The tool can serve at the same time for entering a single point, a polyline with a given number of points, and for open as well as closed polylines.
The template parameter of GraphicsViewPolylineInput<K> must be a Cgal Kernel.
p is a parent object. s is the scene where the polyline is generated. n is the
number of points of the polyline to be generated. If c is equal to 0,
the default value, the number of points of the polyline is not
limited. When closed is true the function displays a
||The object o contains a std:list<K::Point_2>.|