Does this thing exist?  If so, where can I buy one?

In my house, I have a door that opens into a room up to 180 degrees. Frequently, I like to leave the door part way open, with the ability to open it further, close it, or just let it be.  What I want is roughly similar to a detent on a car door.

The reason I need this is because the door doesn't always stay in position when open. Sometimes it becomes unbalanced on a seasonal basis. Other times the breeze from an open window will move it.

One solution is a hypothetical device which can be placed on the floor upon which a door can be swung over and will "catch" in a slot, and then easily moved off the device again with a simple push on the door in either direction.

I don't want to have to reach down and touch the device all the time.  I want to "set it and forget it," unless I want the "catch point" to be in a different spot.

I drew a picture of what I think the device would look like. Very light, very portable. Kind of like a rubber door stop but not really.

Does such a thing exist? If it can be bought, I'd like a link to the item, or its name, or some way to find it.

I'm no inventor. I just want to buy one.

Since Yahoo won't allow me to include the drawing, you can see it here:

https://youtu.be/0aWhL917ET4

Thank You!