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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.
//
// Description: Implements the Avalon Page class
//
using System.Collections;
using System.ComponentModel;
using System.Windows.Navigation;
using System.Windows.Media;
using System.Windows.Markup;
using System.Windows.Documents;
using MS.Internal.KnownBoxes;
using MS.Internal;
//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.Controls
{
#region Page Class
/// <summary>
/// Public class Page
/// </summary>
[ContentProperty("Content")]
public class Page : FrameworkElement, IWindowService, IAddChild
{
#region Constructors
//----------------------------------------------
//
// Constructors
//
//----------------------------------------------
static Page()
{
// We use IWindowService change notifications to propagate the cached values to the Window
Window.IWindowServiceProperty.OverrideMetadata(
typeof(Page),
new FrameworkPropertyMetadata(new PropertyChangedCallback(_OnWindowServiceChanged)));
// (Window/NavigationWindow and Page should not be focusable)
// This makes Page non-focusable. If FocusedElement is set on the Page, focus would
// go to that element, otherwise, it will be null. Page taking focus doesn't make
// sense, instead, it should be forwared to some more meaningful element in the tree.
FocusableProperty.OverrideMetadata(typeof(Page), new FrameworkPropertyMetadata(BooleanBoxes.FalseBox));
DefaultStyleKeyProperty.OverrideMetadata(typeof(Page), new FrameworkPropertyMetadata(typeof(Page)));
_dType = DependencyObjectType.FromSystemTypeInternal(typeof(Page));
}
/// <summary>
/// Default constructor
/// </summary>
public Page()
{
// Initialize the _templateCache to the default value for TemplateProperty.
// If the default value is non-null then wire it to the current instance.
PropertyMetadata metadata = TemplateProperty.GetMetadata(DependencyObjectType);
ControlTemplate defaultValue = (ControlTemplate) metadata.DefaultValue;
if (defaultValue != null)
{
OnTemplateChanged(this, new DependencyPropertyChangedEventArgs(TemplateProperty, metadata, null, defaultValue));
}
}
#endregion Constructors
#region IAddChild
/// <summary>
/// Adds a child. This is called by the parser
/// </summary>
/// <param name="obj"></param>
void IAddChild.AddChild(Object obj)
{
VerifyAccess();
// if content is the first child or being cleared, set directly
if (Content == null || obj == null)
{
Content = obj;
}
else
{
throw new InvalidOperationException(SR.PageCannotHaveMultipleContent);
}
}
///<summary>
/// This method is called by the parser when text appears under the tag in markup.
/// By default Page does not support text; calling this method has no effect.
///</summary>
///<param name="str">
/// Text to add as a child.
///</param>
void IAddChild.AddText (string str)
{
XamlSerializerUtil.ThrowIfNonWhiteSpaceInAddText(str, this);
}
#endregion IAddChild
#region LogicalTree
/// <summary>
/// Returns enumerator to logical children
/// </summary>
protected internal override IEnumerator LogicalChildren
{
get
{
VerifyAccess();
return new SingleChildEnumerator(Content);
}
}
#endregion LogicalTree
#region Public Properties
/// <summary>
/// The DependencyProperty for the Content property.
/// Flags: None
/// Default Value: null
/// </summary>
public static readonly DependencyProperty ContentProperty =
ContentControl.ContentProperty.AddOwner(
typeof(Page),
new FrameworkPropertyMetadata(new PropertyChangedCallback(OnContentChanged)));
/// <summary>
/// Content of the Page
/// </summary>
/// <remarks>
/// Page only supports one child
/// </remarks>
public Object Content
{
get
{
VerifyAccess();
return GetValue(ContentProperty);
}
set
{
VerifyAccess();
SetValue(ContentProperty, value);
}
}
// All these properties are implemented
// as "bound" to the window service. For
// example, getting WindowTitle will return Window.Title,
// setting WindowTitle will set Window.Title.
