Provide a few options for busy throbber

Author: Lenbok

agent-shell.el

@@ -276,6 +276,18 @@ Can be one of:
   :type 'boolean
   :group 'agent-shell)
 
+(defcustom agent-shell-busy-indicator-frames 'wide
+  "Frames for the busy indicator animation.
+Can be a symbol selecting a predefined style, or a vector of frame strings.
+When providing custom frames, do not include leading spaces as padding
+is added automatically."
+  :type '(choice (const :tag "Wave (pulses up and down)" wave)
+                 (const :tag "Dots Block (circular spin)" dots-block)
+                 (const :tag "Dots Round (circular spin)" dots-round)
+                 (const :tag "Wide (horizontal blocks)" wide)
+                 (vector :tag "Custom frames" string))
+  :group 'agent-shell)
+
 (defcustom agent-shell-screenshot-command
   (if (eq system-type 'darwin)
       '("/usr/sbin/screencapture" "-i")
@@ -4285,11 +4297,17 @@ See https://agentclientprotocol.com/protocol/session-modes for details."
 
 (defun agent-shell--status-frame ()
   "Return busy frame string or nil if not busy."
-  (when (and agent-shell-show-busy-indicator
-             (eq 'busy (map-nested-elt (agent-shell--state) '(:heartbeat :status))))
-    (let ((frames [" ░   " " ░░  " " ░░░ " " ░░░░" " ░░░ " " ░░  " " ░   " "     "]))
-      (seq-elt frames (mod (map-nested-elt (agent-shell--state) '(:heartbeat :value))
-                           (length frames))))))
+  (when-let* ((agent-shell-show-busy-indicator)
+              ((eq 'busy (map-nested-elt (agent-shell--state) '(:heartbeat :status))))
+              (frames (pcase agent-shell-busy-indicator-frames
+                        ('wave ["▁" "▂" "▃" "▄" "▅" "▆" "▇" "█" "▇" "▆" "▅" "▄" "▃" "▂"])
+                        ('dots-block ["⣷" "⣯" "⣟" "⡿" "⢿" "⣻" "⣽" "⣾"])
+                        ('dots-round ["⢎⡰" "⢎⡡" "⢎⡑" "⢎⠱" "⠎⡱" "⢊⡱" "⢌⡱" "⢆⡱"])
+                        ('wide ["░   " "░░  " "░░░ " "░░░░" "░░░ " "░░  " "░   " "    "])
+                        ((pred vectorp) agent-shell-busy-indicator-frames)
+                        (_ ["▁" "▂" "▃" "▄" "▅" "▆" "▇" "█" "▇" "▆" "▅" "▄" "▃" "▂"]))))
+    (concat " " (seq-elt frames (mod (map-nested-elt (agent-shell--state) '(:heartbeat :value))
+                                     (length frames))))))
 
 (defun agent-shell--mode-line-format ()
   "Return `agent-shell''s mode-line format.