add Application class

src/application.vala

@@ -1,8 +1,8 @@
-/*
+/**
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
+ * any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -15,15 +15,28 @@
 
 using Gtk;
 
-int main (string[] args) {
+namespace Yggtk {
 
-    Gtk.init (ref args);
+    public class Application : Gtk.Application {
 
-    Yggtk.AppWindow window = new Yggtk.AppWindow ();
-    window.show_all ();
+        public Application () {
+            Object (
+                application_id: "org.yggtk.yggtk",
+                flags: ApplicationFlags.FLAGS_NONE
+            );
+        }
 
-    Gtk.main ();
+        protected override void activate () {
+            AppWindow window = new AppWindow ();
+            add_window (window);
+            window.show ();
+        }
 
-    return 0;
+        public static int main (string[] args) {
+            Application app = new Application ();
+            return app.run (args);
+        }
+
+    }
 
 }

src/meson.build

@@ -1,5 +1,5 @@
 yggtk_sources = [
-  'main.vala',
+  'application.vala',
   'app-window.vala',
   'utils.vala',
 ]