/// <summary>
/// Returns a data descriptor for the access to a collection-like instance
/// <paramref name="maybeCollection"/> with an <paramref name="index"/>.
/// </summary>
/// <param name="maybeCollection">Instance which may be collection-like, like an
/// <see cref="IList{T}"/>, <see cref="ICollection{T}"/> or <see cref="IEnumerable{T}"/>.
/// The returned data descriptor will allow to read the value, and for an
/// <see cref="IList{T}"/> it will also be writeable.</param>
/// <param name="index">Index to access the collection-like instance.</param>
/// <param name="result">Returns the data descriptor for the access to the
/// <paramref name="index"/>th entry in <paramref name="maybeCollection"/>.</param>
/// <returns><c>true</c>, if <paramref name="maybeCollection"/> is a collection-like
/// instance and could be accessed by the specified <paramref name="index"/>, else
/// <c>false</c>.</returns>
public static bool GetEnumerationEntryByIndex(object maybeCollection, int index,
out IDataDescriptor result)
{
if (maybeCollection is IList)
{
result = new IndexerDataDescriptor(maybeCollection, new object[] { index });
return(true);
}
if (maybeCollection is IEnumerable)
{
int i = 0;
foreach (object o in (IEnumerable)maybeCollection)
{
if (i++ == index)
{
result = new ValueDataDescriptor(o);
return(true);
}
}
throw new XamlBindingException("Index '{0}' is out of range (# elements={1})", index, i);
}
result = null;
return(false);
}
/// <summary>
/// Returns the information if the specified <paramref name="other"/> descriptor
/// references the same <see cref="Value"/>.
/// </summary>
/// <param name="other">Other descriptor whose <see cref="Value"/> should be compared.</param>
public bool ValueEquals(ValueDataDescriptor other)
{
return(_value == null ? (other == null) : _value.Equals(other._value));
}
/// <summary>
/// Returns a data descriptor for the access to a collection-like instance
/// <paramref name="maybeCollection"/> with an <paramref name="index"/>.
/// </summary>
/// <param name="maybeCollection">Instance which may be collection-like, like an
/// <see cref="IList{T}"/>, <see cref="ICollection{T}"/> or <see cref="IEnumerable{T}"/>.
/// The returned data descriptor will allow to read the value, and for an
/// <see cref="IList{T}"/> it will also be writeable.</param>
/// <param name="index">Index to access the collection-like instance.</param>
/// <param name="result">Returns the data descriptor for the access to the
/// <paramref name="index"/>th entry in <paramref name="maybeCollection"/>.</param>
/// <returns><c>true</c>, if <paramref name="maybeCollection"/> is a collection-like
/// instance and could be accessed by the specified <paramref name="index"/>, else
/// <c>false</c>.</returns>
public static bool GetEnumerationEntryByIndex(object maybeCollection, int index,
out IDataDescriptor result)
{
if (maybeCollection is IList)
{
result = new IndexerDataDescriptor(maybeCollection, new object[] { index });
return true;
}
if (maybeCollection is IEnumerable)
{
int i = 0;
foreach (object o in (IEnumerable)maybeCollection)
{
if (i++ == index)
{
result = new ValueDataDescriptor(o);
return true;
}
}
throw new XamlBindingException("Index '{0}' is out of range (# elements={1})", index, i);
}
result = null;
return false;
}
/// <summary>
/// Returns the information if the specified <paramref name="other"/> descriptor
/// references the same <see cref="Value"/>.
/// </summary>
/// <param name="other">Other descriptor whose <see cref="Value"/> should be compared.</param>
public bool ValueEquals(ValueDataDescriptor other)
{
return _value == null ? (other == null) : _value.Equals(other._value);
}
/// <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);
}
}
protected IDataDescriptor GetDataDescriptor(UIElement element)
{
string targetName = Storyboard.GetTargetName(this);
object targetObject = null;
if (targetName == null)
targetObject = element;
else
{
INameScope ns = element.FindNameScope();
if (ns != null)
targetObject = ns.FindName(targetName);
if (targetObject == null)
targetObject = element.FindElement(new NameMatcher(targetName));
if (targetObject == null)
return null;
}
try
{
IDataDescriptor result = new ValueDataDescriptor(targetObject);
if (_propertyExpression != null && _propertyExpression.Evaluate(result, out result))
return result;
}
catch (XamlBindingException e)
{
ServiceRegistration.Get<ILogger>().Warn("PropertyAnimationTimeline: Error evaluating expression '{0}' on target object '{1}'", e, _propertyExpression, targetObject);
}
return null;
}
