extension/packages/window-utils.coffee

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