implemented PlaceThePointsNode.dispose #78

phetsims · Apr 23, 2017 · 138e56f · 138e56f
1 parent 8b1101d
commit 138e56f
Showing 1 changed file with 15 additions and 3 deletions.
diff --git a/js/linegame/view/PlaceThePointsNode.js b/js/linegame/view/PlaceThePointsNode.js
@@ -29,8 +29,8 @@ define( function( require ) {
     GraphTheLineNode.call( this, challenge, model, challengeSize, audioPlayer );
 
     var self = this;
-    //TODO #78 unlink in dispose
-    model.playStateProperty.link( function( playState ) {
+
+    var playStateObserver = function( playState ) {
 
       // show user's line only in states where there guess is wrong.
       self.graphNode.setGuessVisible(
@@ -42,13 +42,25 @@ define( function( require ) {
        */
       self.graphNode.setAnswerPointVisible( playState === PlayState.NEXT && !challenge.isCorrect() );
       self.graphNode.setGuessPointVisible( false );
-    } );
+    };
+    model.playStateProperty.link( playStateObserver ); // unlink in dispose
+
+    // @private called by dispose
+    this.disposePlaceThePointsNode = function() {
+      model.playStateProperty.unlink( playStateObserver );
+    };
   }
 
   graphingLines.register( 'PlaceThePointsNode', PlaceThePointsNode );
 
   return inherit( GraphTheLineNode, PlaceThePointsNode, {
 
+    // @public
+    dispose: function() {
+      this.disposePlaceThePointsNode();
+      GraphTheLineNode.prototype.dispose.call( this );
+    },
+
     /**
      * Creates the graph portion of the view.
      * @param {Challenge} challenge