GooCanvaItemSimple
is the base class for most items. It has an antialias
property which is of a type that maps to cairo_antialias_t
.
This is for the C version, not C++, but it should be easy to map to the 'mm' versions of the docs. Here's the equivalent for antialias in goocanvasmm.
When you don't know where a property is, just dig in the parent classes or interfaces implemented until you find it.
Then, set the value of the appropriate Cairo::Antialias type (which is a type defined in cairomm).
rect->property_antialias() = Cairo::ANTIALIAS_NONE;