Add a Terra Draw control to a map — add_terradraw

A convenience wrapper around add_draw_control() with provider = "terra-draw", exposing only the arguments that apply to the Terra Draw engine. The two forms are equivalent; see add_draw_control() for full details of the terra-draw provider's behavior, and terradraw_options() for advanced configuration.

Usage

add_terradraw_control(
  map,
  position = "top-left",
  modes = NULL,
  options = NULL,
  source = NULL,
  attributes = NULL,
  point_color = "#3bb2d0",
  line_color = "#3bb2d0",
  fill_color = "#3bb2d0",
  fill_opacity = 0.1,
  active_color = "#fbb03b",
  vertex_radius = 5,
  line_width = 2,
  download_button = FALSE,
  download_filename = "drawn-features",
  show_measurements = FALSE,
  measurement_units = "both",
  orientation = "vertical"
)

Arguments

map: A map object created by the mapboxgl or maplibre functions.
position: A string specifying the position of the draw control. One of "top-right", "top-left", "bottom-right", or "bottom-left".
modes: A character vector of drawing modes to expose as toolbar buttons: any of "point", "linestring", "polygon", "rectangle", "circle", "freehand", "freehand-linestring", "angled-rectangle", "sector", "sensor", "curve", "curve-linestring", and "select". When NULL (the default), the control shows "point", "linestring", "polygon", and "select".
options: An object created by terradraw_options() with advanced Terra Draw settings (snapping, select-mode editing flags, per-mode overrides).
source: A character string specifying a source ID to add to the draw control. Default is NULL.
attributes: Optional named list defining editable feature attributes. Use draw_attribute() to define fields.
point_color: Color for point features. Default is "#3bb2d0" (light blue).
line_color: Color for line features. Default is "#3bb2d0" (light blue).
fill_color: Fill color for polygon features. Default is "#3bb2d0" (light blue).
fill_opacity: Fill opacity for polygon features. Default is 0.1.
active_color: Color for active (selected) features. Default is "#fbb03b" (orange).
vertex_radius: Radius of vertex points in pixels. Default is 5.
line_width: Width of lines in pixels. Default is 2.
download_button: Logical, whether to add a download button to export drawn features as GeoJSON. Default is FALSE.
download_filename: Base filename for downloaded GeoJSON (without extension). Default is "drawn-features".
show_measurements: Logical, whether to show live measurements while drawing. Default is FALSE.
measurement_units: Units for measurements. Either "metric", "imperial", or "both". Default is "both".
orientation: A string specifying the orientation of the draw control. Either "vertical" (default) or "horizontal".

Value

The modified map object with the draw control added.

Examples

if (FALSE) { # \dontrun{
library(mapgl)

maplibre() |>
    add_terradraw_control()

maplibre() |>
    add_terradraw_control(
        modes = c("polygon", "rectangle", "circle", "freehand", "select"),
        options = terradraw_options(snap_to_coordinates = TRUE),
        download_button = TRUE
    )
} # }