/terminal/ascii)

Improvements:

• Regular notifications are skipped while progress bar is active
• Frame readiness check prevents rendering issues during startup
• Fixed zero-value bug in progress updates (:current 0 and :percent 0 now work correctly)
• Fixed potential timer leak in progress render retry logic
• Added input validation for progress creation parameters

v0.2.6 (2025)

New Features:

• Added :icon-file parameter to knockknock-notify for custom SVG icons
• Use your own SVG files as notification icons instead of nerd-icons
• Custom SVGs are automatically scaled to knockknock-svg-icon-size
• Graceful fallback to nerd-icons if custom file fails to load

v0.2.5 (2025)

Improvements:

• Added knockknock-left-padding and knockknock-right-padding customization variables for better SVG layout control
• Changed default fringe values from 0 to 10 pixels for better spacing
• Changed default position handler to posframe-poshandler-window-bottom-right-corner for less intrusive notifications
• Improved SVG layout with configurable padding for more precise positioning

v0.2.2 (2025)

Bug Fixes & Improvements:

• Fixed crash issues related to SVG rendering and librsvg
• Added XML escaping for safe SVG text rendering
• Implemented automatic error handling with fallback to text layout
• Smart max-image-size handling (temporary adjustment during rendering)
• Added knockknock-debug customization variable for optional debug logging
• Improved stability and crash prevention

Breaking Changes:

• Removed knockknock-max-image-size customization (now handled automatically)

v0.2.1

• Initial stable release with SVG support
• Two layout modes (SVG and text-based)
• Automatic text wrapping
• Customizable appearance

v0.2.0

• Added modern API with knockknock-notify
• SVG-based pixel-perfect layout
• Icon support via nerd-icons
• Title and message display

License

MIT License - see LICENSE file for details

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

Author

Mikael Konradsson