Event notification using header-line

ein-events.el

@@ -25,11 +25,48 @@
 
 ;;; Code:
 
+(eval-when-compile (require 'cl))
+
 (require 'ein-log)
+(require 'ein-utils)
+
+(defvar ein:header-line-format '(:eval (ein:header-line)))
+
+(defun ein:header-line ()
+  (format
+   "IP[y]: %s"
+   (ein:join-str
+    " | "
+    (ein:filter
+     'identity
+     (list (ein:events-header-message-notebook)
+           (ein:events-header-message-kernel))))))
+
+(ein:deflocal ein:events-status-notebook nil)
+(ein:deflocal ein:events-status-kernel nil)
+
+(defun ein:events-header-message-notebook ()
+  (case ein:events-status-notebook
+    (notebook_saving.Notebook "Saving Notebook...")
+    (notebook_saved.Notebook "Notebook is saved")
+    (notebook_save_failed.Notebook "Failed to save Notebook!")))
+
+(defun ein:events-header-message-kernel ()
+  (case ein:events-status-kernel
+    (status_idle.Kernel nil)
+    (status_busy.Kernel "Kernel is busy...")))
 
 (defun ein:events-trigger (event)
-  ;; FIXME: implement event handling
-  (ein:log 'info "Event: %s" event))
+  (ein:log 'debug "Event: %s" event)
+  (case event
+    ((status_busy.Kernel status_idle.Kernel)
+     (setq ein:events-status-kernel event))
+    ((notebook_saving.Notebook
+      notebook_saved.Notebook
+      notebook_save_failed.Notebook)
+     (setq ein:events-status-notebook event))
+    (t
+     (ein:log 'info "Unknown event: %s" event))))
 
 (provide 'ein-events)
 

ein-notebook.el

@@ -205,6 +205,7 @@ the time of execution."
   (ein:notebook-from-json ein:notebook (ein:$notebook-data ein:notebook))
   (setq buffer-undo-list nil)  ; clear undo history
   (ein:notebook-mode)
+  (setq header-line-format ein:header-line-format)
   (ein:notebook-start-kernel)
   (ein:log 'info "Notebook %s is ready"
            (ein:$notebook-notebook-name ein:notebook)))
@@ -773,7 +774,7 @@ Do not clear input prompts when the prefix argument is given."
     ;; This is for putting read-only text properties to the newlines.
     (setf (ein:$notebook-ewoc notebook)
           (ewoc-create 'ein:notebook-pp
-                       (ein:propertize-read-only "IPython notebook\n\n")
+                       (ein:propertize-read-only "\n")
                        nil t))
     (mapc (lambda (cell-data)
             (ein:cell-enter-last

ein-utils.el

@@ -195,6 +195,11 @@ Adapted from twittering-mode.el's `case-string'."
         if key-p do (setq key p)
         else collect `(,key . ,p)))
 
+(defun ein:filter (predicate sequence)
+  (loop for item in sequence
+        when (funcall predicate item)
+        collect item))
+
 (defun ein:get-value (obj)
   "Get value from obj if it is a variable or function."
   (cond