Replaces the widget packed into the tooltip with
custom_widget. custom_widget does not get destroyed when the tooltip goes
away.
By default a box with a #GtkImage and #GtkLabel is embedded in
the tooltip, which can be configured using gtk.tooltip.Tooltip.setMarkup
and gtk.tooltip.Tooltip.setIcon.
Replaces the widget packed into the tooltip with custom_widget. custom_widget does not get destroyed when the tooltip goes away. By default a box with a #GtkImage and #GtkLabel is embedded in the tooltip, which can be configured using gtk.tooltip.Tooltip.setMarkup and gtk.tooltip.Tooltip.setIcon.