std::cerr << "size_allocate " << GTK_WIDGET_REALIZED(widget) << std::endl;
gtk_math_view_size_allocate(GtkWidget* widget, GtkAllocation* allocation){  g_return_if_fail(widget != NULL);  g_return_if_fail(GTK_IS_MATH_VIEW (widget));  g_return_if_fail(allocation != NULL);  GtkMathView* math_view = GTK_MATH_VIEW(widget);    std::cerr << "size_allocate " << GTK_WIDGET_REALIZED(widget) << std::endl;  if (math_view->pixmap != NULL)    {      g_object_unref(math_view->pixmap);      math_view->pixmap = NULL;    }  widget->allocation = *allocation;  if (GTK_WIDGET_REALIZED(widget))    {      gdk_window_move_resize(widget->window,			     allocation->x, allocation->y,			     allocation->width, allocation->height);      paint_widget(math_view);    }}