how to animate a subclassed widget

[marcel]

With Qt 4.3.x you can use the standard widget geometry functions: QWidget::move(), QWidget::resize().
Keep in mind that the parent widget must not have a layout manager in order for you to manually mode the widget.
Also, you will only be able to translate and resize the widget. No skew or rotation.

In 4.4.x you will be able to add widgets in a QGraphicsScene and apply all transformations you usually apply to QGraphicsItems.
See http://labs.trolltech.com/blogs/2007/12/19/q/ and http://trolltech.com/products/qt/whatsnew/qt44-preview