mg_open_url.pro

; docformat = 'rst'

;+
; Open an url in the default web browser. On Windows and Mac this is easy. On 
; UNIX platforms, the first time this routine is called it will ask for the 
; location of your preferred web browser and save this location in 
; APP_USER_DIR.
;
; :Params:
;    url : in, required, type=string
;       url to goto in the default web browser
;
; :Requires: 
;    IDL 6.1
;
; :Author: 
;    Michael Galloy, 2006
;-
pro mg_open_url, url
  compile_opt strictarr
    
  ; launch the default web browser with the url, unfortunately, this is 
  ; platform dependent
  case !version.os_family of
    'Windows' : spawn, 'start ' + url, /hide, /nowait
    else : begin
      ; Mac OS X has a nice way of doing this...
      if (!version.os_name eq 'Mac OS X') then begin
        spawn, 'open ' + url
        return
      endif
            
      ; ...but the other UNIX platforms don't
      app_readme_text = $  
        ['This is the configuration directory for MG_OPEN_URL ', $  
         'routine. It is used to save the location of the default ', $
         'web browser between MG_OPEN_URL invocations on UNIX ', $
         'platforms.', $  
         '', $  
         'It is safe to remove this directory, as it', $  
         'will be recreated on demand. Note that all', $  
         'settings (e.g. smoke injection depth, juicitron', $  
         'angle, etc.) will revert to their default settings.'] 
            
      prefdir = app_user_dir('mg', $
                             'Michael Galloy', $
                             'default-browser', $
                             'Default browser location', $
                             app_readme_text, 1)
      preffile = filepath('default-browser', root=prefdir)

      if (file_test(preffile)) then begin
        openr, lun, preffile, /get_lun
        browser = ''
        readf, lun, browser
        free_lun, lun
        spawn, browser + ' ' + url
      endif else begin
        browser_location = dialog_pickfile()
        openw, lun, preffile, /get_lun
        printf, lun, browser_location
        free_lun, lun
        msg = ['Your browser location has been stored in:', '', $
               '    ' + preffile, '']
        ok = dialog_message(msg, /info)
        spawn, browser_location + ' ' + url
      endelse
    end
  endcase
end