R/utils.R

In palettes: Methods for Colour Vectors and Colour Palettes

str_to_hex <- function(x) {
  print_alpha <- getOption("palettes.print_alpha")
  alpha <- NULL
  col_rgb <- farver::decode_colour(x, alpha = print_alpha)
  if (print_alpha) alpha <- col_rgb[,"alpha"]
  farver::encode_colour(col_rgb, alpha = alpha)
}

is_valid_colour <- function(x) {
  is_named_colour <- x %in% colour_names # From sysdata.rda
  is_hex_colour <- grepl(x, pattern = "^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{8})$")
  is_na_colour <- is.na(x)
  is_valid <- is_named_colour | is_hex_colour | is_na_colour
  is_valid
}