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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 System.Windows.Navigation;
//
// Description:
// Implements the help class of FixedHyperLink.
//
namespace System.Windows.Documents
{
///<summary>
/// The IFixedNavigate interface will be implemented by FixedPage, FixedDocument,
/// and FixedDocumentSequence to support fixed hyperlink.
///</summary>
internal interface IFixedNavigate
{
/// <summary>
/// Find the element which given ID in this document context.
/// </summary>
/// <param name="elementID">The ID of UIElement to search for</param>
/// <param name="rootFixedPage">The fixedPage that contains returns UIElement</param>
/// <returns></returns>
UIElement FindElementByID(string elementID, out FixedPage rootFixedPage);
/// <summary>
/// Navigate to the element with ID= elementID
/// </summary>
/// <param name="elementID"></param>
void NavigateAsync (string elementID);
}
internal static class FixedHyperLink
{
/// <summary>
/// NavigationService property ChangedCallback.
/// </summary>
public static void OnNavigationServiceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
FixedDocument fixedContent = d as FixedDocument;
if (fixedContent != null)
{
NavigationService oldService = (NavigationService) e.OldValue;
NavigationService newService = (NavigationService) e.NewValue;
if (oldService != null)
{
oldService.FragmentNavigation -= new FragmentNavigationEventHandler(FragmentHandler);
}
if (newService != null)
{
newService.FragmentNavigation += new FragmentNavigationEventHandler(FragmentHandler);
}
}
}
/// <summary>
/// Called by NavigationService to let document content to handle the fragment first.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
internal static void FragmentHandler(object sender, FragmentNavigationEventArgs e)
{
NavigationService ns = sender as NavigationService;
if (ns != null)
{
string fragment = e.Fragment;
IFixedNavigate fixedNavigate = ns.Content as IFixedNavigate;
if (fixedNavigate != null)
{
fixedNavigate.NavigateAsync(e.Fragment);
e.Handled = true;
}
}
}
/// <summary>
/// Fire BringinToView event on the element ID.
/// </summary>
/// <param name="ElementHost">The host document of element ID, call any one implents IFixedNavigate</param>
/// <param name="elementID"></param>
internal static void NavigateToElement(object ElementHost, string elementID)
{
FixedPage rootFixedPage = null;
FrameworkElement targetElement = null;
targetElement = ((IFixedNavigate)ElementHost).FindElementByID(elementID, out rootFixedPage) as FrameworkElement;
if (targetElement != null)
{
if (targetElement is FixedPage)
{
//
// For fixedpage, we only need to scroll to page position.
//
targetElement.BringIntoView();
}
else
{
//Just passing in raw rect of targetElement. Let DocumentViewer/Grid handle transforms
targetElement.BringIntoView(targetElement.VisualContentBounds);
}
}
return;
}
}
} |