Well, it's really hard to tell since all those objects inherit from
UIComponent and it has almost every method overridden and to tell you the
truth I just don't know what happens when these handlers are added or
removed. I think in every particular case only the profiler will tell what
is really happening.
That is, the display objects may not be disposed after they are removed from
stage and may be stored for the later use. Think of TabNavigarot for
example, the components on each tab will be removed and then re-added to
stage once every time you switch the tab and so on. What I mean it's not
like in .NET for example, where once you have disposed a component you have
nothing to do with it but just throw it away. Some basic Flash object have a
way to explicitly free their resources, like BitmapData, TextLine or XML (in
AIR), but you cannot explicitly dispose the resource used by display objects
and Flex framework doesn't do anything in that regard.
