disable/enable notify for GtkInstanceButton

Change-Id: I477d5eed61d82cf711df3120c92f6011177f88ab
Reviewed-on: https://gerrit.libreoffice.org/53686Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/unx/gtk3/gtk3gtkinst.cxx

@@ -2519,6 +2519,18 @@ public:
         m_aClickHdl = Link<Button&, void>();
     }
 
+    virtual void disable_notify_events() override
+    {
+        g_signal_handler_block(m_pButton, m_nSignalId);
+        GtkInstanceContainer::disable_notify_events();
+    }
+
+    virtual void enable_notify_events() override
+    {
+        GtkInstanceContainer::enable_notify_events();
+        g_signal_handler_unblock(m_pButton, m_nSignalId);
+    }
+
     virtual ~GtkInstanceButton() override
     {
         g_object_steal_data(G_OBJECT(m_pButton), "g-lo-GtkInstanceButton");