+ * Creates an overlay element used to handle mouse events.
+ * @return {Object} The mouse event element.
+ * @private
+ */
+Dygraph.prototype.createMouseEventElement_ = function() {
+ if (this.isUsingExcanvas_) {
+ var elem = document.createElement("div");
+ elem.style.position = 'absolute';
+ elem.style.backgroundColor = 'white';
+ elem.style.filter = 'alpha(opacity=0)';
+ elem.style.width = this.width_ + "px";
+ elem.style.height = this.height_ + "px";
+ this.graphDiv.appendChild(elem);
+ return elem;
+ } else {
+ return this.canvas_;
+ }
+};
+
+/**