/// <summary>
/// Gets the value at the highest precedence level under the specified one
/// E.G. If a property has a value both on the Animation, Local and Default
/// precedences, and the given precedence is Animation, then the Local value is returned.
/// </summary>
/// <param name="precedence">The value precedence under which to fetch a value</param>
/// <returns>The value at the highest precedence level under the specified one</returns>
internal (object value, DependencyPropertyValuePrecedences precedence) GetValueUnderPrecedence(DependencyPropertyValuePrecedences precedence)
{
// Start from current precedence and find next highest
for (int i = (int)precedence + 1; i < (int)DependencyPropertyValuePrecedences.DefaultValue; i++)
{
object value = Unwrap(_stack[i]);
if (value != DependencyProperty.UnsetValue)
{
return(value, (DependencyPropertyValuePrecedences)i);
}
}
return(_stack[(int)DependencyPropertyValuePrecedences.DefaultValue], DependencyPropertyValuePrecedences.DefaultValue);
}
internal void ClearInvalidProperties(DependencyObject dependencyObject, Style incomingStyle, DependencyPropertyValuePrecedences precedence)
{
var oldSetters = CreateSetterMap();
var newSetters = incomingStyle?.CreateSetterMap();
foreach (var kvp in oldSetters)
{
if (kvp.Key is DependencyProperty dp)
{
if (newSetters == null || !newSetters.ContainsKey(dp))
{
DependencyObjectExtensions.ClearValue(dependencyObject, dp, precedence);
}
}
}
}
/// <summary>
/// Creates a SetValue precedence scoped override. All calls to SetValue
/// on the specified instance will be set to the specified precedence.
/// </summary>
/// <param name="instance">The instance to override</param>
/// <param name="precedence">The precedence to set</param>
/// <returns>A disposable to dispose to cancel the override.</returns>
internal static IDisposable OverrideLocalPrecedence(this object instance, DependencyPropertyValuePrecedences precedence)
{
return(GetStore(instance).OverrideLocalPrecedence(precedence));
}
internal object GetValue(DependencyPropertyValuePrecedences precedence) => Unwrap(_stack[(int)precedence]);
/// <summary>
/// Gets the value for the specified dependency property on the specific instance at
/// the specified precedence. As opposed to GetValue, this will not fall back to the highest
/// precedence if this precedence is currently unset and will return unset value.
/// </summary>
/// <param name="instance">The instance on which the property is attached</param>
/// <param name="property">The dependency property to get</param>
/// <param name="precedence">The value precedence at which to fetch a value</param>
/// <returns></returns>
internal static object GetPrecedenceSpecificValue(this DependencyObject instance, DependencyProperty property, DependencyPropertyValuePrecedences precedence)
{
return(GetStore(instance).GetValue(property, precedence, true));
}
/// <summary>
/// Get the value for the specified dependency property on the specific instance at
/// the highest precedence level under the specified one.
/// E.G. If a property has a value both on the Animation, Local and Default
/// precedences, and the given precedence is Animation, then the Local value is returned.
/// </summary>
/// <param name="instance">The instance on which the property is attached</param>
/// <param name="property">The dependency property to get</param>
/// <param name="precedence">The value precedence under which to fetch a value</param>
/// <returns></returns>
internal static (object value, DependencyPropertyValuePrecedences precedence) GetValueUnderPrecedence(this DependencyObject instance, DependencyProperty property, DependencyPropertyValuePrecedences precedence)
{
return(GetStore(instance).GetValueUnderPrecedence(property, precedence));
}
public ResourceBinding(SpecializedResourceDictionary.ResourceKey resourceKey, ResourceUpdateReason updateReason, object?parseContext, DependencyPropertyValuePrecedences precedence, BindingPath?setterBindingPath)
{
ResourceKey = resourceKey;
UpdateReason = updateReason;
ParseContext = parseContext;
Precedence = precedence;
SetterBindingPath = setterBindingPath;
}
/// <summary>
/// Clears the value for the specified dependency property on the specified instance.
