Move data directory creation/query code to ag_get_user_data_dir()

src/ag-db.c

@@ -456,30 +456,17 @@ static void
 ag_db_init(AgDb *db)
 {
     GdaSqlParser *parser;
-    GFile        *user_data_dir = g_file_new_for_path(g_get_user_data_dir()),
-                 *ag_data_dir   = g_file_get_child(user_data_dir, "astrognome");
+    GFile        *ag_data_dir   = ag_get_user_data_dir();
     AgDbPrivate  *priv          = ag_db_get_instance_private(db);
     gchar        *path          = g_file_get_path(ag_data_dir);
     GError       *err           = NULL;
 
     gda_init();
 
-    if (!g_file_query_exists(ag_data_dir, NULL)) {
-        gchar *path = g_file_get_path(ag_data_dir);
-
-        if (g_mkdir_with_parents(path, 0700) != 0) {
-            g_error(
-                    "Data directory %s does not exist and can not be created.",
-                    path
-                );
-        }
-    }
-
     priv->dsn = g_strdup_printf("SQLite://DB_DIR=%s;DB_NAME=charts", path);
 
     g_free(path);
-    g_object_unref(user_data_dir);
-    g_object_unref(ag_data_dir);
+    g_clear_object(&ag_data_dir);
 
     priv->conn = gda_connection_open_from_string(
             NULL,

src/astrognome.c

@@ -188,6 +188,40 @@ ag_house_system_nick_to_id(const gchar *nick)
     return GSWE_HOUSE_SYSTEM_NONE;
 }
 
+/**
+ * ag_get_user_data_dir:
+ *
+ * Creates the astrognome data directory (~/.local/share/astrognome on XDG
+ * compatible systems) if necessary, and returns a GFile handle to it.
+ *
+ * Returns: (transfer full): a #GFile handle to the application data directory
+ *          that must be freed with g_object_unref().
+ */
+GFile *
+ag_get_user_data_dir(void)
+{
+    GFile *user_data_dir = g_file_new_for_path(g_get_user_data_dir()),
+          *ag_data_dir   = g_file_get_child(user_data_dir, "astrognome");
+
+    g_clear_object(&user_data_dir);
+    g_assert(ag_data_dir);
+
+    if (!g_file_query_exists(ag_data_dir, NULL)) {
+        gchar *path = g_file_get_path(ag_data_dir);
+
+        if (g_mkdir_with_parents(path, 0700) != 0) {
+            g_error(
+                    "Data directory ‘%s’ does not exist and cannot be created.",
+                    path
+                );
+        }
+
+        g_free(path);
+    }
+
+    return ag_data_dir;
+}
+
 int
 main(int argc, char *argv[])
 {

src/astrognome.h

@@ -1,6 +1,7 @@
 #ifndef __ASTROGNOME_H__
 #define __ASTROGNOME_H__
 
+#include <gtk/gtk.h>
 #include <swe-glib.h>
 
 typedef struct {
@@ -34,6 +35,7 @@ enum {
 
 const gchar *ag_house_system_id_to_nick(GsweHouseSystem house_system);
 GsweHouseSystem ag_house_system_nick_to_id(const gchar *nick);
+GFile *ag_get_user_data_dir(void);
 
 #ifndef GDOUBLE_FROM_LE
 inline static gdouble