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//---------------------------------------------------------------------------
// <copyright file="PageContentAsyncResult.cs" company="Microsoft">
// Copyright (C) 2004 by Microsoft Corporation. All rights reserved.
// </copyright>
//
// Description:
// Implements the PageContentAsyncResult
//
// History:
// 02/25/2004 - Zhenbin Xu (ZhenbinX) - Created.
//
//
//---------------------------------------------------------------------------
namespace System.Windows.Documents
{
using System;
using System.Diagnostics;
using System.IO;
using System.Windows.Threading;
using System.Threading;
using MS.Internal;
using MS.Internal.AppModel;
using MS.Internal.Utility;
using MS.Internal.Navigation;
using MS.Utility;
using System.Reflection;
using System.Windows.Controls;
using System.Windows.Markup;
using System.Net;
using System.IO.Packaging;
/// <summary>
/// IAsyncResult for GetPageAsync. This item is passed around and queued up during various
/// phase of async call.
/// </summary>
internal sealed class PageContentAsyncResult : IAsyncResult
{
//--------------------------------------------------------------------
//
// Internal enum
//
//---------------------------------------------------------------------
internal enum GetPageStatus
{
Loading,
Cancelled,
Finished
}
//--------------------------------------------------------------------
//
// Ctor
//
//---------------------------------------------------------------------
#region Ctor
internal PageContentAsyncResult(AsyncCallback callback, object state, Dispatcher dispatcher, Uri baseUri, Uri source, FixedPage child)
{
this._dispatcher = dispatcher;
this._isCompleted = false;
this._completedSynchronously = false;
this._callback = callback;
this._asyncState = state;
this._getpageStatus = GetPageStatus.Loading;
this._child = child;
this._baseUri = baseUri;
Debug.Assert(source == null || source.IsAbsoluteUri);
this._source = source;
}
#endregion Ctor
//--------------------------------------------------------------------
//
// Public Methods
//
//---------------------------------------------------------------------
//--------------------------------------------------------------------
//
// Public Properties
//
//---------------------------------------------------------------------
#region IAsyncResult
//---------------------------------------------------------------------
/// <summary>
/// Gets a user-defined object that contains information about
/// this GetPageAsync call
/// </summary>
public object AsyncState
{
get { return _asyncState; }
}
//---------------------------------------------------------------------
/// <summary>
/// Gets a WaitHandle that is used to wait for the asynchrounus
/// GetPageAsync to complete. We are not providing WaitHandle
/// since this can be called on the main UIThread.
/// </summary>
public WaitHandle AsyncWaitHandle
{
get { Debug.Assert(false); return null; }
}
//---------------------------------------------------------------------
/// <summary>
/// Gets an indication of whether the asynchronous GetPage
/// completed synchronously.
/// </summary>
public bool CompletedSynchronously
{
get { return _completedSynchronously; }
}
//---------------------------------------------------------------------
/// <summary>
/// Gets an indication whether the asynchronous GetPage has finished
/// </summary>
public bool IsCompleted
{
get { return _isCompleted; }
}
#endregion IAsyncResult
//--------------------------------------------------------------------
//
// Internal Methods
//
//---------------------------------------------------------------------
#region DispatcherOperationCallback
//---------------------------------------------------------------------
internal object Dispatch(object arg)
{
if (this._exception != null)
{
// force finish if there was any exception
this._getpageStatus = GetPageStatus.Finished;
}
switch (this._getpageStatus)
{
case GetPageStatus.Loading:
try
{
if (this._child != null)
{
this._completedSynchronously = true;
this._result = this._child;
_getpageStatus = GetPageStatus.Finished;
goto case GetPageStatus.Finished;
}
//
// Note if _source == null, exception will
// be thrown.
//
Stream responseStream;
PageContent._LoadPageImpl(this._baseUri, this._source, out _result, out responseStream);
if (_result == null || _result.IsInitialized)
{
responseStream.Close();
}
else
{
_pendingStream = responseStream;
_result.Initialized += new EventHandler(_OnPaserFinished);
}
_getpageStatus = GetPageStatus.Finished;
}
catch (ApplicationException e)
{
this._exception = e;
}
goto case GetPageStatus.Finished;
case GetPageStatus.Cancelled:
// do nothing
goto case GetPageStatus.Finished;
case GetPageStatus.Finished:
_isCompleted = true;
if (_callback != null)
{
_callback(this);
}
break;
}
return null;
}
#endregion DispatcherOperationCallback
//-----------------------------------------------------------------
internal void Cancel()
{
_getpageStatus = GetPageStatus.Cancelled;
//
}
internal void Wait()
{
_dispatcherOperation.Wait();
}
//--------------------------------------------------------------------
//
// Internal Properties
//
//---------------------------------------------------------------------
#region Internal Properties
//---------------------------------------------------------------------
internal Exception Exception
{
get { return _exception; }
}
//-----------------------------------------------------------------
internal bool IsCancelled
{
get { return _getpageStatus == GetPageStatus.Cancelled; }
}
internal DispatcherOperation DispatcherOperation
{
set { _dispatcherOperation = value; }
}
//-----------------------------------------------------------------
internal FixedPage Result
{
get { return _result; }
}
#endregion Internal Properties
//--------------------------------------------------------------------
//
// Private Methods
//
//---------------------------------------------------------------------
#region Private Methods
private void _OnPaserFinished(object sender, EventArgs args)
{
if (_pendingStream != null)
{
_pendingStream.Close();
_pendingStream = null;
}
}
#endregion Private Methods
//--------------------------------------------------------------------
//
// Private Fields
//
//---------------------------------------------------------------------
#region Private
private object _asyncState;
private bool _isCompleted;
private bool _completedSynchronously;
private AsyncCallback _callback;
private Exception _exception;
private GetPageStatus _getpageStatus;
private Uri _baseUri;
private Uri _source;
private FixedPage _child;
private Dispatcher _dispatcher;
private FixedPage _result;
private Stream _pendingStream;
private DispatcherOperation _dispatcherOperation;
#endregion Private
}
}
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