/// <summary>
/// Fetches the resource corresponding to the given key from this dictionary.
/// Returns a DeferredResourceReference if the object has not been inflated yet.
/// </summary>
internal object FetchResource(
object resourceKey,
bool allowDeferredResourceReference,
bool mustReturnDeferredResourceReference,
out bool canCache)
{
Debug.Assert(resourceKey != null, "ResourceKey cannot be null");
if (allowDeferredResourceReference)
{
if (ContainsBamlObjectFactory(resourceKey) ||
(mustReturnDeferredResourceReference && Contains(resourceKey)))
{
canCache = false;
DeferredResourceReference deferredResourceReference;
if (!IsThemeDictionary)
{
if (_ownerApps != null)
{
deferredResourceReference = new DeferredAppResourceReference(this, resourceKey);
}
else
{
deferredResourceReference = new DeferredResourceReference(this, resourceKey);
}
// Cache the deferredResourceReference so that it can be validated
// in case of a dictionary change prior to its inflation
if (_deferredResourceReferences == null)
{
_deferredResourceReferences = new WeakReferenceList();
}
_deferredResourceReferences.Add( deferredResourceReference, true /*SkipFind*/);
}
else
{
deferredResourceReference = new DeferredThemeResourceReference(this, resourceKey);
}
return deferredResourceReference;
}
}
return GetValue(resourceKey, out canCache);
}
internal virtual void AddInflatedListener(ResourceReferenceExpression listener)
{
if (_inflatedList == null)
{
_inflatedList = new WeakReferenceList(this);
}
_inflatedList.Add(listener);
}
// Add an owner for this dictionary
internal void AddOwner(DispatcherObject owner)
{
if (_inheritanceContext == null)
{
// the first owner gets to be the InheritanceContext for
// all the values in the dictionary that want one.
_inheritanceContext = owner as DependencyObject;
if (_inheritanceContext != null)
{
// set InheritanceContext for the existing values
AddInheritanceContextToValues();
}
else
{
// if the first owner is ineligible, use a dummy
_inheritanceContext = new DependencyObject();
_inheritanceContext.DetachFromDispatcher();
// do not call AddInheritanceContextToValues -
// the owner is an Application, and we'll be
// calling SealValues soon, which takes care
// of InheritanceContext as well
}
}
FrameworkElement fe = owner as FrameworkElement;
if (fe != null)
{
if (_ownerFEs == null)
{
_ownerFEs = new WeakReferenceList(1);
}
else if (_ownerFEs.Contains(fe) && ContainsCycle(this))
{
throw new InvalidOperationException(SR.Get(SRID.ResourceDictionaryInvalidMergedDictionary));
}
// Propagate the HasImplicitStyles flag to the new owner
if (HasImplicitStyles)
{
fe.ShouldLookupImplicitStyles = true;
}
_ownerFEs.Add(fe);
}
else
{
FrameworkContentElement fce = owner as FrameworkContentElement;
if (fce != null)
{
if (_ownerFCEs == null)
{
_ownerFCEs = new WeakReferenceList(1);
}
else if (_ownerFCEs.Contains(fce) && ContainsCycle(this))
{
throw new InvalidOperationException(SR.Get(SRID.ResourceDictionaryInvalidMergedDictionary));
}
// Propagate the HasImplicitStyles flag to the new owner
if (HasImplicitStyles)
{
fce.ShouldLookupImplicitStyles = true;
}
_ownerFCEs.Add(fce);
}
else
{
Application app = owner as Application;
if (app != null)
{
if (_ownerApps == null)
{
_ownerApps = new WeakReferenceList(1);
}
else if (_ownerApps.Contains(app) && ContainsCycle(this))
{
throw new InvalidOperationException(SR.Get(SRID.ResourceDictionaryInvalidMergedDictionary));
}
// Propagate the HasImplicitStyles flag to the new owner
if (HasImplicitStyles)
{
app.HasImplicitStylesInResources = true;
}
_ownerApps.Add(app);
// An Application ResourceDictionary can be accessed across threads
CanBeAccessedAcrossThreads = true;
// Seal all the styles and templates in this app dictionary
SealValues();
}
}
}
AddOwnerToAllMergedDictionaries(owner);
// This dictionary will be marked initialized if no one has called BeginInit on it.
// This is done now because having an owner is like a parenting operation for the dictionary.
TryInitialize();
}
