Sets the icon of the tooltip (which is in front of the text) to be the icon indicated by @gicon with the size indicated by @size. If @gicon is %NULL, the image will be hidden.
a #GIcon representing the icon, or %NULL
See Implementation
Sets the icon of the tooltip (which is in front of the text) to be the icon indicated by @gicon with the size indicated by @size. If @gicon is %NULL, the image will be hidden.