extension/packages/window-utils.coffee

   1 { unload } = require 'unload'
   2 #
   3 # Waits for a browser window to finish loading before running the callback
   4 #
   5 # @usage runOnLoad(window, callback): Apply a callback to to run on a window when it loads.
   6 # @param [function] callback: 1-parameter function that gets a browser window.
   7 # @param [function] winType: a parameter that defines what kind of window is "browser window".
   8 #
   9 runOnLoad = (window, callback, winType) ->
  10   # Listen for one load event before checking the window type
  11   cb = ->
  12     window.removeEventListener('load', arguments.callee, false)
  13
  14     # Now that the window has loaded, only handle browser windows
  15     if window.document.documentElement.getAttribute('windowtype') == winType
  16       callback(window)
  17
  18   window.addEventListener('load', cb, false)
  19
  20 #
  21 # Add functionality to existing browser windows
  22 #
  23 # @usage runOnWindows(callback): Apply a callback to each open browser window.
  24 # @param [function] callback: 1-parameter function that gets a browser window.
  25 # @param [function] winType: a parameter that defines what kind of window is "browser window".
  26 #
  27 runOnWindows = (callback, winType) ->
  28   # Wrap the callback in a function that ignores failures
  29   watcher = (window) -> try callback(window)
  30
  31   # Add functionality to existing windows
  32   browserWindows = Services.wm.getEnumerator(winType)
  33   while browserWindows.hasMoreElements()
  34     # Only run the watcher immediately if the browser is completely loaded
  35     browserWindow = browserWindows.getNext()
  36     if browserWindow.document.readyState == 'complete'
  37       watcher(browserWindow)
  38     # Wait for the window to load before continuing
  39     else
  40       runOnLoad(browserWindow, watcher, winType)
  41
  42 #
  43 # Apply a callback to each open and new browser windows.
  44 #
  45 # @usage watchWindows(callback): Apply a callback to each browser window.
  46 # @param [function] callback: 1-parameter function that gets a browser window.
  47 # @param [function] winType: a parameter that defines what kind of window is "browser window".
  48 #
  49 watchWindows = (callback, winType) ->
  50   # Wrap the callback in a function that ignores failures
  51   watcher = (window) -> try callback(window)
  52
  53   # Add functionality to existing windows
  54   runOnWindows(callback, winType)
  55
  56   # Watch for new browser windows opening then wait for it to load
  57   windowWatcher = (subject, topic) ->
  58     if topic == 'domwindowopened'
  59       runOnLoad(subject, watcher, winType)
  60
  61   Services.ww.registerNotification(windowWatcher)
  62
  63   # Make sure to stop watching for windows if we're unloading
  64   unload -> Services.ww.unregisterNotification(windowWatcher)
  65
  66 exports.runOnLoad    = runOnLoad
  67 exports.runOnWindows = runOnWindows
  68 exports.watchWindows = watchWindows