The window object exposes attributes to find the position (and size) of the window. However, there are no corresponding event, so anyone interested in tracking these must do so by actively polling, which is wasteful and/or laggy, depending on how frequently you poll.

A use case for doing this is when a parent page pops up an child window, and wants to keep it positioned to a particular spot relative to the parent window. That's currently doable, but it takes active polling. Being able to switch to an event would be good.

We already do have the resize event on the Window object, but that only solves half the problem, as there's no equivalent for the position.

So, can we get

window.addEventListener('move', callback);

to go along with

window.addEventListener('resize', callback);

?

cc: @emilio @mrego