/// <summary>
/// Registers a <see cref="AvaloniaProperty"/> on a type.
/// </summary>
/// <param name="type">The type.</param>
/// <param name="property">The property.</param>
/// <remarks>
/// You won't usually want to call this method directly, instead use the
/// <see cref="AvaloniaProperty.Register{TOwner, TValue}(string, TValue, bool, Data.BindingMode, Func{TOwner, TValue, TValue}, Action{IAvaloniaObject, bool})"/>
/// method.
/// </remarks>
public void Register(Type type, AvaloniaProperty property)
{
Contract.Requires <ArgumentNullException>(type != null);
Contract.Requires <ArgumentNullException>(property != null);
if (!_registered.TryGetValue(type, out var inner))
{
inner = new Dictionary <int, AvaloniaProperty>();
inner.Add(property.Id, property);
_registered.Add(type, inner);
}
else if (!inner.ContainsKey(property.Id))
{
inner.Add(property.Id, property);
}
if (!_properties.ContainsKey(property.Id))
{
_properties.Add(property.Id, property);
}
_registeredCache.Clear();
}
internal void PriorityValueChanged(AvaloniaProperty property, int priority, object oldValue, object newValue)
{
oldValue = (oldValue == AvaloniaProperty.UnsetValue) ?
GetDefaultValue(property) :
oldValue;
newValue = (newValue == AvaloniaProperty.UnsetValue) ?
GetDefaultValue(property) :
newValue;
if (!Equals(oldValue, newValue))
{
RaisePropertyChanged(property, oldValue, newValue, (BindingPriority)priority);
Logger.Verbose(
LogArea.Property,
this,
"{Property} changed from {$Old} to {$Value} with priority {Priority}",
property,
oldValue,
newValue,
(BindingPriority)priority);
}
}
private void AddValueInternal(AvaloniaProperty property, object value)
{
Entry[] entries = new Entry[_entries.Length + 1];
for (int i = 0; i < _entries.Length; ++i)
{
if (_entries[i].PropertyId > property.Id)
{
if (i > 0)
{
Array.Copy(_entries, 0, entries, 0, i);
}
entries[i] = new Entry {
PropertyId = property.Id, Value = value
};
Array.Copy(_entries, i, entries, i + 1, _entries.Length - i);
break;
}
}
_entries = entries;
}
/// <summary>
/// Sets the value of a styled property.
/// </summary>
/// <param name="property">The property.</param>
/// <param name="value">The value.</param>
/// <param name="priority">The priority of the value.</param>
private void SetStyledValue(AvaloniaProperty property, object value, BindingPriority priority)
{
var notification = value as BindingNotification;
// We currently accept BindingNotifications for non-direct properties but we just
// strip them to their underlying value.
if (notification != null)
{
if (!notification.HasValue)
{
return;
}
else
{
value = notification.Value;
}
}
var originalValue = value;
if (!TypeUtilities.TryConvertImplicit(property.PropertyType, value, out value))
{
throw new ArgumentException(string.Format(
"Invalid value for Property '{0}': '{1}' ({2})",
property.Name,
originalValue,
originalValue?.GetType().FullName ?? "(null)"));
}
if (_values == null)
{
_values = new ValueStore(this);
}
LogPropertySet(property, value, priority);
_values.AddValue(property, value, (int)priority);
}
/// <summary>
/// Registers an attached <see cref="AvaloniaProperty"/> on a type.
/// </summary>
/// <param name="type">The type.</param>
/// <param name="property">The property.</param>
/// <remarks>
/// You won't usually want to call this method directly, instead use the
/// <see cref="AvaloniaProperty.RegisterAttached{THost, TValue}(string, Type, TValue, bool, Data.BindingMode, Func{THost, TValue, TValue})"/>
/// method.
