Insert renderer into the gutter. If renderer is yet unowned then gutter claims its ownership. Otherwise just increases renderer's reference count. renderer cannot be already inserted to another gutter.
a gutter renderer (must inherit from #GtkSourceGutterRenderer).
the renderer position.
true if operation succeeded. Otherwise false.
Insert renderer into the gutter. If renderer is yet unowned then gutter claims its ownership. Otherwise just increases renderer's reference count. renderer cannot be already inserted to another gutter.