private object CoerceFocusedElement(object newFocus)
{
UIElement uiElement = newFocus as UIElement;
if (uiElement != null)
{
if (this.ShouldDenyFocusChange)
{
this.EndDenyNextFocusChange();
return(DependencyProperty.UnsetValue);
}
if (newFocus != null && !FocusScopeManager.GetAllowedFocus((DependencyObject)uiElement))
{
return(DependencyProperty.UnsetValue);
}
}
return(newFocus);
}
internal static void HandlePreviewGotKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
DependencyObject element = e.NewFocus as DependencyObject;
Visual visual = element as Visual;
if (FocusScopeManager.Instance.ShouldDenyFocusChange)
{
FocusScopeManager.Instance.EndDenyNextFocusChange();
if (!(visual is ExpressionFloatingWindow))
{
e.Handled = true;
return;
}
}
if (element == null || FocusScopeManager.GetAllowedFocus(element))
{
return;
}
FocusScopeManager.Instance.ReturnFocus();
e.Handled = true;
}