Add json test

Gtkmm4/gtk145_gtkui6_a2/src/MyPrefs.cc

@@ -8,6 +8,7 @@ MyPrefs::MyPrefs(){
     ref_builder = Gtk::Builder::create_from_resource("/org/gtk/daleclack/prefs_stack.ui");
 
     // Initalize title widget
+    // Add stack switcher to the titlebar
     stack_switcher = ref_builder->get_widget<Gtk::StackSwitcher>("stack_switch");
     header.set_title_widget(*stack_switcher);
     header.set_decoration_layout("close:menu");

cpp/jsonfile_tests/json_object.cpp

@@ -0,0 +1,55 @@
+/*
+A test for json library from nlohmann,
+the json object will be a data of the json file
+2023/1/29 dale clack
+*/
+#include "../../json_nlohmann/json.hpp"
+#include <iostream>
+#include <fstream>
+
+using json = nlohmann::json;
+
+// Function pointer
+typedef void (*funcs)();
+
+void read_json_file()
+{
+}
+
+void create_json_file()
+{
+    // Create json data
+    json data = json::parse(R"(
+        {
+            data1 : {},
+            data2 : {}
+        }
+    )");
+
+    // Create json object for a key
+    // json data2 = json::parse(R"(
+    //     {
+    //         test1:2,
+    //         test2:3
+    //     }
+    // )");
+
+    // data["data2"] = data;
+    // auto data2 = data["data2"];
+    // std::cout << data2 << std::endl;
+
+    // Save data to a json file
+    std::fstream outfile;
+    outfile.open("test.json", std::ios_base::out);
+    if (outfile.is_open())
+    {
+        outfile << data;
+    }
+    outfile.close();
+}
+
+int main()
+{
+    create_json_file();
+    return 0;
+}