sbServicePaneService.js

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 :miv */
/*
 *=BEGIN SONGBIRD GPL
 *
 * This file is part of the Songbird web player.
 *
 * Copyright(c) 2005-2010 POTI, Inc.
 * http://www.songbirdnest.com
 *
 * This file may be licensed under the terms of of the
 * GNU General Public License Version 2 (the ``GPL'').
 *
 * Software distributed under the License is distributed
 * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
 * express or implied. See the GPL for the specific language
 * governing rights and limitations.
 *
 * You should have received a copy of the GPL along with this
 * program. If not, go to http://www.gnu.org/licenses/gpl.html
 * or write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 *=END SONGBIRD GPL
 */

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cr = Components.results;
const Ce = Components.Exception;
const Cu = Components.utils;

Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
Components.utils.import("resource://app/jsmodules/ArrayConverter.jsm");
Components.utils.import("resource://app/jsmodules/DebugUtils.jsm");
Components.utils.import("resource://app/jsmodules/StringUtils.jsm");

const SP="http://songbirdnest.com/rdf/servicepane#";

const LOG = DebugUtils.generateLogFunction("sbServicePaneService");

function deprecationWarning(msg) {
  // The code that called a deprecated function is two stack frames above us
  let caller = Components.stack;
  if (caller)
    caller = caller.caller;
  if (caller)
    caller = caller.caller;

  // Skip empty frames
  while (caller && !caller.filename)
    caller = caller.caller;

  let consoleService = Cc["@mozilla.org/consoleservice;1"]
                         .getService(Ci.nsIConsoleService);
  let scriptError = Cc["@mozilla.org/scripterror;1"]
                      .createInstance(Ci.nsIScriptError);
  scriptError.init(msg,
                   caller ? caller.filename : null,
                   caller ? caller.sourceLine : null,
                   caller ? caller.lineNumber : null,
                   0,
                   Ci.nsIScriptError.warningFlag,
                   "sbServicePaneService");
  consoleService.logMessage(scriptError);
}

function ServicePaneNode(servicePane, comparisonFunction) {
  this._servicePane = servicePane;
  this._comparisonFunction = comparisonFunction;
  this._attributes = {__proto__: null};
  this._childNodes = [];
  this._notificationQueue = [];

  // Allow accessing internal properties when we get a wrapped node passed
  this.wrappedJSObject = this;
}

ServicePaneNode.prototype = {
  _attributes: null,
  _childNodes: null,
  _parentNode: null,
  _nodeIndex: null,
  _servicePane: null,
  _comparisonFunction: null,
  _stringBundle: null,
  _stringBundleURI: null,
  _isInTree: false,
  _listeners: null,
  _eventListeners: null,
  _notificationQueue: null,
  _notificationQueueBusy: false,

  QueryInterface: XPCOMUtils.generateQI([Ci.sbIServicePaneNode]),

  // Generic properties

  get isContainer() {
    deprecationWarning("sbIServicePaneNode.isContainer is deprecated and may " +
                       "be removed in future. All nodes are containers now.");
    return this.getAttribute("isContainer") != "false";
  },

  get properties() {
    deprecationWarning("sbIServicePaneNode.properties is deprecated and " +
                       "may be removed in future. Consider using " +
                       "sbIServicePaneNode.className instead.");
    return this.className;

  },
  set properties(aValue) {
    deprecationWarning("sbIServicePaneNode.properties is deprecated and " +
                       "may be removed in future. Consider using " +
                       "sbIServicePaneNode.className instead.");
    return (this.className = aValue);
  },

  get displayName() {
    // Only names beginning with & should be translated
    let name = this.name;
    if (!name || name[0] != "&")
      return name;

    // Cache the string bundle so that we don't retrieve it more than once
    if (!this._stringBundle) {
      let stringbundleURI = this.stringbundle;

      if (!stringbundleURI)  {
        // Try module's stringbundle
        let contractid = this.contractid;
        if (contractid && contractid in this._servicePane._modulesByContractId) {
          try {
            let module = this._servicePane._modulesByContractId[contractid];
            stringbundleURI = module.stringbundle;
          }
          catch (e) {
            Components.utils.reportError(e);
          }
        }
      }

      try {
        this._stringBundle = new SBStringBundle(stringbundleURI);
        this._stringBundleURI = stringbundleURI;
      }
      catch (e) {
        LOG("sbServicePaneNode.displayName: failed retrieving string bundle " + stringbundleURI);
        Components.utils.reportError(e);
      }
    }

