Returns #t to indicate that an exit operation is taking place. Does not indicate that the app will actually exit, since the user may cancel the exit.
exiting? : boolean?
Sets a flag that affects the result of exit:exiting?.
Adds a callback to be called when exiting. This callback must not fail. If a callback should stop an exit from happening, use exit:insert-can?-callback.
Use this function to add a callback that determines if an attempted exit can proceed. This callback should not clean up any state, since another callback may veto the exit. Use exit:insert-on-callback for callbacks that clean up state.
Calls the “can-callbacks” and returns their results. See exit:insert-can?-callback for more information.
Calls the “on-callbacks”. See exit:insert-on-callback for more information.
exit:exit performs four actions:
sets the result of the exit:exiting? function to #t.
invokes the exit-callbacks, with exit:can-exit? if none of the “can?” callbacks return #f,
invokes exit:on-exit and then
Opens a dialog that queries the user about exiting. Returns the user’s decision.