Question

I have created a progress bar to keep tabs on the execution of some R scripts. And I want to insert a custom icon in the bar instead of the default ‘Tk’ one. I am able to do this on Windows using a .ico file and the following command

tcl('wm', 'iconbitmap', .win, 'Icon.ico')

But I am a loss about how to do the same in Mac OSX and Linux. Obviously, the .ico format doesn’t work but neither does .png, .jpg, .bmp, .xbm or .xpm. Any suggestion on how I could proceed? Sample image and progress bar code attached below:-

Sample image http://tinypic.com/r/jt8efn/6 – http://tinypic.com/r/jt8efn/6

tkProgressBar2 <- function (title = 'Test progress bar', label = '', min = 0, max = 100, initial = 0, width = 300, userfn='helvetica', backg='white') {
  useText <- FALSE
  have_ttk <- as.character(tcl('info', 'tclversion')) >= '8.5'
  if (!have_ttk && as.character(tclRequire('PBar')) == 'FALSE') useText <- TRUE
  .win <<- tktoplevel(background=backg)
  tkfocus()
  tcl('wm', 'geometry', .win, '500x100+450+350')
  tcl('wm', 'iconbitmap', .win, '@Icon.xbm')
  .val <- initial
  .killed <- FALSE
  tkwm.geometry(.win, sprintf('%dx80', width + 40))
  tkwm.title(.win, title)
  fn <- tkfont.create(family = userfn, size = 12)
  if (useText) {
    .lab <- tklabel(.win, text = label, font = fn, padx = 0, background=backg)
    tkpack(.lab, side = 'left')
    fn2 <- tkfont.create(family = userfn, size = 16)
    .vlab <- tklabel(.win, text = '0%', font = fn2, padx = 20, background=backg)
    tkpack(.vlab, side = 'right')
    up <- function(value) {
      if (!is.finite(value) || value < min || value > max) return()
      .val <<- value
      tkconfigure(.vlab, text = sprintf('%d%%', round(100 * (value - min)/(max - min))))
    }
  } else {
    .lab <- tklabel(.win, text = label, font = fn, pady = 0, background=backg)
    .tkval <- tclVar(0)
    tkpack(.lab, side = 'top')
    tkpack(tklabel(.win, text = '', font = fn, background=backg), side = 'bottom')
    pBar <- if (have_ttk)
      ttkprogressbar(.win, length = width, variable = .tkval) else
        tkwidget(.win, 'ProgressBar', width = width, variable = .tkval)
    tkpack(pBar, side = 'bottom')
    up <- function(value) {
      if (!is.finite(value) || value < min || value > max) return()
      .val <<- value
      tclvalue(.tkval) <<- 100 * (value - min)/(max - min)
    }
  }
  getVal <- function() .val
  kill <- function() if (!.killed) {
    tkdestroy(.win)
    .killed <<- TRUE
  }
  title <- function(title) tkwm.title(.win, title)
  lab <- function(label) tkconfigure(.lab, text = label)
  tkbind(.win, '<Destroy>', function() stop())
  up(initial)
  structure(list(getVal = getVal, up = up, title = title, label = lab, kill = kill), class = 'tkProgressBar')
}

pb <- tkProgressBar2(title='Performing k-Means clustering', label='Some information in %', min=0, max=100, initial=0, width=400, userfn='verdana', backg='white')

Answer 1

On Linux you set the icon with wm iconphoto; wm iconbitmap does something else entirely. To do that, you’ll need to create a photo image with the image data in it.

I’m guessing that you write this in R as:

tcl('wm', 'iconphoto', .win, tcl('image', 'create', 'photo', '-file', 'Icon.gif'))

I’m not quite sure which image formats are supported by the version of Tk you’re using, including any image format support packages it has available. The minimal set is GIF and PPM unless you’re (bravely) using 8.6, when PNG is also available by default.

(You can also create the content of a photo image programatically, but that’s slow for various reasons.)

OSX doesn’t have window icons in the same sense; it’s normal for each minimized window to just show a snapshot of itself when it is minimized to the dock.