Sets our main struct and passes it to the parent class.
Get the main Gtk struct
the main Gtk struct as a void*
the main Gtk struct
the main Gtk struct
Get the main Gtk struct
the main Gtk struct as a void*
Gets the #ShumateViewport used by this layer.
A [class@Shumate.Layer] implementation that fetches tiles from a [class@Shumate.MapSource] and draws them as a grid.