| <!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> |
| |
| <script> |
| var output = "This test ensures that repeatedly forcing synchronous layout without returning to the run loop (as happens when JavaScript forces layout in a loop) does not accumulate one AXLayoutComplete notification per layout.\n\n\n\n"; |
| |
| var layoutCompleteCount = 0; |
| function notificationCallback(element, notification) { |
| if (notification == "AXLayoutComplete") |
| layoutCompleteCount++; |
| } |
| |
| if (window.accessibilityController) { |
| window.jsTestIsAsync = true; |
| |
| // Build the root accessibility object so LayoutComplete notifications are actually posted. |
| accessibilityController.rootElement; |
| accessibilityController.addNotificationListener(notificationCallback); |
| |
| var forcedLayoutCount = 1000; |
| setTimeout(async function() { |
| // Ignore any AXLayoutComplete from the initial page load. |
| layoutCompleteCount = 0; |
| |
| // Force many synchronous layouts in a tight loop without yielding to the run loop, so the |
| // zero-delay notification-post timer never fires between layouts. Each forced layout posts an |
| // AXLayoutComplete for the same (root) object; without coalescing these would accumulate |
| // one-per-layout in m_notificationsToPost. |
| for (var i = 0; i < forcedLayoutCount; i++) { |
| document.body.appendChild(document.createElement("div")); |
| document.body.offsetHeight; // Force synchronous layout. |
| } |
| |
| // Yield to the run loop so the notification-post timer fires and the pending notifications post. |
| await waitFor(() => layoutCompleteCount >= 1); |
| |
| // With coalescing we expect roughly one AXLayoutComplete (per object) for the whole batch. |
| output += expect("layoutCompleteCount < 50", "true"); |
| |
| accessibilityController.removeNotificationListener(notificationCallback); |
| debug(output); |
| finishJSTest(); |
| }, 0); |
| } |
| </script> |
| </body> |
| </html> |