//
string IWindowService.Title
{
get
{
VerifyAccess();
if (WindowService == null)
{
#pragma warning disable 6503
throw new InvalidOperationException(SR.CannotQueryPropertiesWhenPageNotInTreeWithWindow);
#pragma warning restore 6503
}
return WindowService.Title;
}
set
{
VerifyAccess();
if (WindowService == null)
{
PageHelperObject._windowTitle = value;
PropertyIsSet(SetPropertyFlags.WindowTitle);
}
else if (_isTopLevel == true) // only top level page can set this property
{
WindowService.Title = value;
PropertyIsSet(SetPropertyFlags.WindowTitle);
}
}
}
/// <summary>
/// Proxy for Window Title property
/// </summary>
[Localizability(LocalizationCategory.Title)]
public string WindowTitle
{
get
{
VerifyAccess();
return ((IWindowService)this).Title;
}
set
{
VerifyAccess();
((IWindowService)this).Title = value;
}
}
internal bool ShouldJournalWindowTitle()
{
return IsPropertySet(SetPropertyFlags.WindowTitle);
}
/// <summary>
/// Bound to IWindowService property
/// </summary>
double IWindowService.Height
{
get
{
VerifyAccess();
if (WindowService == null)
{
#pragma warning disable 6503
throw new InvalidOperationException(SR.CannotQueryPropertiesWhenPageNotInTreeWithWindow);
#pragma warning restore 6503
}
return WindowService.Height;
}
set
{
VerifyAccess();
if (WindowService == null)
{
PageHelperObject._windowHeight = value;
PropertyIsSet(SetPropertyFlags.WindowHeight);
}
else if (_isTopLevel == true)// only top level page can set this property
{
if (!WindowService.UserResized)
{
WindowService.Height = value;
}
PropertyIsSet(SetPropertyFlags.WindowHeight);
}
}
}
/// <summary>
/// Proxy to Window.Height property
/// </summary>
public double WindowHeight
{
get
{
VerifyAccess();
return ((IWindowService)this).Height;
}
set
{
VerifyAccess();
((IWindowService)this).Height = value;
}
}
/// <summary>
/// Proxy to Window.Width property
/// </summary>
double IWindowService.Width
{
get
{
VerifyAccess();
if (WindowService == null)
{
#pragma warning disable 6503
throw new InvalidOperationException(SR.CannotQueryPropertiesWhenPageNotInTreeWithWindow);
#pragma warning restore 6503
}
return WindowService.Width;
}
set
{
VerifyAccess();
if (WindowService == null)
{
PageHelperObject._windowWidth = value;
PropertyIsSet(SetPropertyFlags.WindowWidth);
}
else if (_isTopLevel == true) // only top level page can set this property
{
if (!WindowService.UserResized)
{
WindowService.Width = value;
}
PropertyIsSet(SetPropertyFlags.WindowWidth);
}
}
}
/// <summary>
/// Bound to IWindowService.Width property
/// </summary>
public double WindowWidth
{
get
{
VerifyAccess();
return ((IWindowService)this).Width;
}
set
{
VerifyAccess();
((IWindowService)this).Width = value;
}
}
/// <summary>
/// The DependencyProperty for the Background property.
/// </summary>
public static readonly DependencyProperty BackgroundProperty =
Panel.BackgroundProperty.AddOwner(
typeof(Page),
new FrameworkPropertyMetadata(
Panel.BackgroundProperty.GetDefaultValue(typeof(Panel)),
FrameworkPropertyMetadataOptions.None));
/// <summary>
/// An object that describes the background.
/// </summary>
[Category("Appearance")]
public Brush Background
{
get { return (Brush) GetValue(BackgroundProperty); }
set { SetValue(BackgroundProperty, value); }
}
/// <summary>
/// The DependencyProperty for the Title property.
/// </summary>
public static readonly DependencyProperty TitleProperty =
DependencyProperty.Register(
"Title", typeof(string), typeof(Page),
new FrameworkPropertyMetadata(null, new PropertyChangedCallback(OnTitleChanged)));
/// <summary>
/// An object that describes the Title.
/// </summary>
public string Title
{
get { return (string)GetValue(TitleProperty); }
set { SetValue(TitleProperty, value); }
}
// If the Title has changed we want to set the flag.
static private void OnTitleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((Page)d).PropertyIsSet(SetPropertyFlags.Title);
}
/// <summary>
/// Determines whether to show the default navigation UI.
