Spinner

Animated loading indicators with 15 built-in animation styles.

Quick Example

(require '[charm.core :as charm])

(def my-spinner (charm/spinner :dots))

;; Initialize to start animation
(let [[spinner cmd] (charm/spinner-init my-spinner)]
  ;; spinner is ready, cmd starts the tick loop
  )

;; In update function
(let [[spinner cmd] (charm/spinner-update spinner msg)]
  ;; Handle spinner tick messages
  )

;; In view function
(charm/spinner-view spinner)  ; => "⠋" (animates)

Creation Options

(charm/spinner type & options)

Option	Type	Default	Description
type	keyword/map	:dots	Spinner type or custom {:frames [...] :interval ms}
:style	style	nil	Style to apply to spinner frames
:id	any	random	Unique identifier for tick messages

Spinner Types

Type	Frames	Interval	Preview
:line	\| / - \	100ms	Classic line spinner
:dots	Braille dots	80ms	Smooth dot animation
:dot	Braille patterns	100ms	Rotating dot
:jump	Braille jump	100ms	Jumping dot
:pulse	█ ▓ ▒ ░	125ms	Pulsing block
:points	∙∙∙ ●∙∙ ∙●∙ ∙∙●	140ms	Moving point
:globe	🌍 🌎 🌏	250ms	Rotating globe
:moon	Moon phases	125ms	Moon cycle
:monkey	🙈 🙉 🙊	300ms	Three monkeys
:meter	▱▱▱ to ▰▰▰	140ms	Loading meter
:hamburger	☱ ☲ ☴	300ms	Trigram animation
:ellipsis	. .. ...	300ms	Growing dots
:arrows	← ↖ ↑ ↗ → ↘ ↓ ↙	100ms	Rotating arrow
:bouncing-bar	[= ]	100ms	Bouncing bar
:clock	Clock faces	100ms	Clock animation

Custom Spinner

(charm/spinner {:frames ["◐" "◓" "◑" "◒"]
                :interval 150})

Functions

spinner-init

(charm/spinner-init spinner) ; => [spinner cmd]

Initialize the spinner and start the tick loop. Returns [spinner cmd] where cmd triggers the first tick.

spinner-update

(charm/spinner-update spinner msg) ; => [spinner cmd]

Handle tick messages. Returns [spinner cmd] to continue animation, or [spinner nil] if message not handled.

spinner-view

(charm/spinner-view spinner) ; => "⠋"

Render current frame as a string.

spinning?

(charm/spinning? spinner msg) ; => boolean

Check if a message is a tick for this spinner.

Full Example

(ns my-app
  (:require [charm.core :as charm]))

(defn init []
  (let [[spinner cmd] (charm/spinner-init (charm/spinner :dots))]
    [{:spinner spinner
      :loading true}
     cmd]))

(defn update-fn [state msg]
  (cond
    (charm/key-match? msg "q")
    [state charm/quit-cmd]

    :else
    (let [[spinner cmd] (charm/spinner-update (:spinner state) msg)]
      [(assoc state :spinner spinner) cmd])))

(defn view [state]
  (str (charm/spinner-view (:spinner state))
       " Loading data..."))

(charm/run {:init init
            :update update-fn
            :view view})

Styled Spinner

(charm/spinner :dots
               :style (charm/style :fg charm/cyan :bold true))