/// </summary>
/// <param name="instance">The instance on which the property is attached</param>
/// <param name="property">The dependency property to get</param>
/// <param name="precedence">The value precendence to assign</param>
internal static void ClearValue(this DependencyObject instance, DependencyProperty property, DependencyPropertyValuePrecedences precedence)
{
SetValue(instance, property, DependencyProperty.UnsetValue, precedence);
}
public ResourceBinding(object resourceKey, bool isThemeResourceExtension, object parseContext, DependencyPropertyValuePrecedences precedence)
{
ResourceKey = new SpecializedResourceDictionary.ResourceKey(resourceKey);
IsThemeResourceExtension = isThemeResourceExtension;
ParseContext = parseContext;
Precedence = precedence;
}
internal static ValueUnsetterHandler GetValueUnsetter(Type type, string property, DependencyPropertyValuePrecedences precedence)
{
var key = CachedTuple.Create(type, property, precedence);
ValueUnsetterHandler result;
lock (_getValueUnsetter)
{
if (!_getValueUnsetter.TryGetValue(key, out result))
{
_getValueUnsetter.Add(key, result = InternalGetValueUnsetter(type, property, precedence));
}
}
return(result);
}
public ResourceBinding(object resourceKey, bool isThemeResourceExtension, object parseContext, DependencyPropertyValuePrecedences precedence)
{
ResourceKey = resourceKey;
IsThemeResourceExtension = isThemeResourceExtension;
ParseContext = parseContext;
Precedence = precedence;
}
private void OnDataContextChanged(object providedDataContext, object actualDataContext, DependencyPropertyValuePrecedences precedence)
{
var dataContextBinding = _properties.FindDataContextBinding();
if (dataContextBinding != null && precedence == DependencyPropertyValuePrecedences.Inheritance)
{
// Set the DataContext for the bindings using the current DataContext, except for the
// binding to the DataContext itself, which must use the inherited DataContext.
//
// This is to avoid recursion when the datacontext.
//
// The inherited DataContext may also be null in the case of non-inherited data binding
// when using the custom target parameter in SetBinding.
if (dataContextBinding.ParentBinding.RelativeSource == null)
{
dataContextBinding.DataContext = providedDataContext;
}
}
else
{
#if !HAS_EXPENSIVE_TRYFINALLY
// The try/finally incurs a very large performance hit in mono-wasm, and SetValue is in a very hot execution path.
// See https://github.com/mono/mono/issues/13653 for more details.
try
#endif
{
if (_isApplyingDataContextBindings || _bindingsSuspended)
{
// If we reach this point, this means that a propagation loop has been detected, and
// we can skip the current binder.
// This can happen if a DependencyObject-typed DependencyProperty contains a reference
// to one of its ancestors.
return;
}
_isApplyingDataContextBindings = true;
using (TryWriteDataContextChangedEventActivity())
{
_properties.ApplyDataContext(actualDataContext);
ApplyChildrenBindable(actualDataContext, isTemplatedParent: false);
}
}
#if !HAS_EXPENSIVE_TRYFINALLY
finally
#endif
{
_isApplyingDataContextBindings = false;
}
}
}
public Style()
{
Precedence = DependencyPropertyValuePrecedences.ExplicitStyle;
}
public ResourceBinding(SpecializedResourceDictionary.ResourceKey resourceKey, bool isThemeResourceExtension, object?parseContext, DependencyPropertyValuePrecedences precedence, BindingPath?setterBindingPath)
{
ResourceKey = resourceKey;
IsThemeResourceExtension = isThemeResourceExtension;
ParseContext = parseContext;
Precedence = precedence;
SetterBindingPath = setterBindingPath;
}
private void OnDataContextChanged(object providedDataContext, object actualDataContext, DependencyPropertyValuePrecedences precedence)
{
var dataContextBinding = _properties.FindDataContextBinding();
if (dataContextBinding != null && precedence == DependencyPropertyValuePrecedences.Inheritance)
{
// Set the DataContext for the bindings using the current DataContext, except for the
// binding to the DataContext itself, which must use the inherited DataContext.
//
// This is to avoid recursion when the datacontext.
//
// The inherited DataContext may also be null in the case of non-inherited data binding
// when using the custom target parameter in SetBinding.
if (dataContextBinding.ParentBinding.RelativeSource == null)
{
dataContextBinding.DataContext = providedDataContext;
}
}
else
{
try
{
if (_isApplyingDataContextBindings || _bindingsSuspended)
{
// If we reach this point, this means that a propagation loop has been detected, and
// we can skip the current binder.
// This can happen if a DependencyObject-typed DependencyProperty contains a reference
// to one of its ancestors.
return;
}
_isApplyingDataContextBindings = true;
using (TryWriteDataContextChangedEventActivity())
{
_properties.ApplyDataContext(actualDataContext);
ApplyChildrenBindable(actualDataContext, isTemplatedParent: false);
}
}
finally
{
_isApplyingDataContextBindings = false;
}
}
}
