Tweaked the script to get icon path

src/graph/Graph.js

@@ -88,7 +88,7 @@ function Graph (container, data, options) {
     },
     navigation: {
       enabled: false,
-      iconPath: this._getIconURL()
+      iconPath: this._getScriptPath() + '/img'
     },
     keyboard: {
       enabled: false,
@@ -195,23 +195,22 @@ function Graph (container, data, options) {
 }
 
 /**
- * get the URL where the navigation icons are located
+ * Get the script path where the vis.js library is located
  *
- * @returns {string}
+ * @returns {string | null} path   Path or null when not found. Path does not
+ *                                 end with a slash.
  * @private
  */
-Graph.prototype._getIconURL = function() {
+Graph.prototype._getScriptPath = function() {
   var scripts = document.getElementsByTagName( 'script' );
-  var scriptNamePosition, srcPosition, imagePath;
+
+  // find script named vis.js or vis.min.js
   for (var i = 0; i < scripts.length; i++) {
-    srcPosition = scripts[i].outerHTML.search("src");
-    if (srcPosition != -1) {
-      scriptNamePosition = util.getLowestPositiveNumber(scripts[i].outerHTML.search("vis.js"),
-                                                  scripts[i].outerHTML.search("vis.min.js"));
-      if (scriptNamePosition != -1) {
-        imagePath = scripts[i].outerHTML.substring(srcPosition+5,scriptNamePosition).concat("img/");
-        return imagePath;
-      }
+    var src = scripts[i].src;
+    var match = src && /\/?vis(.min)?\.js$/.exec(src);
+    if (match) {
+      // return path without the script name
+      return src.substring(0, src.length - match[0].length);
     }
   }
 

src/graph/NavigationMixin.js

@@ -52,22 +52,22 @@ var NavigationMixin = {
     var offset = 15;
     var intermediateOffset = 7;
     var navigationNodes = [
-      {id: 'navigation_up',    shape: 'image', image: DIR + 'uparrow.png',   triggerFunction: "_moveUp",
+      {id: 'navigation_up',    shape: 'image', image: DIR + '/uparrow.png',   triggerFunction: "_moveUp",
         verticalAlignTop: false,  x: 45 + offset + intermediateOffset,  y: this.navigationClientHeight - 45 - offset - intermediateOffset},
-      {id: 'navigation_down',  shape: 'image', image: DIR + 'downarrow.png', triggerFunction: "_moveDown",
+      {id: 'navigation_down',  shape: 'image', image: DIR + '/downarrow.png', triggerFunction: "_moveDown",
         verticalAlignTop: false,  x: 45 + offset + intermediateOffset,  y: this.navigationClientHeight - 15 - offset},
-      {id: 'navigation_left',  shape: 'image', image: DIR + 'leftarrow.png', triggerFunction: "_moveLeft",
+      {id: 'navigation_left',  shape: 'image', image: DIR + '/leftarrow.png', triggerFunction: "_moveLeft",
         verticalAlignTop: false,  x: 15 + offset,  y: this.navigationClientHeight - 15 - offset},
-      {id: 'navigation_right', shape: 'image', image: DIR + 'rightarrow.png',triggerFunction: "_moveRight",
+      {id: 'navigation_right', shape: 'image', image: DIR + '/rightarrow.png',triggerFunction: "_moveRight",
         verticalAlignTop: false,  x: 75 + offset + 2 * intermediateOffset,  y: this.navigationClientHeight - 15 - offset},
 
-      {id: 'navigation_plus',  shape: 'image', image: DIR + 'plus.png',      triggerFunction: "_zoomIn",
+      {id: 'navigation_plus',  shape: 'image', image: DIR + '/plus.png',      triggerFunction: "_zoomIn",
         verticalAlignTop: false, horizontalAlignLeft: false,
         x: this.navigationClientWidth - 45 - offset - intermediateOffset, y: this.navigationClientHeight - 15 - offset},
-      {id: 'navigation_min', shape: 'image', image: DIR + 'minus.png',       triggerFunction: "_zoomOut",
+      {id: 'navigation_min', shape: 'image', image: DIR + '/minus.png',       triggerFunction: "_zoomOut",
         verticalAlignTop: false, horizontalAlignLeft: false,
         x: this.navigationClientWidth - 15 - offset, y: this.navigationClientHeight - 15 - offset},
-      {id: 'navigation_zoomExtends', shape: 'image', image: DIR + 'zoomExtends.png', triggerFunction: "zoomToFit",
+      {id: 'navigation_zoomExtends', shape: 'image', image: DIR + '/zoomExtends.png', triggerFunction: "zoomToFit",
         verticalAlignTop: false, horizontalAlignLeft: false,
         x: this.navigationClientWidth - 15 - offset, y: this.navigationClientHeight - 45 - offset - intermediateOffset}
     ];