/// </summary>
public bool ShowsNavigationUI
{
get
{
VerifyAccess();
if (WindowService == null)
{
#pragma warning disable 6503
throw new InvalidOperationException(SR.CannotQueryPropertiesWhenPageNotInTreeWithWindow);
#pragma warning restore 6503
}
// Return false if it is not NavigationWindow.
NavigationWindow navWin = WindowService as NavigationWindow;
if (navWin != null)
{
return navWin.ShowsNavigationUI;
}
else
{
return false;
}
}
set
{
VerifyAccess();
if (WindowService == null)
{
PageHelperObject._showsNavigationUI = value;
PropertyIsSet(SetPropertyFlags.ShowsNavigationUI);
}
else if (_isTopLevel == true) // only top level page can set this property
{
SetShowsNavigationUI(value);
PropertyIsSet(SetPropertyFlags.ShowsNavigationUI);
}
}
}
/// <summary>
/// The DependencyProperty for the KeepAlive property.
/// </summary>
public static readonly DependencyProperty KeepAliveProperty =
JournalEntry.KeepAliveProperty.AddOwner(typeof(Page));
/// <summary>
/// An object that describes the KeepAlive status of the Page.
/// </summary>
public bool KeepAlive
{
get
{
return JournalEntry.GetKeepAlive(this);
}
set
{
JournalEntry.SetKeepAlive(this, value);
}
}
/// <summary>
/// NavigationServiceProperty
/// </summary>
public NavigationService NavigationService
{
get
{
return NavigationService.GetNavigationService(this);
}
}
/// <summary>
/// The DependencyProperty for the Foreground property.
/// Flags: Can be used in style rules
/// Default Value: System Font Color
/// </summary>
public static readonly DependencyProperty ForegroundProperty =
TextElement.ForegroundProperty.AddOwner(typeof(Page));
/// <summary>
/// An brush that describes the foreground color which is used by
/// via inheritance.
/// </summary>
[Bindable(true), Category("Appearance")]
public Brush Foreground
{
get { return (Brush) GetValue(ForegroundProperty); }
set { SetValue(ForegroundProperty, value); }
}
/// <summary>
/// The DependencyProperty for the FontFamily property.
/// Flags: Can be used in style rules
/// Default Value: System Dialog Font
/// </summary>
public static readonly DependencyProperty FontFamilyProperty =
TextElement.FontFamilyProperty.AddOwner(typeof(Page));
/// <summary>
/// The font family of the desired font which is used via inheritance
/// </summary>
[Bindable(true), Category("Appearance")]
[Localizability(
LocalizationCategory.Font,
Modifiability = Modifiability.Unmodifiable
)]
public FontFamily FontFamily
{
get { return (FontFamily) GetValue(FontFamilyProperty); }
set { SetValue(FontFamilyProperty, value); }
}
/// <summary>
/// The DependencyProperty for the FontSize property.
/// Flags: Can be used in style rules
/// Default Value: System Dialog Font Size
/// </summary>
public static readonly DependencyProperty FontSizeProperty =
TextElement.FontSizeProperty.AddOwner(typeof(Page));
/// <summary>
/// The size of the desired font which will be used via inheritance.