    // Try to get displayed name from string bundle - fall back to key name
    if (this._stringBundle)
      return this._stringBundle.get(name.substr(1), name);

    return name;
  },

  get isInTree() this._isInTree,
  set isInTree(aValue) {
    // Convert the parameter to a real boolean value, for sake of comparisons
    aValue = !!aValue;

    if (aValue == this._isInTree)
      return aValue;

    // Set the value and propagate the change to child nodes
    this._isInTree = aValue;
    for each (let child in this._childNodes)
      child.isInTree = aValue;

    // Update service pane data
    let notificationMethod = (aValue ? "_registerNode" : "_unregisterNode");
    for each (let attr in ["id", "url", "contentPrefix"])
      if (attr in this._attributes)
        this._servicePane[notificationMethod](attr, this._attributes[attr], this);

    return this._isInTree;
  },

  // Attribute functions without namespace

  hasAttribute: function(aName) aName in this._attributes,

  getAttribute: function(aName) {
    if (aName in this._attributes)
      return this._attributes[aName];
    else
      return null;
  },

  setAttribute: function(aName, aValue) {
    if (this.isInTree && (aName == "id" || aName == "url" || aName == "contentPrefix")) {
      if (aName in this._attributes)
        this._servicePane._unregisterNode(aName, this._attributes[aName], this);
      if (aValue !== null)
        this._servicePane._registerNode(aName, aValue, this);
    }
    else if (aName == "stringbundle" || aName == "contractid")
      delete this._stringBundle;

    let oldValue = (aName in this._attributes ? this._attributes[aName] : null);

    if (aValue === null)
      delete this._attributes[aName];
    else
      this._attributes[aName] = aValue;

    // Trigger mutation listeners
    let attr = aName;
    let namespace = null;
    if (/(.*):/.test(attr))
      [namespace, attr] = [RegExp.$1, RegExp.rightContext];
    this._notifyMutationListeners("attrModified", [this, attr, namespace,
                                                   oldValue, aValue]);

    return aValue;
  },

  removeAttribute: function(aName) {
    if (this.isInTree && (aName == "id" || aName == "url" || aName == "contentPrefix") &&
                          aName in this._attributes) {
      this._servicePane._unregisterNode(aName, this._attributes[aName], this);
    }
    else if (aName == "stringbundle" || aName == "contractid")
      delete this._stringBundle;

    let oldValue = (aName in this._attributes ? this._attributes[aName] : null);
    delete this._attributes[aName];

    // Trigger mutation listeners
    let attr = aName;
    let namespace = null;
    if (/(.*):/.test(attr))
      [namespace, attr] = [RegExp.$1, RegExp.rightContext];
    this._notifyMutationListeners("attrModified", [this, attr, namespace,
                                                   oldValue, null]);
  },

  // Attribute functions with namespace - these simply combine namespace and
  // attribute name and fall back to the regular attribute functions

  hasAttributeNS: function(aNamespace, aName)
    this.hasAttribute(aNamespace + ":" + aName),

  getAttributeNS: function(aNamespace, aName)
    this.getAttribute(aNamespace + ":" + aName),

  setAttributeNS: function(aNamespace, aName, aValue)
    this.setAttribute(aNamespace + ":" + aName, aValue),

  removeAttributeNS: function(aNamespace, aName)
    this.removeAttribute(aNamespace + ":" + aName),

  // DOM Properties

  get attributes() {
    let attrNames = [];
    for (let name in this._attributes)
      attrNames.push(name);
    return ArrayConverter.stringEnumerator(attrNames);
  },

  get childNodes() ArrayConverter.enumerator(this._childNodes),

  get firstChild() {
    if (this._childNodes.length)
      return this._childNodes[0];
    else
      return null;
  },

  get lastChild() {
    if (this._childNodes.length)
      return this._childNodes[this._childNodes.length - 1];
    else
      return null;
  },

  get parentNode() this._parentNode,

  get previousSibling() {
    let parent = this._parentNode;
    if (!parent)
      return null;

    let index = this._nodeIndex - 1;
    if (index >= 0)
      return parent._childNodes[index];
    else
      return null;
  },

  get nextSibling() {
    let parent = this._parentNode;
    if (!parent)
      return null;

    let index = this._nodeIndex + 1;
    if (index < parent._childNodes.length)
      return parent._childNodes[index];
    else
      return null;
  },

