Add LayerGroup Collision Plugin

Integrates the LayerGroup Collision plugin into a Leaflet map, which hides overlapping markers and only displays the first added marker in a collision group. Markers must be static; dynamic changes, dragging, and deletions are not supported. The function transforms spatial data into GeoJSON format and uses `L.DivIcon`, allowing you to pass HTML content and CSS classes to style the markers.

Usage

addLayerGroupCollision(
  map,
  group = NULL,
  className = NULL,
  html = NULL,
  margin = 5,
  data = getMapData(map)
)

Arguments

map

the map to add awesome Markers to.

group

the name of the group. It needs to be single string.

className

A single CSS class or a vector of CSS classes.

html

A single HTML string or a vector of HTML strings.

margin

defines the margin between markers, in pixels

data

the data object from which the argument values are derived; by default, it is the data object provided to leaflet() initially, but can be overridden

Value

A leaflet map object with the LayerGroup Collision plugin added.

References

https://github.com/MazeMap/Leaflet.LayerGroup.Collision

Examples

library(leaflet)
library(sf)
#> Linking to GEOS 3.12.1, GDAL 3.8.4, PROJ 9.4.0; sf_use_s2() is TRUE
library(leaflet.extras2)

df <- sf::st_as_sf(atlStorms2005)
#> Loading required package: sp
df <- suppressWarnings(st_cast(df, "POINT"))
df$classes <- sample(x = 1:5, nrow(df), replace = TRUE)

leaflet() %>%
  addProviderTiles("CartoDB.Positron") %>%
  leaflet::addLayersControl(overlayGroups = c("Labels")) %>%
  addPolylines(data = sf::st_as_sf(atlStorms2005), label = ~Name) %>%
  addLayerGroupCollision(
    data = df, margin = 40,
    html = ~ paste0(
      '<div style="width: max-content; background-color: #cbc0c04f" class="custom-html">',
      '<div class="title">', Name, "</div>",
      '<div class="subtitle">MaxWind: ', MaxWind, "</div>",
      "</div>"
    ),
    className = ~ paste0("my-label my-label-", classes),
    group = "Labels"
  )