//----------------------------------------------------------------------
// IDP Async
//----------------------------------------------------------------------
// An async request from the client code
// It is translated into an async request into child paginator
private object _GetPageAsyncDelegate(object arg)
{
DocumentsTrace.FixedDocumentSequence.IDF.Trace(string.Format("_GetPageAsyncDelegate"));
GetPageAsyncRequest asyncRequest = (GetPageAsyncRequest)arg;
int pageNumber = asyncRequest.Page.PageNumber;
if (asyncRequest.Cancelled ||
!TranslatePageNumber(pageNumber, out asyncRequest.Page.ChildPaginator, out asyncRequest.Page.ChildPageNumber) ||
asyncRequest.Cancelled // Check again for cancellation, as previous line may have loaded FixedDocument and taken a while
)
{
_NotifyGetPageAsyncCompleted(DocumentPage.Missing, pageNumber, null, true, asyncRequest.UserState);
_asyncOps.Remove(asyncRequest.UserState);
return(null);
}
if (!_pendingPages.Contains(asyncRequest.Page))
{
// Initiate an async request to child paginator only if this page has not been requested.
_pendingPages.Add(asyncRequest.Page);
asyncRequest.Page.ChildPaginator.GetPageCompleted += new GetPageCompletedEventHandler(_OnGetPageCompleted);
// use this asyncRequest as UserState
asyncRequest.Page.ChildPaginator.GetPageAsync(asyncRequest.Page.ChildPageNumber, asyncRequest);
}
return(null);
}
/// <summary>
/// <see cref="System.Windows.Documents.DocumentPaginator.GetPageAsync(int,object)"/>
/// </summary>
internal void GetPageAsync(int pageNumber, object userState)
{
DocumentsTrace.FixedFormat.IDF.Trace(string.Format("IDP.GetPageAsync({0}, {1})", pageNumber, userState));
// Make sure that the call is in the right context.
// Dispatcher.VerifyAccess();
// Page number cannot be negative.
if (pageNumber < 0)
{
throw new ArgumentOutOfRangeException("pageNumber", SR.Get(SRID.IDPNegativePageNumber));
}
if (userState == null)
{
throw new ArgumentNullException("userState");
}
// Add to outstanding AsyncOp list
GetPageAsyncRequest asyncRequest = new GetPageAsyncRequest(new RequestedPage(pageNumber /*childPaginator, childPageNumber*/), userState);
_asyncOps[userState] = asyncRequest;
DispatcherOperationCallback queueTask = new DispatcherOperationCallback(_GetPageAsyncDelegate);
Dispatcher.BeginInvoke(DispatcherPriority.Background, queueTask, asyncRequest);
}
// Callback from inner IDP.GetPageAsync
private void _OnGetPageCompleted(object sender, GetPageCompletedEventArgs args)
{
DocumentsTrace.FixedDocumentSequence.IDF.Trace(string.Format("_OnGetPageCompleted"));
// this job is complete
GetPageAsyncRequest completedRequest = (GetPageAsyncRequest)args.UserState;
_pendingPages.Remove(completedRequest.Page);
// wrap the returned result into FixedDocumentSequenceDocumentPage
DocumentPage sdp = DocumentPage.Missing;
int pageNumber = completedRequest.Page.PageNumber;
if (!args.Cancelled && (args.Error == null) && (args.DocumentPage != DocumentPage.Missing))
{
sdp = new FixedDocumentSequenceDocumentPage(this, (DynamicDocumentPaginator)sender, args.DocumentPage);
_SynthesizeGlobalPageNumber((DynamicDocumentPaginator)sender, args.PageNumber, out pageNumber);
}
if (!args.Cancelled)
{
// Notify all outstanding request for this particular page
ArrayList notificationList = new ArrayList();
IEnumerator <KeyValuePair <Object, GetPageAsyncRequest> > ienum = _asyncOps.GetEnumerator();
try
{
