void MentorChanged(object sender, EventArgs e)
{
try {
var mentor = Target.Mentor;
if (Binding.RelativeSource != null && Binding.RelativeSource.Mode == RelativeSourceMode.TemplatedParent)
{
// If we're using a RelativeSource binding and listening to the mentor, it means we should use the
// Templateparent itself as the source object. For the case of OneTime bindings we need to refresh
// the binding explictly as we won't be listening to the change notification on PropertyPathWalker.
if (mentor == null)
{
PropertyPathWalker.Update(null);
}
else
{
PropertyPathWalker.Update(mentor.TemplateOwner);
}
Refresh();
}
else
{
// If we hit here it means we're databound to the DataContext on our mentor and so we should
// be listening for DataContextChanged events on it.
SetDataContextSource(mentor);
}
} catch (Exception ex) {
try {
Console.WriteLine("Moonlight: Unhandled exception in BindingExpressionBase.MentorChanged: {0}", ex);
} catch {
// Ignore
}
}
}
internal BindingExpressionBase(Binding binding, DependencyObject target, DependencyProperty property)
{
Binding = binding;
Target = target;
Property = property;
bool bindsToView = property == FrameworkElement.DataContextProperty || property.PropertyType == typeof(IEnumerable) || property.PropertyType == typeof(ICollectionView);
PropertyPathWalker = new PropertyPathWalker(Binding.Path.ParsePath, binding.BindsDirectlyToSource, bindsToView, IsBoundToAnyDataContext);
if (Binding.Mode != BindingMode.OneTime)
{
PropertyPathWalker.IsBrokenChanged += PropertyPathValueChanged;
PropertyPathWalker.ValueChanged += PropertyPathValueChanged;
}
}
internal override void OnDetached(DependencyObject element)
{
if (!Attached)
{
return;
}
base.OnDetached(element);
if (TwoWayTextBoxText)
{
((TextBox)Target).LostFocus -= TextBoxLostFocus;
}
var targetFE = element as FrameworkElement;
if (IsMentorDataContextBound)
{
Target.MentorChanged -= MentorChanged;
SetDataContextSource(null);
}
else if (IsParentDataContextBound)
{
targetFE.VisualParentChanged -= ParentChanged;
SetDataContextSource(null);
}
else if (IsSelfDataContextBound)
{
SetDataContextSource(null);
}
targetFE = targetFE ?? Target.Mentor;
if (targetFE != null && CurrentError != null)
{
Validation.RemoveError(targetFE, CurrentError);
CurrentError = null;
}
if (updateDataSourceCallback != null)
{
Target.RemovePropertyChangedHandler(Property, updateDataSourceCallback);
updateDataSourceCallback = null;
}
PropertyPathWalker.Update(null);
}
void DataContextChanged(IntPtr dependency_object, IntPtr propertyChangedEventArgs, ref MoonError error, IntPtr closure)
{
try {
var fe = (FrameworkElement)NativeDependencyObjectHelper.Lookup(dependency_object);
PropertyPathWalker.Update(fe.DataContext);
// OneTime bindings refresh when the datacontext changes. As these bindings do not listen
// for the ValueChanged notifications from the PropertyPathWalker we need to force a refresh
if (Binding.Mode == BindingMode.OneTime)
{
Refresh();
}
} catch (Exception ex) {
try {
error = new MoonError(ex);
} catch {
}
}
}
void SetDataContextSource(FrameworkElement fe)
{
if (DataContextSource != null)
{
DataContextSource.RemovePropertyChangedHandler(FrameworkElement.DataContextProperty, DataContextChanged);
}
DataContextSource = fe;
if (DataContextSource != null)
{
DataContextSource.AddPropertyChangedHandler(FrameworkElement.DataContextProperty, DataContextChanged);
}
// If a FrameworkElement binds to its own datacontext and the VisualParent is null, we end
// up here with a null DataContextSource. In this scenario we do not want to update.
if (DataContextSource != null || IsMentorDataContextBound)
{
PropertyPathWalker.Update(DataContextSource == null ? null : DataContextSource.DataContext);
}
}
void HandleFeTargetLoaded(object sender, RoutedEventArgs e)
{
// This is only called if we have an ElementName based binding
// and could not find the object named by 'ElementName'. This means
// that the element has been added to the live tree and has been loaded
// so the odds are we should be able to find the named element.
