public void ClearValue <T>(StyledPropertyBase <T> property)
{
property = property ?? throw new ArgumentNullException(nameof(property));
VerifyAccess();
_values?.ClearLocalValue(property);
}
public T GetValue <T>(StyledPropertyBase <T> property)
{
property = property ?? throw new ArgumentNullException(nameof(property));
VerifyAccess();
return(GetValueOrInheritedOrDefault(property));
}
private T GetValueOrInheritedOrDefault <T>(StyledPropertyBase <T> property)
{
var o = this;
var inherits = property.Inherits;
var value = default(T);
while (o != null)
{
var values = o._values;
if (values?.TryGetValue(property, out value) == true)
{
return(value);
}
if (!inherits)
{
break;
}
o = o.InheritanceParent as AvaloniaObject;
}
return(property.GetDefaultValue(GetType()));
}
/// <summary>
/// Sets a <see cref="AvaloniaProperty"/> value.
/// </summary>
/// <typeparam name="T">The type of the property.</typeparam>
/// <param name="property">The property.</param>
/// <param name="value">The value.</param>
/// <param name="priority">The priority of the value.</param>
public void SetValue <T>(
StyledPropertyBase <T> property,
T value,
BindingPriority priority = BindingPriority.LocalValue)
{
property = property ?? throw new ArgumentNullException(nameof(property));
VerifyAccess();
LogPropertySet(property, value, priority);
if (value is UnsetValueType)
{
if (priority == BindingPriority.LocalValue)
{
Values.ClearLocalValue(property);
}
else
{
throw new NotSupportedException(
"Cannot set property to Unset at non-local value priority.");
}
}
else if (!(value is DoNothingType))
{
Values.SetValue(property, value, priority);
}
}
void IValueSink.ValueChanged <T>(
StyledPropertyBase <T> property,
BindingPriority priority,
Optional <T> oldValue,
BindingValue <T> newValue)
{
oldValue = oldValue.HasValue ? oldValue : GetInheritedOrDefault(property);
newValue = newValue.HasValue ? newValue : newValue.WithValue(GetInheritedOrDefault(property));
LogIfError(property, newValue);
if (!EqualityComparer <T> .Default.Equals(oldValue.Value, newValue.Value))
{
RaisePropertyChanged(property, oldValue, newValue, priority);
Logger.TryGet(LogEventLevel.Verbose)?.Log(
LogArea.Property,
this,
"{Property} changed from {$Old} to {$Value} with priority {Priority}",
property,
oldValue,
newValue,
(BindingPriority)priority);
}
}
void IValueSink.Completed <T>(
StyledPropertyBase <T> property,
IPriorityValueEntry entry,
Optional <T> oldValue)
{
((IValueSink)this).ValueChanged(property, BindingPriority.Unset, oldValue, default);
}
private T GetInheritedOrDefault <T>(StyledPropertyBase <T> property)
{
if (property.Inherits && InheritanceParent is AvaloniaObject o)
{
return(o.GetValueOrInheritedOrDefault(property));
}
return(property.GetDefaultValue(GetType()));
}
/// <summary>
/// Binds a <see cref="AvaloniaProperty"/> to an observable.
/// </summary>
/// <typeparam name="T">The type of the property.</typeparam>
/// <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 <T>(
StyledPropertyBase <T> property,
IObservable <BindingValue <T> > source,
BindingPriority priority = BindingPriority.LocalValue)
{
property = property ?? throw new ArgumentNullException(nameof(property));
source = source ?? throw new ArgumentNullException(nameof(source));
VerifyAccess();
return(Values.AddBinding(property, source, priority));
}
public Optional <T> GetBaseValue <T>(StyledPropertyBase <T> property, BindingPriority maxPriority)
{
property = property ?? throw new ArgumentNullException(nameof(property));
VerifyAccess();
if (_values is object &&
_values.TryGetValue(property, maxPriority, out var value))
{
return(value);
}
return(default);
public bool TryGetValue <T>(StyledPropertyBase <T> property, out T value)
{
if (_values.TryGetValue(property, out var slot))
{
var v = (IValue <T>)slot;
if (v.Value.HasValue)
{
value = v.Value.Value;
return(true);
}
}
value = default !;
/// <summary>
/// Binds a <see cref="AvaloniaProperty"/> to an observable.
/// </summary>
/// <typeparam name="T">The type of the property.</typeparam>
/// <param name="target">The object.</param>
/// <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 static IDisposable Bind <T>(
this IAvaloniaObject target,
AvaloniaProperty <T> property,
IObservable <BindingValue <T> > source,
BindingPriority priority = BindingPriority.LocalValue)
{
target = target ?? throw new ArgumentNullException(nameof(target));
property = property ?? throw new ArgumentNullException(nameof(property));
source = source ?? throw new ArgumentNullException(nameof(source));
return(property switch
{
StyledPropertyBase <T> styled => target.Bind(styled, source, priority),
DirectPropertyBase <T> direct => target.Bind(direct, source),
_ => throw new NotSupportedException("Unsupported AvaloniaProperty type."),
});
public bool TryGetValue <T>(
StyledPropertyBase <T> property,
BindingPriority maxPriority,
out T value)
{
if (_values.TryGetValue(property, out var slot))
{
var v = ((IValue <T>)slot).GetValue(maxPriority);
if (v.HasValue)
{
value = v.Value;
return(true);
}
}
value = default !;
/// <summary>
/// Called for each inherited property when the <see cref="InheritanceParent"/> changes.
/// </summary>
/// <typeparam name="T">The type of the property value.</typeparam>
/// <param name="property">The property.</param>
/// <param name="oldParent">The old inheritance parent.</param>
internal void InheritanceParentChanged <T>(
StyledPropertyBase <T> property,
IAvaloniaObject oldParent)
{
var oldValue = oldParent switch
{
AvaloniaObject o => o.GetValueOrInheritedOrDefault(property),
null => property.GetDefaultValue(GetType()),
_ => oldParent.GetValue(property)
};
var newValue = GetInheritedOrDefault(property);
if (!EqualityComparer <T> .Default.Equals(oldValue, newValue))
{
RaisePropertyChanged(property, oldValue, newValue);
}
}
/// <summary>
/// Initializes a new instance of the <see cref="StyledPropertyBase{T}"/> class.
/// </summary>
/// <param name="source">The property to add the owner to.</param>
/// <param name="ownerType">The type of the class that registers the property.</param>
protected StyledPropertyBase(StyledPropertyBase <TValue> source, Type ownerType)
: base(source, ownerType, null)
{
_inherits = source.Inherits;
}
/// <summary>
/// Coerces the specified <see cref="AvaloniaProperty"/>.
/// </summary>
/// <typeparam name="T">The type of the property.</typeparam>
/// <param name="property">The property.</param>
public void CoerceValue <T>(StyledPropertyBase <T> property)
{
_values?.CoerceValue(property);
}
/// <summary>
/// Initializes a new instance of the <see cref="StyledPropertyBase{T}"/> class.
/// </summary>
/// <param name="source">The property to add the owner to.</param>
/// <param name="ownerType">The type of the class that registers the property.</param>
internal StyledProperty(StyledPropertyBase <TValue> source, Type ownerType)
: base(source, ownerType)
{
}
