Add pal_impact()

R/pal_impact.R

@@ -0,0 +1,34 @@
+#' @title Return function to interpolate an IMPACT color palette
+#'
+#' @param palette Character name of a palette in IMPACT palettes
+#' @param reverse Boolean indicating whether the palette should be reversed
+#' @param color_ramp_palette Should the output be a `grDevices::colorRampPalette` function or a vector of hex codes? Default to the former with `TRUE`
+#' @param show_palettes Should the ouput be the set of palettes names to pick from? Default to `FALSE`
+#' @param ... Additional arguments to pass to colorRampPalette()
+#'
+#' @return A color palette
+#'
+#' @export
+pal_impact <- function(palette = "main", reverse = FALSE, color_ramp_palette = FALSE, show_palettes = FALSE, ...) {
+
+
+  palettes_impact <- list(
+    `main`            = cols_impact("black", "white", "main_blue", "main_grey"),
+    `primary`         = cols_impact("black", "white"),
+    `secondary`       = cols_impact("main_blue", "main_grey")
+  )
+
+  if (show_palettes) return(names(palettes_impact))
+
+  pal <- palettes_impact[[palette]]
+
+  if (reverse) pal <- rev(pal)
+
+  if (color_ramp_palette) {
+    rlang::check_installed("grDevices", reason = "Package \"grDevices\" needed for `pal_impact()` woth 'color_ramp_palette' set to `TRUE` to work. Please install it.")
+
+    pal <- grDevices::colorRampPalette(pal, ...)
+  }
+
+  return(pal)
+}