// Unmanaged DLL calls back on this to notify a UIAccess client of an event.
internal void OnEvent(IntPtr argsAddr, object[,] requestedData, string treeStructure)
{
AutomationEventArgs e = UiaCoreApi.GetUiaEventArgs(argsAddr);
if (e.EventId == AutomationElement.AutomationFocusChangedEvent)
{
uint eventTime = SafeNativeMethods.GetTickCount();
if (eventTime == 0) // 0 is used as a marker value, so bump up to 1 if we get it.
{
eventTime = 1;
}
// There's no FocusChangedEventArgs in core, but clients expect one, so substitute if needed...
// (otherwise the cast in InvokeHandlers will fail...)
e = new InternalAutomationFocusChangedEventArgs(0, 0, eventTime);
}
UiaCoreApi.UiaCacheResponse cacheResponse = new UiaCoreApi.UiaCacheResponse(requestedData, treeStructure, _eventListener.CacheRequest);
// Invoke the listener's callback but not on this thread. Queuing this onto a worker thread allows
// OnEvent to return (which allows the call on the server-side to complete) and avoids a deadlock
// situation when the client accesses properties on the source element.
ClientEventManager.CBQ.PostWorkItem(new CalloutQueueItem(_clientCallback, cacheResponse, e, _eventListener.CacheRequest));
}
