Add hooks to run before and after the popup appear

flycheck-popup-tip.el

@@ -67,10 +67,17 @@
 (defvar flycheck-popup-tip-old-display-function nil
   "The former value of `flycheck-display-errors-function'.")
 
+(defvar flycheck-popup-tip-show-hook nil
+  "Hook run before when showing a popup.")
+
+(defvar flycheck-popup-tip-delete-hook nil
+  "Hook run before when deleting a popup.")
+
 (defun flycheck-popup-tip-delete-popup ()
   "Delete messages currently being shown if any."
   (when (popup-live-p flycheck-popup-tip-object)
-    (popup-delete flycheck-popup-tip-object))
+    (popup-delete flycheck-popup-tip-object)
+    (run-hook-with-args 'flycheck-popup-tip-delete-hook))
   (remove-hook 'pre-command-hook 'flycheck-popup-tip-delete-popup t))
 
 (defun flycheck-popup-tip-format-errors (errors)
@@ -102,6 +109,7 @@
            (flycheck-popup-tip-format-errors errors)
            :nostrip t
            :nowait t))
+    (run-hook-with-args 'flycheck-popup-tip-show-hook)
     (add-hook 'pre-command-hook 'flycheck-popup-tip-delete-popup nil t)))
 
 ;;;###autoload