How to intercept iconifyStack (OS X)

[Sarah Reichelt]

Hi All,

I want to program a custom effect when the iconify button is clicked,
like iTunes where you can have it going to a mini window instead of
down into the Dock. I've programmed it all and it works fine, showing
the mini window and hiding the usual window. The problem is that I
can't stop the original window moving down into the Dock first, THEN
my script happens. It hides the original window which removes it from
the Dock.

I don't really care except visually - I don't want it to look as if
the window is going to the Dock, then disappearing.
I've tried lock screen & lock messages, but nothing stops this.

Does anyone have any ideas (apart from crafting my own title bar and
scripting the red, orange & green blobs myself).

Cheers,
Sarah