/// </summary>
[TypeConverter(typeof(FontSizeConverter))]
[Bindable(true), Category("Appearance")]
[Localizability(LocalizationCategory.None)] // FontSize is localizable
public double FontSize
{
get { return (double) GetValue(FontSizeProperty); }
set { SetValue(FontSizeProperty, value); }
}
/// <summary>
/// TemplateProperty
/// </summary>
public static readonly DependencyProperty TemplateProperty =
Control.TemplateProperty.AddOwner(
typeof(Page),
new FrameworkPropertyMetadata(
(ControlTemplate) null, // default value
FrameworkPropertyMetadataOptions.AffectsMeasure,
new PropertyChangedCallback(OnTemplateChanged)));
/// <summary>
/// Template Property
/// </summary>
public ControlTemplate Template
{
get { return _templateCache; }
set { SetValue(TemplateProperty, value); }
}
// Internal Helper so the FrameworkElement could see this property
internal override FrameworkTemplate TemplateInternal
{
get { return Template; }
}
// Internal Helper so the FrameworkElement could see the template cache
internal override FrameworkTemplate TemplateCache
{
get { return _templateCache; }
set { _templateCache = (ControlTemplate)value; }
}
// Internal helper so FrameworkElement could see call the template changed virtual
internal override void OnTemplateChangedInternal(FrameworkTemplate oldTemplate, FrameworkTemplate newTemplate)
{
OnTemplateChanged((ControlTemplate)oldTemplate, (ControlTemplate)newTemplate);
}
// Property invalidation callback invoked when TemplateProperty is changed
private static void OnTemplateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Page p = (Page) d;
StyleHelper.UpdateTemplateCache(p, (FrameworkTemplate) e.OldValue, (FrameworkTemplate) e.NewValue, TemplateProperty);
}
/// <summary>
/// Template has changed
/// </summary>
/// <remarks>
/// When a Template changes, the VisualTree is removed. The new Template's
/// VisualTree will be created when ApplyTemplate is called
/// </remarks>
/// <param name="oldTemplate">The old Template</param>
/// <param name="newTemplate">The new Template</param>
protected virtual void OnTemplateChanged(
ControlTemplate oldTemplate, ControlTemplate newTemplate)
{
}
#endregion Public Properties
//---------------------------------------------------
//
// Public Events
//
//---------------------------------------------------
//---------------------------------------------------
//
// Protected Methods
//
//---------------------------------------------------
#region Protected Methods
/// <summary>
/// Measurement override.
/// </summary>
/// <param name="constraint">
/// Sizing constraint.
/// </param>
protected override Size MeasureOverride(Size constraint)
{
VerifyAccess();
int count = this.VisualChildrenCount;
if (count > 0)
{
UIElement child = this.GetVisualChild(0) as UIElement;
if (child != null)
{
child.Measure(constraint);
return child.DesiredSize;
}
}
return (new Size(0, 0));
}
/// <summary>
/// ArrangeOverride allows for the customization of the positioning of children.
/// </summary>
/// <param name="arrangeBounds">
/// Measured size.
/// </param>
protected override Size ArrangeOverride(Size arrangeBounds)
{
VerifyAccess();
int count = this.VisualChildrenCount;
if (count > 0)
{
UIElement child = this.GetVisualChild(0) as UIElement;
if (child != null)
{
child.Arrange(new Rect(new Point(), arrangeBounds));
}
}
return arrangeBounds;
}
/// <summary>
/// OnVisualParentChanged is called when the parent of the Visual is changed.
/// </summary>
/// <param name="oldParent">Old parent or null if the Visual did not have a parent before.</param>
protected internal sealed override void OnVisualParentChanged(DependencyObject oldParent)
{
VerifyAccess();
base.OnVisualParentChanged(oldParent);
// When Page is added to a tree, it can only be the root element of Window's or Frame's Content.
// In code, it means you can only add Page to a tree via Window.Content = Page, Frame.Content = Page,
// or equivalent such as navigation.
// So we only allow a Page to be parented by a Visual (parent) in the following
// cases:
// 1. The visual parent is null.
// 2. The logical parent is Window (Frame's Content is not its logical child).
// 3. When the logical parent is not Window, it can only be the case of Page inside of a Frame. We can verify that
// by checking the Content of the Page's NavigationService is the Page itself.
// The NavigationService dp and its Content property both are set before logical and/or visual Parent change.
// 4. Exception should be thrown in any other situations, except for the v1 compatibility case below.
Visual visualParent = VisualTreeHelper.GetParent(this) as Visual;
// Need to check whether visual parent is null first, because if the app caught the exception as a result of setting illegal parent,
// and it removes the Page from the wrongly set parent, the visual link is removed first before the logical link.
// As a result when OnVisualParentChanged is fired, visualParent is null while the logical Parent is still the old one; Parent getter
// here will return the illegal one.
if ((visualParent == null) ||
(Parent is Window) ||
((NavigationService != null) && (NavigationService.Content == this)))
{
return;
}
// NOTE (Huwang 03/09/2007): The code below walks up the TemplatedParent chain until it finds the first Frame or Window. It does not
// check whether Window.Content or Frame.Content is Page. So it allows the scenario where Page can be in any element’s template and
// be parented by any element as long as the template is nested inside a Window or Frame, as demoed below
//
// <Window>
// <Window.Template>
// ...
