/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Speak Words.
 *
 * The Initial Developer of the Original Code is The Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Edward Lee <edilee@mozilla.com>
 *   Erik Vold <erikvvold@gmail.com>
 *   Timothy Baldock <tb@entropy.me.uk>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/**
 * Waits for a browser window to finish loading before running the callback
 *
 * @usage runOnLoad(window, callback): Apply a callback to to run on a window when it loads.
 * @param [function] callback: 1-parameter function that gets a browser window.
 */
function runOnLoad (window, callback)
{
    // Listen for one load event before checking the window type
    window.addEventListener("load", function ()
    {
        window.removeEventListener("load", arguments.callee, false);

        // Now that the window has loaded, only handle browser windows
        if (window.document.documentElement.getAttribute("windowtype") === "navigator:browser")
        {
            callback(window);
        }
    }, false);
}


/**
 * Add functionality to existing browser windows
 *
 * @usage runOnWindows(callback): Apply a callback to each open browser window.
 * @param [function] callback: 1-parameter function that gets a browser window.
 */
function runOnWindows (callback)
{
    // Wrap the callback in a function that ignores failures
    function watcher(window) {
        try
        {
            callback(window);
        }
        catch(ex)
        {
        }
    }

    // Add functionality to existing windows
    let browserWindows = Services.wm.getEnumerator("navigator:browser");
    while (browserWindows.hasMoreElements())
    {
        // Only run the watcher immediately if the browser is completely loaded
        let browserWindow = browserWindows.getNext();
        if (browserWindow.document.readyState === "complete")
        {
            watcher(browserWindow);
        }
        // Wait for the window to load before continuing
        else
        {
            runOnLoad(browserWindow, watcher);
        }
    }
}

/**
 * Apply a callback to each open and new browser windows.
 *
 * @usage watchWindows(callback): Apply a callback to each browser window.
 * @param [function] callback: 1-parameter function that gets a browser window.
 */
function watchWindows (callback)
{
    // Wrap the callback in a function that ignores failures
    function watcher(window) {
        try
        {
            callback(window);
        }
        catch(ex)
        {
        }
    }

    // Add functionality to existing windows
    runOnWindows(callback);

    // Watch for new browser windows opening then wait for it to load
    function windowWatcher (subject, topic)
    {
        if (topic === "domwindowopened")
        {
            runOnLoad(subject, watcher);
        }
    }
    Services.ww.registerNotification(windowWatcher);

    // Make sure to stop watching for windows if we're unloading
    unload(function() Services.ww.unregisterNotification(windowWatcher));
}

/**
 * Save callbacks to run when unloading. Optionally scope the callback to a
 * container, e.g., window. Provide a way to run all the callbacks.
 *
 * @usage unload(): Run all callbacks and release them.
 *
 * @usage unload(callback): Add a callback to run on unload.
 * @param [function] callback: 0-parameter function to call on unload.
 * @return [function]: A 0-parameter function that undoes adding the callback.
 *
 * @usage unload(callback, container) Add a scoped callback to run on unload.
 * @param [function] callback: 0-parameter function to call on unload.
 * @param [node] container: Remove the callback when this container unloads.
 * @return [function]: A 0-parameter function that undoes adding the callback.
 */
function unload (callback, container)
{
    // Initialize the array of unloaders on the first usage
    let unloaders = unload.unloaders;
    if (unloaders === null)
    {
        unloaders = unload.unloaders = [];
    }

    // Calling with no arguments runs all the unloader callbacks
    if (callback === null)
    {
        unloaders.slice().forEach(function(unloader) unloader());
        unloaders.length = 0;
        return;
    }

    // The callback is bound to the lifetime of the container if we have one
    if (container !== null)
    {
        // Remove the unloader when the container unloads
        container.addEventListener("unload", removeUnloader, false);

        // Wrap the callback to additionally remove the unload listener
        let origCallback = callback;
        callback = function()
        {
            container.removeEventListener("unload", removeUnloader, false);
            origCallback();
        }
    }

    // Wrap the callback in a function that ignores failures
    function unloader ()
    {
        try
        {
            callback();
        }
        catch (ex)
        {
        }
    }
    unloaders.push(unloader);

    // Provide a way to remove the unloader
    function removeUnloader ()
    {
        let index = unloaders.indexOf(unloader);
        if (index !== -1)
        {
            unloaders.splice(index, 1);
        }
    }
    return removeUnloader;
}


@@ -5367,16 +5367,17 @@
     if (
+!
 unloader
@@ -5377,25 +5377,16 @@
 nloaders
- === null
 )%0A    %7B%0A
@@ -5508,24 +5508,25 @@
     if (
+!
 callback
  === nul
@@ -5521,17 +5521,8 @@
 back
- === null
 )%0A  
@@ -5742,17 +5742,8 @@
 iner
- !== null
 )%0A  

Fix bug introduced by previous commit