public virtual signal void map ()
The map signal is emitted when
widget is going to be mapped, that is when the widget is visible (which
is controlled with set_visible) and all its parents up to the toplevel
widget are also visible.
Once the map has occurred, map_event will be emitted.
The map signal can be used to determine whether a widget will be drawn, for instance it can resume an animation that was stopped during the emission of unmap.