public override object ProvideValue(IServiceProvider serviceProvider)
{
if (serviceProvider == null)
{
throw new ArgumentNullException(nameof(serviceProvider));
}
// Other useful services:
// - IDestinationTypeProvider
// - IRootObjectProvider
if (!(serviceProvider.GetService(typeof(IProvideValueTarget)) is IProvideValueTarget service))
{
return(null);
}
if (service.TargetObject is DependencyObject depObj)
{
if (Binding != null || _bindings?.Count > 0)
{
if (false == (service.TargetProperty is DependencyProperty))
{
// The what bindings are implemented in WPF provides no way to obtain the value
// produced by the binging. The only way is to update the property directly. Therefore,
// the extension cannot support bindings on non-dependency properties (same as WPF).
throw new NotSupportedException("Bindings are supported only on dependency properties.");
}
}
LocalizedProperty localizedProperty;
if (service.TargetProperty is DependencyProperty depProperty)
{
localizedProperty = new LocalizedDepProperty(depProperty);
}
else if (service.TargetProperty is PropertyInfo propertyInfo)
{
localizedProperty = new LocalizedNonDepProperty(propertyInfo);
}
else
{
throw new NotSupportedException($"The default property provider supports only dependency and non-dependency properties of dependency objects. Properties of type {service.TargetProperty.GetType()} are not supported.");
}
var localizedValue = new LocalizedValue(depObj, localizedProperty)
{
Key = this.Key,
StringFormat = this.StringFormat,
Callback = this.Callback,
CallbackParameter = this.CallbackParameter,
Binding = this.Binding,
Bindings = this._bindings,
Converter = this.Converter,
ConverterParameter = this.ConverterParameter,
};
LocalizationManager.Add(localizedValue);
if (localizedValue.IsInDesignMode)
{
// At design time VS designer does not set the parent of any control
// before its properties are set. For this reason the correct values
// of inherited attached properties cannot be obtained.
// Therefore, to display the correct localized value it must be updated
// later after the parent of the control has been set.
depObj.Dispatcher.BeginInvoke(
DispatcherPriority.ApplicationIdle,
new SendOrPostCallback(x => ((LocalizedValue)x).UpdateValue()),
localizedValue
);
return(localizedProperty.DefaultValue);
}
else
{
return(localizedValue.GetValue(depObj));
}
}
else if (service.TargetObject is Setter)
{
/* // DEPRECATED
* if (Binding != null || _bindings?.Count > 0)
* {
* throw new NotSupportedException("Bindings are not supported in style setters.");
* }
*/
var rootObjectProvider = (IRootObjectProvider)serviceProvider.GetService(typeof(IRootObjectProvider));
Debug.Assert(rootObjectProvider != null);
var rootObject = rootObjectProvider.RootObject as DependencyObject;
Debug.Assert(rootObject != null);
#if DEPRECATED // Unfortunately "GetDestinationType" throws NullReferenceException therefore, this approach is not applicable for retrieving the property's type
var destinationTypeProvider = (IDestinationTypeProvider)serviceProvider.GetService(typeof(IDestinationTypeProvider));
Debug.Assert(destinationTypeProvider != null);
var targetPropertyType = destinationTypeProvider.GetDestinationType();
var localizedValue = new SetterLocalizedValue(rootObject, targetPropertyType)
{
Key = this.Key,
Callback = this.Callback,
CallbackParameter = this.CallbackParameter,
Converter = this.Converter,
ConverterParameter = this.ConverterParameter,
};
#endif
var localizedValue = new LocalizedSetterValue(rootObject)
{
Key = this.Key,
StringFormat = this.StringFormat,
Callback = this.Callback,
CallbackParameter = this.CallbackParameter,
Binding = this.Binding,
Bindings = this._bindings,
Converter = this.Converter,
ConverterParameter = this.ConverterParameter,
};
BindingBase finalBinding;
if (Binding != null || _bindings?.Count > 0)
{
var binding = new MultiBinding()
{
Mode = BindingMode.OneWay,
Converter = localizedValue,
};
if (Binding != null)
{
binding.Bindings.Add(Binding);
if (_bindings?.Count > 0)
{
foreach (var item in Bindings)
{
binding.Bindings.Add(item);
}
}
}
finalBinding = binding;
}
else
{
finalBinding = new Binding(nameof(LocalizedSetterValue.Value))
{
Source = localizedValue,
Mode = BindingMode.OneWay,
Converter = localizedValue,
};
}
LocalizationManager.Add(localizedValue);
return(finalBinding);
}
else if (service.TargetProperty is DependencyProperty || service.TargetProperty is PropertyInfo)
{
// The extension is used in a template and will be evaluated once the template is instantiated
return(this);
}
else
{
throw new NotSupportedException($"The localization extension can be used only with {nameof(DependencyObject)}s.");
}
}
