onAppEvents([callback], [remove])

Registers, gets, or unregisters event handler callbacks for application events on macOS.

Name	Type	Default	Description
`[callback]`	function		A callback function that receives an AppEvent object. Set to `null` to unregister all callbacks for this event. Omit to get an array of callbacks for this event.
`[remove]`	boolean	false	Remove the callback from this event.

If called without parameters, an array of registered callbacks is returned; otherwise this instance of SwingUI class is returned.

Type: SwingUI | Array.<function()>