R/geom-rrect.r

In statebins: Create United States Uniform Cartogram Heatmaps

geom_rrect <- function(mapping = NULL, data = NULL,
                      stat = "identity", position = "identity",
                      radius = grid::unit(6, "pt"),
                      ...,
                      na.rm = FALSE,
                      show.legend = NA,
                      inherit.aes = TRUE) {
  layer(
    data = data,
    mapping = mapping,
    stat = stat,
    geom = GeomRrect,
    position = position,
    show.legend = show.legend,
    inherit.aes = inherit.aes,
    params = list(
      radius = radius,
      na.rm = na.rm,
      ...
    )
  )
}

GeomRrect <- ggplot2::ggproto("GeomRrect", ggplot2::Geom,

  default_aes = ggplot2::aes(
    colour = NA, fill = "grey35", size = 0.5, linetype = 1, alpha = NA
  ),

  required_aes = c("xmin", "xmax", "ymin", "ymax"),

  draw_panel = function(self, data, panel_params, coord,
                        radius = grid::unit(6, "pt")) {

    coords <- coord$transform(data, panel_params)

    lapply(1:length(coords$xmin), function(i) {

      grid::roundrectGrob(
        coords$xmin[i], coords$ymax[i],
        width = (coords$xmax[i] - coords$xmin[i]),
        height = (coords$ymax[i] - coords$ymin)[i],
        r = radius,
        default.units = "native",
        just = c("left", "top"),
        gp = grid::gpar(
          col = coords$colour[i],
          fill = alpha(coords$fill[i], coords$alpha[i]),
          lwd = coords$size[i] * .pt,
          lty = coords$linetype[i],
          lineend = "butt"
        )
      )

    }) -> gl

    grobs <- do.call(grid::gList, gl)

    ggname("geom_rrect", grid::grobTree(children = grobs))

  },

  draw_key = ggplot2::draw_key_polygon

)