PC World 2008 September/PCWorld_2008-09_cd.bin/v cisle/sadanastroju/bookmark_previews-0.6.5-fx.xpi/components/bookmarkpreviews.js

Text File | 2008-05-27 | 5.4 KB | 156 lines

const Ci = Components.interfaces, Cc = Components.classes, Cr = Components.results;
function UnloadComponent() {

}
UnloadComponent.prototype = {
  classID: Components.ID("{a3c05366-aa2c-4e1b-9ab0-5168e50cec61}"), // xxx generate guid
  contractID: "@mozdev.org/bookmarkpreviews;1", // XXX generated contractid too
  classDescription: "Bookmark Previews Uninstall Component",
  QueryInterface: function(aIID) {
    if(!aIID.equals(Ci.nsISupports) && !aIID.equals(Ci.nsIObserver) && !aIID.equals(Ci.nsISupportsWeakReference)) // you can claim you implement more interfaces here
      throw Cr.NS_ERROR_NO_INTERFACE;
    return this;
  },

  _prefs : null,
  get prefs(){
    if (!this._prefs){
      this._prefs = Components.classes["@mozilla.org/preferences-service;1"].
                    getService(Components.interfaces.nsIPrefService);
      this._prefs = this._prefs.getBranch("extensions.bookmarkpreviews.");
    }
    return this._prefs;
  },

  // nsIObserver implementation
  observe: function(aSubject, aTopic, aData) {
    //dump("bookmark previews observer "+aTopic+"\n");
    switch(aTopic) {
      case "xpcom-startup":
        //dump("xpcom-startup");
        // this is run very early, right after XPCOM is initialized, but before
        // user profile information is applied. Register ourselves as an observer
        // for 'quit-application'.
        var obsSvc = Cc["@mozilla.org/observer-service;1"].getService(Ci.nsIObserverService);
        obsSvc.addObserver(this, "quit-application", true);
        break;

      case "quit-application":
        /*
        Check if this is being uninstalled.
        If so, delete the bookmarkpreviews folder.
        */
        const PREFIX_ITEM_URI    = "urn:mozilla:item:";
        const PREFIX_NS_EM       = "http://www.mozilla.org/2004/em-rdf#";
        const OP_NEEDS_UNINSTALL = "needs-uninstall";
        var itemId = "[e-mail]";

        var rdf = Cc["@mozilla.org/rdf/rdf-service;1"].getService(Ci.nsIRDFService);
        var itemResource = rdf.GetResource(PREFIX_ITEM_URI + itemId);
        if (itemResource) {
          var extmgr = Cc["@mozilla.org/extensions/manager;1"].getService(Ci.nsIExtensionManager);
          var ds = extmgr.datasource;
          var target = ds.GetTarget(itemResource, rdf.GetResource(PREFIX_NS_EM + "opType"), true);
          if (target && target instanceof Ci.nsIRDFLiteral){
            if (target.Value == OP_NEEDS_UNINSTALL){
              this.uninstall();
            }
          }
        }
        break;
      default:
        throw Components.Exception("Unknown topic: " + aTopic);
    }
  },
  uninstall : function(){
    var dir = Components.classes["@mozilla.org/file/directory_service;1"]
          .getService(Components.interfaces.nsIProperties)
          .get("ProfD", Components.interfaces.nsIFile);
    dir.append("bookmarkpreviews");
    if (dir.exists()){
      dir.remove(true);
    }
    /* remove firstrun pref so previews will be created again if reinstalled */
    this.prefs.resetBranch("");
  }
};

// constructors for objects we want to XPCOMify
var objects = [UnloadComponent];

/*
 * Registration code.
 *
 */
const UNLOAD_OBSERVER_NAME = "Bookmark Previews Uninstall Observer";

function FactoryHolder(aObj) {
  this.CID        = aObj.prototype.classID;
  this.contractID = aObj.prototype.contractID;
  this.className  = aObj.prototype.classDescription;
  this.factory = {
    createInstance: function(aOuter, aIID) {
      if(aOuter)
        throw Cr.NS_ERROR_NO_AGGREGATION;
      return (new this.constructor).QueryInterface(aIID);
    }
  };
  this.factory.constructor = aObj;
}

var gModule = {
  registerSelf: function (aComponentManager, aFileSpec, aLocation, aType)
  {
    aComponentManager.QueryInterface(Ci.nsIComponentRegistrar);
    for (var key in this._objects) {
      var obj = this._objects[key];
      aComponentManager.registerFactoryLocation(obj.CID, obj.className,
        obj.contractID, aFileSpec, aLocation, aType);
    }

    // this can be deleted if you don't need to init on startup
    var catman = Cc["@mozilla.org/categorymanager;1"].getService(Ci.nsICategoryManager);
    catman.addCategoryEntry("xpcom-startup", UNLOAD_OBSERVER_NAME,
      UnloadComponent.prototype.contractID, true, true);
    //catman.addCategoryEntry("xpcom-shutdown", UNLOAD_OBSERVER_NAME,
    //  UnloadComponent.prototype.contractID, true, true);
  },

  unregisterSelf: function(aCompMgr, aFileSpec, aLocation) {
    // this must be deleted if you delete the above code dealing with |catman|
    var catman = Cc["@mozilla.org/categorymanager;1"].getService(Ci.nsICategoryManager);
    catman.deleteCategoryEntry("xpcom-startup", UNLOAD_OBSERVER_NAME, true);
    // end of deleteable code

    aComponentManager.QueryInterface(Ci.nsIComponentRegistrar);
    for (var key in this._objects) {
      var obj = this._objects[key];
      aComponentManager.unregisterFactoryLocation(obj.CID, aFileSpec);
    }
  },

  getClassObject: function(aComponentManager, aCID, aIID) {
    if (!aIID.equals(Ci.nsIFactory)) throw Cr.NS_ERROR_NOT_IMPLEMENTED;

    for (var key in this._objects) {
      if (aCID.equals(this._objects[key].CID))
        return this._objects[key].factory;
    }

    throw Cr.NS_ERROR_NO_INTERFACE;
  },

  canUnload: function(aComponentManager) {
    return true;
  },

  _objects: {} //FactoryHolder
};

function NSGetModule(compMgr, fileSpec)
{
  for(var i in objects)
    gModule._objects[i] = new FactoryHolder(objects[i]);
  return gModule;
}