show in window<%>

Shows or hides a window.

The visibility of a window can be changed by the user clicking the window's close box, for example, and such changes do not go through this method; use on-superwindow-show or on-close to monitor visibility changes.

• (send a-window show show?) -> void
     show? : boolean

  If show? is #f, the window is hidden. Otherwise, the window is shown.