`leaflet::clearGroup` clear all groups

[kongdd]

The original map:

After click recalc and execute leaflet::clearGroup.

library(shiny)
library(leaflet)

library(rgee)
rgee::ee_Initialize()

sf_prov = ee$FeatureCollection("users/kongdd/shp/China/bou2_4p_ChinaProvince")
ee_draw_sf <- function(shp, title = NULL, color = '000000', width=1.5) {
  empty = ee$Image()$byte()
  if (is.null(title)) title = shp$get("system:id") %>% getInfo() %>% basename()
  # Paint all the polygon edges with the same number and width, display.
  outline = empty$paint(featureCollection = shp, color = 1, width = width)
  Map$addLayer(outline, list(palette = color), title)
}

ui <- fluidPage(
  tags$style(type = "text/css", "html, body {width:100%;height:100%}"),
  actionButton("recalc", "Add SRTM Global Map"),
  leafletOutput("mymap"),
)

server <- function(input, output, session) {
  output$mymap <- renderLeaflet({
    Map$addLayer(ee$Image("srtm90_v4"), list(min = 0, max = 1000)) + 
      ee_draw_sf(sf_prov, "prov")
  })

  observe({
    proxy <- leafletProxy("mymap")
    # Remove any existing legend, and only if the legend is
    # enabled, create a new one.
    if (input$recalc) {
      print("click")
      proxy %>%
        # clearImages()
        # clearControls()
        clearGroup("srtm90_v4")
      proxy + Map$addLayer(ee$Image("srtm90_v4"), list(min = 0, max = 1000))
    }
  })
}
shinyApp(ui = ui, server = server)