clapper-app: Add "New Window" menu option

Allow creating new windows from within the app

src/bin/clapper-app/clapper-app-application.c

@@ -217,6 +217,21 @@ add_uri (GSimpleAction *action, GVariant *param, gpointer user_data)
   clapper_app_uri_dialog_open_uri (gtk_app);
 }
 
+static void
+new_window (GSimpleAction *action, GVariant *param, gpointer user_data)
+{
+  GtkApplication *gtk_app = GTK_APPLICATION (user_data);
+  GtkWidget *stack = gtk_window_get_child (gtk_application_get_active_window (gtk_app));
+  const gchar *child_name = gtk_stack_get_visible_child_name (GTK_STACK (stack));
+
+  /* Do not allow to open new windows during initial state,
+   * there already is a free one to use */
+  if (g_strcmp0 (child_name, "initial_state") != 0) {
+    GtkWidget *window = clapper_app_window_new (gtk_app);
+    gtk_window_present (GTK_WINDOW (window));
+  }
+}
+
 static void
 show_preferences (GSimpleAction *action, GVariant *param, gpointer user_data)
 {
@@ -648,6 +663,7 @@ clapper_app_application_constructed (GObject *object)
   static const GActionEntry app_actions[] = {
     { "add-files", add_files, NULL, NULL, NULL },
     { "add-uri", add_uri, NULL, NULL, NULL },
+    { "new-window", new_window, NULL, NULL, NULL },
     { "info", show_info, NULL, NULL, NULL },
     { "preferences", show_preferences, NULL, NULL, NULL },
     { "about", show_about, NULL, NULL, NULL },

src/bin/clapper-app/ui/clapper-app-headerbar.ui

@@ -178,6 +178,12 @@
     </child>
   </template>
   <menu id="app_menu">
+    <section>
+      <item>
+        <attribute name="label" translatable="yes">New Window</attribute>
+        <attribute name="action">app.new-window</attribute>
+      </item>
+    </section>
     <section>
       <item>
         <attribute name="label" translatable="yes">Preferences</attribute>