// <Button>
// <Button.Template>
// ...
// <DockPanel>
// ...
// <Page>
// ...
//
// This is not what we intend to establish and support. But we discovered this after shipping V1. We need to maintain this behavior until
// V4.0 when we will have an opportunity to do BC. Will file a bug for V4.0.
bool isParentValid = false;
// Don't worry about FCE since FCE is not a visual
FrameworkElement feParent = visualParent as FrameworkElement;
if (feParent != null)
{
DependencyObject parent = feParent as DependencyObject;
// walk the StyledParent chain
while ((feParent != null) && (feParent.TemplatedParent != null))
{
parent = feParent.TemplatedParent;
// don't care if this cast fails to null b/c StyledParent
// are supposed to be FE or FCE and FCE is not part of the
// visual tree.
feParent = parent as FrameworkElement;
// (Page throws InvalidOperationException when
// navigated to by a Frame which is part of the style visual
// tree of an element)
// We need this here for the case when Frame is in the style
// of an element
if (feParent is Frame)
{
break;
}
}
if ((parent is Window) || (parent is Frame))
{
isParentValid = true;
}
}
if (isParentValid == false)
{
throw new InvalidOperationException(SR.ParentOfPageMustBeWindowOrFrame);
}
}
#endregion Protected Methods
//---------------------------------------------------
//
// Private Methods
//
//---------------------------------------------------
#region Private Methods
private static void OnContentChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Page page = (Page) d;
page.OnContentChanged(e.OldValue, e.NewValue);
}
private void OnContentChanged(object oldContent, object newContent)
{
RemoveLogicalChild(oldContent);
AddLogicalChild(newContent);
}
private static void _OnWindowServiceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
Page p = d as Page;
Debug.Assert( p != null, "DependencyObject must be of type Page." );
p.OnWindowServiceChanged(e.NewValue as IWindowService);
}
/// <summary>
/// When IWindowService is changed, it means that this control is either placed into
/// a window's visual tree or taken out. If we are in a new Window's visual tree and this
/// was a top level Page in the old Window, want to unhook events from the old window.
/// Additionally, if this Page is a top level Page in the new Window's visual tree, we hook
/// the events up to the new window. Moreover, we also want to propagate the cached properties
/// for top level Pages, otherwise, we clear the cache.
/// NOTE: the property values are propaged to the first window Page is attached to. For
/// subsequent windows these properties are not propagated.
/// </summary>
private void OnWindowServiceChanged(IWindowService iws)
{
_currentIws = iws;
DetermineTopLevel();
if (_currentIws != null)
{
if (_isTopLevel == true)
{
PropagateProperties();
}
}
}
private void DetermineTopLevel()
{
FrameworkElement feParent = this.Parent as FrameworkElement;
if ((feParent != null) && (feParent.InheritanceBehavior == InheritanceBehavior.Default))
{
_isTopLevel = true;
}
else
{
_isTopLevel = false;
}
}
private void PropagateProperties()
{
Debug.Assert(_currentIws != null, "_currentIws cannot be null here. Caller should always verify it");
if (_pho == null)
{
return;
}
if (IsPropertySet(SetPropertyFlags.WindowTitle))
{
_currentIws.Title = PageHelperObject._windowTitle;
}
if (IsPropertySet(SetPropertyFlags.WindowHeight) && (! _currentIws.UserResized))
{
_currentIws.Height = PageHelperObject._windowHeight;
}
if (IsPropertySet(SetPropertyFlags.WindowWidth) && (! _currentIws.UserResized))
{
_currentIws.Width = PageHelperObject._windowWidth;
}
if (IsPropertySet(SetPropertyFlags.ShowsNavigationUI))
{
SetShowsNavigationUI(PageHelperObject._showsNavigationUI);
}
}
bool IWindowService.UserResized
{
get
{
Invariant.Assert(_currentIws != null, "_currentIws cannot be null here.");
return _currentIws.UserResized;
}
}
private void SetShowsNavigationUI(bool showsNavigationUI)
{
NavigationWindow navWin = _currentIws as NavigationWindow;
if (navWin != null)
{
navWin.ShowsNavigationUI = showsNavigationUI;
}
}
private bool IsPropertySet(SetPropertyFlags property)
{
return (_setPropertyFlags & property) != 0;
}
private void PropertyIsSet(SetPropertyFlags property)
{
_setPropertyFlags |= property;
}
#region ShouldSerialize methods
/// <summary>
/// This method is used by TypeDescriptor to determine if this property should
/// be serialized.