  // DOM methods

  appendChild: function(aChild) {
    return this.insertBefore(aChild, null);
  },

  insertBefore: function(aChild, aBefore) {
    // Unwrap parameters so that we can access internal properties
    if (aChild)
      aChild = aChild.wrappedJSObject;
    if (aBefore)
      aBefore = aBefore.wrappedJSObject;

    if (!aChild)
      throw Ce("Node to be inserted/appended is a required parameter");

    function checkConditions() {
      // Don't check aBefore if we have a custom comparison function, we won't
      // use it anyway in that case.
      if (!this._comparisonFunction && aBefore && aBefore._parentNode != this)
        throw Ce("Cannot insert before a node that isn't a child");

      for (let parent = this; parent; parent = parent._parentNode)
        if (parent == aChild)
          throw Ce("Cannot insert/append a node to its child");
    }

    checkConditions.apply(this);

    if (!this._comparisonFunction && aBefore == aChild)
      return aChild;    // nothing to do

    if (aChild._parentNode) {
      aChild._parentNode.removeChild(aChild);
      if (aChild._parentNode)
        throw Ce("Mutation listener prevented removal of node from its previous location");

      // Check conditions again, mutation listeners might have modified the tree
      checkConditions.apply(this);
    }
    if (this._comparisonFunction) {
      // Use comparison function to determine node position
      let index = 0;
      for (; index < this._childNodes.length; index++)
        if (this._comparisonFunction(aChild, this._childNodes[index]) < 0)
          break;
      if (index < this._childNodes.length)
        aBefore = this._childNodes[index];
      else
        aBefore = null;
    }

    let index = aBefore ? aBefore._nodeIndex : this._childNodes.length;
    for (let i = index; i < this._childNodes.length; i++)
      this._childNodes[i]._nodeIndex++;

    this._childNodes.splice(index, 0, aChild);
    aChild._nodeIndex = index;
    aChild._parentNode = this;
    aChild.isInTree = this.isInTree;

    // Trigger mutation listeners
    aChild._notifyMutationListeners("nodeInserted", [aChild, this, aBefore]);

    return aChild;
  },

  removeChild: function(aChild) {
    // Unwrap parameters so that we can access internal properties
    if (aChild)
      aChild = aChild.wrappedJSObject;

    if (!aChild || aChild._parentNode != this)
      throw Ce("Cannot remove a node that isn't a child");

    let wasInTree = aChild.isInTree;
    let oldParentNode = aChild._parentNode;

    let index = aChild._nodeIndex;
    for (let i = index + 1; i < this._childNodes.length; i++)
      this._childNodes[i]._nodeIndex--;

    this._childNodes.splice(index, 1);
    delete aChild._nodeIndex;
    delete aChild._parentNode;
    aChild.isInTree = null;

    // Trigger mutation listeners
    aChild._notifyMutationListeners("nodeRemoved", [aChild, this], wasInTree, oldParentNode);

    return aChild;
  },

  replaceChild: function(aChild, aOldChild) {
    // Unwrap parameters so that we can access internal properties
    if (aChild)
      aChild = aChild.wrappedJSObject;
    if (aOldChild)
      aOldChild = aOldChild.wrappedJSObject;

    if (!aOldChild || aOldChild._parentNode != this)
      throw Ce("Cannot replace a node that isn't a child");

    let insertBefore = aOldChild.nextSibling;
    this.removeChild(aOldChild);
    this.insertBefore(aChild, insertBefore);
  },

  addEventListener: function(aListener) {
    if (this._eventListeners == null)
      this._eventListeners = [];

