GUI: Open from CSV file, if one file is chosen

gui_gtk/main.cpp

 #include <math.h>
 #include <iostream>
+#include <clocale>
 using namespace std;
 
 #include <gtk/gtk.h>
 
     bool ok = true;
     if (gtk_dialog_run(GTK_DIALOG(dialog)) == GTK_RESPONSE_ACCEPT) {
-        GSList *list = gtk_file_chooser_get_filenames(GTK_FILE_CHOOSER(dialog));
-        vector<string> new_list;
-
-        GSList *element = list;
-        while (element != NULL) {
-            ok = ok && gui->stack.add_from_file_path((const char*)(element->data));
-            g_free(element->data);
-            element = g_slist_next(element);
-            if (!ok) {
-                break;
+        vector<string> path_list;
+
+        {
+            GSList *list = gtk_file_chooser_get_filenames(GTK_FILE_CHOOSER(dialog));
+
+            GSList *element = list;
+            while (element != NULL) {
+                path_list.push_back(string((const char*)(element->data)));
+                g_free(element->data);
+                element = g_slist_next(element);
+                if (!ok) {
+                    break;
+                }
             }
+
+            g_slist_free(list);
         }
 
-        g_slist_free(list);
+        if (path_list.size() == 1) {
+            ok = gui->stack.read_from_csv_file(path_list[0].c_str());
+        } else {
+            for (unsigned int i = 0; i < path_list.size(); i++) {
+                ok = ok && gui->stack.add_from_file_path(path_list[i].c_str());
+            }
+        }
     }
 
     if (ok) {
 
     gtk_widget_show_all(gui.window);
 
+    // Set C-locale number format.
+    // Make strtod work with strings like "0.1" (instead of "0,1")
+    std::setlocale(LC_NUMERIC, "C");
+
     gtk_main ();
 
     return 0;