Derive one default label per draggable region

Derive one default label per draggable region

Usage

make_region_labels(
  x,
  region_col,
  label_col = region_col,
  point = c("point_on_surface", "centroid")
)

Arguments

x

An sf object in a projected CRS.

region_col

Column defining draggable groups.

label_col

Column used for label text. Defaults to region_col.

point

One of "point_on_surface" or "centroid".

Value

A drag label table with label_id, region, label, x, and y.

See also

as_drag_labels() for user-supplied labels; as_drag_annotations() for draggable info boxes; apply_label_state() to restore saved positions; drag_map_prototype() which accepts the result as its labels argument.

Examples

poly <- sf::st_sf(
  region = c("North", "South"),
  geometry = sf::st_sfc(
    sf::st_polygon(list(rbind(c(0,1e5),c(1e5,1e5),c(1e5,2e5),c(0,2e5),c(0,1e5)))),
    sf::st_polygon(list(rbind(c(0,0),c(1e5,0),c(1e5,1e5),c(0,1e5),c(0,0)))),
    crs = 3857
  )
)
make_region_labels(poly, region_col = "region")
#>   label_id region label     x      y label_type width_px height_px connector
#> 1    North  North North 50000 150000      label       NA        NA     FALSE
#> 2    South  South South 50000  50000      label       NA        NA     FALSE
#>   connector_type connector_mid_x connector_mid_y connector_start_x
#> 1       straight              NA              NA                NA
#> 2       straight              NA              NA                NA
#>   connector_start_y
#> 1                NA
#> 2                NA