    // Don't add listeners twice
    for each (let listener in this._eventListeners)
      if (listener == aListener)
        return;

    this._eventListeners.push(aListener);
  },

  removeEventListener: function(aListener) {
    if (this._eventListeners == null)
      return;

    for (let i = 0; i < this._eventListeners.length; i++)
      if (this._eventListeners[i] == aListener)
        this._eventListeners.splice(i--, 1);

    if (this._eventListeners.length == 0)
      this._eventListeners = null;
  },

  dispatchEvent: function(aEventName) {
    for each (let listener in this._eventListeners)
      listener.handleEvent(aEventName);
  },

  addMutationListener: function(aListener) {
    if (this._listeners == null)
      this._listeners = [];

    // Don't add listeners twice
    for each (let listener in this._listeners)
      if (listener == aListener)
        return;

    this._listeners.push(aListener);
  },

  removeMutationListener: function(aListener) {
    if (this._listeners == null)
      return;

    for (let i = 0; i < this._listeners.length; i++)
      if (this._listeners[i] == aListener)
        this._listeners.splice(i--, 1);

    if (this._listeners.length == 0)
      this._listeners = null;
  },

  _notifyMutationListeners: function(aMethod, aArgs, aIsInTree, aParentNode) {
    // Don't trigger listeners if we haven't been added to the service pane tree
    let isInTree = (typeof aIsInTree != "undefined" ? aIsInTree : this.isInTree);
    if (!isInTree)
      return;

    // Queue the notification before sending it out, just in case one of the
    // listeners decides to mess with the DOM structure. Add to the queue
    // of this node and all of its parent nodes (bubbling).
    let notification = [aMethod, aArgs];
    let nodes = [];
    let node = this;
    let parent = (typeof aParentNode != "undefined" ? aParentNode : node._parentNode);
    while (node) {
      if (node._listeners != null) {
        nodes.push(node);
        node._notificationQueue.push(notification);
      }

      node = parent;
      if (node)
        parent = node._parentNode;
    }

    // Now actually trigger listeners for all nodes
    for each (let node in nodes)
      node._processNotificationQueue();
  },

  _processNotificationQueue: function() {
    if (this._listeners == null)
      return;

    // Protect against reentrance
    if (this._notificationQueueBusy)
      return;
    this._notificationQueueBusy = true;

    // Create a local copy of the listeners in case the list is modified while
    // we are calling listeners.
    let listeners = this._listeners.slice();

    while (this._notificationQueue.length) {
      let [method, args] = this._notificationQueue.shift();
      for each (let listener in listeners) {
        try {
          listener[method].apply(listener, args);
        }
        catch (e) {
          Cu.reportError(e);
        }
      }
    }

    this._notificationQueueBusy = false;
  },

  // Attribute shortcuts

  get id() this.getAttribute("id"),
  set id(aValue) this.setAttribute("id", aValue),
  get className() this.getAttribute("class"),
  set className(aValue) this.setAttribute("class", aValue),
  get url() this.getAttribute("url"),
  set url(aValue) this.setAttribute("url", aValue),
  get contentPrefix() this.getAttribute("contentPrefix"),
  set contentPrefix(aValue) this.setAttribute("contentPrefix", aValue),
  get image() this.getAttribute("image"),
  set image(aValue) this.setAttribute("image", aValue),
  get name() this.getAttribute("name"),
  set name(aValue) this.setAttribute("name", aValue),
  get tooltip() this.getAttribute("tooltip"),
  set tooltip(aValue) this.setAttribute("tooltip", aValue),
  get hidden() this.getAttribute("hidden") == "true",
  set hidden(aValue) {
    return this.setAttribute("hidden", aValue ? "true" : "false");
  },
  get editable() this.getAttribute("editable") == "true",
  set editable(aValue) this.setAttribute("editable", aValue ? "true" : "false"),
  get isOpen() this.getAttribute("isOpen") != "false",
  set isOpen(aValue) this.setAttribute("isOpen", aValue ? "true" : "false"),
  get contractid() this.getAttribute("contractid"),
  set contractid(aValue) this.setAttribute("contractid", aValue),
  get searchtype() { return this.getAttribute("searchtype") || "internal"; },
  set searchtype(aValue) this.setAttribute("searchtype", aValue),
  get stringbundle() this.getAttribute("stringbundle"),
  set stringbundle(aValue) this.setAttribute("stringbundle", aValue),
  get dndDragTypes() this.getAttribute("dndDragTypes"),
  set dndDragTypes(aValue) this.setAttribute("dndDragTypes", aValue),
  get dndAcceptNear() this.getAttribute("dndAcceptNear"),
  set dndAcceptNear(aValue) this.setAttribute("dndAcceptNear", aValue),
  get dndAcceptIn() this.getAttribute("dndAcceptIn"),
  set dndAcceptIn(aValue) this.setAttribute("dndAcceptIn", aValue),
};


function MutationEventTranslator(aListener) {
  this.listener = aListener;
}
MutationEventTranslator.prototype = {
  listener: null,

