R/sm_add_text.R

In smin95/sesR: Create Standalone and Composite Plots in 'ggplot2' for Publications

#' Add a text annotation onto the combined plot
#'
#' @param label
#' Text label in strings.
#' @param x
#' Location of the text annotation along the x-axis of the combined figure. Default is the middle origin (0.5). Values from 0 to 1.
#' @param y
#' Location of the text annotation along the y-axis of the combined figure. Default is the middle origin (0.5). Values from 0 to 1.
#' @param angle
#' Angle of the text. Default is set to 0 (i.e., horizontal orientation).
#' @param color
#' Color of the text. Default is set to 'black'.
#' @param fontface
#' The default is to set the text as plain This can be changed, to
#' either "plain", "bold", "italic", "bold.italic" .
#' @param size
#' Size of the text annotation
#' @param ...
#' Other parameters of the text that will be transferred to the function annotate()
#' from ggplot2.
#' @return
#' Prints a text in the combined plot.
#' @export
#' @importFrom cowplot ggdraw draw_plot theme_nothing
#'
#' @examples
#' library(smplot2)
#' library(ggplot2)
#' ggplot(data = mtcars, mapping = aes(x = drat, y = mpg)) +
#'   geom_point(
#'     shape = 21, fill = "#0f993d", color = "white",
#'     size = 3
#'   ) -> p1
#'
#' ggplot(data = mtcars, mapping = aes(x = drat, y = mpg)) +
#'   geom_point(shape = 21, fill = "#0f993d", color = "white", size = 3) +
#'   sm_hvgrid() -> p2
#'
#' combined_fig <- sm_put_together(list(p1, p2), ncol = 2, nrow = 1)
#' combined_fig + sm_add_text(label = "My label", x = .5, y = .5)
#'
sm_add_text <- function(label, x = 0.5, y = 0.5, angle = 0, color = "black",
                        fontface = "plain", size = 10, ...) {
  ggplot(NULL) +
    theme_nothing() +
    annotate("text",
      label = label, x = .5, y = .5,
      angle = angle, color = color,
      size = size / .pt,
      fontface = fontface, ...
    ) +
    scale_x_continuous(
      limits = c(0, 1),
      expand = c(0, 0)
    ) +
    scale_y_continuous(
      limits = c(0, 1),
      expand = c(0, 0)
    ) -> annot

  x <- x - 0.5
  y <- y - 0.5

  output <- draw_plot(annot, x, y)
  return(output)
}