|
// 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.
//
//
// Description:
// implements the Avalon Journal Entry Object
//
//
//
//
using System.IO.Packaging;
using System.Runtime.Serialization;
using MS.Internal.AppModel;
using MS.Internal;
using MS.Internal.Utility;
//In order to avoid generating warnings about unknown message numbers and
//unknown pragmas when compiling your C# source code with the actual C# compiler,
//you need to disable warnings 1634 and 1691. (Presharp Documentation)
#pragma warning disable 1634, 1691
namespace System.Windows.Navigation
{
/// <summary>
/// Derived classes encapsulate content/view state associated with custom journal entries.
/// Object instances are passed to AddBackEntry() and also requested by the framework via the
/// IProvideCustomContentState interface.
/// </summary>
[Serializable]
public abstract class CustomContentState
{
/// <summary>
/// Provides the display name for the journal entry created for this custom content state.
/// If the returned string is null or empty, the name will be obtained, in order of
/// precedence, from either: the JournalEntry.Name or Page.Title attached property set on
/// the content root; the Window's title; or the current source URI.
/// </summary>
public virtual string JournalEntryName
{
get { return null; }
}
/// <summary>
/// Called by the framework when navigation to a custom journal entry occurs. The method
/// re-applies the encapsulated content/view state to the base content (element tree).
/// </summary>
public abstract void Replay(NavigationService navigationService, NavigationMode mode);
};
/// <summary>
/// Interface to be implemented by a navigator's Content object (root element). Provides
/// snapshots of the content state for custom journal entries.
/// </summary>
/// <remarks> As an alternative to implementing this interface, an application can handle
/// the Navigating event and set the NavigatingCancelEventArgs.ContentStateToSave property.
/// However, this method does not preserve the state of child frames.
/// </remarks>
public interface IProvideCustomContentState
{
/// <summary>
/// Override this method to capture the custom content state or the content's view state.
/// </summary>
/// <returns></returns>
CustomContentState GetContentState();
};
/// <summary>
/// The base class for all journal entries.
/// </summary>
/// <remarks>
/// Custom serialization implementation is needed (ISerializable) because the DependencyObject base
/// is not [Serializable]. The Name DP is saved explicitly. (Even though it is registered as
/// attached, it is also set on JE. KeepAlive is not saved, because KA entries are pruned before
/// TravelLog serialization.)
/// </remarks>
[Serializable]
public class JournalEntry : DependencyObject, ISerializable
{
// Ctors
/////////////////////////////////////////////////////////////////////
#region Ctors
internal JournalEntry(JournalEntryGroupState jeGroupState, Uri uri)
{
_jeGroupState = jeGroupState;
if (jeGroupState != null)
{
// Seems convenient to always do this here.
jeGroupState.GroupExitEntry = this;
}
Source = uri;
}
/// <summary>
/// Serialization constructor. Marked Protected so derived classes can be deserialized correctly
/// </summary>
protected JournalEntry(SerializationInfo info, StreamingContext context)
{
_id = info.GetInt32("_id");
_source = (Uri)info.GetValue("_source", typeof(Uri));
_entryType = (JournalEntryType)info.GetValue("_entryType", typeof(JournalEntryType));
_jeGroupState = (JournalEntryGroupState)info.GetValue("_jeGroupState", typeof(JournalEntryGroupState));
_customContentState = (CustomContentState)info.GetValue("_customContentState", typeof(CustomContentState));
_rootViewerState = (CustomJournalStateInternal)info.GetValue("_rootViewerState", typeof(CustomJournalStateInternal));
this.Name = info.GetString("Name");
}
/// <summary>
/// ISerializable implementation
/// </summary>
public virtual void GetObjectData(SerializationInfo info, StreamingContext context)
{
ArgumentNullException.ThrowIfNull(info);
info.AddValue("_id", _id);
info.AddValue("_source", _source);
info.AddValue("_entryType", _entryType);
// All these have to be written even if they are null. Othewise info.GetValue() would throw
// in the serialization ctor.
info.AddValue("_jeGroupState", _jeGroupState);
info.AddValue("_customContentState", _customContentState);
info.AddValue("_rootViewerState", _rootViewerState);
info.AddValue("Name", this.Name); // see Remarks on class declaration
}
#endregion
// Public methods
/////////////////////////////////////////////////////////////////////
#region Public Methods
/// <summary>
/// Reads the attached property JournalEntry.Name from the given element.
