add new example 'meshtastic' (WIP!) -- just a proof of concept version

examples/meshtastic/lisp/messages.lisp

@@ -0,0 +1,44 @@
+(in-package :msg)
+
+(defvar *messages*   nil)
+(defvar *message-id* 0)
+(defvar *states*     '(:not-received :out-there :received))
+
+(defun add-message (message &optional loading)
+  "Adds passed MESSAGE (a PLIST) to both the QML item model and *MESSAGES*.
+  The model keys are:
+  :m-text :m-sender :m-timestamp :m-id :m-ack-state"
+  (qjs |addMessage| ui:*messages* message)
+  (unless loading
+    (push message *messages*)
+    (qlater 'save-messages)))
+
+(defun change-state (state id)
+  (let ((i-state (position state *states*)))
+    (qjs |changeState| ui:*messages*
+         i-state id)
+    (dolist (msg *messages*)
+      (when (eql (getf msg :m-id) id) ; EQL: might be NIL
+        (setf (getf msg :m-ack-state) i-state)
+        (return))))
+  (qlater 'save-messages))
+
+(defvar *file* (merge-pathnames "data/messages.exp"))
+
+(defun load-messages ()
+  "Loads *MESSAGES* which can directly be passed to the QML item model."
+  (when (probe-file *file*)
+    (with-open-file (s *file*)
+      (setf *messages* (read s)))
+    (dolist (msg (reverse *messages*))
+      (setf *message-id* (max (or (getf msg :m-id) 0)
+                              *message-id*))
+      (add-message msg t))))
+
+(defun save-messages ()
+  "Saves *MESSAGES* by simply printing them into a file."
+  (ensure-directories-exist *file*)
+  (with-open-file (s *file* :direction :output :if-exists :supersede)
+    (let ((*print-pretty* nil))
+      (prin1 *messages* s))))
+