/// </summary>
[EditorBrowsable(EditorBrowsableState.Never)]
public bool ShouldSerializeWindowTitle()
{
return IsPropertySet(SetPropertyFlags.WindowTitle);
}
/// <summary>
/// This method is used by TypeDescriptor to determine if this property should
/// be serialized.
/// </summary>
[EditorBrowsable(EditorBrowsableState.Never)]
public bool ShouldSerializeWindowHeight()
{
return IsPropertySet(SetPropertyFlags.WindowHeight);
}
/// <summary>
/// This method is used by TypeDescriptor to determine if this property should
/// be serialized.
/// </summary>
[EditorBrowsable(EditorBrowsableState.Never)]
public bool ShouldSerializeWindowWidth()
{
return IsPropertySet(SetPropertyFlags.WindowWidth);
}
/// <summary>
/// This method is used by TypeDescriptor to determine if this property should
/// be serialized.
/// </summary>
[EditorBrowsable(EditorBrowsableState.Never)]
public bool ShouldSerializeTitle()
{
return IsPropertySet(SetPropertyFlags.Title);
}
/// <summary>
/// This method is used by TypeDescriptor to determine if this property should
/// be serialized.
/// </summary>
[EditorBrowsable(EditorBrowsableState.Never)]
public bool ShouldSerializeShowsNavigationUI()
{
return IsPropertySet(SetPropertyFlags.ShowsNavigationUI);
}
#endregion
#endregion Private Methods
//---------------------------------------------------
//
// Private Properties
//
//---------------------------------------------------
#region Private Properties
/// <summary>
/// Returns IWindowService for the window page is hosted in.
/// </summary>
private IWindowService WindowService
{
get
{
return _currentIws;
}
}
private PageHelperObject PageHelperObject
{
get
{
if (_pho == null)
{
_pho = new PageHelperObject();
}
return _pho;
}
}
//
// This property
// 1. Finds the correct initial size for the _effectiveValues store on the current DependencyObject
// 2. This is a performance optimization
//
internal override int EffectiveValuesInitialSize
{
get { return 19; }
}
#endregion Private Properties
//----------------------------------------------
//
// Private Fields
//
//----------------------------------------------
#region Private Fields
private IWindowService _currentIws;
private PageHelperObject _pho;
private SetPropertyFlags _setPropertyFlags = SetPropertyFlags.None;
private bool _isTopLevel;
private ControlTemplate _templateCache;
#endregion Private Fields
#region DTypeThemeStyleKey
// Returns the DependencyObjectType for the registered ThemeStyleKey's default
// value. Controls will override this method to return approriate types.
internal override DependencyObjectType DTypeThemeStyleKey
{
get { return _dType; }
}
private static DependencyObjectType _dType;
#endregion DTypeThemeStyleKey
#endregion Page Class
}
class PageHelperObject
{
//----------------------------------------------
//
// Internal Fields
//
//----------------------------------------------
#region Internal Fields
//we start to cache these properties because the window is not necessarly available
//when the values are set. Also we need to be able to tell whether a property has been
//set per property so that we will know which one is set. We have a bool variable per property
//for that purpose.
internal String _text;
internal String _windowTitle;
internal double _windowHeight;
internal double _windowWidth;
internal bool _showsNavigationUI;
#endregion Internal Fields
}
[Flags]
internal enum SetPropertyFlags : byte
{
WindowTitle = 0x01,
WindowHeight = 0x02,
WindowWidth = 0x04,
Title = 0x08,
ShowsNavigationUI = 0x10,
None = 0x00,
}
}
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