//------------------------------------------------------
//
// Privte Methods
//
//------------------------------------------------------
#region Private Methods
// Private helper that adds a new UIElementPropertyUndoUnit to the undo stack.
private static void AddPrivate(ITextContainer textContainer, UIElement uiElement, DependencyProperty property, object newValue)
{
UndoManager undoManager = TextTreeUndo.GetOrClearUndoManager(textContainer);
if (undoManager == null)
{
return;
}
object currentValue = uiElement.ReadLocalValue(property);
if (currentValue is Expression)
{
// Can't undo when old value is an expression, so clear the stack.
if (undoManager.IsEnabled)
{
undoManager.Clear();
}
return;
}
if (currentValue.Equals(newValue))
{
// No property change.
return;
}
undoManager.Add(new UIElementPropertyUndoUnit(uiElement, property, currentValue));
}
