/// <summary>
/// Given the instance <paramref name="obj"/> and the <paramref name="memberName"/>,
/// this method searches the best matching member on the instance. It first searches
/// a property with name [PropertyName]Property, casts it to
/// <see cref="AbstractProperty"/> and returns a <see cref="DependencyPropertyDataDescriptor"/>
/// for it in the parameter <paramref name="dd"/>. If there is no such property, this method
/// searches a simple property with the given name, returning a property descriptor for it.
/// Then, the method will search for a field with the specified name, returning a
/// <see cref="FieldDataDescriptor"/> for it.
/// If there is no member found with the given name, this method returns false and a
/// <c>null</c> value in <paramref name="dd"/>.
/// </summary>
/// <param name="obj">The object where to search the member with the
/// specified <paramref name="memberName"/>.</param>
/// <param name="memberName">The name of the member to be searched.</param>
/// <param name="dd">Data descriptor which will be returned for the property or member,
/// if it was found, else a <c>null</c> value will be returned.</param>
/// <returns><c>true</c>, if a member with the specified name was found, else <c>false</c>.</returns>
public static bool FindMemberDescriptor(object obj, string memberName, out IDataDescriptor dd)
{
if (obj == null)
{
throw new NullReferenceException("Property target object 'null' is not supported");
}
DependencyPropertyDataDescriptor dpdd;
if (DependencyPropertyDataDescriptor.CreateDependencyPropertyDataDescriptor(
obj, memberName, out dpdd))
{
dd = dpdd;
return(true);
}
SimplePropertyDataDescriptor spdd;
if (SimplePropertyDataDescriptor.CreateSimplePropertyDataDescriptor(
obj, memberName, out spdd))
{
dd = spdd;
return(true);
}
FieldDataDescriptor fdd;
if (FieldDataDescriptor.CreateFieldDataDescriptor(obj, memberName, out fdd))
{
dd = fdd;
return(true);
}
dd = null;
return(false);
}
public static bool CreateDependencyPropertyDataDescriptor(object targetObj,
string propertyName, out DependencyPropertyDataDescriptor result)
{
result = null;
if (targetObj == null)
{
throw new NullReferenceException("Target object 'null' is not supported");
}
AbstractProperty prop;
if (!FindDependencyProperty(targetObj, ref propertyName, out prop))
{
return(false);
}
result = new DependencyPropertyDataDescriptor(targetObj, propertyName, prop);
return(true);
}
/// <summary>
/// Returns the information if the specified <paramref name="other"/> descriptor
/// is targeted at the same property on the same object.
/// </summary>
/// <param name="other">Other descriptor whose target object and property should be compared.</param>
public bool TargetEquals(DependencyPropertyDataDescriptor other)
{
return(_obj.Equals(other._obj) && _propertyName.Equals(other._propertyName));
}
public bool Evaluate(IDataDescriptor source, out IDataDescriptor result)
{
result = null;
Type type;
object obj;
MemberInfo mi;
if (!ExtractWorkingData(source, _memberName + "Property", out type, out obj, out mi))
{
if (!ExtractWorkingData(source, _memberName, out type, out obj, out mi))
{
return(false);
}
}
if (mi is FieldInfo)
{ // Field access
result = new FieldDataDescriptor(obj, (FieldInfo)mi);
return(true);
}
if (mi is PropertyInfo)
{ // Property access
PropertyInfo pi = (PropertyInfo)mi;
// Handle indexed property
object[] convertedIndices = null;
// Check property indexer
bool indicesOnProperty = _indices != null && _indices.Length > 0 &&
ReflectionHelper.ConsumeParameters(_indices, pi.GetIndexParameters(),
false, out convertedIndices);
if (!indicesOnProperty)
{
convertedIndices = null;
}
if (pi.PropertyType == typeof(AbstractProperty))
{ // Property value -> request value and return DependencyPropertyDataDescriptor
object val = pi.GetValue(obj, convertedIndices);
if (val == null)
{
return(false);
}
result = new DependencyPropertyDataDescriptor(obj, _memberName, (AbstractProperty)val);
}
else
{ // Simple property
result = new SimplePropertyDataDescriptor(obj, pi);
if (convertedIndices != null && convertedIndices.Length > 0)
{
((SimplePropertyDataDescriptor)result).Indices = convertedIndices;
}
}
if (_indices != null && _indices.Length > 0 && !indicesOnProperty)
{
// Item or collection index -> handle index expression per IndexerPathSegment
return(new IndexerPathSegment(_indices).Evaluate(result, out result));
}
return(true);
}
if (mi is MethodInfo)
{
// Method invocation is not supported in evaluation
return(false);
}
// Unsupported member type
return(false);
}
/// <summary>
/// Returns the information if the specified <paramref name="other"/> descriptor
/// is targeted at the same property on the same object.
