<?xml version="1.0"?>
<?xml-stylesheet type="text/css" href="chrome://global/skin"?>
<?xml-stylesheet type="text/css" href="/tests/SimpleTest/test.css"?>
<!--
https://bugzilla.mozilla.org/show_bug.cgi?id=453650
-->
<window title="Mozilla Bug 453650"
        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">

  <script type="application/javascript"
          src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>

  <!-- test code goes here -->
  <script type="application/javascript">
  <![CDATA[

  /** Test for Bug 453650 **/
  SimpleTest.waitForExplicitFinish();

  var Ci = Components.interfaces;
  var Cr = Components.results;

  var iter = runTests();
  nextTest();

  function runTests() {
    var iframe = document.createElement("iframe");
    iframe.style.width = "300px";
    iframe.style.height = "300px";
    iframe.setAttribute("src", "data:text/html,<h1 id='h'>hello</h1>");

    document.documentElement.appendChild(iframe);
    yield whenLoaded(iframe);
    info("iframe loaded");

    var h1 = iframe.contentDocument.getElementById("h");
    h1.style.width = "400px";
    yield waitForInterruptibleReflow(iframe.docShell);

    h1.style.width = "300px";
    waitForReflow(iframe.docShell);
    yield is(300, h1.offsetWidth, "h1 has correct width");
  }

  function waitForInterruptibleReflow(docShell) {
    waitForReflow(docShell, true);
  }

  function waitForReflow(docShell, interruptible = false) {
    function done() {
      docShell.removeWeakReflowObserver(observer);
      SimpleTest.executeSoon(nextTest);
    }

    var observer = {
      reflow: function (start, end) {
        if (interruptible) {
          ok(false, "expected interruptible reflow");
        } else {
          ok(true, "observed uninterruptible reflow");
        }

        info("times: " + start + ", " + end);
        ok(start < end, "reflow start time lower than end time");
        done();
      },

      reflowInterruptible: function (start, end) {
        if (!interruptible) {
          ok(false, "expected uninterruptible reflow");
        } else {
          ok(true, "observed interruptible reflow");
        }

        info("times: " + start + ", " + end);
        ok(start < end, "reflow start time lower than end time");
        done();
      },

      QueryInterface: function (iid) {
        if (Ci.nsIReflowObserver.equals(iid) ||
            Ci.nsISupportsWeakReference.equals(iid) ||
            Ci.nsISupports.equals(iid))
          return this;
        throw Cr.NS_ERROR_NO_INTERFACE;
      },
    };

    docShell.addWeakReflowObserver(observer);
  }

  function whenLoaded(iframe) {
    iframe.addEventListener("load", function onLoad() {
      iframe.removeEventListener("load", onLoad);
      SimpleTest.executeSoon(nextTest);
    });
  }

  function nextTest() {
    try {
      iter.next();
    } catch (e if e instanceof StopIteration) {
      SimpleTest.finish();
    }
  }

  ]]>
  </script>

  <!-- test results are displayed in the html:body -->
  <body xmlns="http://www.w3.org/1999/xhtml">
  <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=453650"
     target="_blank">Mozilla Bug 453650</a>
  </body>
</window>
