I found the basis for my solution here. mousemove-when-over-an-iframe
I modified this slightly in that my particular page didn't need to save the original onMouseMove and onMouseUp handlers.
To wire this up add a client listener to the popup
<af:clientListener type="popupOpened" method="popupOpened"/>
// This method attaches the frame with id of "fid" to the mouse event handler
function popupOpened(e){ var frame = document.getElementById( e.getSource().findComponent("fid").getClientId()+'::f'); bubbleIframeMouseMove(frame); }// iframe causes the page to lose the mouse events when dragging the dialog
// this fixes it by propagating mouse events in the iframe to the parent page
function bubbleIframeMouseMove(iframe){ iframe.contentWindow.onmousemove = propagateToParent; iframe.contentWindow.onmouseup = propagateToParent; function propagateToParent(e){ // Create a new event for the this window var evt = document.createEvent("MouseEvents"); // We'll need this to offset the mouse move appropriately var boundingClientRect = iframe.getBoundingClientRect(); // Initialize the event, copying exiting event values // for the most part evt.initMouseEvent( e.type, true, // bubbles false, // not cancelable window, e.detail, e.screenX, e.screenY, e.clientX + boundingClientRect.left, e.clientY + boundingClientRect.top, e.ctrlKey, e.altKey, e.shiftKey, e.metaKey, e.button, null // no related element ); // Dispatch the mousemove event on the iframe element iframe.dispatchEvent(evt); }; }