This method does two things: it fills the point fields with the current coordinates of the mouse cursor and returns the number of the screen device where the pointer is located.

  This method does two things: it fills the point fields with
the current coordinates of the mouse cursor and returns the
number of the screen device where the pointer is located.
The number of the screen device is only returned for independent
devices (which are not parts of a virtual screen device).
For virtual screen devices, 0 is returned.
Mouse coordinates are also calculated depending on whether
or not the screen device is virtual. For virtual screen
devices, pointer coordinates are calculated in the virtual
coordinate system. Otherwise, coordinates are calculated in
the coordinate system of the screen device where the pointer
is located.
See java.awt.GraphicsConfiguration documentation for more
details about virtual screen devices.

  Returns whether or not the window is located under the mouse pointer.

  Returns whether or not the window is located under the mouse
pointer. The window is considered to be under the mouse pointer
if it is showing on the screen, and the mouse pointer is above
the part of the window that is not obscured by any other windows.