/// <summary>
/// Sets the value of a direct property.
/// </summary>
/// <param name="property">The property.</param>
/// <param name="value">The value.</param>
private void SetDirectValue(AvaloniaProperty property, object value)
{
var notification = value as BindingNotification;
if (notification != null)
{
notification.LogIfError(this, property);
value = notification.Value;
}
if (notification == null || notification.ErrorType == BindingErrorType.Error || notification.HasValue)
{
var metadata = (IDirectPropertyMetadata)property.GetMetadata(GetType());
var accessor = (IDirectPropertyAccessor)GetRegistered(property);
var finalValue = value == AvaloniaProperty.UnsetValue ?
metadata.UnsetValue : value;
LogPropertySet(property, value, BindingPriority.LocalValue);
accessor.SetValue(this, finalValue);
}
if (notification != null)
{
UpdateDataValidation(property, notification);
}
}
/// <summary>
/// Binds a property on an <see cref="IAvaloniaObject"/> to an <see cref="IBinding"/>.
/// </summary>
/// <param name="target">The object.</param>
/// <param name="property">The property to bind.</param>
/// <param name="binding">The binding.</param>
/// <param name="anchor">
/// An optional anchor from which to locate required context. When binding to objects that
/// are not in the logical tree, certain types of binding need an anchor into the tree in
/// order to locate named controls or resources. The <paramref name="anchor"/> parameter
/// can be used to provice this context.
/// </param>
/// <returns>An <see cref="IDisposable"/> which can be used to cancel the binding.</returns>
public static IDisposable Bind(
this IAvaloniaObject target,
AvaloniaProperty property,
IBinding binding,
object anchor = null)
{
Contract.Requires <ArgumentNullException>(target != null);
Contract.Requires <ArgumentNullException>(property != null);
Contract.Requires <ArgumentNullException>(binding != null);
var metadata = property.GetMetadata(target.GetType()) as IDirectPropertyMetadata;
var result = binding.Initiate(
target,
property,
anchor,
metadata?.EnableDataValidation ?? false);
if (result != null)
{
return(BindingOperations.Apply(target, property, result, anchor));
}
else
{
return(Disposable.Empty);
}
}
/// <summary>
/// Sets the value of a direct property.
/// </summary>
/// <param name="property">The property.</param>
/// <param name="value">The value.</param>
private void SetDirectValue(AvaloniaProperty property, object value)
{
var notification = value as BindingNotification;
if (notification != null)
{
if (notification.ErrorType == BindingErrorType.Error)
{
Logger.Error(
LogArea.Binding,
this,
"Error in binding to {Target}.{Property}: {Message}",
this,
property,
ExceptionUtilities.GetMessage(notification.Error));
}
if (notification.HasValue)
{
value = notification.Value;
}
}
if (notification == null || notification.HasValue)
{
var metadata = (IDirectPropertyMetadata)property.GetMetadata(GetType());
var accessor = (IDirectPropertyAccessor)GetRegistered(property);
var finalValue = value == AvaloniaProperty.UnsetValue ?
metadata.UnsetValue : value;
LogPropertySet(property, value, BindingPriority.LocalValue);
accessor.SetValue(this, finalValue);
}
if (notification != null)
{
UpdateDataValidation(property, notification);
}
}
/// <summary>
/// Converts an unset value to the default value for a direct property.
/// </summary>
/// <param name="value">The value.</param>
/// <param name="property">The property.</param>
/// <returns>The value.</returns>
private object DirectUnsetToDefault(object value, AvaloniaProperty property)
{
return(value == AvaloniaProperty.UnsetValue ?
((IDirectPropertyMetadata)property.GetMetadata(GetType())).UnsetValue :
value);
}
