/// <summary>
/// This method is an alternative to WPF's
/// <see cref="VisualTreeHelper.GetParent"/> method, which also
/// supports content elements. Keep in mind that for content element,
/// this method falls back to the logical tree of the element!
/// </summary>
/// <param name="child">The item to be processed.</param>
/// <returns>The submitted item's parent, if available. Otherwise
/// null.</returns>
public static DependencyObject GetParentObject(this DependencyObject child)
{
if (child == null)
{
return(null);
}
// handle content elements separately
if (child is ContentElement contentElement)
{
DependencyObject parent = ContentOperations.GetParent(contentElement);
if (parent != null)
{
return(parent);
}
return(contentElement is FrameworkContentElement fce ? fce.Parent : null);
}
var childParent = VisualTreeHelper.GetParent(child);
if (childParent != null)
{
return(childParent);
}
// also try searching for parent in framework elements (such as DockPanel, etc)
if (child is FrameworkElement frameworkElement)
{
DependencyObject parent = frameworkElement.Parent;
if (parent != null)
{
return(parent);
}
}
return(null);
}
/// <summary>
/// This method is an alternative to WPF's
/// <see cref="VisualTreeHelper.GetParent"/> method, which also
/// supports content elements. Keep in mind that for content element,
/// this method falls back to the logical tree of the element!
/// </summary>
/// <param name="child">The item to be processed.</param>
/// <returns>The submitted item's parent, if available. Otherwise
/// null.</returns>
public static DependencyObject GetParentObject(this DependencyObject child)
{
if (child == null)
{
return(null);
}
#if !SILVERLIGHT
//handle content elements separately
var contentElement = child as ContentElement;
if (contentElement != null)
{
DependencyObject parent = ContentOperations.GetParent(contentElement);
if (parent != null)
{
return(parent);
}
var fce = contentElement as FrameworkContentElement;
return(fce != null ? fce.Parent : null);
}
#endif
// also try searching for parent in framework elements (such as DockPanel, etc)
var frameworkElement = child as FrameworkElement;
if (frameworkElement != null)
{
DependencyObject parent = frameworkElement.Parent;
if (parent != null)
{
return(parent);
}
}
//if it's not a ContentElement/FrameworkElement, rely on VisualTreeHelper
return(VisualTreeHelper.GetParent(child));
}
/// <summary>
/// This is a recursive function that walks up the tree Adding or Removing
/// HasLoadedChangeHander bits. It also inits the IsLoadedCache on Add.
/// </summary>
/// <param name="d">
/// Node to update
/// </param>
/// <param name="addHandler">
/// Is it an AddHandler/ Add Child with Handler Operation
/// </param>
private static void UpdateHasLoadedChangeHandlerFlagInAncestry(DependencyObject d, bool addHandler)
{
FrameworkObject fo = new FrameworkObject(d);
if (!addHandler)
{
if (AreThereLoadedChangeHandlersInSubtree(ref fo))
{
return; // done
}
}
if (fo.IsValid)
{
if (fo.SubtreeHasLoadedChangeHandler != addHandler)
{
DependencyObject coreParent = (fo.IsFE) ? VisualTreeHelper.GetParent(fo.FE) : null;
DependencyObject logicalParent = fo.Parent;
DependencyObject parent = null;
fo.SubtreeHasLoadedChangeHandler = addHandler;
// Propagate the change to your visual ancestry
if (coreParent != null)
{
UpdateHasLoadedChangeHandlerFlagInAncestry(coreParent, addHandler);
parent = coreParent;
}
// Propagate the change to your logical ancestry
if (logicalParent != null && logicalParent != coreParent)
{
UpdateHasLoadedChangeHandlerFlagInAncestry(logicalParent, addHandler);
if (fo.IsFCE)
{
parent = logicalParent;
}
}
// Propagate the change to your mentor, if any
if (logicalParent == null && coreParent == null)
{
parent = Helper.FindMentor(fo.DO.InheritanceContext);
if (parent != null)
{
fo.ChangeSubtreeHasLoadedChangedHandler(parent);
}
}
if (addHandler)
{
// The HasLoadedChangeHandler flag is used for two purposes.
