R/view_pjo_palettes.R

In MaiaPelletier/pjocolours: Color Palettes based on Percy Jackson and the Olympians book covers

#' A PJO palette generator
#'
#'
#' @param n Number of colors desired.
#' @param name Name of desired palette.
#' @return A vector of colours.
#' @export
#' @keywords colors

view_pjo_palette <- function(name, n) {


  pal <- pjo_palettes[[name]]
  if (is.null(pal))
    stop("Palette not found.")

  if (missing(n)) {
    n <- length(pal)
  }

  if (n > length(pal)) {
    stop("Number of requested colors greater than what palette can offer")
  }

  out <- pal[1:n]

  structure(out, class = "palette", name = name)
}

#' @export
#' @importFrom graphics rect par image text
#' @importFrom grDevices rgb
print.palette <- function(x, ...) {
  n <- length(x)
  old <- par(mar = c(0.5, 0.5, 0.5, 0.5))
  on.exit(par(old))

  image(1:n, 1, as.matrix(1:n), col = x,
        ylab = "", xaxt = "n", yaxt = "n", bty = "n")

  rect(0, 0.9, n + 1, 1.1, col = rgb(1, 1, 1, 0.8), border = NA)
  text((n + 1) / 2, 1, labels = attr(x, "name"), cex = 1, family = "sans", col = "#32373D")
}