I want to build a foot-activated bottom drawer to hide a bathroom scale.

This is how it should work, I push in with a foot, the drawer unlatches and springs open the drawer exposing the built-in scale for use. When done, I push in the drawer back into place with my foot.

What is this push/lock, push/unlock mechanism called? I know I've seen this somewhere but can't recall. :(

If you are wondering how is the drawer going to hold a person's weight. The drawer will have no bottom and will have a mechanism to place the scale on the tiled floor when fully opened. As it closes, it picks up the scale onto brackets, but I will build this. The part I am not clear about is the drawer locking/unlocking mechanism.