example 'meshtastic': add proper local data paths on desktop

examples/meshtastic/app.asd

@@ -19,3 +19,4 @@
                (:file "lisp/lora")
                (:file "lisp/location")
                (:file "lisp/main")))
+

examples/meshtastic/cpp/qt.cpp

@@ -146,6 +146,17 @@ QVariant QT::sqlQuery(const QVariant& vQuery, const QVariant& vValues) {
 
 // etc
 
+QVariant QT::dataPath() {
+  // for desktop
+  static QString path;
+  if (path.isEmpty()) {
+    path = QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation);
+    path.truncate(path.lastIndexOf(QChar('/')));
+    path.append("/cl-meshtastic/data/");
+  }
+  return path;
+}
+
 QVariant QT::localIp() {
   // Returns the local IP string. Private networks may use:
   // 10.*.*.*

examples/meshtastic/cpp/qt.h

@@ -34,6 +34,7 @@ public:
   Q_INVOKABLE QVariant sqlQuery(const QVariant&, const QVariant&);
 
   // etc
+  Q_INVOKABLE QVariant dataPath();
   Q_INVOKABLE QVariant localIp();
   Q_INVOKABLE QVariant startTileServer();
 

examples/meshtastic/lisp/db.lisp

@@ -1,11 +1,12 @@
 (in-package :db)
 
-(defvar *file* (merge-pathnames "data/db"))
+(defvar *file* nil)
 
 (defun query (query &rest values)
   (qt:sql-query qt:*cpp* query values))
 
 (defun ini ()
+  (setf *file* (app:in-data-path "db"))
   (ensure-directories-exist *file*)
   (qt:ini-db qt:*cpp* (namestring *file*))
   (query "create table if not exists messages (mid integer primary key, uid integer, message text)"))

examples/meshtastic/lisp/location.lisp

@@ -81,7 +81,7 @@
         0)))
 
 (defun tile-path ()
-  (namestring (merge-pathnames "data/tiles/")))
+  (namestring (app:in-data-path "tiles/")))
 
 (defun activate-map ()
   (unless (q< |active| ui:*map-loader*)

examples/meshtastic/lisp/main.lisp

@@ -18,6 +18,12 @@
     (ensure-permissions :bluetooth-scan :bluetooth-connect)) ; android >= 12
   (lora:start-device-discovery (or (setting :device) "")))
 
+(defun in-data-path (file)
+  #+mobile
+  (merge-pathnames (x:cc "data/" file))
+  #-mobile
+  (x:cc (qt:data-path qt:*cpp*) file))
+
 (defun view-index-changed (index) ; see QML
   (when (and (= 1 index)
              (not (app:setting :latest-receiver)))
@@ -37,17 +43,17 @@
 
 ;;; settings
 
-(defvar *file* (merge-pathnames "data/settings.exp"))
-
+(let (file)
   (defun load-settings ()
-  (when (probe-file *file*)
-    (with-open-file (s *file*)
+    (unless file
+      (setf file (in-data-path "settings.exp")))
+    (when (probe-file file)
+      (with-open-file (s file)
         (setf lora:*settings* (read s)))))
-
   (defun save-settings ()
-  (with-open-file (s *file* :direction :output :if-exists :supersede)
+    (with-open-file (s file :direction :output :if-exists :supersede)
       (let ((*print-pretty* nil))
-      (prin1 lora:*settings* s))))
+        (prin1 lora:*settings* s)))))
 
 (defun kw (string)
   "Intern in KEYWORD package."

examples/meshtastic/lisp/package.lisp

@@ -3,6 +3,7 @@
   (:export
    #:change-setting
    #:icon-press-and-hold
+   #:in-data-path
    #:ini
    #:load-settings
    #:my-ip

examples/meshtastic/lisp/qt.lisp

@@ -2,6 +2,7 @@
   (:use :cl :qml)
   (:export
    #:*cpp*
+   #:data-path
    #:ini
    #:ini-db
    #:ini-positioning

examples/meshtastic/readme-usage.md

@@ -99,8 +99,9 @@ Save / Restore data
 -------------------
 
 A local web-server is included on mobile for saving and restoring the message
-DB and the app settings. Just use special text message `:w` (for 'web-server')
-and `:ws` (for 'stop web-server') after you're done.
+DB, the app settings, plus eventually cached map tiles (for offline usage).
+Just use special text message `:w` (for 'web-server') and `:ws` (for 'stop
+web-server') after you're done.
 
 After starting the server, just enter the shown URL in your desktop browser,
 and follow the instructions.
@@ -108,6 +109,12 @@ and follow the instructions.
 Using this method you can easily transfer all data from one mobile device to
 any other device.
 
+The desktop data paths are:
+
+* Linux: `~/.local/share/cl-meshtastic/data/`
+* macOS: `~/Library/Application Support/cl-meshtastic/data/`
+* Windows: TODO
+
 
 Tips
 ----