Add a note that geom_raster() ignores colour (#4943)

Author: yutannihilation

R/geom-tile.r

@@ -7,7 +7,7 @@
 #' `y`, `width`, `height`). `geom_raster()` is a high
 #' performance special case for when all the tiles are the same size.
 #'
-#' @eval rd_aesthetics("geom", "tile")
+#' @eval rd_aesthetics("geom", "tile", "Note that `geom_raster()` ignores `colour`.")
 #' @inheritParams layer
 #' @inheritParams geom_point
 #' @inheritParams geom_segment

R/utilities-help.r

@@ -1,4 +1,6 @@
-rd_aesthetics <- function(type, name) {
+# Use extra_note arg to add some notes (e.g. the document is shared with multiple
+# Geoms and there's some difference among their aesthetics).
+rd_aesthetics <- function(type, name, extra_note = NULL) {
   obj <- switch(type,
     geom = check_subclass(name, "Geom", env = globalenv()),
     stat = check_subclass(name, "Stat", env = globalenv())
@@ -14,6 +16,7 @@ rd_aesthetics <- function(type, name) {
     "\\itemize{",
     paste0("  \\item ", aes),
     "}",
+    if (!is.null(extra_note)) paste0(extra_note, "\n"),
     "Learn more about setting these aesthetics in \\code{vignette(\"ggplot2-specs\")}."
   )
 }