Q:

WPF if sizechanged event does not bubble, does it tunnel?

I noted that according to:
http://msdn.microsoft.com/en-us/library/system.windows.frameworkelement.sizechanged%28v=vs.95%29.aspx
the sizechanged event does not bubble upwards to parent elements. Does it tunnel downward then? I'm just curious how sizechanged works exactly. After a size on an element changes, does the event propagate in some direction until it is handled? if it doesn't propagate then how is it a routed event.

A:

There is actually 3rd routing strategy. Direct events which neither bubble nor tunnel and are raised only by one control and FrameworkElement.SizeChanged is exactly one of these events.

