//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
internal CalloutQueueItem(Delegate clientCallback, UiaCoreApi.UiaCacheResponse cacheResponse, AutomationEventArgs e, UiaCoreApi.UiaCacheRequest cacheRequest)
{
_clientCallback = clientCallback;
_cacheResponse = cacheResponse;
_e = e;
_cacheRequest = cacheRequest;
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
internal static AutomationElement BuildAutomationElementsFromResponse(
UiaCoreApi.UiaCacheRequest cacheRequest,
UiaCoreApi.UiaCacheResponse response)
{
if (response.TreeStructure == null)
{
Debug.Assert(response.RequestedData == null, "both RequestedData and TreeStructure should be null or non-null");
return(null);
}
// FrozenCacheRequest should not be null one new AE code, but may
// still be null on old code paths - eg. top level window events - where
// prefetching is not yet enabled.
if (cacheRequest == null)
{
cacheRequest = CacheRequest.DefaultUiaCacheRequest;
}
// ParseTreeDescription is the method that parses the returned data
// and builds up the tree, setting properties on each node as it goes along...
// index and propIndex keep track of where it is, and we check afterwards
// that all are pointing to the end, to ensure that everything matched
// up as expected.
int index = 0;
int propIndex = 0;
bool askedForChildren = (cacheRequest.TreeScope & TreeScope.Children) != 0;
bool askedForDescendants = (cacheRequest.TreeScope & TreeScope.Descendants) != 0;
AutomationElement root = ParseTreeDescription(response.TreeStructure, response.RequestedData,
ref index,
ref propIndex,
cacheRequest,
askedForChildren,
askedForDescendants);
if (index != response.TreeStructure.Length)
{
Debug.Assert(false, "Internal error: got malformed tree description string (extra chars at end)");
return(null);
}
if (response.RequestedData != null && propIndex != response.RequestedData.GetLength(0))
{
Debug.Assert(false, "Internal error: mismatch between count of property buckets and nodes claiming them");
return(null);
}
// Properties are wrapped (eg. pattern classes inserted in front of interface) as
// they are being returned to the caller, in the AutomationElement accessors, not here.
return(root);
}
// 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));
}
// 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));
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
internal override void Process()
{
// Grab properties for cache request here...
AutomationElement src;
if (_srcEl == null)
{
src = null;
}
else
{
UiaCoreApi.UiaCacheResponse response = UiaCoreApi.UiaGetUpdatedCache(_srcEl.RawNode, _request, UiaCoreApi.NormalizeState.View, null);
src = CacheHelper.BuildAutomationElementsFromResponse(_request, response);
}
// We need to find out why this situation should occur at (aside from a window closed event) and
// handle the cause.
if (!(src == null && _e.EventId == AutomationElement.AutomationFocusChangedEvent))
{
InvokeHandlers.InvokeClientHandler(_clientCallback, src, _e);
}
}
//------------------------------------------------------
//
// Internal Methods
//
//------------------------------------------------------
#region Internal Methods
internal override void Process()
{
// Grab properties for cache request here...
AutomationElement src;
if (_srcEl == null)
{
src = null;
}
else
{
UiaCoreApi.UiaCacheResponse response = UiaCoreApi.UiaGetUpdatedCache(_srcEl.RawNode, _request, UiaCoreApi.NormalizeState.View, null);
src = CacheHelper.BuildAutomationElementsFromResponse(_request, response);
}
//
if (!(src == null && _e.EventId == AutomationElement.AutomationFocusChangedEvent))
{
InvokeHandlers.InvokeClientHandler(_clientCallback, src, _e);
}
}
