Contract/expand movieclip based on contents within it
I have a movieclip, slider, which holds several different shaped movieclips inside of it. What I would like to do is remove the shapes within slider when a button is pressed and have slider contract/collapse the space where the shape was. Following the same idea, I would like the shapes to be added back in when a different button is pressed and have the area expand. The shapes need to stay in the order they're in whether they are removed or added in.
Is there an easy way to accomplish this without creating multiple movieclips or having a really long timeline on one movieclip? Maybe something similar to a horizontal accordian? Someone suggested tweening using scaleX but that doesn't really accomplish what I'm trying to do - it would also scale the contents of slider.
Here are the files I am working with to give you a better idea of what I currently have working.
