Editor.setExitFunction

Set the Function that Xopus should call when the exit button is clicked.

The specified function can return false to abort the exit process.

Xopus will not exit by itself. You have to specify an exit URL to exit.

Potential use case for setExitFunction without setExitURL() would be if you want a close button that only hides Xopus. In that case your method should do the hiding and return false.