void ReplaceDependencySources()
{
if (!ParentBindingExpression.IsDetaching)
{
int size = PW.Length;
if (PW.NeedsDirectNotification)
{
++size;
}
WeakDependencySource[] newSources = new WeakDependencySource[size];
int n = 0;
if (IsDynamic)
{
for (int k = 0; k < PW.Length; ++k)
{
DependencyProperty dp = PW.GetAccessor(k) as DependencyProperty;
if (dp != null)
{
DependencyObject d = PW.GetItem(k) as DependencyObject;
if (d != null)
{
newSources[n++] = new WeakDependencySource(d, dp);
}
}
}
if (PW.NeedsDirectNotification)
{
// subproperty notifications can only arise from Freezables
// (as of today - 11/14/08), so we only need to propagate
// them when the raw value is a Freezable.
DependencyObject d = PW.RawValue() as Freezable;
if (d != null)
{
newSources[n++] = new WeakDependencySource(d, DependencyObject.DirectDependencyProperty);
}
}
}
ParentBindingExpression.ChangeWorkerSources(newSources, n);
}
}
internal override void UpdateValue(object value)
{
int k = PW.Length - 1;
object item = PW.GetItem(k);
if (item == null || item == BindingExpression.NullDataItem)
{
return;
}
// if the binding is async, post a request to set the value
if (ParentBinding.IsAsync && !(PW.GetAccessor(k) is DependencyProperty))
{
RequestAsyncSetValue(item, value);
return;
}
PW.SetValue(item, value);
}
void RequestAsyncSetValue(object item, object value)
{
// get information about the property whose value we want
string name = GetNameFromInfo(PW.GetAccessor(PW.Length - 1));
Invariant.Assert(name != null, "Async SetValue expects a name");
// abandon any previous request
AsyncSetValueRequest pendingSetValueRequest = (AsyncSetValueRequest)GetValue(Feature.PendingSetValueRequest, null);
if (pendingSetValueRequest != null)
{
pendingSetValueRequest.Cancel();
}
// issue the new request
pendingSetValueRequest =
new AsyncSetValueRequest(item, name, value, ParentBinding.AsyncState,
DoSetValueCallback, CompleteSetValueCallback,
this);
SetValue(Feature.PendingSetValueRequest, pendingSetValueRequest);
Engine.AddAsyncRequest(TargetElement, pendingSetValueRequest);
}