grooveshark.js

/*
 * Chrome-Last.fm-Scrobbler Grooveshark Connector
 *
 * Matt Runkle - matt[at]mrunkle[dot]com
 *
 * Inspired by Pandora connector, written by Jordan Perr, jordan[at]jperr[dot]com
 *
 * Note, this connector will only scrobble when no user is authenticated. If you
 * maintain a Grooveshark account, configure the built-in Last.fm scrobbling to
 * keep track of song plays while logged-in to the site.
 */

/*** Configuration ***/

// Determines whether this plugin will scrobble
GS_SCROBBLE = true;

// Changes to this div may toggle scrobbling
GS_LOGIN_CONTAINER = "div#header-user-assets";

// Additions to this div will trigger update
GS_WATCHED_CONTAINER = "div#now-playing-metadata";

// Returns the currently playing artist name
function GS_getArtist( ) {
   // Grab title element, since text portion can be truncated
   var artist = $("div#now-playing-metadata a.artist").attr('title');
   if( artist == undefined ) {
      // Fall back to text portion if title attr is empty
      artist = $("div#now-playing-metadata a.artist").text();
   }
   return GS_cleanLabel( artist );
}

// Returns the currently playing track title
// Grab title element, since text portion can be truncated
function GS_getTrack( ) {
   var track = $("div#now-playing-metadata a.song").attr('title');
   if( track == undefined ) {
      // Fall back to text portion if title attr is empty
      track = $("div#now-playing-metadata a.song").text();
   }
   return GS_cleanLabel( track );
}

// Returns the song length in seconds
function GS_getDuration( ) {
   var timeArr = $("span#time-total").text().split(":");
   return parseInt( timeArr[0] ) * 60 + parseInt( timeArr[1] );
}

// Perform some common cleanup of artist/song strings
function GS_cleanLabel( label ) {
   label = label.replace( '&', '&' );
   return $.trim( label );
}

/*** Scrobbler Interface ***/
GS_LAST_TRACK = "";
GS_TIMEOUT = "";


// Validates and scrobbles the currently playing song
function GS_updateNowPlaying() {
   if( GS_SCROBBLE != true ) {
      // Abort scrobbling
      return;
   }   
   var title = GS_getTrack();
   var artist = GS_getArtist();
   var duration = GS_getDuration();
   var newTrack = title + " " + artist;

   // Update scrobbler if necessary
   if ( newTrack != " " && newTrack != GS_LAST_TRACK ) {
      //console.log("Submitting a now playing request. artist: "+artist+", title: "+title+", duration: "+duration);

      GS_LAST_TRACK = newTrack;
      chrome.extension.sendRequest({type: 'validate', artist: artist, track: title}, function(response) {
         if (response != false) {
            // submit the validated song for scrobbling
            var song = response;
            chrome.extension.sendRequest({type: 'nowPlaying', artist: song.artist, track: song.track, duration: duration});
         } else {
            // on failure send nowPlaying 'unknown song'
            console.log( "Song validation failed!" );
            chrome.extension.sendRequest({type: 'nowPlaying', duration: duration});
         }
      });
   }
}

// Turns scrobbling on or off depending on user login state
function GS_updateScrobbling() {
   var loginButton = $("a#header-login-btn")[0];
   if( loginButton != undefined && !GS_SCROBBLE ) {
      // "Sign In" button is present, non-logged in user
      // OK to scrobble
      console.log("User logout detected. Enabling Chrome Last.fm scrobbler on Grooveshark.");
      GS_SCROBBLE = true;
   } else if ( loginButton == undefined && GS_SCROBBLE ) {
      // "Sign In" button is gone, assume user is logged in
      // Use built-in Grookshark scrobbling
      console.log("User login detected. Disabling Chrome Last.fm scrobbler on Grooveshark.");
      GS_resetScrobbling();
      GS_SCROBBLE = false;
   }
}

// Resets the plugin, cancelling any queued scrobbles
function GS_resetScrobbling() {
   console.log("Resetting scrobbler.");
   chrome.extension.sendRequest({type: 'reset'});
}

// Attach listener for song changes, filter out duplicate event firings
$(function(){
   console.log("Grooveshark scrobbling module starting up");

   // Attach listener to login container
   $(GS_LOGIN_CONTAINER).live('DOMSubtreeModified', function(e) {
      GS_updateScrobbling();
   });
   
   // Attach listener to "recently played" song list
   $(GS_WATCHED_CONTAINER).live('DOMSubtreeModified', function(e) {
      //console.log( "Update triggered" );

      var nowPlaying = GS_getTrack() + " " + GS_getArtist();

      if ( nowPlaying != " " && nowPlaying != GS_LAST_TRACK ) {
         // Stop any non-scrobbled songs (i.e. song skipped)
         if( GS_TIMEOUT != "" ) {
            clearTimeout( GS_TIMEOUT );
         }

         // Schedule the next scrobble
         GS_TIMEOUT = setTimeout( GS_updateNowPlaying, 10000 );

         return;
      }
   });
   
   // Turn on scrobbling if user is logged out on page load
   GS_updateScrobbling();
   
   $(window).unload(function() {
      GS_resetScrobbling();
      return true;
   });
});