include "draw.m";
draw:= load Draw Draw->PATH;
Screen: adt
{
 id:        int;
 image:     ref Image;
 fill:      ref Image;
 allocate: fn(image, fill: ref Image, public: int):  
                      ref Screen;
 newwindow:fn(screen: self ref Screen, r: Rect, color:int):
                       ref Image;
 top:      fn(screen: self ref Screen, wins: 
                       array of ref Image);
};

allocate (image, fill, public)

Using a non-zero public argument allocates a public screen, while a zero public argument requests a private screen. Public screens may be attached by any process on any machine with access to the Display upon which the screen is allocated, enabling remote processes to create windows on the screen. Knowing only the id field of the original Screen, the remote process can call the Display.publicscreen function to acquire a handle to the screen. The image and fill fields of a Screen obtained this way are nil, but they are not needed for ordinary window management.

screen.newwindow (r)

screen.top (wins)