while (ienum.MoveNext())
{
GetPageAsyncRequest asyncRequest = ienum.Current.Value;
// Process any outstanding request for this PageContent
if (completedRequest.Page.Equals(asyncRequest.Page))
{
notificationList.Add(ienum.Current.Key);
// this could throw depending on event handlers that are added
_NotifyGetPageAsyncCompleted(sdp, pageNumber, args.Error, asyncRequest.Cancelled, asyncRequest.UserState);
}
}
}
finally
{
// Remove completed requests from current async ops list
foreach (Object userState in notificationList)
{
_asyncOps.Remove(userState);
}
}
}
}
/// <summary>
/// <see cref="System.Windows.Documents.DocumentPaginator.CancelAsync"/>
/// </summary>
internal void CancelAsync(object userState)
{
DocumentsTrace.FixedFormat.IDF.Trace(string.Format("IDP.GetPageAsyncCancel([{0}])", userState));
if (userState == null)
{
throw new ArgumentNullException("userState");
}
if (_asyncOps.ContainsKey(userState))
{
GetPageAsyncRequest asyncRequest = _asyncOps[userState];
if (asyncRequest != null)
{
asyncRequest.Cancelled = true;
if (asyncRequest.Page.ChildPaginator != null)
{
asyncRequest.Page.ChildPaginator.CancelAsync(asyncRequest);
}
}
}
}
/// <summary>
/// <see cref="System.Windows.Documents.DocumentPaginator.GetPageAsync(int,object)"/>
/// </summary>
internal void GetPageAsync(int pageNumber, object userState)
{
DocumentsTrace.FixedFormat.IDF.Trace(string.Format("IDP.GetPageAsync({0}, {1})", pageNumber, userState));
// Make sure that the call is in the right context.
// Dispatcher.VerifyAccess();
// Page number cannot be negative.
if (pageNumber < 0)
{
throw new ArgumentOutOfRangeException("pageNumber", SR.Get(SRID.IDPNegativePageNumber));
}
if (userState == null)
{
throw new ArgumentNullException("userState");
}
// Add to outstanding AsyncOp list
GetPageAsyncRequest asyncRequest = new GetPageAsyncRequest(new RequestedPage(pageNumber/*childPaginator, childPageNumber*/), userState);
_asyncOps[userState] = asyncRequest;
DispatcherOperationCallback queueTask = new DispatcherOperationCallback(_GetPageAsyncDelegate);
Dispatcher.BeginInvoke(DispatcherPriority.Background, queueTask, asyncRequest);
}
/// <summary>
/// <see cref="System.Windows.Documents.DocumentPaginator.GetPageAsync(int,object)"/>
/// </summary>
/// <exception cref="ArgumentOutOfRangeException">pageNumber is less than zero.</exception>
/// <exception cref="ArgumentNullException">userState is NULL.</exception>
internal void GetPageAsync(int pageNumber, object userState)
{
DocumentsTrace.FixedFormat.IDF.Trace(string.Format("IDP.GetPageAsync({0}, {1})", pageNumber, userState));
// Make sure that the call is in the right context.
// Dispatcher.VerifyAccess();
// Page number cannot be negative.
if (pageNumber < 0)
{
throw new ArgumentOutOfRangeException("pageNumber", SR.Get(SRID.IDPNegativePageNumber));
}
if (userState == null)
{
throw new ArgumentNullException("userState");
}
if (pageNumber < Pages.Count)
{
PageContent pc = Pages[pageNumber];
// Add to outstanding AsyncOp list
GetPageAsyncRequest asyncRequest = new GetPageAsyncRequest(pc, pageNumber, userState);
_asyncOps[userState] = asyncRequest;
DispatcherOperationCallback queueTask = new DispatcherOperationCallback(GetPageAsyncDelegate);
Dispatcher.BeginInvoke(DispatcherPriority.Background, queueTask, asyncRequest);
}
else
{
_NotifyGetPageAsyncCompleted(DocumentPage.Missing, pageNumber, null, false, userState);
}
}
