postMessage_chrome_helper.html

Enable keyboard shortcuts

<!DOCTYPE html>

<html>

<head>

  <title>postMessage chrome message receiver</title>

  <script type="application/javascript">

    var gPrePath = "";

    function receiveMessage(evt)

      if (evt.data.substring(0,9) == "chrome://") {

        gPrePath = evt.data;

        respond("path-is-set");

      } else {

        // Content cannot post to chrome without privileges

        try {

          window.parent.postMessage("SHOULD NOT GET THIS!", "*");

        catch (ex) {

        var msg = "post-to-content-response";

        if (evt.source !== null)

          msg += " wrong-source(" + evt.source + ")";

        if (!evt.isTrusted)

          msg += " unexpected-untrusted-event";

        if (evt.type !== "message")

          msg += " wrong-type(" + evt.type + ")";

        if (evt.origin !== gPrePath)

          msg += " wrong-origin(" + evt.origin + ")";

        if (evt.data !== "post-to-content")

          msg += " wrong-message(" + evt.data + ")";

        respond(msg);

    function respond(msg)

      SpecialPowers.wrap(window).parent.postMessage(msg, "*");

    window.addEventListener("message", receiveMessage);

  </script>

</head>

<body>

<h1 id="domain">example.org</h1>

</body>

</html>