test.r

map <- ggplot(
  # use the same dataset as before
  data = municipality_prod_geo
) +
  # first: draw the relief
  geom_raster(
    data = relief,
    aes(
      x = x,
      y = y,
      alpha = value
    )
  ) +
  # use the "alpha hack" (as the "fill" aesthetic is already taken)
  scale_alpha(name = "",
              range = c(0.6, 0),
              guide = F) + # suppress legend
  # color municipalities according to their gini / income combination
  geom_sf(
    aes(
      fill = fill
    ),
    # use thin white stroke for municipalities
    color = "white",
    size = 0.1
  ) +
  # as the sf object municipality_prod_geo has a column with name "fill" that
  # contains the literal color as hex code for each municipality, we can use
  # scale_fill_identity here
  scale_fill_identity() +
  # use thicker white stroke for cantons
  geom_sf(
    data = canton_geo,
    fill = "transparent",
    color = "white",
    size = 0.5
  ) +
  # draw lakes in light blue
  geom_sf(
    data = lake_geo,
    fill = "#D6F1FF",
    color = "transparent"
  ) +
  # add titles
  labs(x = NULL,
       y = NULL,
       title = "Switzerland's regional income (in-)equality",
       subtitle = paste0("Average yearly income and income",
                         " (in-)equality in Swiss municipalities, 2015"),
       caption = default_caption) +
  # add the theme
  theme_map()

# add annotations one by one by walking over the annotations data frame
# this is necessary because we cannot define nudge_x, nudge_y and curvature
# in the aes in a data-driven way like as with x and y, for example
annotations %>%
  pwalk(function(...) {
    # collect all values in the row in a one-rowed data frame
    current <- tibble(...)
    
    # convert all columns from x to vjust to numeric
    # as pwalk apparently turns everything into a character (why???)
    current %<>%
      mutate_at(vars(x:vjust), as.numeric)
    
    # update the plot object with global assignment
    map <<- map +
      # for each annotation, add an arrow
      geom_curve(
        data = current,
        aes(
          x = x,
          xend = xend,
          y = y,
          yend = yend
        ),
        # that's the whole point of doing this loop:
        curvature = current %>% pull(curvature),
        size = 0.2,
        arrow = arrow(
          length = unit(0.005, "npc")
        )
      ) +
      # for each annotation, add a label
      geom_text(
        data = current,
        aes(
          x = x,
          y = y,
          label = label,
          hjust = hjust,
          vjust = vjust
        ),
        # that's the whole point of doing this loop:
        nudge_x = current %>% pull(nudge_x),
        nudge_y = current %>% pull(nudge_y),
        # other styles
        family = default_font_family,
        color = default_font_color,
        size = 3
      )
  })