R/control_switch_pair.R

In switchboard: An Agile Widget Engine for Real-Time, Dynamic Visualizations

#' A pair of switches to toggle on/off two simulation variables.
#'
#' The \code{control_switch_pair} widget displays two switches to toggle the state
#' (e.g., on or off, \code{TRUE} or \code{FALSE}) of two simulation variables.
#' A switch is blue when "on", and gray when "off".
#'
#' @section Usage:
#'    \preformatted{control_switch_pair(inject = c("", ""), label = c("", ""),
#'    size = 1, placeOnGrid = c(1, 1))}
#'
#' @param inject A vector of the two strings for each variable name to be
#'    modified/injected by the switch widget. For example, \code{inject = c("A", "B")}.
#'    These two variables should be in boolean form (e.g., 0 or 1, FALSE or TRUE).
#' @param label A vector of two short strings designating labels/captions
#'    for each switch.
#' @param size A number used to designate the size (magnification) of the
#'    widget. The default is set to \code{1} which is 80 by 80 pixels. For
#'    example, setting to \code{3} will results in a widget 3-times the default
#'    size (240 by 240 pixels) and will occupy a grid area of 3 by 3.
#' @param placeOnGrid A row by column coordinate (e.g., \code{c(row-number, column-number)})
#'    of a grid that designates the position to draw the widget on the
#'    \code{switchboard}. Use \code{showGrid()} to help organize widget placement
#'    on dashboard. The default places the first widget in pipe chain to
#'    the \code{c(1, 1)} position, and all following on the same row stacked to
#'    the right.
#'
#' @return Nothing.
#'
#' @examples \dontrun{
#'
#'      varToSlideA <- 0
#'      varToSlideB <- 0
#'      for (i in 1:500) {
#'        switchboard(delay = 0.01) %>%
#'          control_switch_pair(inject = c("varToSlideA", "varToSlideB"),
#'                              label = c("0 to 1", "0 to 1")) %>%
#'          number_pair(c(varToSlideA, varToSlideB))
#'      }
#'      switchboard_close()
#'
#' }
#'
#' @family injectors
#' @name control_switch_pair
NULL


#' @inheritParams control_switch_pair
#' @import tcltk magrittr
#' @export
control_switch_pair <- function(.switchboard, ...) {
  switchboard_engine(.switchboard,
                     constructor = control_switch_pair_construct(.switchboard, ...),
                     updater = NULL, ...)
}


#' helper function that constructs canvas items of a control_switch_pair widget
#' @keywords internal
control_switch_pair_construct <- function(.switchboard,
                                  inject = c("", ""),
                                  label = c("", ""),
                                  size = 1,
                                  ...) {

  aCanvas <- tcltk::tkcanvas(.switchboard, width = 80 * size, height = 80 * size, background = switchboard.env$mainColors[2], borderwidth = 0, highlightthickness = 0)

  if(inject[1] != "") {
    if(as.integer(tcltk::tcl("info", "exists", inject[1])) == 1) tcltk::tcl("unset", inject[1])
    valueWithinLoop <- mget(inject[1], envir = parent.frame(n = 3), ifnotfound = NA)
    tcltk::.Tcl(paste("set", inject[1], ifelse(valueWithinLoop == FALSE, 0, 1)))
    injectorSwitch1 <- ttkcheckbutton(aCanvas, style = "Switch", variable = inject[1],
                                      command = function(...){
                                        theSwitchState <- as.numeric(tcltk::tclvalue(inject[1]))
                                        if(theSwitchState == 0) assign(inject[1], FALSE, envir = parent.frame(n = 5))
                                        else assign(inject[1], TRUE, envir = parent.frame(n = 5))
                                      })
    tcltk::tkcreate(aCanvas, "window", 37.5, 15, anchor = "center", window = injectorSwitch1)
  }

  if(inject[2] != "") {
    if(as.integer(tcltk::tcl("info", "exists", inject[2])) == 1) tcltk::tcl("unset", inject[2])
    valueWithinLoop <- mget(inject[2], envir = parent.frame(n = 3), ifnotfound = NA)
    tcltk::.Tcl(paste("set", inject[2], ifelse(valueWithinLoop == FALSE, 0, 1)))
    injectorSwitch2 <- ttkcheckbutton(aCanvas, style = "Switch", variable = inject[2],
                                      command = function(...){
                                        theSwitchState <- as.numeric(tcltk::tclvalue(inject[2]))
                                        if(theSwitchState == 0) assign(inject[2], FALSE, envir = parent.frame(n = 5))
                                        else assign(inject[2], TRUE, envir = parent.frame(n = 5))
                                      })
    tcltk::tkcreate(aCanvas, "window", 37.5, 55, anchor = "center", window = injectorSwitch2)
  }

  tcltk::tkcreate(aCanvas, "text", 37.5 - 4, 15 + 17, text = label[1], anchor = "center", font = paste(switchboard.env$font, floor(9 / 1.2)), fill = switchboard.env$mainColors[4])
  tcltk::tkcreate(aCanvas, "text", 37.5 - 4, 55 + 17, text = label[2], anchor = "center", font = paste(switchboard.env$font, floor(9 / 1.2)), fill = switchboard.env$mainColors[4])

  return(aCanvas)
}