// 1. To indicate that the sub-tree starting at the current node has
// handlers for Loaded / Unloaded event. So broadcast logic
// can walk down that path to fire the events.
// 2. To indicate that the IsLoaded cache on the node is valid.
// If we are adding a handler:
// On the POP side of the recursion, as we come back down from the root,
// pull the value of IsLoadedCache from the parent in to the child.
if (fo.IsFE)
{
UpdateIsLoadedCache(fo.FE, parent);
}
else
{
UpdateIsLoadedCache(fo.FCE, parent);
}
}
}
}
else // neither a FE or an FCE
{
DependencyObject coreParent = null;
Visual v;
Visual3D v3D;
ContentElement ce;
// This is neither an FE nor and FCE
// Propagate the change to your visual ancestry
if ((v = d as Visual) != null)
{
coreParent = VisualTreeHelper.GetParent(v);
}
else if ((ce = d as ContentElement) != null)
{
coreParent = ContentOperations.GetParent(ce);
}
else if ((v3D = d as Visual3D) != null)
{
coreParent = VisualTreeHelper.GetParent(v3D);
}
if (coreParent != null)
{
UpdateHasLoadedChangeHandlerFlagInAncestry(coreParent, addHandler);
}
}
}
// Token: 0x06000318 RID: 792 RVA: 0x00008B80 File Offset: 0x00006D80
private static void UpdateHasLoadedChangeHandlerFlagInAncestry(DependencyObject d, bool addHandler)
{
FrameworkObject frameworkObject = new FrameworkObject(d);
if (!addHandler && BroadcastEventHelper.AreThereLoadedChangeHandlersInSubtree(ref frameworkObject))
{
return;
}
if (frameworkObject.IsValid)
{
if (frameworkObject.SubtreeHasLoadedChangeHandler != addHandler)
{
DependencyObject dependencyObject = frameworkObject.IsFE ? VisualTreeHelper.GetParent(frameworkObject.FE) : null;
DependencyObject parent = frameworkObject.Parent;
DependencyObject dependencyObject2 = null;
frameworkObject.SubtreeHasLoadedChangeHandler = addHandler;
if (dependencyObject != null)
{
BroadcastEventHelper.UpdateHasLoadedChangeHandlerFlagInAncestry(dependencyObject, addHandler);
dependencyObject2 = dependencyObject;
}
if (parent != null && parent != dependencyObject)
{
BroadcastEventHelper.UpdateHasLoadedChangeHandlerFlagInAncestry(parent, addHandler);
if (frameworkObject.IsFCE)
{
dependencyObject2 = parent;
}
}
if (parent == null && dependencyObject == null)
{
dependencyObject2 = Helper.FindMentor(frameworkObject.DO.InheritanceContext);
if (dependencyObject2 != null)
{
frameworkObject.ChangeSubtreeHasLoadedChangedHandler(dependencyObject2);
}
}
if (addHandler)
{
if (frameworkObject.IsFE)
{
BroadcastEventHelper.UpdateIsLoadedCache(frameworkObject.FE, dependencyObject2);
return;
}
BroadcastEventHelper.UpdateIsLoadedCache(frameworkObject.FCE, dependencyObject2);
return;
}
}
}
else
{
DependencyObject dependencyObject3 = null;
Visual reference;
ContentElement reference2;
Visual3D reference3;
if ((reference = (d as Visual)) != null)
{
dependencyObject3 = VisualTreeHelper.GetParent(reference);
}
else if ((reference2 = (d as ContentElement)) != null)
{
dependencyObject3 = ContentOperations.GetParent(reference2);
}
else if ((reference3 = (d as Visual3D)) != null)
{
dependencyObject3 = VisualTreeHelper.GetParent(reference3);
}
if (dependencyObject3 != null)
{
BroadcastEventHelper.UpdateHasLoadedChangeHandlerFlagInAncestry(dependencyObject3, addHandler);
}
}
}
