R/theme_pitch.R

In Torvaney/ggsoccer: Plot Soccer Event Data

#' Removes background and axes details from a ggplot plot.
#'
#' Functionally very similar to `ggplot2::theme_void`.
#'
#' @param aspect_ratio Aspect ratio (`y / x`) for the plot.
#'   Use `NULL` to let the plot take any aspect ratio.
#'
#' @return list of ggplot themes to be added to a ggplot plot
#'
#' @examples
#' library(ggplot2)
#'
#' shots_data <- data.frame(x = c(90, 85, 82, 78, 83),
#'                          y = c(43, 40, 52, 56, 44))
#'
#' p <- ggplot(shots_data, aes(x = x, y = y)) +
#'   annotate_pitch() +
#'   geom_point()
#'
#' # Pitch fixed to 68/105 by default
#' p + theme_pitch()
#'
#' # Free aspect
#' p + theme_pitch(aspect_ratio = NULL)
#'
#' @export
theme_pitch <- function(aspect_ratio = 68/105) {

  theme_basic <- ggplot2::theme(
      panel.grid.major = ggplot2::element_blank(),
      panel.grid.minor = ggplot2::element_blank(),
      axis.title       = ggplot2::element_blank(),
      axis.ticks       = ggplot2::element_blank(),
      axis.text        = ggplot2::element_blank(),
      axis.line        = ggplot2::element_blank(),
      panel.background = ggplot2::element_blank(),
      panel.border     = ggplot2::element_blank()
  )

  if (!is.null(aspect_ratio)) {
    return(list(theme_basic,
                ggplot2::theme(aspect.ratio = aspect_ratio)))
  }

  list(theme_basic)
}