  QueryInterface: XPCOMUtils.generateQI([Ci.sbIServicePaneMutationListener]),

  attrModified: function(aNode, aAttrName, aNamespace, aOldValue, aNewValue) {
    if (aNode.id)
      this.listener.nodePropertyChanged(aNode.id,
                                        aNamespace == null ? aAttrName : aNamespace + aAttrName);
  },

  nodeInserted: function() {},
  nodeRemoved: function() {}
}

function ServicePaneService () {
  LOG("Service pane initialization started");

  // Create root node - children are sorted automatically

  this._nodesById = {__proto__: null};
  this._nodesByUrl = {__proto__: null};
  this._nodesByContentPrefix = {__proto__: null};
  this._root = new ServicePaneNode(this, function(aNode1, aNode2) {
    // Nodes with lower weight go first
    let weight1 = parseInt(aNode1.getAttributeNS(SP, 'Weight')) || 0;
    let weight2 = parseInt(aNode2.getAttributeNS(SP, 'Weight')) || 0;
    if (weight1 != weight2)
      return weight1 - weight2;

    // For equal weight, sort alphabetically
    let name1 = aNode1.displayName;
    let name2 = aNode2.displayName;
    if (name1 < name2)
      return -1;
    else if (name1 > name2)
      return 1;

    return 0;
  });
  this._root.isInTree = true;

  // Initialize modules

  let catMgr = Cc["@mozilla.org/categorymanager;1"]
                 .getService(Ci.nsICategoryManager);
  let enumerator = catMgr.enumerateCategory("service-pane");
  let moduleEntries = ArrayConverter.JSArray(enumerator).map(
    function(entry) entry.QueryInterface(Ci.nsISupportsCString).data
  );
  moduleEntries.sort();

  this._modules = [];
  this._modulesByContractId = {__proto__: null};
  this._categoryEntriesCache = {__proto__: null};
  for each (let entry in moduleEntries)
    this._loadModule(catMgr, entry);
  LOG("Service pane initialization completed successfully");

  // Listen for modules being added or removed
  let observerService = Cc["@mozilla.org/observer-service;1"]
                          .getService(Ci.nsIObserverService);
  observerService.addObserver(this, "xpcom-category-entry-added", true);
  observerService.addObserver(this, "xpcom-category-entry-removed", true);
  observerService.addObserver(this, "quit-application", false);
}

ServicePaneService.prototype = {
  // XPCOM component info
  classID: Components.ID("{eb5c665a-bfe2-49f1-a747-cd3554e55606}"),
  classDescription: "Songbird Service Pane Service",
  contractID: "@songbirdnest.com/servicepane/service;1",

  _modules: null,
  _modulesByContractId: null,
  _categoryEntriesCache: null,
  _root: null,
  _nodesById: null,
  _nodesByUrl: null,
  _nodeIndex: 0,

  get root() this._root,

  QueryInterface: XPCOMUtils.generateQI([Ci.sbIServicePaneService,
                                         Ci.nsIObserver,
                                         Ci.nsISupportsWeakReference]),

  observe: function(subject, topic, data) {
    switch (topic) {
      case "xpcom-category-entry-added":
        if (data == "service-pane" && subject instanceof Ci.nsISupportsCString) {
          let catMgr = Cc["@mozilla.org/categorymanager;1"]
                         .getService(Ci.nsICategoryManager);
          this._loadModule(catMgr, subject.data);
        }
        break;
      case "xpcom-category-entry-removed":
        if (data == "service-pane" && subject instanceof Ci.nsISupportsCString) {
          this._removeModule(subject.data);
        }
        break;
      case "quit-application":
        this._shutdown();
        break;
    }
  },

