R/pulseIcon.R

In leaflet.extras: Extra Functionality for 'leaflet' Package

pulseIconDependency <- function() {
  list(
    html_dep_prod("lfx-pulse-icon", "0.1.1", has_style = TRUE, has_binding = TRUE)
  )
}


#' Make pulse-icon set
#'
#' @param ... icons created from \code{\link{makePulseIcon}()}
#' @rdname pulseMarkers
#' @export
#' @examples
#'
#' iconSet <- pulseIconList(
#'   red = makePulseIcon(color = "#ff0000"),
#'   blue = makePulseIcon(color = "#0000ff")
#' )
#'
#' iconSet[c("red", "blue")]
#'
pulseIconList <- function(...) {
  res <- structure(
    list(...),
    class = "leaflet_pulse_icon_set"
  )
  cls <- unlist(lapply(res, inherits, "leaflet_pulse_icon"))
  if (any(!cls)) {
    stop("Arguments passed to pulseIconList() must be icon objects returned from makePulseIcon()")
  }
  res
}

#' @param x icons
#' @param i offset
#' @export
#' @rdname pulseMarkers
`[.leaflet_pulse_icon_set` <- function(x, i) {
  if (is.factor(i)) {
    i <- as.character(i)
  }

  if (!is.character(i) && !is.numeric(i) && !is.integer(i)) {
    stop("Invalid subscript type '", typeof(i), "'")
  }

  structure(.subset(x, i), class = "leaflet_pulse_icon_set")
}

pulseIconSetToPulseIcons <- function(x) {
  cols <- names(formals(makePulseIcon))
  cols <- structure(as.list(cols), names = cols)

  # Construct an equivalent output to pulseIcons().
  leaflet::filterNULL(lapply(cols, function(col) {
    # Pluck the `col` member off of each item in pulseIconObjs and put them in an
    # unnamed list (or vector if possible).
    colVals <- unname(sapply(x, `[[`, col))

    # If this is the common case where there"s lots of values but they"re all
    # actually the same exact thing, then just return one value; this will be
    # much cheaper to send to the client, and we'll do recycling on the client
    # side anyway.
    if (length(unique(colVals)) == 1) {
      return(colVals[[1]])
    } else {
      return(colVals)
    }
  }))
}

#' Make Pulse Icon
#'
#' @inheritParams pulseIcons
#' @export
#' @rdname pulseMarkers
makePulseIcon <- function(
    color = "#ff0000",
    iconSize = 12,
    animate = TRUE,
    heartbeat = 1) {
  icon <- leaflet::filterNULL(list(
    color = color, iconSize = iconSize, animate = animate, heartbeat = heartbeat
  ))
  structure(icon, class = "leaflet_pulse_icon")
}

#' Create a list of pulse icon data see
#' \url{https://github.com/mapshakers/leaflet-icon-pulse}
#'
#' An icon can be represented as a list of the form \code{list(color, iconSize,
#' ...)}. This function is vectorized over its arguments to create a list of
#' icon data. Shorter argument values will be re-cycled. \code{NULL} values for
#' these arguments will be ignored.
#' @param color Color of the icon
#' @param iconSize Size of Icon in Pixels.
#' @param animate To animate the icon or not, defaults to TRUE.
#' @param heartbeat Interval between each pulse in seconds.
#' @export
#' @rdname pulseMarkers
pulseIcons <- function(
    color = "#ff0000",
    iconSize = 12,
    animate = TRUE,
    heartbeat = 1) {
  leaflet::filterNULL(list(
    color = color, iconSize = iconSize, animate = animate, heartbeat = heartbeat
  ))
}

#' Add Pulse Markers
#' @inheritParams leaflet::addMarkers
#' @rdname pulseMarkers
#' @export
#' @examples
#' leaflet() %>%
#'   addTiles() %>%
#'   addPulseMarkers(
#'     lng = -118.456554, lat = 34.078039,
#'     label = "This is a label",
#'     icon = makePulseIcon(heartbeat = 0.5)
#'   )
#'
#'
#' ## for more examples see
#' # browseURL(system.file("examples/pulseIcon.R", package = "leaflet.extras"))
addPulseMarkers <- function(
    map, lng = NULL, lat = NULL, layerId = NULL, group = NULL,
    icon = NULL,
    popup = NULL,
    popupOptions = NULL,
    label = NULL,
    labelOptions = NULL,
    options = leaflet::markerOptions(),
    clusterOptions = NULL,
    clusterId = NULL,
    data = leaflet::getMapData(map)) {
  map$dependencies <- c(
    map$dependencies,
    pulseIconDependency()
  )

  if (!is.null(icon)) {
    # If formulas are present, they must be evaluated first so we can pack the
    # resulting values
    icon <- leaflet::evalFormula(list(icon), data)[[1]]

    if (inherits(icon, "leaflet_pulse_icon_set")) {
      icon <- pulseIconSetToPulseIcons(icon)
    }
    icon <- leaflet::filterNULL(icon)
  }

  if (!is.null(clusterOptions)) {
    map$dependencies <- c(map$dependencies, leaflet::leafletDependencies$markerCluster())
  }

  pts <- leaflet::derivePoints(
    data, lng, lat, missing(lng), missing(lat), "addPulseMarkers"
  )
  leaflet::invokeMethod(
    map, data, "addPulseMarkers", pts$lat, pts$lng, icon, layerId,
    group, options, popup, popupOptions,
    clusterOptions, clusterId, leaflet::safeLabel(label, data), labelOptions
  ) %>% leaflet::expandLimits(pts$lat, pts$lng)
}