/////////////////////////////////////////////////////////////////////////////////////////////////
//
// RegisterFocusChangedListener()
//
// Add a UIA event handler to react to focus change events sent from UIA.
//
// Runs on the background thread.
//
/////////////////////////////////////////////////////////////////////////////////////////////////
void RegisterFocusChangedListener()
{
// Create a cache request for the properties we know we'll need when a focus change occurs.
// By setting up this cache request, we won't incur a cross-proc call later to get the
// properties when we receive the event.
IUIAutomationCacheRequest cacheRequest = _automation.CreateCacheRequest();
cacheRequest.AddProperty(_propertyIdName);
cacheRequest.AddProperty(_propertyIdBoundingRectangle);
// The above properties are all we'll need, so we have have no need for a reference
// to the source element when we receive the event.
cacheRequest.AutomationElementMode = AutomationElementMode.AutomationElementMode_None;
// Now set up the event handler.
_automation.AddFocusChangedEventHandler(cacheRequest, this);
_fAddedEventHandler = true;
}
