x-show-tip

x-show-tip is a built-in function in `C source code'.

(x-show-tip STRING &optional FRAME PARMS TIMEOUT DX DY)

Show STRING in a "tooltip" window on frame FRAME.
A tooltip window is a small X window displaying a string.

This is an internal function; Lisp code should call `tooltip-show'.

FRAME nil or omitted means use the selected frame.

PARMS is an optional list of frame parameters which can be used to
change the tooltip's appearance.

Automatically hide the tooltip after TIMEOUT seconds. TIMEOUT nil
means use the default timeout of 5 seconds.

If the list of frame parameters PARMS contains a `left' parameters,
the tooltip is displayed at that x-position. Otherwise it is
displayed at the mouse position, with offset DX added (default is 5 if
DX isn't specified). Likewise for the y-position; if a `top' frame
parameter is specified, it determines the y-position of the tooltip
window, otherwise it is displayed at the mouse position, with offset
DY added (default is -10).

A tooltip's maximum size is specified by `x-max-tooltip-size'.
Text larger than the specified size is clipped.