leaflegend Recipes

library(leaflet)
library(leaflegend)
mapData <- data.frame(x = c(2, 1, 5, 4,3) , y = c('A', 'B', 'C', 'B', 'A'), 
                      lng = -(118:122), lat = rep(42, 5))
map <- leaflet::leaflet(data = mapData, 
                        options = leafletOptions(zoomControl = FALSE))

numPal <- colorNumeric('inferno', mapData$x)
lgd <- 
  map |> addLegendNumeric(pal = numPal, values = ~x, decreasing = TRUE) |> 
  addLegendNumeric(pal = numPal, values = ~x, orientation = 'horizontal',
                   width = 120, height = 20, position = 'topright')
lgd

quantPal <- colorQuantile('Reds', mapData$x, n = 3)
lgd <- 
  map |> addLegendQuantile(pal = quantPal, values = ~x) |> 
    addLegendQuantile(pal = quantPal, values = ~x, numberFormat = NULL, 
                      position = 'topright')
lgd

binPal <- colorBin(c('grey', 'blue'), mapData$x, bins = 3, pretty = FALSE)
lgd <- 
  map |> addLegendBin(pal = binPal, shape = 'triangle')
lgd

factorPal <- colorFactor('Dark2', domain = mapData$y)
reOrder <- c('C', 'A', 'B')
factorPalRev <- colorFactor('Dark2', domain = reOrder, ordered = TRUE)
lgd <- 
  map |> addLegendFactor(pal = factorPal, values = ~y) |> 
    addLegendFactor(pal = factorPalRev, 
                    values = ~factor(y, levels = reOrder), 
                    position = 'topright')
lgd

lgd <- 
  map |> addLegendSize(values = ~x, color = 'black', shape  = 'plus', 
                       breaks = 3) |> 
    addSymbolsSize(lng = ~lng, lat = ~lat, values = ~x, shape = 'plus', 
                   color = 'black')
lgd

lgd <- 
  map |> addLegendSize(values = ~x, shape  = 'plus', breaks = 3, pal = numPal,
                       color = 'black') |> 
    addSymbolsSize(lng = ~lng, lat = ~lat, values = ~x, shape = 'plus', 
                   color = 'black', fillColor = ~numPal(x))
lgd

lgd <- 
  map |> addLegendSize(values = ~x, shape  = 'plus', breaks = 3, pal = numPal,
                       color = 'black', fillColor = 'transparent') |> 
    addSymbolsSize(lng = ~lng, lat = ~lat, values = ~x, shape = 'plus', 
                   color = 'black', fillColor = ~factorPal(y)) |> 
    addLegendFactor(pal = factorPal, values = ~y, position = 'topright')
lgd

lgd <- 
  map |> addSymbols(lng = ~lng, lat = ~lat, values = ~y, color = 'black') |> 
    addLegendSymbol(values = ~y, color = 'black')
lgd

lgd <- 
  map |> addSymbols(lng = ~lng, lat = ~lat, values = ~y, 
                    fillColor = ~factorPal(y), color = 'black',
                    shape = c('cross', 'diamond', 'star')) |> 
    addLegendSymbol(values = ~y, pal = factorPal, 
                    shape = c('cross', 'diamond', 'star'), color = 'black')
lgd

lgd <- 
  map |> addLegendLine(values = ~x, color = 'black', 
                       orientation = 'horizontal', width = 50)
lgd

# use raster image
leafImg <- system.file('img/leaf-blue.png', package = 'leaflegend')
# use svg
circle <- makeSymbol('rect', fillColor = 'red', color = 'black', width = 20)
lgd <- 
  map |> 
    addLegendImage(images = list(leafImg, circle), labels = c('png', 'svg'),
                   height = 30, width = 20)
lgd

shapes <- c('rect', 'circle', 'triangle', 'plus', 'cross', 'star')
colors <- c('blue', 'red', 'yellow', 'green', 'orange', 'purple')
symbols <- Map(f = makeSymbol, shape = shapes, fillColor = colors, 
               color = 'black', opacity = 1, fillOpacity = .5, width = 20, 
               `stroke-width` = 2)
lgd <- 
  map |> addLegendImage(images = symbols, labels = shapes, 
                        orientation = 'horizontal')
lgd

iconSet <- awesomeIconList(
  `Font Awesome` = makeAwesomeIcon(icon = "font-awesome", library = "fa",
                                   markerColor= 'red', iconColor = 'black'),
  Ionic = makeAwesomeIcon(icon='R', library = 'fa', 
                          text = fontawesome::fa("r-project"))
)
lgd <- 
  map |> addLegendAwesomeIcon(iconSet = iconSet)
lgd

lgd <- 
  map |> addLegendFactor(values = ~y, pal = factorPal, 
                         class = 'leaflet-control', 
                         labelStyle = 'color: black;')
lgd

lgd <- 
  map |> addLegendFactor(values = ~y, pal = factorPal, 
                         title = htmltools::tags$div('Red Title', 
                                                     style = 'color:red;'))
lgd

lgd <- 
  map |> addLegendFactor(values = ~y, pal = factorPal, 
                         labelStyle = 'color: blue; font-size: 10px;')
lgd

lgd <- 
  map |> addLegendFactor(values = ~y, pal = factorPal, shape = 'polygon',
                         fillOpacity = .5, width = 20, height = 20)
lgd

symbolSet <- makeSymbolIcons(shape = c('rect', 'circle', 'triangle'), 
                             width = 10, color = 'grey', opacity = 1)
lgd <- 
  map |> addMarkers(lng = ~lng, lat = ~lat, icon = ~symbolSet[as.factor(y)])
lgd

lgd <- 
  map |> addMarkers(lng = ~lng, lat = ~lat, 
                    icon = ~makeSymbolsSize(x, color = 'black', 
                                            fillColor = 'black',
                                            baseSize = 20, 
                                            fillOpacity = .5))
lgd

lgd <- 
  map |> addLegendFactor(values = ~y, pal = factorPal, group = 'Legend') |> 
    addLayersControl(overlayGroups = 'Legend', 
                     options = layersControlOptions(collapsed = FALSE))
lgd