gtk-render-expander (context cr x y width height)

context -- a gtk-style-context object
cr -- a cairo-t context
x -- a number, coerced to a double float, with the x origin of the rectangle
y -- a number, coerced to a double float, with the y origin of the rectangle
width -- a number, coerced to a double float, with a rectangle width
height -- a number, coerced to a double float, with a rectangle height

Renders an expander as used in the gtk-tree-view widget and gtk-expander widget in the area defined by x, y, width, height. The :active state of the gtk-state-flags flags determines whether the expander is collapsed or expanded.