Album Art

Windows:

/Users/[username]/App Data/Local/Songbird2/Profiles/[profile]/artwork

Linux:

/home/[username]/.songbird2/[profile]/artwork

OS X:

/Users/[username]/Library/Application Data/Songbird2/Profiles/[profile]/artwork

First create your folder structure for the extension

/root
    /chrome/
        chrome.manifest
        /locale/en-US
            [fetchername]-fetcher.properties
    /components
        sb[FetcherName]ArtFetcher.js
    /defaults/preferences
        prefs.js
    install.rdf

Create the chrome.manifest

locale  [fetchername]-fetcher  en-US  chrome/locale/en-US/

Create the install.rdf

<?xml version="1.0" encoding="UTF-8"?>
<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:em="http://www.mozilla.org/2004/em-rdf#"
     xmlns:songbird="http://www.songbirdnest.com/2007/addon-metadata-rdf#">
  <Description about="urn:mozilla:install-manifest">
    <em:id>{bac3da27-34f4-4085-9da4-84595ef36a39}</em:id>
    <em:type>2</em:type>
    <em:name>[Fetcher Name] Album Art Fetcher</em:name>
    <em:version>1.0.0.0</em:version>
    <em:creator></em:creator>
    <em:description>Fetch album art from [Fetcher Name].</em:description>

    <em:targetApplication>
      <Description>
        <em:id>songbird@songbirdnest.com</em:id>
        <em:minVersion>1.1.0</em:minVersion>
        <em:maxVersion>1.2.0</em:maxVersion>
      </Description>
    </em:targetApplication>
  </Description>
</RDF>

Create the properties file

extensions.albumart.[fetchername].name=[Fetcher Name]
extensions.albumart.[fetchername].description=A New Fetcher

Create the prefs file

// Album Art Fetching preferences
// Dump status to console
pref("extensions.albumart.[fetchername].debug", false);
// Enable the Fetcher
pref("extensions.albumart.[fetchername].enabled", true);
// Priority of the Fetcher. Use a number between 1 and 999
// A lower number is higher priority.
pref("extensions.albumart.[fetchername].priority", XXX);

Create the sbFetchernameArtFetcher.js

/*
//
// BEGIN SONGBIRD GPL
//
// This file is part of the Songbird web player.
//
// Copyright(c) 2005-2009 POTI, Inc.
// http://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
//
*/


/* This is a XPCOM component for the Album Art Fetcher interface.
 */

const Cc = Components.classes;
const CC = Components.Constructor;
const Ci = Components.interfaces;
const Cr = Components.results;
const Cu = Components.utils;

// The root of our preferences branch
const PREF_BRANCH = "extensions.albumart.[fetchername].";
// The string bundle location
const STRING_BUNDLE = "chrome://[fetchername]-fetcher/locale/[fetchername]-fetcher.properties";

// Importing helper modules
Cu.import('resource://app/jsmodules/sbProperties.jsm');
Cu.import("resource://app/jsmodules/StringUtils.jsm");
Cu.import('resource://gre/modules/XPCOMUtils.jsm');

/**
 * Since we can't use the FUEL components until after all other components have
 * been loaded we define a lazy getter here for when we need it.
 */
__defineGetter__("Application", function() {
  delete this.Application;
  return this.Application = Cc["@mozilla.org/fuel/application;1"]
                              .getService(Ci.fuelIApplication);
});

/**
 * Album Art Fetcher - sb[FetcherName]AlbumArtFetcher
 */
function sb[FetcherName]AlbumArtFetcher() {
  var stringBundleService = Cc["@mozilla.org/intl/stringbundle;1"]
                             .getService(Ci.nsIStringBundleService);
  this._bundle = stringBundleService.createBundle(STRING_BUNDLE);

  this.DEBUG = Application.prefs.getValue(PREF_BRANCH + "debug", false);
  if (this.DEBUG) {
    this._consoleService = Cc["@mozilla.org/consoleservice;1"]
                            .getService(Ci.nsIConsoleService);
  }
  this._debug("Starting [FetcherName] Album Art Fetcher Component");
};
sb[FetcherName]AlbumArtFetcher.prototype = {
  // XPCOM Magic
  className: 'sb[FetcherName]AlbumArtFetcher',
  classDescription: '[FetcherName] Album Cover Fetcher',
  classID: Components.ID('{}'), // Use uuidgen to get an ID
  contractID: '@songbirdnest.com/Songbird/album-art/[fetchername]-fetcher;1',
  _xpcom_categories: [{
    category: "songbird-album-art-fetcher"
  }],

  // Variables
  DEBUG: false,               // Debug flag
  _shutdown: false,           // Flag to shutdown
  _albumArtSourceList: null,  // Source list
  _bundle: null,              // String bundle
  _shortName: "[fetchername]",
 
