economist.R

#' Economist color palette (discrete)
#'
#' The hues in the palette are blues, grays, and greens. Red is not
#' included in these palettes and should be used to indicate
#' important data.
#'
#' @param fill Use the fill palette.
#' @family colour economist
#' @export
#' @example inst/examples/ex-economist_pal.R
economist_pal <- function(fill = TRUE) {
  colors <- deframe(ggthemes::ggthemes_data[["economist"]][["fg"]])
  if (fill) {
    max_n <- 9
    f <- function(n) {
      check_pal_n(n, max_n)
      if (n == 1L) {
        i <- "dark blue"
      } else if (n == 2L) {
        i <- c("blue", "dark blue")
      } else if (n == 3L) {
        i <- c("blue-gray", "dark blue", "blue")
      } else if (n == 4L) {
        i <- c("blue-gray", "dark blue", "blue", "gray")
      } else if (n %in% 5:6) {
        ## 20120901_woc904
        i <- c(
          "blue-gray", "dark blue", "light blue", "blue",
          "light green", "dark green"
        )
      } else if (n == 7L) {
        # 20120818_AMC820
        i <- c(
          "blue-gray", "dark blue", "blue", "light blue",
          "dark green", "light green", "gray"
        )
      } else if (n >= 8L) {
        # 20120915_EUC094
        i <- c(
          "blue-gray", "dark blue", "blue", "light blue",
          "dark green", "light green", "dark red", "pink",
          "gray"
        )
      }
      unname(colors[i][seq_len(n)])
    }
  } else {
    max_n <- 9
    f <- function(n) {
      check_pal_n(n, max_n)
      if (n <= 3) {
        # 20120818_AMC20
        # 20120901_FBC897
        i <- c("dark blue", "blue", "light blue")
      } else if (n %in% 4:5) {
        # i <- c("dark blue", "blue", "light blue", "red", "gray")
        i <- c("dark blue", "blue", "light blue", "blue-gray", "gray")
      } else if (n == 6) {
        # 20120825_IRC829
        i <- c(
          "light green", "dark green", "gray",
          "blue-gray", "light blue", "dark blue"
        )
      } else if (n > 6) {
        # 20120825_IRC829
        i <- c(
          "light green", "dark green", "gray",
          "blue-gray", "light blue", "dark blue", "dark red",
          "pink", "brown"
        )
      }
      unname(colors[i][seq_len(n)])
    }
  }
  attr(f, "max_n") <- max_n
  f
}

#' Economist color scales
#'
#' Color scales using the colors in the Economist graphics.
#'
#' @inheritParams ggplot2::scale_colour_hue
#' @inheritParams economist_pal
#' @family colour economist
#' @rdname scale_economist
#' @seealso \code{\link{theme_economist}()} for examples.
#' @export
scale_colour_economist <- function(...) {
  discrete_scale("colour", "economist", economist_pal(), ...)
}

#' @rdname scale_economist
#' @export
scale_color_economist <- scale_colour_economist

#' @rdname scale_economist
#' @export
scale_fill_economist <- function(...) {
  discrete_scale("fill", "economist", economist_pal(), ...)
}

