hs-notifications

A Super Simple Desktop Notification Server in Haskell.

DBUS_SESSION_BUS_ADDRESS needs to be set, which can be accomplished by adding export $(dbus-launch) to your ~/.xinitrc.

Install stack & gobject-introspection:

sudo pacman -S stack gobject-introspection

Build:

stack build

Run:

stack exec hs-notifications

Install to ~/.local/bin:

stack install
export PATH="$HOME/.local/bin/:$PATH"
hs-notifications

Mod4-Shift-Ctrl-w removes all the notifications. Mod4-Ctrl-w removes the oldest notification. You can also click them.

You can change the colors & keybindings by creating a ~/.config/hs-notifications/config.ini, see the config-example.ini for available options.

My plan is to import this into my xmond config, build my notification Config in there, & use forkProcess to run the application.

I've built this to my needs - if you would like to use this but want some more features or customizability, feel free to open an issue.

TODO

• Add icon support

• Add ability to override colors & icon - matching by app name or title/body text. Specify overrides in config file sections.

• Add action support?

• objectUnref the pixbufs we make after creating the GtkImage.

• Notification Spec says to never auto-expire Critical urgency notifications.

• Refactor to ReaderT Env IO

  • Add data Env = Env Config AppState
  • Use TQueue for Queues instead of wrapping all of AppState in a TVar.
  • Write typeclasses for accessing & modifying small parts of the Env. E.g., class Monad m => RootPosition m where getRootPosition :: m (Int32, Int32)
  • Refactor function types to use typeclasses to restrict their scope - instead of passing the entire Config & AppState around & using the IO monad everywhere.

Architecture

This was hacked together in a day or so, there's lots of room for improvement.

There's a DBus client & a GTK app. Main just initializes the shared state, forks the DBus client and starts the GTk app.

Init

The DBus client connects to the current dbus session, identifies itself as the notification server, and sets up it's event handlers.

The GTK app initializes itself, gets the notification placement position, attaches some CSS styles, and sets up some keybindings & timers.

New Notification

When the DBus client receives a notification, it adds it to the notification queue in the shared state.

Every second, the GTK loop checks the notification queue for any new messages. Any messages are rendered & added to the window list.

As windows are added, the application tracks the position of the next window by adding the new window's height & some spacing.

Removing Notifications

You can click notifications to remove them, press Mod4-Ctrl-w to remove the oldest, or press Mod4-Ctrl-Shift-w to remove them all.

Removing a notification updates the window list, re-adjusts the positions of windows below it, & adds its NotificationID to the removal queue.

The DBus client wakes up every second to check the removal queue & send the NotificationClosed signal for any removed notifications.

License

GPL-3.0