on-focus

Called when a window receives or loses the keyboard focus. If the argument is #t, the keyboard focus was received, otherwise it was lost.

Note that under X, keyboard focus can move to the menu bar when the user is selecting a menu item.

• (send a-canvas:info-mixin on-focus) -> void

  Enables or disables the caret in the display's editor, if there is one.

  sets the canvas that the frame displays info about.