#' ggplot color theme based on the Economist
#'
#' A theme that approximates the style of \emph{The Economist}.
#'
#' \code{theme_economist} implements the standard bluish-gray
#' background theme in the print \emph{The Economist} and
#' \href{https://www.economist.com/}{economist.com}.
#'
#' \code{theme_economist_white} implements a variant with a while
#' panel and light gray (or white) background often used by \emph{The Economist}
#' blog \href{https://www.economist.com/blogs/graphicdetail}{Graphic Detail}.
#'
#' Use \code{\link{scale_color_economist}()} with this theme.
#' The x axis should be displayed on the right hand side.
#'
#' \emph{The Economist} uses "ITC Officina Sans" as its font for graphs. If
#' you have access to this font, you can use it with the
#' \pkg{extrafont} package. "Verdana" is a good substitute.
#'
#' @inheritParams ggplot2::theme_grey
#' @param horizontal \code{logical} Horizontal axis lines?
#' @param dkpanel \code{logical} Darker background for panel region?
#' @param gray_bg \code{logical} If \code{TRUE}, use gray background, else
#'    use white
#' background.
#'
#' @return An object of class \code{\link[ggplot2]{theme}()}.
#'
#' @export
#' @family themes economist
#'
#' @references
#' \itemize{
#' \item \href{https://www.economist.com/}{The Economist}
#' \item \href{https://spiekermann.com/en/itc-officina-display/}{Spiekerblog, "ITC Officina Display", January 1, 2007.}
#' }
#'
#' @example inst/examples/ex-theme_economist.R
theme_economist <- function(base_size = 10, base_family = "sans",
                            horizontal = TRUE, dkpanel = FALSE) {
  bgcolors <- deframe(ggthemes::ggthemes_data[["economist"]][["bg"]])
  ## From measurements
  ## Ticks = 1 / 32 in, with margin about 1.5 / 32
  ## Title = 3 / 32 in (6 pt)
  ## Legend Labels = 2.5 / 32 in (5pt)
  ## Axis Labels = 2
  ## Axis Titles and other text ~ 2
  ## Margins: Top / Bottom = 6 / 32, sides = 5 / 32
  ret <-
    theme_foundation(base_size = base_size, base_family = base_family) +
    theme(
      line = element_line(colour = "black"),
      rect = element_rect(
        fill = bgcolors["ebg"], colour = NA,
        linetype = 1
      ),
      text = element_text(colour = "black"),
      ## Axis
      axis.line = element_line(linewidth = rel(0.8)),
      axis.line.y = element_blank(),
      axis.text = element_text(size = rel(1)),
      axis.text.x = element_text(
        vjust = 0,
        margin = margin(
          t = base_size,
          unit = "pt"
        )
      ),
      axis.text.x.top = element_text(vjust = 0, margin = margin(b = base_size, unit = "pt")),
      axis.text.y = element_text(
        hjust = 0,
        margin = margin(
          r = base_size,
          unit = "pt"
        )
      ),
      ## I cannot figure out how to get ggplot to do 2 levels of ticks
      ## axis.ticks.margin = unit(3 / 72, "in"),
      axis.ticks = element_line(),
      axis.ticks.y = element_blank(),
      axis.title = element_text(size = rel(1)),
      axis.title.x = element_text(),
      axis.title.y = element_text(angle = 90),
      # axis.ticks.length = unit( -1/32, "in"),
      axis.ticks.length = unit(-base_size * 0.5, "points"),
      legend.background = element_rect(linetype = 0),
      legend.spacing = unit(base_size * 1.5, "points"),
      legend.key = element_rect(linetype = 0),
      legend.key.size = unit(1.2, "lines"),
      legend.key.height = NULL,
      legend.key.width = NULL,
      legend.text = element_text(size = rel(1.25)),
      legend.title = element_text(size = rel(1), hjust = 0),
      legend.position = "top",
      legend.direction = NULL,
      legend.justification = "center",
      ## legend.box = element_rect(fill = palette_economist['bgdk'],
      ## colour=NA, linetype=0),
      ## Economist only uses vertical lines
      panel.background = element_rect(linetype = 0),
      panel.border = element_blank(),
      panel.grid.major = element_line(colour = "white", linewidth = rel(1.75)),
      panel.grid.minor = element_blank(),
      panel.spacing = unit(0.25, "lines"),
      strip.background = element_rect(
        fill = bgcolors["ebg"],
        colour = NA, linetype = 0
      ),
      strip.text = element_text(size = rel(1.25)),
      strip.text.x = element_text(),
      strip.text.y = element_text(angle = -90),
      plot.background = element_rect(
        fill = bgcolors["blue-gray"],
        colour = NA
      ),
      plot.title = element_text(
        size = rel(1.5),
        hjust = 0, face = "bold"
      ),
      plot.margin = unit(c(6, 5, 6, 5) * 2, "points"),
      complete = TRUE
    )
  if (horizontal) {
    ret <- ret + theme(panel.grid.major.x = element_blank())
  } else {
    ret <- ret + theme(panel.grid.major.y = element_blank())
  }
  if (dkpanel == TRUE) {
    ret <- ret + theme(
      panel.background =
        element_rect(
          fill =
            unname(bgcolors["dark blue-gray"])
        ),
      strip.background =
        element_rect(
          fill =
            unname(bgcolors["dark blue-gray"])
        )
    )
  }
  ret
}

#' @rdname theme_economist
#' @export
theme_economist_white <- function(base_size = 11, base_family = "sans",
                                  gray_bg = TRUE, horizontal = TRUE) {
  if (gray_bg) {
    bgcolor <- get_colors(c("economist", "bg"), "light gray")
  } else {
    bgcolor <- "white"
  }
  theme_economist(
    base_family = base_family,
    base_size = base_size,
    horizontal = horizontal
  ) +
    theme(
      rect = element_rect(fill = bgcolor),
      plot.background = element_rect(fill = bgcolor),
      panel.background = element_rect(fill = "white"),
      panel.grid.major =
        element_line(
          colour =
            get_colors(c("economist", "bg"), "dark gray")
        ),
      strip.background = element_rect(fill = "white")
    )
}