LayoutTests/accessibility/mac/label-changed-notification.html

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<html>
<head>
<script src="../../resources/accessibility-helper.js"></script>
<script src="../../resources/js-test.js"></script>
</head>
<body>

<label id="label" for="control">Original label</label>
<input id="control" type="text">

<script>
var output = "This tests that changing a label's text posts AXTitleChanged, and that the labeled control already resolves to the new label text when the notification arrives.\n\n";

if (window.accessibilityController) {
    window.jsTestIsAsync = true;

    var titleChangedCount = 0;
    var titleChangedListener = null;
    var labelTextAtDelivery = null;

    function labelTextForControl() {
        var control = accessibilityController.accessibleElementById("control");
        var label = control ? control.titleUIElement() : null;
        var staticText = label ? traverseChildrenToFirstStaticText(label) : null;
        return staticText ? stripAXPrefix(staticText.stringValue) : "";
    }

    // AXObjectCache::handleLabelChanged re-resolves the label-for relation before posting, so
    // the new label text must already be reachable from the control by delivery time.
    function titleChangedDeliveries() {
        if (!titleChangedListener) {
            titleChangedListener = function(element, notification, userInfo) {
                if (notification != "AXTitleChanged")
                    return;
                titleChangedCount++;
                labelTextAtDelivery = labelTextForControl();
            };
            accessibilityController.addNotificationListener(titleChangedListener);
        }
        return titleChangedCount;
    }

    // Installs the listener, which must happen before the label is mutated.
    titleChangedDeliveries();
    output += expect("labelTextForControl()", "'Original label'");

    setTimeout(async function() {
        // Adding the label posts AXTitleChanged too, so wait that out and start counting from
        // zero. Otherwise the initial notification alone would satisfy the assertions below.
        output += await expectAsync("titleChangedDeliveries() >= 1", "true");
        titleChangedCount = 0;
        labelTextAtDelivery = null;

        output += evalAndReturn("document.getElementById('label').textContent = 'Updated label';");
        output += await expectAsync("titleChangedDeliveries()", "1");
        output += expect("labelTextAtDelivery", "'Updated label'");

        document.getElementById("label").style.display = "none";
        accessibilityController.removeNotificationListener(titleChangedListener);
        debug(output);
        finishJSTest();
    }, 0);
}
</script>
</body>
</html>