CAPI supports multiple monitors by providing APIs (such as
screen-internal-geometries
) to query "screen rectangles" representing the area of each monitor. The function
virtual-screen-geometry
returns a rectangle just enclosing all the screen rectangles.
There is a "primary monitor" which displays any system areas. The origin of the coordinate system (as returned by
top-level-interface-geometry
and
screen-internal-geometry
) is the topmost/leftmost visible pixel of the primary monitor. Thus (0,0) may be in a system area such as the Mac OS X menu bar.
Note also that CAPI does not currently support multiple desktops, which are called workspaces in Linux distros, and called Spaces on Mac OS X.
CAPI User Guide (Unix version) - 30 Aug 2011