// ===========================================================================
// These methods are invoked when a Property is being
// invalidated via a Style/Template
// ===========================================================================
#region InvalidateMethods
//
// This method
// 1. Is invoked when the StyleProperty is invalidated on a FrameworkElement or
// FrameworkContentElement or a sub-class thereof.
//
internal static void DoStyleInvalidations(
FrameworkElement fe,
FrameworkContentElement fce,
Style oldStyle,
Style newStyle)
{
Debug.Assert(fe != null || fce != null);
if (oldStyle != newStyle)
{
//
// Style is changing
//
DependencyObject container = (fe != null) ? (DependencyObject)fe : (DependencyObject)fce;
// If the style wants to watch for the Loaded and/or Unloaded events, set the
// flag that says we want to receive it. Otherwise, if it was set in the old style, clear it.
StyleHelper.UpdateLoadedFlag( container, oldStyle, newStyle );
// Set up any per-instance state relating to the new Style
// We do this here instead of OnStyleInvalidated because
// this needs to happen for the *first* Style.
StyleHelper.UpdateInstanceData(
StyleHelper.StyleDataField,
fe, fce,
oldStyle, newStyle,
null /* oldFrameworkTemplate */, null /* newFrameworkTemplate */,
(InternalFlags)0);
// If this new style has resource references (either for the container
// or for children in the visual tree), then, mark it so that it will
// not be ignored during resource change invalidations
if ((newStyle != null) && (newStyle.HasResourceReferences))
{
if (fe != null)
{
fe.HasResourceReference = true;
}
else
{
fce.HasResourceReference = true;
}
}
FrugalStructList<ContainerDependent> oldContainerDependents =
oldStyle != null ? oldStyle.ContainerDependents : StyleHelper.EmptyContainerDependents;
FrugalStructList<ContainerDependent> newContainerDependents =
newStyle != null ? newStyle.ContainerDependents : StyleHelper.EmptyContainerDependents;
// Propagate invalidation for Style dependents
FrugalStructList<ContainerDependent> exclusionContainerDependents =
new FrugalStructList<ContainerDependent>();
StyleHelper.InvalidateContainerDependents(container,
ref exclusionContainerDependents,
ref oldContainerDependents,
ref newContainerDependents);
// Propagate invalidation for resource references that may be
// picking stuff from the style's ResourceDictionary
DoStyleResourcesInvalidations(container, fe, fce, oldStyle, newStyle);
// Notify Style has changed
// CALLBACK
if (fe != null)
{
fe.OnStyleChanged(oldStyle, newStyle);
}
else
{
fce.OnStyleChanged(oldStyle, newStyle);
}
}
}
