Finding rectangles in the IO Manager

Your callback from the muse handler, you have a position change. Move the cursors, then call the window tree. Five steps down the tree finds the appropriate window, execute the call back.  All of these separate modules are Snippets, API thingies, ganged together.

A 64 bit address field, everyone is in user space. Everyone agrees on a common form for a rectangle and all calls have universal interface, there is generally a commons for the format.  The range o9f window managers is extensions, from games in high speed to high def to strategy. Snippets with universal interface and common sense about distributing functionality.