diff -uprN mate-control-center/font-viewer/font-view.c mate-control-center-test/font-viewer/font-view.c

--- mate-control-center/font-viewer/font-view.c	2015-08-24 14:09:50.203993000 +0200

+++ mate-control-center-test/font-viewer/font-view.c	2015-08-24 18:19:12.425945769 +0200

@@ -287,6 +287,16 @@ font_install_finished_cb (GObject      *

 }

 static void

+font_model_config_changed_cb (FontViewModel *model,

+                              gpointer user_data)

+{

+    FontViewApplication *self = user_data;

+

+    if (self->font_file != NULL)

+        install_button_refresh_appearance (self, NULL);

+}

+

+static void

 install_button_clicked_cb (GtkButton *button,

                            gpointer user_data)

 {

@@ -611,6 +621,8 @@ font_view_application_startup (GApplicat

     g_object_unref (menu);

     self->model = font_view_model_new ();

+    g_signal_connect (self->model, "config-changed",

+                      G_CALLBACK (font_model_config_changed_cb), self);

     self->main_window = window = gtk_application_window_new (GTK_APPLICATION (application));

     gtk_window_set_resizable (GTK_WINDOW (window), TRUE);