Controlling in which direction window resizes?

[Agathorn]

I am, through a script, resizing my parent window from a larger size to a smaller one and back to the larger one based on a button click. The basic window is designed to expand from larger window DOWN to a smaller window. However when I change the window size, the window resizes upwards, IE the window upper left never changes.

Is there any way to get the resize to work off say the bottom right instead of the upper left? I'm guessing there might be some pack setting that does this but all the pack stuff makes my head spin

Note i'm talking about resize taking place via script (setting the window's size value) NOT via user resizing.