/// </remarks>
public void RegisterAttached(Type type, AvaloniaProperty property)
{
Contract.Requires <ArgumentNullException>(type != null);
Contract.Requires <ArgumentNullException>(property != null);
if (!property.IsAttached)
{
throw new InvalidOperationException(
"Cannot register a non-attached property as attached.");
}
if (!_attached.TryGetValue(type, out var inner))
{
inner = new Dictionary <int, AvaloniaProperty>();
inner.Add(property.Id, property);
_attached.Add(type, inner);
}
else
{
inner.Add(property.Id, property);
}
_attachedCache.Clear();
}
/// <summary>
/// Sets a property value for a direct property binding.
/// </summary>
/// <param name="property">The property.</param>
/// <param name="value">The value.</param>
/// <returns></returns>
private void DirectBindingSet(AvaloniaProperty property, object value)
{
var error = value as BindingError;
if (error == null)
{
SetValue(property, value);
}
else
{
if (error.UseFallbackValue)
{
SetValue(property, error.FallbackValue);
}
Logger.Error(
LogArea.Binding,
this,
"Error binding to {Target}.{Property}: {Message}",
this,
property,
error.Exception.Message);
}
}
/// <summary>
/// Raises the <see cref="PropertyChanged"/> event.
/// </summary>
/// <param name="property">The property that has changed.</param>
/// <param name="oldValue">The old property value.</param>
/// <param name="newValue">The new property value.</param>
/// <param name="priority">The priority of the binding that produced the value.</param>
protected void RaisePropertyChanged(
AvaloniaProperty property,
object oldValue,
object newValue,
BindingPriority priority = BindingPriority.LocalValue)
{
Contract.Requires <ArgumentNullException>(property != null);
VerifyAccess();
AvaloniaPropertyChangedEventArgs e = new AvaloniaPropertyChangedEventArgs(
this,
property,
oldValue,
newValue,
priority);
property.Notifying?.Invoke(this, true);
try
{
OnPropertyChanged(e);
property.NotifyChanged(e);
_propertyChanged?.Invoke(this, e);
if (_inpcChanged != null)
{
PropertyChangedEventArgs e2 = new PropertyChangedEventArgs(property.Name);
_inpcChanged(this, e2);
}
}
finally
{
property.Notifying?.Invoke(this, false);
}
}
/// <summary>
/// Gets a <see cref="AvaloniaProperty"/> value.
/// </summary>
/// <typeparam name="T">The type of the property.</typeparam>
/// <param name="property">The property.</param>
/// <returns>The value.</returns>
public T GetValue <T>(AvaloniaProperty <T> property)
{
Contract.Requires <ArgumentNullException>(property != null);
return((T)GetValue((AvaloniaProperty)property));
}
/// <summary>
/// Throws an exception indicating that the specified property is not registered on this
/// object.
/// </summary>
/// <param name="p">The property</param>
private void ThrowNotRegistered(AvaloniaProperty p)
{
throw new ArgumentException($"Property '{p.Name} not registered on '{this.GetType()}");
}
/// <summary>
/// Binds a <see cref="AvaloniaProperty"/> to an observable.
/// </summary>
/// <param name="property">The property.</param>
/// <param name="source">The observable.</param>
/// <param name="priority">The priority of the binding.</param>
/// <returns>
/// A disposable which can be used to terminate the binding.
