R/remove.R

In devOpifex/g2r: Interactive Grammar of Graphics

#' Remove a figure
#'
#' Remove a figure from the plot.
#'
#' @inheritParams fig_point
#' @param index Index of figure to remove. Either
#' the numeric index of figure (layer number in order
#' it was added to the visualisation), or the `id` of
#' the figure as set by [config()] (see examples).
#'
#' @examples
#' g <- g2(mtcars, asp(qsec, wt)) %>%
#'   fig_point(config(id = "myPoints")) %>%
#'   fig_point(asp(y = drat))
#'
#' # all figures
#' g
#'
#' # remove figure
#' remove_figure(g, "myPoints")
#'
#' library(shiny)
#'
#' df <- data.frame(
#'   x = 1:100,
#'   y = runif(100),
#'   z = runif(100)
#' )
#'
#' ui <- fluidPage(
#'   g2Output("plot"),
#'   actionButton("rm", "Randomly remove a figure")
#' )
#'
#' server <- function(input, output) {
#'   output$plot <- renderG2({
#'     g2(df, asp(x, y)) %>%
#'       fig_point() %>%
#'       fig_line(asp(y = z))
#'   })
#'
#'   observeEvent(input$rm, {
#'     g2_proxy("plot") %>%
#'       remove_figure(sample(1:2, 1))
#'   })
#' }
#'
#' if (interactive()) {
#'   shinyApp(ui, server)
#' }
#' @export
remove_figure <- function(g, index) UseMethod("remove_figure")

#' @method remove_figure g2r
#' @export
remove_figure.g2r <- function(g, index) {
  if (missing(index)) {
    stop("Missing `index`", call. = FALSE)
  }

  if (is.numeric(index)) {
    g$x$views[[index]] <- NULL
  }

  if (is.character(index)) {
    pos <- map(g$x$views, function(x, id) {
      !isTRUE(x$conf$id == id)
    }, id = index) %>%
      unlist()

    g$x$views <- g$x$views[pos]
  }

  g
}

#' @method remove_figure g2Proxy
#' @export
remove_figure.g2Proxy <- function(g, index) {
  if (missing(index)) {
    stop("Missing `index`", call. = FALSE)
  }

  # R index to JavaScript
  if (is.numeric(index)) {
    index <- index - 1
  }

  g$session$sendCustomMessage(
    "remove-figure",
    list(
      id = g$x$id,
      index = index
    )
  )

  invisible(g)
}