Merge pull request #677 from danvk/split-iframe-tarp

[dygraphs.git] / src / iframe-tarp.js

diff --git a/src/iframe-tarp.js b/src/iframe-tarp.js
new file mode 100644 (file)
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+++ b/src/iframe-tarp.js
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+/**
+ * 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 IFrameTarp();
+ *   tarper.cover();
+ *   var mouseUpHandler = function() {
+ *     ...
+ *     window.removeEventListener(mouseUpHandler);
+ *     tarper.uncover();
+ *   };
+ *   window.addEventListener('mouseup', mouseUpHandler);
+ * };
+ *
+ * @constructor
+ */
+function IFrameTarp() {
+  /** @type {Array.<!HTMLDivElement>} */
+  this.tarps = [];
+};
+
+/**
+ * Find all the iframes in the document and cover them with high z-index
+ * transparent divs.
+ */
+IFrameTarp.prototype.cover = function() {
+  var iframes = document.getElementsByTagName("iframe");
+  for (var i = 0; i < iframes.length; i++) {
+    var iframe = iframes[i];
+    var pos = utils.findPos(iframe),
+        x = pos.x,
+        y = pos.y,
+        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.
+ */
+IFrameTarp.prototype.uncover = function() {
+  for (var i = 0; i < this.tarps.length; i++) {
+    this.tarps[i].parentNode.removeChild(this.tarps[i]);
+  }
+  this.tarps = [];
+};
+
+export default IFrameTarp;