set-icon

Sets the large or small icon bitmap for this frame. Future changes to the bitmap do not affect the frame's icon.

The icon is used in a platform-specific way:

• Windows -- the small icon is used for the frame's icon (in the top-left) and in the task bar, and the large icon is used for the Atl-Tab task switcher.
• MacOS -- both icons are ignored.
• X -- many window managers use the small icon in the same way as Windows, and others use the small icon when iconifying the frame; the large icon is ignored.

The bitmap for either icon can be any size, but most platforms scale the small bitmap to 16 by 16 pixels and the large bitmap to 32 by 32 pixels.

If a mask bitmap is not provided, then the entire (rectangular) bitmap is used as an icon.

If a mask bitmap is provided, the mask must be monochrome. In the mask bitmap, use black pixels to indicate the icon's region and use white pixels outside the icon's region. In the icon bitmap, use black pixels for the region outside the icon.

• (send a-frame set-icon icon mask which) -> void
      icon : bitmap% object
      mask = #f : bitmap% object
      which = 'both : symbol in '(small large both)