+
+/**
+ * To create a "drag" interaction, you typically register a mousedown event
+ * handler on the element where the drag begins. In that handler, you register a
+ * mouseup handler on the window to determine when the mouse is released,
+ * wherever that release happens. This works well, except when the user releases
+ * the mouse over an off-domain iframe. In that case, the mouseup event is
+ * handled by the iframe and never bubbles up to the window handler.
+ *
+ * To deal with this issue, we cover iframes with high z-index divs to make sure
+ * they don't capture mouseup.
+ *
+ * Usage:
+ * element.addEventListener('mousedown', function() {
+ * var tarper = new Dygraph.IFrameTarp();
+ * tarper.cover();
+ * var mouseUpHandler = function() {
+ * ...
+ * window.removeEventListener(mouseUpHandler);
+ * tarper.uncover();
+ * };
+ * window.addEventListener('mouseup', mouseUpHandler);
+ * };
+ *
+ *
+ * @constructor
+ */
+Dygraph.IFrameTarp = function() {
+ this.tarps = [];
+};
+
+/**
+ * Find all the iframes in the document and cover them with high z-index
+ * transparent divs.
+ */
+Dygraph.IFrameTarp.prototype.cover = function() {
+ var iframes = document.getElementsByTagName("iframe");
+ for (var i = 0; i < iframes.length; i++) {
+ var iframe = iframes[i];
+ var x = Dygraph.findPosX(iframe),
+ y = Dygraph.findPosY(iframe),
+ width = iframe.offsetWidth,
+ height = iframe.offsetHeight;
+
+ var div = document.createElement("div");
+ div.style.position = "absolute";
+ div.style.left = x + 'px';
+ div.style.top = y + 'px';
+ div.style.width = width + 'px';
+ div.style.height = height + 'px';
+ div.style.zIndex = 999;
+ document.body.appendChild(div);
+ this.tarps.push(div);
+ }
+};
+
+/**
+ * Remove all the iframe covers. You should call this in a mouseup handler.
+ */
+Dygraph.IFrameTarp.prototype.uncover = function() {
+ for (var i = 0; i < this.tarps.length; i++) {
+ this.tarps[i].parentNode.removeChild(this.tarps[i]);
+ }
+ this.tarps = [];
+};