window-pixel-edges
window-pixel-edges is a built-in function in `C source code
'.
(window-pixel-edges &optional WINDOW)
Return a list of the edge pixel coordinates of WINDOW.
WINDOW must be a valid window and defaults to the selected one.
The returned list has the form (LEFT TOP RIGHT BOTTOM), all relative to
0, 0 at the top left corner of the frame.
RIGHT is one more than the rightmost x position occupied by WINDOW.
BOTTOM is one more than the bottommost y position occupied by WINDOW.
The pixel edges include the space used by WINDOW's scroll bar, display
margins, fringes, header line, and/or mode line. For the pixel edges
of just the text area, use `window-inside-pixel-edges'.