Input event processing for translucent windows...

One of the remaining bits of design we have to go through
is the semantics of input event propagation of translucent
windows.

So I want to kick off a discussion of the issues to see
what results.

Here are (some of) the possibilities:
   1) make them like regular input/output windows.
      Problem: events go to the new window, even in large areas
      where you don't see them.
   2) make them like output only windows.
      Problem: how do you get input when you want them.
   3) make them do something fancier.  e.g.

      If the pixel where the input event hits is fully transparent,
      deliver to the lower window; if even slightly translucent,
      deliver to the translucent window on top.

      An additional or alternate possibility would be to have some
      sort of passive grab like mechanism, so that if the client
      using translucent window on top wants, it would get
      the event first, but be able to replay it to windows
      underneath if it then wants.

      Additionally, during the replay, one might be able to
      translate/scale the event before processing, to make 
      it possible for the event to go to some other window scaled
      and translated in some fashion.

In any case, this is fodder for thought and discussion...
                            - Jim

-- 
Jim Gettys <[email protected]>
HP Labs, Cambridge Research Laboratory