/// <summary>
/// Manually triggers update of the target value from source
/// </summary>
public override void RefreshTargetValue()
{
if (TargetDependency.RootNode.IsChainBroken) return;
TTarget targetValue;
if (SourceDependency.LeafNode.IsChainBroken)
{
targetValue = DefaultValue;
}
else
{
SourceDependency.RefreshChildNodeValue();
TSource sourceValue = SourceDependency.LeafValue;
if (ForwardConverter != null)
{
targetValue = ForwardConverter(sourceValue);
}
else
{
targetValue = (TTarget)(object)sourceValue;
}
}
//assign to target
var parent = TargetDependency.LeafNode.ParentNode.NodeValue;
SetMemberValue(TargetMember, parent, targetValue);
}
/// <summary>
/// Event listener that is being invoked in two-way binding scenarios whenever
/// the target node value is being changed.
/// </summary>
private void OnTargetChanged(object sender, DependencyChangeEventArgs<TTarget> e)
{
//if the target is broken or the source is not accessible, do not update the source
if (SourceDependency.RootNode.IsChainBroken || TargetDependency.RootNode.IsChainBroken) return;
TTarget targetValue = e.TryGetLeafValue();
TSource sourceValue;
if (ReverseConverter != null)
{
sourceValue = ReverseConverter(targetValue);
}
else
{
sourceValue = (TSource) (object) targetValue;
}
SourceDependency.RefreshChildNodeValue(); // FIX: SourceDependency.LeafValue may be out of sync.
//only update the source if its value is different than the
//current one - re-assiging the same value produces a recursive
//update
if (sourceValue.Equals(SourceDependency.LeafValue)) return;
//assign to source
var parent = SourceDependency.LeafNode.ParentNode.NodeValue;
SetMemberValue(SourceMember, parent, sourceValue);
}
/// <summary>
/// Disposes the underlying bindings.
/// </summary>
public override void Dispose()
{
//deregister event listeners
SourceDependency.DependencyChanged -= OnSourceChanged;
if (IsTwoWayBinding) TargetDependency.DependencyChanged -= OnTargetChanged;
//clear dependencies and references
SourceDependency.Dispose();
TargetDependency.Dispose();
SourceDependency = null;
TargetDependency = null;
}