/// </summary>
/// <param name="other">Other descriptor whose target object and property should be compared.</param>
public bool TargetEquals(DependencyPropertyDataDescriptor other)
{
return _obj.Equals(other._obj) && _propertyName.Equals(other._propertyName);
}
public static bool CreateDependencyPropertyDataDescriptor(object targetObj,
string propertyName, out DependencyPropertyDataDescriptor result)
{
result = null;
if (targetObj == null)
throw new NullReferenceException("Target object 'null' is not supported");
AbstractProperty prop;
if (!FindDependencyProperty(targetObj, ref propertyName, out prop))
return false;
result = new DependencyPropertyDataDescriptor(targetObj, propertyName, prop);
return true;
}
/// <summary>
/// Does the lookup for our binding source data. This includes evaluation of our source
/// properties and the lookup for the data context.
/// </summary>
/// <remarks>
/// During the lookup, change handlers will be attached to all relevant properties
/// on the search path to the binding source. If one of the properties changes,
/// this binding will re-evaluate.
/// </remarks>
/// <param name="result">Resulting source descriptor, if it could be resolved.</param>
/// <returns><c>true</c>, if the binding source could be found and evaluated,
/// <c>false</c> if it could not be resolved (yet).</returns>
protected bool GetSourceDataDescriptor(out IDataDescriptor result)
{
ResetChangeHandlerAttachments();
result = null;
try
{
switch (_typeOfSource)
{
case SourceType.DataContext:
return FindDataContext(out result);
case SourceType.SourceProperty:
#if DEBUG_BINDINGS
if (Source == null)
DebugOutput("GetSourceDataDescriptor doesn't have a Source", Source);
#endif
result = new DependencyPropertyDataDescriptor(this, "Source", _sourceProperty);
return true;
case SourceType.RelativeSource:
DependencyObject current = _contextObject;
if (current == null)
return false;
switch (RelativeSource.Mode)
{
case RelativeSourceMode.Self:
result = new ValueDataDescriptor(current);
return true;
case RelativeSourceMode.TemplatedParent:
while (current != null)
{
DependencyObject last = current;
FindParent(last, out current, FindParentMode.HybridPreferVisualTree);
UIElement lastUIElement = last as UIElement;
if (lastUIElement != null)
{
AttachToSourcePathProperty(lastUIElement.TemplateNameScopeProperty);
if (lastUIElement.IsTemplateControlRoot)
{
result = new ValueDataDescriptor(current);
return true;
}
}
}
#if DEBUG_BINDINGS
DebugOutput("GetSourceDataDescriptor didn't find TemplateParent");
#endif
return false;
case RelativeSourceMode.FindAncestor:
if (FindAncestor(current, out current, FindParentMode.HybridPreferVisualTree,
RelativeSource.AncestorLevel, RelativeSource.AncestorType))
{
result = new ValueDataDescriptor(current);
return true;
}
return false;
//case RelativeSourceMode.PreviousData:
// // TODO: implement this
// throw new NotImplementedException(RelativeSourceMode.PreviousData.ToString());
default:
// Should never occur. If so, we have forgotten to handle a RelativeSourceMode
throw new NotImplementedException(
string.Format("RelativeSourceMode '{0}' is not implemented", RelativeSource.Mode));
}
case SourceType.ElementName:
INameScope nameScope;
if (!FindNameScope(out nameScope))
return false;
object obj = nameScope.FindName(ElementName) as UIElement;
if (obj == null)
{
#if DEBUG_BINDINGS
DebugOutput("GetSourceDataDescriptor didn't find object with name '{0}'", ElementName);
#endif
return false;
}
result = new ValueDataDescriptor(obj);
return true;
default:
// Should never occur. If so, we have forgotten to handle a SourceType
throw new NotImplementedException(
string.Format("SourceType '{0}' is not implemented", _typeOfSource));
}
}
finally
{
AttachToSource(result);
IObservable observable = result == null ? null : result.Value as IObservable;
if (observable != null)
AttachToSourceObservable(observable);
}
}