  // Services
  _consoleService: null,

  /**
   * Internal debugging functions
   */
  /**
   * \brief Dumps out a message if the DEBUG flag is enabled with
   *        the className pre-appended.
   * \param message String to print out.
   */
  _debug: function (message)
  {
    if (!this.DEBUG) return;
    try {
      dump(this.className + ": " + message + "\n");
      this._consoleService.logStringMessage(this.className + ": " + message);
    } catch (err) {
      // We do not want to throw an exception here
    }
  },
 
  /**
   * \brief Dumps out an error message with the className + ": [ERROR]"
   *        pre-appended, and will report the error so it will appear in the
   *        error console.
   * \param message String to print out.
   */
  _logError: function (message)
  {
    try {
      dump(this.className + ": [ERROR] - " + message + "\n");
      Cu.reportError(this.className + ": [ERROR] - " + message);
    } catch (err) {
      // We do not want to thow an exception here
    }
  },

  /*********************************
   * sbIAlbumArtFetcher
   ********************************/
  // These are a bunch of getters for attributes in the sbIAlbumArtFetcher.idl
  get shortName() {
    this._debug("Getting shortName: " + this._shortName);
    return this._shortName;
  },
 
  // These next few use the .properties file to get the information
  get name() {
    var mName = SBString(PREF_BRANCH + "name", null, this._bundle);
    this._debug("Getting Name: " + mName);
    return mName;
  },
 
  get description() {
    var mDescription = SBString(PREF_BRANCH + "description", null, this._bundle);
    this._debug("Getting Description: " + mDescription);
    return mDescription;
  },
 
  get isLocal() {
    var mLocal = Application.prefs.getValue(PREF_BRANCH + "islocal", true);
    this._debug("Getting isLocal: " + mLocal);
    return mLocal;
  },
 
  // These are preference settings
  get priority() {
    var priority = parseInt(Application.prefs.getValue(PREF_BRANCH + "priority", 15), 10);
    this._debug("Getting Priority: " + priority);
    return priority;
  },
  set priority(aNewVal) {
    this._debug("Setting Priority: " + aNewVal);
    return Application.prefs.setValue(PREF_BRANCH + "priority", aNewVal);
  },
 
  get isEnabled() {
    return Application.prefs.getValue(PREF_BRANCH + "enabled", false);
  },
  set isEnabled(aNewVal) {
    this._debug("Setting isEnabled: " + aNewVal);
    return Application.prefs.setValue(PREF_BRANCH + "enabled", aNewVal);
  },
 
  get albumArtSourceList() {
    this._debug("Getting albumArtSourceList: " +
                 this._albumArtSourceList.Length() +
                 " items");
    return this._albumArtSourceList;
  },
  set albumArtSourceList(aNewVal) {
    if (aNewVal) {
      this._debug("Setting albumArtSourceList: " + aNewVal.Length() + " items");
    } else {
      this._debug("Setting albumArtSourceList: NULL");
    }
    this._albumArtSourceList = aNewVal;
  },

  fetchAlbumArtForAlbum: function (aMediaItems, aListener) {
    this._debug("fetchAlbumArtForAlbum called.");

    // Do what you need to do to fetch artwork for an album.
    // Then if successful call aListener.onAlbumResult(artworkURL, aMediaItems);
    // You can also call aListener.onTrackResult(artworkURL, aMediaItem); for each
    //  one you find an artwork for.
    // If you do not find artwork you do not need to call either of those functions.
    
    // Finally call aListener.onAlbumComplete(aMediaItems);
  },
 
  fetchAlbumArtForTrack: function (aMediaItem, aListener) {
    this._debug("fetchAlbumArtForTrack called.");
 
    // Do what you need to do to fetch artwork for a single track.
    // Then if successful call aListener.onTrackResult(artworkURL, aMediaItem);
    // If not successful then you do not need to call anything.

    // Finally call aListener.onAlbumComplete(items);
    // A helpful piece of code for this is
    // var items = Cc["@songbirdnest.com/moz/xpcom/threadsafe-array;1"]
    //                .createInstance(Ci.nsIMutableArray);
    //  items.appendElement(aMediaItem, false);

  },
 
  shutdown: function () {
    this._debug("Shutdown called.");
  },

  /*********************************
   * nsISupports
   ********************************/
  QueryInterface: XPCOMUtils.generateQI([Ci.sbIAlbumArtFetcher])
}

// This is for XPCOM to register this Fetcher as a module
function NSGetModule(compMgr, fileSpec) {
  return XPCOMUtils.generateModule([sb[FetcherName]AlbumArtFetcher]);
}

If you wish to test the extension you can install the Developer Tools [here] and select the "Link Extension in Test Mode...".

Now you can zip up the folder making sure to have the extension as .xpi and upload it to http://addons.songbirdnest.com.