ggraph doesn't respect `ggplot2.discrete.colour` and friends

[malcolmbarrett]

I believe this is because scale_edge_color_discrete() is an alias for scale_edge_colour_hue() and thus calls ggplot2::scale_colour_hue() instead of ggplot2::scale_colour_discrete()

ggraph/R/scale_edge_colour.R

Lines 23 to 27 in 9a0bfb1

	scale_edge_colour_hue <- function(..., h = c(0, 360) + 15, c = 100, l = 65, h.start = 0,
	direction = 1, na.value = "grey50", aesthetics = "edge_colour") {
	scale_colour_hue(..., h = h, c = c, l = l, h.start = h.start,
	direction = direction, na.value = na.value, aesthetics = aesthetics)
	}

I haven't checked if other scales have this problem of ignoring the ggplot2 options

[teunbrand]

The scale_colour_discrete(type) mechanism is superseded in ggplot2 4.0.0, so I don't think that ggraph should opt-in that mechanism. It may be good to adopt the theme palette mechanism though.