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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using MS.Internal;
using MS.Internal.Documents;
using MS.Internal.Utility;
using System.Windows.Navigation;
using System.Windows.Markup;
using System.IO;
//
// Description:
// Implements the DocumentReference element
//
namespace System.Windows.Documents
{
//=====================================================================
/// <summary>
/// DocumentReference is the class that references a Document.
/// Each document
/// </summary>
[UsableDuringInitialization(false)]
public sealed class DocumentReference : FrameworkElement, IUriContext
{
//--------------------------------------------------------------------
//
// Connstructors
//
//---------------------------------------------------------------------
#region Constructors
/// <summary>
/// Default DocumentReference constructor
/// </summary>
/// <remarks>
/// Automatic determination of current Dispatcher. Use alternative constructor
/// that accepts a Dispatcher for best performance.
/// </remarks>
public DocumentReference() : base()
{
_Init();
}
#endregion Constructors
//--------------------------------------------------------------------
//
// Public Methods
//
//---------------------------------------------------------------------
#region Public Methods
/// <summary>
/// Synchonrously download and parse the document based on the Source specification.
/// If a document was attached earlier and forceReload == false, the attached
/// document will be returned. forceReload == true results in downloading of the referenced
/// document based on Source specification, any previously attached document is ignored
/// in this case.
/// Regardless of forceReload, the document will be loaded based on Source specification if
/// it hasn't been loaded earlier.
/// </summary>
/// <param name="forceReload">Force reloading the document instead of using cached value</param>
/// <returns>The document tree</returns>
public FixedDocument GetDocument(bool forceReload)
{
DocumentsTrace.FixedDocumentSequence.IDF.Trace($"DocumentReference.GetDocument ({(Source == null ? new Uri("", UriKind.RelativeOrAbsolute) : Source)}, {forceReload})");
VerifyAccess();
FixedDocument idp = null;
if (_doc != null)
{
idp = _doc;
}
else
{
if (!forceReload)
{
idp = CurrentlyLoadedDoc;
}
if (idp == null)
{
FixedDocument idpReloaded = _LoadDocument();
if (idpReloaded != null)
{
DocumentsTrace.FixedDocumentSequence.IDF.Trace(
$"DocumentReference.GetDocument Loaded IDP {idpReloaded.GetHashCode()}");
// save the doc's identity
_docIdentity = idpReloaded;
idp = idpReloaded;
}
}
}
if (idp != null)
{
LogicalTreeHelper.AddLogicalChild(this.Parent, idp);
}
return idp;
}
/// <summary>
/// Attach a document to this DocumentReference
/// You can only attach a document if it is not attached before or it is not created from URI before.
/// </summary>
/// <param name="doc"></param>
public void SetDocument(FixedDocument doc)
{
VerifyAccess();
_docIdentity = null;
_doc = doc;
}
#endregion Public Methods
//--------------------------------------------------------------------
//
// Public Properties
//
//---------------------------------------------------------------------
#region Public Properties
/// <summary>
/// Dynamic Property to reference an external document stream.
/// </summary>
public static readonly DependencyProperty SourceProperty =
DependencyProperty.Register(
"Source",
typeof(Uri),
typeof(DocumentReference),
new FrameworkPropertyMetadata(
(Uri) null,
new PropertyChangedCallback(OnSourceChanged)));
static void OnSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
DocumentsTrace.FixedDocumentSequence.IDF.Trace("DocumentReference.Source_Invaidated");
DocumentReference docRef = (DocumentReference)d;
if (!object.Equals(e.OldValue, e.NewValue))
{
Uri oldSource = (Uri) e.OldValue;
Uri newSource = (Uri) e.NewValue;
DocumentsTrace.FixedDocumentSequence.IDF.Trace($"====Replace old doc {(oldSource == null ? "null" : oldSource.ToString())} with new {(newSource == null ? "null" : newSource.ToString())}");
// drop loaded document if source changed
docRef._doc = null;
//
// #966803: Source change won't be a support scenario.
//
}
}
/// <summary>
/// Get/Set Source property that references an external page stream.
/// </summary>
public Uri Source
{
get { return (Uri) GetValue(SourceProperty); }
set { SetValue(SourceProperty, value); }
}
#endregion Public Properties
#region IUriContext
/// <summary>
/// <see cref="IUriContext.BaseUri" />
/// </summary>
Uri IUriContext.BaseUri
{
get { return (Uri)GetValue(BaseUriHelper.BaseUriProperty); }
set { SetValue(BaseUriHelper.BaseUriProperty, value); }
}
#endregion IUriContext
//--------------------------------------------------------------------
//
// Public Events
//
//---------------------------------------------------------------------
#region Public Event
#endregion Public Event
//--------------------------------------------------------------------
//
// Internal Methods
//
//---------------------------------------------------------------------
#region Internal Methods
#if DEBUG
internal void Dump()
{
DocumentsTrace.FixedDocumentSequence.Content.Trace(
$"""
This {this.GetHashCode()}
Source {(this.Source == null ? "null" : this.Source.ToString())}
_doc {_doc?.GetHashCode() ?? 0}
_docIdentity {_docIdentity?.GetHashCode() ?? 0}
""");
}
#endif
#endregion Internal Methods
//--------------------------------------------------------------------
//
// Internal Properties
//
//---------------------------------------------------------------------
#region Internal Properties
// return most recent result of GetDocument, if it is still alive
internal FixedDocument CurrentlyLoadedDoc
{
get
{
return _docIdentity;
}
}
#endregion Internal Properties
//--------------------------------------------------------------------
//
// private Properties
//
//---------------------------------------------------------------------
#region Private Properties
#endregion Private Properties
//--------------------------------------------------------------------
//
// Private Methods
//
//---------------------------------------------------------------------
#region Private Methods
private void _Init()
{
this.InheritanceBehavior = InheritanceBehavior.SkipToAppNow;
}
private Uri _ResolveUri()
{
Uri uriToNavigate = this.Source;
if (uriToNavigate != null)
{
uriToNavigate = BindUriHelper.GetUriToNavigate(this, ((IUriContext)this).BaseUri, uriToNavigate);
}
return uriToNavigate;
}
// sync load a document
private FixedDocument _LoadDocument()
{
FixedDocument idp = null;
Uri uriToLoad = _ResolveUri();
if (uriToLoad != null)
{
ContentType mimeType = null;
Stream docStream = null;
docStream = WpfWebRequestHelper.CreateRequestAndGetResponseStream(uriToLoad, out mimeType);
if (docStream == null)
{
throw new ApplicationException(SR.DocumentReferenceNotFound);
}
ParserContext pc = new ParserContext();
pc.BaseUri = uriToLoad;
if (BindUriHelper.IsXamlMimeType(mimeType))
{
XpsValidatingLoader loader = new XpsValidatingLoader();
idp = loader.Load(docStream, ((IUriContext)this).BaseUri, pc, mimeType) as FixedDocument;
}
else if (MS.Internal.MimeTypeMapper.BamlMime.AreTypeAndSubTypeEqual(mimeType))
{
idp = XamlReader.LoadBaml(docStream, pc, null, true) as FixedDocument;
}
else
{
throw new ApplicationException(SR.DocumentReferenceUnsupportedMimeType);
}
idp.DocumentReference = this;
}
return idp;
}
#endregion Private Methods
//--------------------------------------------------------------------
//
// Private Fields
//
//---------------------------------------------------------------------
#region Private Fields
private FixedDocument _doc;
private FixedDocument _docIdentity; // used to cache the identity of the IDF so the IDF knows where it come from.
#endregion Private Fields
}
}
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