Change cursor color when Yasnippet can be fired

init.el

@@ -1210,3 +1210,35 @@
            (file-directory-p (helm-get-selection)))
       (helm-execute-persistent-action)
     (insert "/")))
+
+(setq default-cursor-color (frame-parameter nil 'cursor-colbxuor))
+(setq yasnippet-can-fire-cursor-color "purple")
+
+;; It will test whether it can expand, if yes, cursor color -> purple.
+(defun yasnippet-can-fire-p (&optional field)
+  (interactive)
+  (setq yas--condition-cache-timestamp (current-time))
+  (let (templates-and-pos)
+    (unless (and yas-expand-only-for-last-commands
+                 (not (member last-command yas-expand-only-for-last-commands)))
+      (setq templates-and-pos (if field
+                                  (save-restriction
+                                    (narrow-to-region (yas--field-start field)
+                                                      (yas--field-end field))
+                                    (yas--templates-for-key-at-point))
+                                (yas--templates-for-key-at-point))))
+    (and templates-and-pos (first templates-and-pos))))
+
+;; Taken from http://pages.sachachua.com/.emacs.d/Sacha.html
+(defun sachachua/change-cursor-color-when-can-expand (&optional field)
+  (interactive)
+  (when (eq last-command 'self-insert-command)
+    (set-cursor-color (if (sachachua/can-expand)
+                          yasnippet-can-fire-cursor-color
+                        default-cursor-color))))
+
+(defun sachachua/can-expand ()
+  "Return true if right after an expandable thing."
+  (or (abbrev--before-point) (yasnippet-can-fire-p)))
+
+(add-hook 'post-command-hook 'sachachua/change-cursor-color-when-can-expand)