R/loon2ggplot-l_layer_graph.R

In loon.ggplot: A Grammar of Interactive Graphics

#' @rdname loon2ggplot
#' @export
#'
loon2ggplot.l_layer_graph <- function(target, asAes = TRUE, selectedOnTop = TRUE,
                                      showNearestColor = FALSE, ...) {

  widget <- loon::l_create_handle(attr(target, "widget"))
  ggObj <- list(...)$ggObj
  n <- widget['n']
  if(n == 0) return(ggObj)

  states <- get_layer_states(widget, native_unit = FALSE)
  states$color <- l_colorName(states$color, error = FALSE,
                              precise = !showNearestColor)
  # no active nodes
  active <- states$active
  if(!any(active)) return(ggObj)

  nav_ids <- loon::l_navigator_ids(widget)

  if(asAes)
    message("In graph transformation, `asAes` is not available yet.")

  # with pipe '%>%' may make the code more readable
  ggObj <- if(length(nav_ids) == 0) {
    # graph no navigators
    ggObj <- ggEdges(ggObj, states = states)
    ggObj <- ggNodes(ggObj, states = states)
    ggLabels(ggObj, states = states)
  } else {
    # graph with navigators
    ggObj <- ggEdges(ggObj, states = states)
    ggObj <- ggNavPaths(ggObj,
                        states = states,
                        nav_ids = nav_ids,
                        widget = widget)
    ggObj <- ggNodes(ggObj, states = states)
    ggObj <- ggLabels(ggObj, states = states)
    ggNavPoints(ggObj,
                states = states,
                nav_ids = nav_ids,
                widget = widget)

  }

  return(ggObj)
}