/// </returns>
public IDisposable Bind(
AvaloniaProperty property,
IObservable <object> source,
BindingPriority priority = BindingPriority.LocalValue)
{
Contract.Requires <ArgumentNullException>(property != null);
Contract.Requires <ArgumentNullException>(source != null);
VerifyAccess();
var description = GetDescription(source);
var scheduler = AvaloniaLocator.Current.GetService <IScheduler>() ?? ImmediateScheduler.Instance;
source = source.ObserveOn(scheduler);
if (property.IsDirect)
{
if (property.IsReadOnly)
{
throw new ArgumentException($"The property {property.Name} is readonly.");
}
Logger.Verbose(
LogArea.Property,
this,
"Bound {Property} to {Binding} with priority LocalValue",
property,
description);
IDisposable subscription = null;
if (_directBindings == null)
{
_directBindings = new List <IDisposable>();
}
subscription = source
.Select(x => CastOrDefault(x, property.PropertyType))
.Do(_ => { }, () => _directBindings.Remove(subscription))
.Subscribe(x => SetDirectValue(property, x));
_directBindings.Add(subscription);
return(Disposable.Create(() =>
{
subscription.Dispose();
_directBindings.Remove(subscription);
}));
}
else
{
PriorityValue v;
if (!AvaloniaPropertyRegistry.Instance.IsRegistered(this, property))
{
ThrowNotRegistered(property);
}
if (!_values.TryGetValue(property, out v))
{
v = CreatePriorityValue(property);
_values.Add(property, v);
}
Logger.Verbose(
LogArea.Property,
this,
"Bound {Property} to {Binding} with priority {Priority}",
property,
description,
priority);
return(v.Add(source, (int)priority));
}
}
/// <summary>
/// Gets a description of a property that van be used in observables.
/// </summary>
/// <param name="o">The object.</param>
/// <param name="property">The property</param>
/// <returns>The description.</returns>
private static string GetDescription(IAvaloniaObject o, AvaloniaProperty property)
{
return($"{o.GetType().Name}.{property.Name}");
}
/// <summary>
/// Checks whether a <see cref="AvaloniaProperty"/> is registered on a object.
/// </summary>
/// <param name="o">The object.</param>
/// <param name="property">The property.</param>
/// <returns>True if the property is registered, otherwise false.</returns>
public bool IsRegistered(object o, AvaloniaProperty property)
{
return(IsRegistered(o.GetType(), property));
}
/// <summary>
/// Gets an observable for a <see cref="AvaloniaProperty"/>.
/// </summary>
/// <param name="o">The object.</param>
/// <typeparam name="T">The property type.</typeparam>
/// <param name="property">The property.</param>
/// <returns>
/// An observable which fires immediately with the current value of the property on the
/// object and subsequently each time the property value changes.
/// </returns>
/// <remarks>
/// The subscription to <paramref name="o"/> is created using a weak reference.
/// </remarks>
public static IObservable <T> GetObservable <T>(this IAvaloniaObject o, AvaloniaProperty <T> property)
{
return(new AvaloniaPropertyObservable <T>(
o ?? throw new ArgumentNullException(nameof(o)),
property ?? throw new ArgumentNullException(nameof(property))));
}
internal void BindingNotificationReceived(AvaloniaProperty property, BindingNotification notification)
{
UpdateDataValidation(property, notification);
}
public void ClearValue(AvaloniaProperty property)
{
property = property ?? throw new ArgumentNullException(nameof(property));
property.RouteClearValue(this);
}
/// <summary>
/// Binds a <see cref="AvaloniaProperty"/> to an observable.
/// </summary>
/// <param name="property">The property.</param>
/// <param name="source">The observable.</param>
/// <param name="priority">The priority of the binding.</param>
/// <returns>
/// A disposable which can be used to terminate the binding.
/// </returns>
public IDisposable Bind(
AvaloniaProperty property,
IObservable <object> source,
BindingPriority priority = BindingPriority.LocalValue)
{
Contract.Requires <ArgumentNullException>(property != null);
VerifyAccess();
if (property.IsDirect)
{
if (property.IsReadOnly)
{
throw new ArgumentException($"The property {property.Name} is readonly.");
}
Logger.Verbose(
LogArea.Property,
this,
"Bound {Property} to {Binding} with priority LocalValue",
property,
GetDescription(source));
IDisposable subscription = null;
IDisposable validationSubcription = null;
if (_directBindings == null)
{
_directBindings = new List <IDisposable>();
}
subscription = source
.Where(x => !(x is IValidationStatus))
.Select(x => CastOrDefault(x, property.PropertyType))
.Do(_ => { }, () => _directBindings.Remove(subscription))
.Subscribe(x => DirectBindingSet(property, x));
validationSubcription = source
.OfType <IValidationStatus>()
.Subscribe(x => DataValidationChanged(property, x));
_directBindings.Add(subscription);
return(Disposable.Create(() =>
{
validationSubcription.Dispose();
subscription.Dispose();
_directBindings.Remove(subscription);
}));
}
else
{
PriorityValue v;
if (!AvaloniaPropertyRegistry.Instance.IsRegistered(this, property))
{
ThrowNotRegistered(property);
}
if (!_values.TryGetValue(property, out v))
{
v = CreatePriorityValue(property);
_values.Add(property, v);
}
Logger.Verbose(
LogArea.Property,
this,
"Bound {Property} to {Binding} with priority {Priority}",
property,
GetDescription(source),
priority);
return(v.Add(source, (int)priority));
}
}
/// <summary>
/// Called when the validation state on a tracked property is changed.
