How to get "Control no longer visible" notification in Silverlight when any parent is hidden?

Question

I need to receive some kind of notification when control is no longer visible in view. That is if I have control deep in tree (like Border -> Grid -> StackPanel -> TextBox) I need notification on TextBox when Border gets hidden. I DO NOT have access to Border itself, imagine like wrapping control of everything gets collapsed, I still need notificaiton on TextBox that is deep in child controls.

Answer 1

UIElements don't notify their children about Visibility changes.

What are you doing that the TextBox needs to respond to Border visibility? Maybe we can help with a solution that doesn't require knowledge of the parents.

Answer 2

I didn't manage to find any event or property that wouold indicate if Control is visible/not visible when parent is invisible, therefore I had to hook to LayoutUpdated event and check VisibilityProperty of all visual ancestors.

here's snippet if interested:

    private bool IsControlVisible(FrameworkElement element)
    {
        var ancestors = element.GetVisualAncestorsAndSelf().ToList();

        foreach(var a in ancestors)
        {
            Visibility visibility = (Visibility)a.GetValue(FrameworkElement.VisibilityProperty);

            if (visibility == Visibility.Collapsed)
                return false;
        }

        return true;
    }