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ok?

cursor% : class?

  superclass: object%

A cursor is a small icon that indicates the location of the mouse pointer. The bitmap image typically indicates the current mode or meaning of a mouse click at its current location.

A cursor is assigned to each window (or the window may use its parent’s cursor; see set-cursor for more information), and the pointer image is changed to match the window’s cursor when the pointer is moved over the window. Each cursor object may be assigned to many windows.

(make-object cursor% image    
  mask    
  [hot-spot-x    
  hot-spot-y])  (is-a?/c cursor%)
  image : (is-a?/c bitmap%)
  mask : (is-a?/c bitmap%)
  hot-spot-x : (integer-in 0 15) = 0
  hot-spot-y : (integer-in 0 15) = 0
(make-object cursor% id)  (is-a?/c cursor%)
  id : 
(one-of/c 'arrow 'bullseye 'cross 'hand 'ibeam 'watch 'blank
          'size-n/s 'size-e/w 'size-ne/sw 'size-nw/se)
The first case creates a cursor using an image bitmap and a mask bitmap. Both bitmaps must have depth 1 and size 16 by 16 pixels. The hot-spot-x and hot-spot-y arguments determine the focus point of the cursor within the cursor image, relative to its top-left corner.

The second case creates a cursor using a stock cursor, specified as one of the following:

If the cursor is created successfully, ok? returns #t, otherwise the cursor object cannot be assigned to a window.

(send a-cursor ok?)  boolean?
Returns #t if the cursor is can be assigned to a window, #f otherwise.