/// </summary>
/// <param name="property">The property whose validation state changed.</param>
/// <param name="status">The new validation state.</param>
protected virtual void DataValidationChanged(AvaloniaProperty property, IValidationStatus status)
{
}
/// <summary>
/// Clears a <see cref="AvaloniaProperty"/>'s local value.
/// </summary>
/// <param name="property">The property.</param>
public void ClearValue(AvaloniaProperty property)
{
Contract.Requires <ArgumentNullException>(property != null);
SetValue(property, AvaloniaProperty.UnsetValue);
}
/// <summary>
/// Called to update the validation state for properties for which data validation is
/// enabled.
/// </summary>
/// <param name="property">The property.</param>
/// <param name="value">The new binding value for the property.</param>
protected virtual void UpdateDataValidation <T>(
AvaloniaProperty <T> property,
BindingValue <T> value)
{
}
void IValueSink.Completed(AvaloniaProperty property, IPriorityValueEntry entry)
{
}
/// <summary>
/// Forces the specified property to be revalidated.
/// </summary>
/// <param name="property">The property.</param>
public void Revalidate(AvaloniaProperty property)
{
VerifyAccess();
_values?.Revalidate(property);
}
public void Changed(AvaloniaProperty property, int priority, object oldValue, object newValue)
{
_owner.PriorityValueChanged(property, priority, oldValue, newValue);
}
public void BindingNotificationReceived(AvaloniaProperty property, BindingNotification notification)
{
_owner.BindingNotificationReceived(property, notification);
}
/// <summary>
/// Checks whether a <see cref="AvaloniaProperty"/> is registered on a type.
/// </summary>
/// <param name="type">The type.</param>
/// <param name="property">The property.</param>
/// <returns>True if the property is registered, otherwise false.</returns>
public bool IsRegistered(Type type, AvaloniaProperty property)
{
return(FindRegistered(type, property) != null);
}
/// <summary>
/// Called to update the validation state for properties for which data validation is
/// enabled.
/// </summary>
/// <param name="property">The property.</param>
/// <param name="status">The new validation status.</param>
protected virtual void UpdateDataValidation(
AvaloniaProperty property,
BindingNotification status)
{
}
/// <inheritdoc/>
void IPriorityValueOwner.BindingNotificationReceived(AvaloniaProperty property, BindingNotification notification)
{
UpdateDataValidation(property, notification);
}
public object this[AvaloniaProperty property]
{
get { return(GetValue(property)); }
set { SetValue(property, value); }
}
/// <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);
}
public object GetValue(AvaloniaProperty property)
{
property = property ?? throw new ArgumentNullException(nameof(property));
return(property.RouteGetValue(this));
}
/// <summary>
/// Finds <see cref="AvaloniaProperty"/> registered on an object.
/// </summary>
/// <param name="o">The object.</param>
/// <param name="property">The property.</param>
/// <returns>The registered property or null if not found.</returns>
/// <remarks>
/// Calling AddOwner on a AvaloniaProperty creates a new AvaloniaProperty that is a
/// different object but is equal according to <see cref="object.Equals(object)"/>.
/// </remarks>
public AvaloniaProperty FindRegistered(object o, AvaloniaProperty property)
{
return(FindRegistered(o.GetType(), property));
}