[Usability] Window contents changing

[Maciej Stachowiak <mjs noisehavoc org>]

In Mac OS X, when the controls in a window change, for example because
you turn off the toolbar, you go to the next screen of the login
dialog, you change which pane you're in a dialog, the window resizes
with smooth animation. The content area of the window is kept the same
size in the case of turning off toolbars or the like on a document
window. This looks really slick and feels right.

Also, when you hide elements like sidebars and such, the hiding is
animated so you see where it went and have a better idea of how to get
it back.

Is there any way we can start deploying the same kinds of ideas in
GNOME? We may need support from the Gtk resize mechanisms perhaps.

 - Maciej