Fixed bug caused by assigning "thisObj" as global variable in Feature…

…Track

constuctor, and subsequent use of thisObj in event handlers.  Revised
event handlinng so that "this" in the FeatureTrack event handler now
refers to the feature track (and same approach for DraggableFeatureTrack)

js/FeatureTrack.js

@@ -30,11 +30,12 @@ function FeatureTrack(trackMeta, url, refSeq, browserParams) {
     this.trackMeta = trackMeta;
     this.load(this.baseUrl + url);
 
-    thisObj = this;
+    var thisObj = this;
     this.subfeatureCallback = function(i, val, param) {
         thisObj.renderSubfeature(param.feature, param.featDiv, val,
                                  param.displayStart, param.displayEnd);
     };
+    this.featureClick = function(event) { thisObj.onFeatureClick(event); }
 }
 
 FeatureTrack.prototype = new Track("");
@@ -96,7 +97,8 @@ FeatureTrack.prototype.loadSuccess = function(trackInfo) {
 
 /* Broken out of loadSuccess so that DraggableFeatureTrack can overload it */
 FeatureTrack.prototype.onFeatureClick = function(event) {
-    var fields = thisObj.fields;
+    // var fields = thisObj.fields;
+    var fields = this.fields;
     event = event || window.event;
     if (event.shiftKey) return;
     var elem = (event.currentTarget || event.srcElement);
@@ -447,11 +449,7 @@ FeatureTrack.prototype.renderFeature = function(feature, uniqueId, block, scale,
         featDiv.target = "_new";
     } else {
         featDiv = document.createElement("div");
-        featDiv.onclick = this.onFeatureClick;
-        // Needed by DraggableFeatureTrack (which doesn't overload this function, renderFeature)
-        featDiv.onmouseover = this.onMouseOver;
-        featDiv.onmousedown = this.onMouseDown;
-        featDiv.onmouseup = this.onMouseUp;
+	featDiv.onclick = this.featureClick;
     }
 
     featDiv.feature = feature;