add demo for testing gtk_menu_popup_at_* ()

https://bugzilla.gnome.org/show_bug.cgi?id=756579

tests/Makefile.am

@@ -172,6 +172,7 @@ noinst_PROGRAMS =  $(TEST_PROGS)	\
 	gdkgears			\
 	listmodel			\
 	testpopup			\
+	testpopupat			\
 	$(NULL)
 
 if USE_X11

tests/testpopupat.c

@@ -0,0 +1,64 @@
+#include <gtk/gtk.h>
+
+static void
+destroy_cb (GtkWidget  *window,
+            GtkBuilder *builder)
+{
+  gtk_main_quit ();
+}
+
+static void
+populate_popup_cb (GtkAppChooserWidget *app_chooser_widget,
+                   GtkMenu             *menu,
+                   GAppInfo            *app_info,
+                   gpointer             user_data)
+{
+  GtkWidget *menu_item;
+
+  menu_item = gtk_menu_item_new_with_label ("Menu Item A");
+  gtk_widget_show (menu_item);
+  gtk_menu_shell_append (GTK_MENU_SHELL (menu), menu_item);
+
+  menu_item = gtk_menu_item_new_with_label ("Menu Item B");
+  gtk_widget_show (menu_item);
+  gtk_menu_shell_append (GTK_MENU_SHELL (menu), menu_item);
+
+  menu_item = gtk_menu_item_new_with_label ("Menu Item C");
+  gtk_widget_show (menu_item);
+  gtk_menu_shell_append (GTK_MENU_SHELL (menu), menu_item);
+
+  menu_item = gtk_menu_item_new_with_label ("Menu Item D");
+  gtk_widget_show (menu_item);
+  gtk_menu_shell_append (GTK_MENU_SHELL (menu), menu_item);
+
+  menu_item = gtk_menu_item_new_with_label ("Menu Item E");
+  gtk_widget_show (menu_item);
+  gtk_menu_shell_append (GTK_MENU_SHELL (menu), menu_item);
+}
+
+int
+main (int   argc,
+      char *argv[])
+{
+  GtkBuilder *builder;
+  GtkWidget *window;
+  GtkWidget *app_chooser_widget;
+
+  gtk_init (&argc, &argv);
+
+  builder = gtk_builder_new_from_file ("popupat.ui");
+
+  window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
+  g_signal_connect (window, "destroy", G_CALLBACK (destroy_cb), builder);
+
+  app_chooser_widget = GTK_WIDGET (gtk_builder_get_object (builder, "appchooserwidget"));
+  g_signal_connect (app_chooser_widget, "populate-popup", G_CALLBACK (populate_popup_cb), builder);
+
+  gtk_widget_show_all (window);
+
+  gtk_main ();
+
+  g_object_unref (builder);
+
+  return 0;
+}