// create dependency property entry and set its default and initial inherited value
private IDependencyPropertyValueEntry CreateDependencyPropertyValueEntry(DependencyProperty dependencyProperty, PropertyMetadata propertyMetadata)
{
bool isContained = dependencyProperty.IsAttached || dependencyProperty.IsContainedBy(GetType());
IDependencyPropertyValueEntry entry = new DependencyPropertyValueEntry(this, dependencyProperty, isContained ? propertyMetadata.CoerceValueCallback : null);
entry.SetBaseValue((int)BaseValueSource.Default, propertyMetadata.DefaultValue);
if (isContained)
{
entry.ValueChanged += containedEntryValueChangedEventHandler;
}
else
{
entry.ValueChanged += entryValueChangedEventHandler;
}
return(entry);
}
public object GetValue(DependencyProperty dependencyProperty)
{
IDependencyPropertyValueEntry entry;
if (!entries.TryGetValue(dependencyProperty, out entry))
{
PropertyMetadata propertyMetadata = dependencyProperty.GetMetadata(GetType());
// no need to create a new entry if the value is not inherited or coerced
if (!propertyMetadata.Inherits && (propertyMetadata.CoerceValueCallback == null || !dependencyProperty.IsAttached && !dependencyProperty.IsContainedBy(GetType())))
{
return(propertyMetadata.DefaultValue);
}
entry = CreateDependencyPropertyValueEntry(dependencyProperty, propertyMetadata);
entries.Add(dependencyProperty, entry);
}
return(entry.Value);
}