/// Setting it at the root element of a navigator will update NavWin’s dropdown menu when navigating inside of that navigator.
/// </summary>
/// <param name="dependencyObject">The element from which to read the attached property.</param>
/// <returns>The property's value.</returns>
public static string GetName(DependencyObject dependencyObject)
{
// not verifying Context on static method
return dependencyObject != null ? (string)dependencyObject.GetValue(NameProperty) : null;
}
/// <summary>
/// Writes the attached property JournalEntry.Name to the given element.
/// </summary>
/// <param name="dependencyObject">The element to which to write the attached property.</param>
/// <param name="name">The property value to set</param>
public static void SetName(DependencyObject dependencyObject, string name)
{
// not verifying Context on static method
ArgumentNullException.ThrowIfNull(dependencyObject);
dependencyObject.SetValue(NameProperty, name);
}
/// <summary>
/// Reads the attached property KeepAlive from the given element. This is not a property of the
/// journal, but rather a flag to indicate that this tree should be keep alived
/// as part of journaling. If KeepAlive == true, then the entire tree will be saved.
/// </summary>
/// <param name="dependencyObject">The element from which to read the attached property.</param>
/// <returns>The property's value.</returns>
/// <seealso cref="JournalEntry.KeepAliveProperty" />
public static bool GetKeepAlive(DependencyObject dependencyObject)
{
// not verifying Context on static method
ArgumentNullException.ThrowIfNull(dependencyObject);
return (bool)dependencyObject.GetValue(KeepAliveProperty);
}
/// <summary>
/// Writes the attached property KeepAlive to the given element. See above.
/// </summary>
/// <param name="dependencyObject">The element to which to write the attached property.</param>
/// <param name="keepAlive">The property value to set</param>
/// <seealso cref="JournalEntry.KeepAliveProperty" />
public static void SetKeepAlive(DependencyObject dependencyObject, bool keepAlive)
{
// not verifying Context on static method
ArgumentNullException.ThrowIfNull(dependencyObject);
dependencyObject.SetValue(KeepAliveProperty, keepAlive);
}
#endregion
// Public properties
/////////////////////////////////////////////////////////////////////
#region Public Properties
/// <summary>
/// The Uri of the stored Page
/// </summary>
public Uri Source
{
get { return _source; }
set { _source = BindUriHelper.GetUriRelativeToPackAppBase(value); }
}
/// <summary> The custom content state or content view state associated with the entry </summary>
public CustomContentState CustomContentState
{
get { return _customContentState; }
internal set { _customContentState = value; }
}
/// <summary>
/// The name of the journal entry to be displayed in the drop-down list
/// on the Back/Forward buttons
/// </summary>
public string Name
{
get { return (string)GetValue(NameProperty); }
set { SetValue(NameProperty, value); }
}
/// <summary>
/// Attached DependencyProperty for Name property.
/// Setting it at the root element of a navigator will update NavWin’s dropdown menu when navigating inside of that navigator.
/// </summary>
public static readonly DependencyProperty NameProperty =
DependencyProperty.RegisterAttached("Name", typeof(string), typeof(JournalEntry), new PropertyMetadata(String.Empty));
/// <summary>
/// DependencyProperty for KeepAlive property.
/// </summary>
public static readonly DependencyProperty KeepAliveProperty =
DependencyProperty.RegisterAttached("KeepAlive", typeof(bool), typeof(JournalEntry), new PropertyMetadata(false));
#endregion
// Internal methods
/////////////////////////////////////////////////////////////////////
#region Internal Methods
/// <summary>
/// Is this journal entry journaling a page function?
/// </summary>
internal virtual bool IsPageFunction()
{
return false;
}
/// <summary>
/// Is this journal entry holding on to a tree?
/// </summary>
/// <returns></returns>
internal virtual bool IsAlive()
{
return false;
}
internal virtual void SaveState(object contentObject)
{
ArgumentNullException.ThrowIfNull(contentObject);
if (!IsAlive())
{
if (_jeGroupState.JournalDataStreams != null)
{
Debug.Assert(!_jeGroupState.JournalDataStreams.HasAnyData,
"JournalDataSreams should have been emptied by the last RestoreState() call.");
}
else
{
_jeGroupState.JournalDataStreams = new DataStreams();
}
_jeGroupState.JournalDataStreams.Save(contentObject);
}
}
internal virtual void RestoreState(object contentObject)
{
ArgumentNullException.ThrowIfNull(contentObject);
if (IsAlive())
{
Debug.Assert(_jeGroupState.JournalDataStreams == null);
}
else
{
DataStreams jds = _jeGroupState.JournalDataStreams;
if (jds != null)
{
jds.Load(contentObject);
// DataStreams not needed anymore. Clear for fresh saving when the next navigation
// occurs.
