Add window state to GSettings schema

data/eu.polonkai.gergely.gnome-gitlab.gschema.xml.in.in

@@ -6,4 +6,25 @@
       <_description>List of GitLab instances to show.</_description>
     </key>
   </schema>
+
+  <schema id="eu.polonkai.gergely.gnome-gitlab.state" path="/eu/polonkai/gergely/gnome-gitlab/state/">
+    <child schema="eu.polonkai.gergely.gnome-gitlab.state.window" name="window"/>
+  </schema>
+
+  <schema id="eu.polonkai.gergely.gnome-gitlab.state.window" path="/eu/polonkai/gergely/gnome-gitlab/state/window/">
+    <key type="i" name="state">
+      <default>0</default>
+      <_summary>Window state</_summary>
+      <_description>
+        State of the window: i.e. maximized.
+      </_description>
+    </key>
+    <key type="(ii)" name="size">
+      <default>(800, 600)</default>
+      <_summary>Window width and height</_summary>
+      <_description>
+        Width and height of the window
+      </_description>
+    </key>
+  </schema>
 </schemalist>

src/gg-window.vala

@@ -12,12 +12,32 @@ namespace GnomeGitlab
         [GtkChild]
         private Gtk.HeaderBar header_bar;
 
+        private GLib.Settings settings;
+
         public Window (Application app)
         {
             Object (application: app);
 
             add_action_entries (action_entries, this);
 
+            settings = new Settings ("eu.polonkai.gergely.gnome-gitlab.state.window");
+            settings.delay ();
+
+            destroy.connect (() => {
+                settings.apply ();
+            });
+
+            Gdk.WindowState window_state = (Gdk.WindowState)settings.get_int ("state");
+
+            if (Gdk.WindowState.MAXIMIZED in window_state) {
+                maximize ();
+            }
+
+            int width, height;
+
+            settings.get ("size", "(ii)", out width, out height);
+            resize (width, height);
+
             show_all ();
         }