R/pauseBttn.R

In abbey-thomas/speechcollectr: R Tools for Collecting Speech Production & Perception Data

#' Pause Button for Audio Playback
#'
#' Add an action button to a `shiny` user interface with a built-in function of pausing the audio currently playing.
#' @param inputId The input ID that will be added to the list of other inputs in a shiny app.
#' @param audioId The input ID associated with an audio tag called with `htmltools::tags$audio()`.
#' @param label An optional text label to add to the button. Defaults to blank. NOTE: If icon is `NULL`, this variable should be given a value explicitly.
#' @param inline Boolean. If FALSE (the default), the pause button will be on its own line in the UI (i.e., wrapped in a `div` tag). If TRUE, the button will be on a line with the preceeding shiny UI object (i.e., wrapped in a `span` tag).
#' @param icon An optional `shiny::icon()` to add to the button. Defaults to the font-awesome "pause" icon. NOTE: If no text label is present, icon cannot be null.
#'
#' @return On the server side of a shiny app, this function returns an integer of class "shinyActionButtonValue", which means it can be used in all the ways an ordinary shiny action button can (e.g., you can add functions to be called when the button is pressed with `shiny::observeEvent()` and `shiny::eventReactive`).
#' @export
#'
#' @examples
#' # First use wwwPrep() to get a wav file in the correct directory.
#' wwwPrep(volumeCalibration = TRUE)
#'
#' ## Only run examples in interactive R sessions
#' if (interactive()) {
#' ui <- fluidPage(
#'   "Play a sound: ",
#'    playBttn(inputId = "play", src = "cal_noise.wav",
#'         audioId = "cal_noise"),
#'    disabled(pauseBttn(inputId = "pause", audioId = "cal_noise"))
#'  )
#'
#' # Disable the play button and enable the pause button after play button is clicked.
#' # Then, pause and enable play when the pause button is clicked.
#' server <- function(input, output, session) {
#'  observeEvent(input$play, {
#'    disable("play")
#'    enable("pause")
#'   })
#'
#'  observeEvent(input$pause, {
#'    enable("play")
#'    disable("pause")
#'   })
#'  }
#' shinyApp(ui = ui, server = server)
#' }
#'
#' ## Use inline = TRUE to display the button on the same line as the preceding UI element.
#' if (interactive()) {
#' ui <- fluidPage(
#'   "Play a sound: ",
#'    playBttn(inputId = "play", src = "cal_noise.wav",
#'         audioId = "cal_noise", inline = TRUE),
#'    pauseBttn(inputId = "pause", audioId = "cal_noise", inline = TRUE)
#'  )
#'
#' server <- function(input, output, session) {}
#'
#' shinyApp(ui = ui, server = server)
#' }
#'
#' ## Use parameter 'label =' to add a text label to the button.
#' ## Use icon = NULL to remove the icon.
#' if (interactive()) {
#' ui <- fluidPage(
#'    playBttn(inputId = "play", label = "Play noise", src = "cal_noise.wav",
#'         audioId = "cal_noise", inline = TRUE, icon = NULL),
#'    pauseBttn(inputId = "pause", audioId = "cal_noise", icon = NULL,
#'         label = "Stop playing that noise!", inline = TRUE)
#'  )
#'
#' server <- function(input, output, session) {}
#'
#' shinyApp(ui = ui, server = server)
#' }
pauseBttn <- function(inputId, audioId, label = "",
                      inline = FALSE, icon = "pause") {
  jsCode <- htmltools::HTML(
    "pauseAudio = function(audioId) {
      document.getElementById(audioId).pause();
    }"
  )

  ui <- htmltools::tags$span(
    htmltools::tags$head(htmltools::tags$script(jsCode)),
    shiny::actionButton(inputId = inputId,
                        label = label,
                        icon = shiny::icon(icon),
                        inline = inline,
                        onclick = paste0("pauseAudio('", audioId, "')")
    )
  )
  return(ui)
}