  _loadModule: function ServicePaneService__loadModule(catMgr, entry) {
    let contractId = catMgr.getCategoryEntry("service-pane", entry);
    this._categoryEntriesCache[entry] = contractId;

    // Don't load if already loaded
    if (contractId in this._modulesByContractId)
      return;

    LOG("Trying to load service pane module: " + contractId);
    try {
      let module = Cc[contractId].getService(Ci.sbIServicePaneModule);
      module.servicePaneInit(this);
      this._modules.push(module);
      this._modulesByContractId[contractId] = module;
      LOG("Service pane module successfully initialized");
    } catch (e) {
      LOG("Error instantiating service pane module: " + e);
    }
  },

  _removeModule: function ServicePaneService__removeModule(entry) {
    // Don't bother if we don't know this module
    if (!(entry in this._categoryEntriesCache))
      return;
    let contractId = this._categoryEntriesCache[entry];
    if (!(contractId in this._modulesByContractId))
      return;

    let module = this._modulesByContractId[contractId];
    for (let i = 0; i < this._modules.length; i++)
      if (this._modules[i] == module)
        this._modules.splice(i--, 1);
    delete this._modulesByContractId[contractId];
    LOG("Service pane module " + contractId + " removed");
  },

  init: function ServicePaneService_init() {
    deprecationWarning("sbIServicePaneService.init() is deprecated, you no " +
                       "longer need to call it.");
  },

  _clearNodeListeners: function ServicePaneService__clearNodeListeners(aNode) {
    if (aNode._eventListeners) {
      delete aNode._eventListeners;
    }
    for each (let child in aNode.childNodes) {
      this._clearNodeListeners(child);
    }
  },
  _shutdown: function ServicePaneService__shutdown() {
    this._clearNodeListeners(this.root);

    let observerService = Cc["@mozilla.org/observer-service;1"]
                            .getService(Ci.nsIObserverService);
    observerService.removeObserver(this, "quit-application");
    observerService.removeObserver(this, "xpcom-category-entry-added");
    observerService.removeObserver(this, "xpcom-category-entry-removed");
    for each (let module in this._modules) {
      try {
        module.shutdown();
      } catch (e) {
        // Components.utils.reportError can't report to anywhere visible at
        // this point, since to get here we must have closed the Error Console.
        // Dump to stderr instead.
        dump("**********************************************\n");
        dump(e + "\n");
        dump("**********************************************\n");
      }
    }
    this._modules = [];
    this._modulesByContractId = {};
  },

  createNode: function ServicePaneService_createNode() {
    return new ServicePaneNode(this, null);
  },

  _registerNode: function ServicePaneService__registerNode(
                                                      aAttr, aValue, aNode) {
    let table;
    switch (aAttr) {
      case "id":
        table = this._nodesById;
        break;
      case "url":
        table = this._nodesByUrl;
        break;
      case "contentPrefix":
        table = this._nodesByContentPrefix;
        break;
      default:
        return;
    }

    if (!(aValue in table))
      table[aValue] = [];

    table[aValue].push(aNode);
  },

  _unregisterNode: function ServicePaneService__unregisterNode(
                                                      aAttr, aValue, aNode) {
    let table;
    switch (aAttr) {
      case "id":
        table = this._nodesById;
        break;
      case "url":
        table = this._nodesByUrl;
        break;
      case "contentPrefix":
        table = this._nodesByContentPrefix;
        break;
      default:
        return;
    }

    if (aValue in table)
    {
      let list = table[aValue];
      for (let i = 0; i < list.length; i++)
        if (list[i] == aNode)
          list.splice(i--, 1);
    }
  },

  getNode: function ServicePaneService_getNode(aId) {
    if (aId in this._nodesById && this._nodesById[aId].length) {
      if (this._nodesById[aId].length > 1) {
        // Warn if multiple nodes with same ID exist
        let caller = Components.stack.caller;

