geom_polygon_interactive.R

library(ggplot2)
library(ggiraph)

# create data
ids <- factor(c("1.1", "2.1", "1.2", "2.2", "1.3", "2.3"))

values <- data.frame(
	id = ids,
	value = c(3, 3.1, 3.1, 3.2, 3.15, 3.5) )
positions <- data.frame(
	id = rep(ids, each = 4),
	x = c(2, 1, 1.1, 2.2, 1, 0, 0.3, 1.1, 2.2, 1.1, 1.2, 2.5, 1.1, 0.3,
		0.5, 1.2, 2.5, 1.2, 1.3, 2.7, 1.2, 0.5, 0.6, 1.3),
	y = c(-0.5, 0, 1, 0.5, 0, 0.5, 1.5, 1, 0.5, 1, 2.1, 1.7, 1, 1.5,
		2.2, 2.1, 1.7, 2.1, 3.2, 2.8, 2.1, 2.2, 3.3, 3.2) )

datapoly <- merge(values, positions, by=c("id"))

datapoly$oc = "alert(this.getAttribute(\"data-id\"))"

# create a ggplot -----
gg_poly_1 <- ggplot(datapoly, aes( x = x, y = y ) ) +
	geom_polygon_interactive(aes(fill = value, group = id,
		tooltip = value, data_id = value, onclick = oc))

# display ------
x <- girafe(ggobj = gg_poly_1)
if( interactive() ) print(x)

if (packageVersion("grid") >= "3.6") {
  # As of R version 3.6 geom_polygon() supports polygons with holes
  # Use the subgroup aesthetic to differentiate holes from the main polygon

  holes <- do.call(rbind, lapply(split(datapoly, datapoly$id), function(df) {
    df$x <- df$x + 0.5 * (mean(df$x) - df$x)
    df$y <- df$y + 0.5 * (mean(df$y) - df$y)
    df
  }))
  datapoly$subid <- 1L
  holes$subid <- 2L
  datapoly <- rbind(datapoly, holes)
  p <- ggplot(datapoly, aes(x = x, y = y)) +
    geom_polygon_interactive(aes(fill = value, group = id, subgroup = subid,
                                 tooltip = value, data_id = value, onclick = oc))
  x <- girafe(ggobj = p)
  if( interactive() ) print(x)
}