R/get_colours.R

In s-andrews/friendlypallettes: Query and Use friendly colour pallettes

#' Get the colours from a specific pallette
#'
#' @param short_name The pallette short name
#' @param num_colours Number of colours to return
#'
#' @return A vector of colours
#' @export
#'
#' @examples
#' get_colours("haicdf")
#' get_colours("ptccc", num_colours=4)
get_colours <- function(short_name, num_colours=0) {

  NULL -> pallette
  NULL -> index
  NULL -> colour

  if (! short_name %in% friendlypallettes::all_colours$pallette) {
    base::stop(base::paste("Couldn't find a pallette called",short_name))
  }

  assertthat::assert_that(assertthat::is.number(num_colours))

  assertthat::assert_that(
    friendlypallettes::all_colours %>% dplyr::filter(pallette==short_name) %>% base::nrow() >= num_colours,
    msg = "Not enough colours in this pallette"
  )


  friendlypallettes::all_colours %>%
    dplyr::filter(pallette == short_name) %>%
    dplyr::arrange(index) -> return_colours

  if (num_colours > 0) {
    return_colours %>%
      dplyr::filter(index <= num_colours) -> return_colours
  }

  return_colours %>% dplyr::pull(colour) %>% return()
}