R/map_legend.R

In Racmacs: Antigenic Cartography Macros

#' Set acmap legend
#'
#' This sets the acmap legend used when viewing a map for example.
#'
#' @param map The acmap object
#' @param legend A character vector of legend labels
#' @param fill The fill color to be used with the boxes that appear alongside
#'   the legend labels
#' @param style.bottom "bottom" style of the div, specifying how far from the
#'   bottom of the viewport the bottom of the legend is spaced.
#' @param style.right "right" style of the div, specifying how far from the
#'   right of the viewport the bottom of the legend is spaced.
#'
#' @returns Returns the updated acmap object
#' @family functions to view maps
#' @export
#'
setLegend <- function(
  map,
  legend,
  fill,
  style.bottom = "8px",
  style.right = "8px"
  ) {

  # Check input
  check.acmap(map)

  # Return the map with legend added
  map$legend <- list(
    legend       = unname(legend),
    fill         = unname(fill),
    style.bottom = style.bottom,
    style.right  = style.right
  )

  map

}


# Helper function to create the html used for a legend
make_html_legend <- function(
  args
  ) {

  # Set variables
  args$box.width      <- "14px"
  args$box.height     <- "14px"
  args$font.size      <- "14px"
  args$legend.spacing <- "4px"

  # Create the legend holder
  div.legend <- htmltools::div(
    style = sprintf(
      "position:absolute; bottom:%s; right:%s;",
      args$style.bottom,
      args$style.right
    )
  )

  # Add the legend entries
  for (x in seq_along(args$legend)) {

    # Create the entry
    div.entry <- htmltools::div(
      style = sprintf(
        "line-height:%s; margin:%s;",
        args$font.size, args$legend.spacing
      ),
      htmltools::div(
        style = sprintf(
          paste0(
            "line-height:%s;",
            "width:%s;",
            "height:%s;",
            "background-color:%s;",
            "display:inline-block;"
          ),
          args$font.size,
          args$box.width,
          args$box.height,
          args$fill[x]
        ),
        onClick = NULL
      ),
      htmltools::div(
        args$legend[x],
        style = sprintf(
          "font-size:%s;display:inline-block;",
          args$font.size
        )
      )
    )

    # Append the entry to the legend
    div.legend <- htmltools::tagAppendChild(
      div.legend,
      div.entry
    )

  }

  # Return the div legend
  div.legend

}