Gutter and Marks

GtkSourceGutter - Gutter object for GtkSourceView
GtkSourceGutterRenderer - Gutter cell renderer
GtkSourceGutterRendererPixbuf - Renders a pixbuf in the gutter
GtkSourceGutterRendererText - Renders text in the gutter
GtkSourceMark - Mark object for GtkSourceBuffer
GtkSourceMarkAttributes - The source mark attributes object