        // Skip empty frames
        while (caller && !caller.filename)
          caller = caller.caller;

        let consoleService = Cc["@mozilla.org/consoleservice;1"]
                               .getService(Ci.nsIConsoleService);
        let scriptError = Cc["@mozilla.org/scripterror;1"]
                            .createInstance(Ci.nsIScriptError);
        scriptError.init("Multiple service pane nodes with ID '" + aId + "' exist, only returning one node.",
                         caller ? caller.filename : null,
                         caller ? caller.sourceLine : null,
                         caller ? caller.lineNumber : null,
                         0,
                         Ci.nsIScriptError.warningFlag,
                         "sbServicePaneService");
        consoleService.logMessage(scriptError);
      }
      return this._nodesById[aId][0];
    }
    else
      return null;
  },

  getNodeForURL: function ServicePaneService_getNodeForURL(aUrl, aMatchLevel) {

    // Check to see if aUrl (a string url spec) begins with a node's
    // contentPrefix. Only do this if the caller specifically requests a
    // prefix match.
    var prefixMatch = null;
    if (!(typeof(aMatchLevel) == 'undefined') &&
        aMatchLevel == Ci.sbIServicePaneService.URL_MATCH_PREFIX)
    {
      for (let prefix in this._nodesByContentPrefix) {
        if (aUrl.indexOf(prefix) == 0 &&
            this._nodesByContentPrefix[prefix].length)
        {
          prefixMatch = this._nodesByContentPrefix[prefix][0];
        }
      }
    }

    // Check for an exact url match. This is done for both URL_MATCH_PREFIX and
    // URL_MATCH_EXACT intentionally so that calls using URL_MATCH_PREFIX will
    // still find a node if the url attribute is an exact match (even in the
    // absence of a contentPrefix attribute)
    if (aUrl in this._nodesByUrl && this._nodesByUrl[aUrl].length) {
      // We prefer exact matches to prefix matches
      return this._nodesByUrl[aUrl][0];
    }
    else {
      // We didn't find an exact match. Return a prefix match if we found one.
      // prefixMatch will always be null if the caller didn't pass in
      // aMatchLevel or they passed URL_MATCH_EXACT
      return prefixMatch;
    }
  },

  getNodesByAttributeNS: function ServicePaneService_getNodesByAttributeNS(
                                                  aNamespace, aName, aValue) {
    function findNodeRecursive(aNode, aAttrName, aValue, aResult) {
      for each (let child in aNode._childNodes) {
        if (child.getAttribute(aAttrName) == aValue)
          aResult.push(child);

        findNodeRecursive(child, aAttrName, aValue, aResult);
      }
    }

    let result = [];
    let attrName = (aNamespace == null ? aName : aNamespace + ":" + aName);
    findNodeRecursive(this._root, attrName, aValue, result);
    return ArrayConverter.nsIArray(result);
  },

  addListener: function ServicePaneService_addListener(aListener) {
    deprecationWarning("sbIServicePaneService.addListener() is deprecated " +
                       "and may be removed in future. Consider using " +
                       "root.addMutationListener() instead.");
    this.root.addMutationListener(new MutationEventTranslator(aListener));
  },

  removeListener: function ServicePaneService_removeListener(aListener) {
    deprecationWarning("sbIServicePaneService.addListener() is deprecated " +
                       "and may be removed in future. Consider using " +
                       "root.removeMutationListener() instead.");

    // Make a copy of the listeners in case they change while we are in the loop
    let listeners = this.root._listeners.slice();
    for each (let listener in listeners)
      if (listener instanceof MutationEventTranslator && listener.listener == aListener)
        this.root.removeMutationListener(listener);
  },

  fillContextMenu: function ServicePaneService_fillContextMenu(
                                          aNode, aContextMenu, aParentWindow) {
    for each (let module in this._modules) {
      try {
        module.fillContextMenu(aNode, aContextMenu, aParentWindow);
      } catch (ex) {
        Components.utils.reportError(ex);
      }
    }
  },

  fillNewItemMenu: function ServicePaneService_fillNewItemMenu(
                                          aNode, aContextMenu, aParentWindow) {
    for each (let module in this._modules) {
      try {
        module.fillNewItemMenu(aNode, aContextMenu, aParentWindow);
      } catch (ex) {
        Components.utils.reportError(ex);
      }
    }
  },

  onSelectionChanged: function ServicePaneService_onSelectionChanged(
                                          aNode, aContainer, aParentWindow) {
    for each (let module in this._modules) {
      try {
        module.onSelectionChanged(aNode, aContainer, aParentWindow);
      } catch (ex) {
        Components.utils.reportError(ex);
      }
    }
  },

  onBeforeRename: function ServicePaneService_onBeforeRename(aNode) {
    if (!aNode || !aNode.editable)
      return;