FrameworkElement fe = (FrameworkElement)sender;
fe.Loaded -= HandleFeTargetLoaded;
object source = FindSourceByElementName();
if (source != null)
{
PropertyPathWalker.Update(source);
}
Invalidate();
Target.SetValue(Property, this);
}
public override object GroupNameFromItem(object item, int level, CultureInfo culture)
{
object value;
if (string.IsNullOrEmpty(PropertyName))
{
value = item;
}
else
{
PropertyPathWalker = PropertyPathWalker ?? new PropertyPathWalker(PropertyName);
value = PropertyPathWalker.GetValue(item);
}
if (converter != null)
{
value = converter.Convert(value, typeof(object), level, culture);
}
return(value);
}
void InvalidateAfterMentorChanged(object sender, EventArgs e)
{
// This is only called if we bound to a DependencyObject with an ElementName
// based binding and the DO initially had no mentor. We now have a mentor so
// we can do our name lookup.
Target.MentorChanged -= InvalidateAfterMentorChanged;
object source = FindSourceByElementName();
if (source == null)
{
Target.Mentor.Loaded += HandleFeTargetLoaded;
}
else
{
PropertyPathWalker.Update(source);
}
Invalidate();
Target.SetValue(Property, this);
}
internal BindingExpressionBase (Binding binding, DependencyObject target, DependencyProperty property)
{
Binding = binding;
Target = target;
Property = property;
bool bindsToView = property == FrameworkElement.DataContextProperty || property.PropertyType == typeof (IEnumerable) || property.PropertyType == typeof (ICollectionView);
PropertyPathWalker = new PropertyPathWalker (Binding.Path.ParsePath, binding.BindsDirectlyToSource, bindsToView, IsBoundToAnyDataContext);
if (Binding.Mode != BindingMode.OneTime) {
PropertyPathWalker.IsBrokenChanged += PropertyPathValueChanged;
PropertyPathWalker.ValueChanged += PropertyPathValueChanged;
}
}
internal BindingExpressionBase (Binding binding, DependencyObject target, DependencyProperty property)
{
Binding = binding;
Target = target;
Property = property;
mentorDataContextChangedCallback = OnNativeMentorDataContextChangedSafe;
bool bindsToView = property == FrameworkElement.DataContextProperty || property.PropertyType == typeof (IEnumerable) || property.PropertyType == typeof (ICollectionView);
PropertyPathWalker = new PropertyPathWalker (Binding.Path.Path, binding.BindsDirectlyToSource, bindsToView);
if (Binding.Mode != BindingMode.OneTime)
PropertyPathWalker.ValueChanged += PropertyPathValueChanged;
}
// This is the object we're databound to
void CalculateDataSource()
{
object source = null;
// There are four possible ways to get the source:
// Binding.Source, Binding.ElementName, Binding.RelativeSource and finally the fallback to DataContext.
// Only one of the first three will be non-null
if (Binding.Source != null)
{
PropertyPathWalker.Update(Binding.Source);
}
else if (Binding.ElementName != null)
{
// If we 'Target' in a custom DP it's possible
// 'Target' won't be able to find the ElementName.
// In this case we just use the Mentor and hope.
source = FindSourceByElementName();
// When doing ElementName bindings we need to know when we've been
// added to the live tree in order to invalidate the binding and do
// the name lookup again. If we can't find a mentor and Target isn't
// a FrameworkElement, we need to wait for the mentor to be attached
// and then do the lookup when it's loaded.
var feTarget = Target as FrameworkElement ?? Target.Mentor;
if (feTarget == null)
{
Target.MentorChanged += InvalidateAfterMentorChanged;
}
else
{
feTarget.Loaded += HandleFeTargetLoaded;
}
PropertyPathWalker.Update(source);
}
else if (Binding.RelativeSource != null && Binding.RelativeSource.Mode == RelativeSourceMode.Self)
{
PropertyPathWalker.Update(Target);
}
else
{
// If we've bound to a FrameworkElements own DataContext property or the ContentProperty, we need
// to read the datacontext of the parent element.
var fe = Target as FrameworkElement;
if (fe != null && (Property == FrameworkElement.DataContextProperty || Property == ContentPresenter.ContentProperty))
{
fe.VisualParentChanged += ParentChanged;
fe = (FrameworkElement)fe.VisualParent;
SetDataContextSource(fe);
}
else
{
if (fe == null)
{
Target.MentorChanged += MentorChanged;
fe = Target.Mentor;
}
if (fe != null && Binding.RelativeSource != null && Binding.RelativeSource.Mode == RelativeSourceMode.TemplatedParent)
{
PropertyPathWalker.Update(fe.TemplateOwner);
}
else
{
SetDataContextSource(fe);
}
}
}
}
