rotate_themes.R

# hacky but fun code to change the RStudio theme every (e.g.) 15 minutes,
# cycling through the themes in the {rsthemes} package.
# https://gist.github.com/BenjaminWolfe/fc00c480f8a7185779669d2895829069
# 
# start is 9am on the day rstudio::conf(2021L) kicks off.
# applies the current theme, then starts a timer to change it periodically.
# to rotate less often (or more), adjust theme_period below.
# (fractional minutes may not work.)
# note that breaks are just based on lubridate::round_date logic.
# 
# hacky b/c I use options() to give the functions a separate namespace.
# ideally I'd just do a pull request!
# 
# I'd like to do some refactoring though first.
# a) how can the user set and share their own playlist / start / period?
# b) it would add lubridate as a suggests. is gadenbuie OK with that?
# c) do I want it to be savvy to daytime / nighttime?
# 
# and then in an ideal world it would be fun to do a quick blog post about this.
#
# be sure to devtools::install("gadenbuie/rsthemes")
# and install.packages(c("later", "lubridate")) if needed.
# then file.edit("~/.Rprofile") and add this code, and restart R.
if (
  interactive() &&
  requireNamespace("rsthemes" , quietly = TRUE) &&
  requireNamespace("later"    , quietly = TRUE) &&
  requireNamespace("lubridate", quietly = TRUE)
) {
  later::later(function() {
    options(
      theme_period = lubridate::minutes(15),
      theme_start = lubridate::ymd_h("2021-01-18 09", tz = "America/New_York"),
      theme_playlist = rsthemes::list_rsthemes(),

      # wait for the minute to turn (0 seconds)
      wait_for_minute = function() {
        this_second <- floor(lubridate::second(lubridate::now()))

        if (this_second == 0) return(getOption("wait_for_loop")())
        later::later(getOption("wait_for_minute"), delay = 1)
      },

      # wait for the next break (e.g. every 15 minutes)
      wait_for_loop = function() {
        breaks <- lubridate::minute(c(
          lubridate::floor_date(lubridate::now(), getOption("theme_period")),
          lubridate::ceiling_date(lubridate::now(), getOption("theme_period"))
        ))
        if (lubridate::minute(lubridate::now()) %in% breaks) {
          return(getOption("apply_theme")())
        }
        later::later(getOption("wait_for_loop"), delay = 60)
      },

      # apply the theme of the moment from {rsthemes}
      apply_theme = function(delayed = TRUE) {
        start    <- getOption("theme_start")
        period   <- getOption("theme_period")
        playlist <- getOption("theme_playlist")

        current  <- (lubridate::now() - start) / lubridate::as.duration(period)
        this_theme <- playlist[floor(current %% length(playlist)) + 1]

        message(
          lubridate::now(), ":",
          " changing theme to ", this_theme,
          " until ", lubridate::ceiling_date(lubridate::now(), period)
        )
        rstudioapi::applyTheme(this_theme)

        if (!isTRUE(delayed)) return(invisible())
        later::later(getOption("apply_theme"), delay = as.numeric(period))
      }
    )
    getOption("apply_theme")(delayed = FALSE)
    getOption("wait_for_minute")()
  }, delay = 1)
}