<html>
<head>
    <script>
        function log(msg)
        {
            document.getElementById('log').appendChild(document.createTextNode(msg + '\n'));
        }

        function description(element)
        {
            if (element.tagName && element.tagName.match(/input/i)) {
                return '<input value="' + element.value + '" tabindex="' + element.tabIndex + '">';
            } else {
                return element.toString();
            }
        }

        function dispatchTabPress(element, shiftKey)
        {
            var event = document.createEvent('KeyboardEvents');
            var tabKeyIdentifier = 'U+0009';
            event.initKeyboardEvent('keydown', true, true, document.defaultView, tabKeyIdentifier, 0, false, false, shiftKey, false, false);
            element.dispatchEvent(event);
        }

        var lastFocusedElement = null;
        function focusListener(event)
        {
            log('<input value="' + event.target.value + '" tabindex="' + event.target.tabIndex + '"> focused');
            lastFocusedElement = event.target;
        }

        function addEventListenersToInputs(inputs)
        {
            for (var i = 0; i < inputs.length; ++i) {
                inputs[i].addEventListener('focus', focusListener, false);
            }
        }

        function test()
        {
            if (window.testRunner) {
                testRunner.dumpAsText();
            }

            var inputs = document.getElementsByTagName('input');

            // Put focus in the page
            inputs[0].focus();
            inputs[0].blur();

            addEventListenersToInputs(inputs);

            log('Tabbing forward....\n');
            for (var i = 0; i < inputs.length; ++i) {
                if (inputs[i].tabIndex >= 0)
                    dispatchTabPress(document, false);
            }

            lastFocusedElement.blur();

            log('\nTabbing backward....\n');
            for (var i = 0; i < inputs.length; ++i) {
                if (inputs[i].tabIndex >= 0)
                    dispatchTabPress(document, true);
            }

            log('\nTest finished\n');
        }
    </script>
</head>
<body onload="test()">
    <p>This page tests that the <a href="http://www.w3.org/TR/html4/interact/forms.html#h-17.11.1" title="HTML4 tabbing order spec">HTML4 tabbing order</a> is respected properly.</p>
    <p>To test, put focus in &quot;a&quot;. Pressing Tab should focus &quot;a&quot; through &quot;k&quot; in order, and pressing Shift-Tab should reverse the order.</p>

    <input tabindex="6" value="g"><br>
    <input tabindex="1" value="a"><br>
    <input tabindex="-5" value="not in tab order (negative tabindex)"><br>
    <input tabindex="1" value="b"><br>
    <input tabindex="0" value="i"><br>
    <input tabindex="6" value="h"><br>
    <input tabindex="1" value="c"><br>
    <input tabindex="1" value="d"><br>
    <input tabindex="0" value="j"><br>
    <input tabindex="-1" value="not in tab order (negative tabindex)"><br>
    <input tabindex="0" value="k"><br>
    <input tabindex="4" value="f"><br>
    <input tabindex="3" value="e"><br>

    <pre id="log"></pre>
</body>
</html>