jds.Clear();
}
}
}
internal virtual bool Navigate(INavigator navigator, NavigationMode navMode)
{
Debug.Assert(navMode == NavigationMode.Back || navMode == NavigationMode.Forward);
// This is fallback functionality if somebody creates a JournalEntry and gives it a URI.
if (this.Source != null)
{
return navigator.Navigate(Source, new NavigateInfo(Source, navMode, this));
}
else
{
Invariant.Assert(false, "Cannot navigate to a journal entry that does not have a Source.");
return false;
}
}
/// <summary>
/// Returns a string that contains the URI for display in a JournalEntry.
/// It removes pack://application:,,,/ and any component, and replaces
/// pack://siteoforigin:,,,/ with the actual site of origin URI.
/// </summary>
/// <param name="uri">The URI to display</param>
/// <param name="siteOfOrigin">The site of origin URI</param>
/// <returns>display name</returns>
internal static string GetDisplayName(Uri uri, Uri siteOfOrigin)
{
// In case this is a fragment navigation in a tree that was not navigated to by URI...
if (!uri.IsAbsoluteUri)
{
return uri.ToString();
}
string displayName;
if (string.Equals(uri.Scheme, PackUriHelper.UriSchemePack, StringComparison.OrdinalIgnoreCase))
{
Uri relative = BaseUriHelper.MakeRelativeToSiteOfOriginIfPossible(uri);
if (!relative.IsAbsoluteUri)
{
displayName = (new Uri(siteOfOrigin, relative)).ToString();
}
else
{
string relativeUri = uri.AbsolutePath + uri.Query + uri.Fragment;
string part, assy, assyVers, assyKey;
BaseUriHelper.GetAssemblyNameAndPart(new Uri(relativeUri, UriKind.Relative), out part, out assy, out assyVers, out assyKey);
if (!string.IsNullOrEmpty(assy))
{
displayName = part;
}
else
{
displayName = relativeUri;
}
}
}
else
{
displayName = uri.ToString();
}
if (!string.IsNullOrEmpty(displayName) && displayName[0] == '/')
{
displayName = displayName.Substring(1);
}
return displayName;
}
#endregion
// Internal properties
/////////////////////////////////////////////////////////////////////
#region Internal properties
internal JournalEntryGroupState JEGroupState
{
#if DEBUG
[DebuggerStepThrough]
#endif
get { return _jeGroupState; }
set { _jeGroupState = value; }
}
/// <summary>
/// We will now store the entire entry data in the travellog so Journaling will
/// work even if you renavigate back to the app from html pages as long as it is
/// linear history navigations.
/// </summary>
internal int Id
{
get { return _id; }
set { _id = value; }
}
/// <summary>
/// The NavigationService(toplevel || frame) where this entry was last displayed.
/// </summary>
internal Guid NavigationServiceId
{
get { return _jeGroupState.NavigationServiceId; }
}
/// <summary>
/// Journal entry type
/// </summary>
internal JournalEntryType EntryType
{
#if DEBUG
[DebuggerStepThrough]
#endif
get { return _entryType; }
set { _entryType = value; }
}
/// <summary>
/// Can this be navigated to?
/// </summary>
internal bool IsNavigable()
{
return _entryType == JournalEntryType.Navigable;
}
internal uint ContentId
{
get { return _jeGroupState.ContentId; }
}
internal CustomJournalStateInternal RootViewerState
{
get { return _rootViewerState; }
set { _rootViewerState = value; }
}
#endregion
// Private fields
//
// If you add any fields here, check if it needs to be serialized.
// If yes, then add it to the ISerializable implementation and make
// corresponding changes in the Serialization constructor.
//
/////////////////////////////////////////////////////////////////////
#region Private fields
private int _id;
private JournalEntryGroupState _jeGroupState;
/// <summary>
/// Converted relative to pack://application, if possible
/// </summary>
private Uri _source;
private JournalEntryType _entryType = JournalEntryType.Navigable;
private CustomContentState _customContentState;
private CustomJournalStateInternal _rootViewerState;
#endregion
}
//**
//** All derived classes are in MS.Internal.AppModel.
}
|