doc: improve gen_grob manual

R/grid_grobs.R

@@ -83,6 +83,9 @@
 #'
 #' @return a grob (gTree) object made with package `grid`
 #' @examples
+#' \dontshow{
+#' data.table::setDTthreads(1)
+#' }
 #' library(ragg)
 #' library(gdtools)
 #' register_liberationsans()
@@ -110,6 +113,28 @@
 #' )
 #' plot(gr)
 #' dev.off()
+#'
+#'
+#' if (require("ggplot2")) {
+#'   png_f_3 <- tempfile(fileext = ".png")
+#'   z <- summarizor(iris, by = "Species") |>
+#'     as_flextable(spread_first_col = TRUE) |>
+#'     color(color = "gray", part = "all")
+#'   gg <- ggplot(data = iris, aes(Sepal.Length, Petal.Width)) +
+#'     annotation_custom(
+#'       gen_grob(z, scaling = "full"),
+#'       xmin  = 4.5, xmax = 7.5, ymin = 0.25, ymax = 2.25) +
+#'     geom_point() +
+#'     theme_minimal()
+#'   ragg::agg_png(
+#'     filename = png_f_3, width = 7,
+#'     height = 7, units = "in", res = 150
+#'   )
+#'   print(gg)
+#'   dev.off()
+#' }
+#'
+#'
 #' @family flextable print function
 #' @importFrom grid gTree
 gen_grob <- function(x,