Change shape of window / animate window

Hi,
I have a window in my program and a command button in that window. I need to create a window when I click on that button. I do that, My probs is that... I need to animate the window, when it appear on the screen, any animation, like, display the new window from the bottom of main window or appear the new window in any other style.
I need to change the shape of window.
How can i do this. Please help me...........

Well you can always use a QTimeLine and call resize(w, h) on the window. Might not be pretty though.

for setting the shape use QWidget::setMask();
you could fade in the widget . Use QWidget::setOpacity() for this.

Not that I encourage using private parts of Qt, but notice this wiki article: Fade and scroll effects.