    // Pass the message on to the node owner
    if (aNode.contractid && aNode.contractid in this._modulesByContractId) {
      let module = this._modulesByContractId[aNode.contractid];
      module.onBeforeRename(aNode);
    }
  },

  onRename: function ServicePaneService_onRename(aNode, aNewName) {
    if (!aNode || !aNode.editable)
      return;

    // Pass the message on to the node owner
    if (aNode.contractid && aNode.contractid in this._modulesByContractId) {
      let module = this._modulesByContractId[aNode.contractid];
      module.onRename(aNode, aNewName);
    }
  },

  addNode: function ServicePaneService_addNode(aId, aParent, aContainer) {
    deprecationWarning("sbIServicePaneService.addNode() is deprecated and " +
                       "may be removed in future. Consider using " +
                       "sbIServicePaneService.createNode() instead and " +
                       "adding it to the parent yourself.");

    if (!aParent)
      throw Ce("You need to supply a parent for addNode().");

    if (aId && this.getNode(aId)) {
      // Original implementation returned null for attempts to duplicate a node
      return null;
    }

    let node = this.createNode();
    aParent.appendChild(node);
    node.id = (aId !== null ? aId : "_generatedNodeId" + ++this._nodeIndex);
    if (!aContainer)
      node.setAttribute("isContainer", "false");

    return node;
  },

  removeNode: function ServicePaneService_removeNode(aNode) {
    deprecationWarning("sbIServicePaneService.removeNode() is deprecated and " +
                       "may be removed in future. Consider using " +
                       "sbIServicePaneNode.removeChild() instead.");

    if (!aNode)
      throw Ce("You need to supply a node for removeNode().");
    if (!aNode.parentNode)
      throw Ce("Cannot remove a node that doesn't have a parent.");

    aNode.parentNode.removeChild(aNode);
  },

  sortNode: function ServicePaneService_sortNode() {
    deprecationWarning("sbIServicePaneService.sortNode() is deprecated, you no " +
                       "longer need to call it.");
  },

  save: function ServicePaneService_save() {
    deprecationWarning("sbIServicePaneService.save() is deprecated, you no " +
                       "longer need to call it.");
  },

  canDrop: function ServicePaneService_canDrop(
                                  aNode, aDragSession, aOrientation, aWindow) {
    if (!aNode) {
      return false;
    }

    LOG("canDrop(" + aNode.id + ")");

    // let the module that owns this node handle this
    if (aNode.contractid && aNode.contractid in this._modulesByContractId) {
      let module = this._modulesByContractId[aNode.contractid];
      return module.canDrop(aNode, aDragSession, aOrientation, aWindow);
    }
    return false;
  },

  onDrop: function ServicePaneService_onDrop(
                                    aNode, aDragSession, aOrientation, aWindow) {
    if (!aNode) {
      return;
    }

    LOG("onDrop(" + aNode.id + ")");

    // or let the module that owns this node handle it
    if (aNode.contractid && aNode.contractid in this._modulesByContractId) {
      let module = this._modulesByContractId[aNode.contractid];
      module.onDrop(aNode, aDragSession, aOrientation, aWindow);
    }
  },

  onDragGesture: function ServicePaneService_onDragGesture(aNode, aDataTransfer) {
    if (!aNode) {
      return false;
    }

    LOG("onDragGesture(" + aNode.id + ")");

    if (!aNode.id) {
      Cu.reportError(new Exception("Cannot drag a service pane node without ID"));
      return false;
    }

    let success = false;

    // get drag types from the node data
    if (aNode.dndDragTypes) {
      let types = aNode.dndDragTypes.split(',');
      for each (let type in types) {
        aDataTransfer.setData(type, aNode.id);
        success = true;
      }
    }

    if (aNode.contractid && aNode.contractid in this._modulesByContractId) {
      let module = this._modulesByContractId[aNode.contractid];
      if (module.onDragGesture(aNode, aDataTransfer)) {
        success = true;
      }
    }

    LOG(" success=" + success);

    return success;
  }
};

var NSGetModule = XPCOMUtils.generateNSGetModule([ServicePaneService]);