R/add_idw_plot_labels.R

In afsc-gap-products/akgfmaps: Alaska Groundfish and Ecosystem Survey Area Mapping

#' Add labels to IDW plots
#'
#' Select which place labels should be included on the map based on category and region. Currently supports regions: 'bs.all' and 'bs.south'. See data/placenames for the default list of locations.
#'
#' @param x A list containing the ggplot object returned by \code{make_idw_map()} or \code{change_fill_color()}. Alternatively, a gg object.
#' @param lab.select A vector indicating which types of labels to include on the map.
#' @param region Vector indicating the plotting region. Only specify if x is a gg object.
#' @param new.places A data frame containing new locations and labels to add to the map.
#' @param lab.replace Logical indicating whether new.places should be added to the default labels or replace the default labels.
#' @param transform.new.places Logical indicating whether the data frame passed to new.places should be transformed to match the map projection.
#' @param add.scale.bar A character vector indicating where to add the scale bar. "br" for bottom right, "tl" for top left, etc. Default = "br"
#' @return Returns input list with IDW plot labels added.
#' @export

add_map_labels <- function(x,
                           lab.select = c("islands", "bathymetry", "convention line", "mainland", "peninsula"),
                           region = NA,
                           new.places = NULL,
                           lab.replace = FALSE,
                           transform.new.places = TRUE,
                           add.scale.bar = "br") {
  if(is(x, "list")) {
    in.dat <- x

    # Load labels and plotting locations--------------------------------------------------------------
    placenames <- utils::read.csv(file = system.file("extdata",
                                              file = "placenames.csv",
                                              package = "akgfmaps",
                                              mustWork = TRUE),
                           stringsAsFactors = FALSE) |>
      transform_data_frame_crs(in.crs = "WGS84",
                               out.crs = sf::st_crs(in.dat$crs)) # Transform placenames based on extrapolation grid CRS

    # Find new and default place names----------------------------------------------------------------
    if(!is.null(new.places)) {
      if(!all(c("x", "y") %in% names(new.places))) {stop("new.places must include a longitude column named 'x' and latitude column named 'y'")}

      if(transform.new.places) {new.places <- new.places |>
        transform_data_frame_crs(out.crs = sf::st_crs(in.dat$crs))}

      if(lab.replace) {
        placenames <- new.places
      } else {
        placenames <- rbind(placenames, new.places)
      }
    }

    placenames <- subset(placenames, region == in.dat$region & type %in% lab.select)

    # Make plot
    if(in.dat$region %in% c("bs.all", "ebs")) {
      in.dat$plot <- in.dat$plot +
        ggplot2::geom_text(data = subset(placenames, type == "mainland"),
                           ggplot2::aes(x = x, y = y, label = lab),
                           size = 14, group = 99) +
        shadowtext::geom_shadowtext(data = subset(placenames, type == "peninsula"),
                        ggplot2::aes(x = x, y = y, label = lab),
                        size = 8,
                        angle = 28, bg.color = "white", color = "black", group = 99) +
        shadowtext::geom_shadowtext(data = subset(placenames, type %in% c("bathymetry", "islands")),
                        ggplot2::aes(x = x, y = y, label = lab),
                        bg.color = "white", color = "black", size = 3.88, group = 99) +
        shadowtext::geom_shadowtext(data = subset(placenames, type == "convention line"),
                        ggplot2::aes(x = x, y = y, label = lab),
                        angle = 29.5, size = 3,
                        bg.color = "white", color = "black", group = 99)
    }

    if(!is.na(add.scale.bar)) {
      in.dat$plot <- in.dat$plot + ggspatial::annotation_scale(location = add.scale.bar)
    }
  } else if("gg" %in% class(x)){
    # Add labels to ggplot object ------------------------------------------------------------------
    placenames <- subset(new.places, region == region & type %in% lab.select)
    if(region %in% c("bs.all", "bs.south", "sebs")) {
      in.dat <- x +
        ggplot2::geom_text(data = subset(placenames, type == "mainland"),
                           ggplot2::aes(x = x, y = y, label = lab), size = 14, group = 99) +
        shadowtext::geom_shadowtext(data = subset(placenames, type == "peninsula"),
                                    ggplot2::aes(x = x, y = y, label = lab), size = 8,
                        angle = 40, bg.color = "white", color = "black", group = 99) +
        shadowtext::geom_shadowtext(data = subset(placenames, type %in% c("bathymetry", "islands")),
                                    ggplot2::aes(x = x, y = y, label = lab),
                        bg.color = "white", color = "black", size = 3.88, group = 99) +
        shadowtext::geom_shadowtext(data = subset(placenames, type == "convention line"),
                                    ggplot2::aes(x = x, y = y, label = lab),
                        angle = 42, size = 3,
                        bg.color = "white", color = "black", group = 99)
    }
  }
  return(in.dat)
}