Rust Programming By Example

Preventing the default behavior of an event

The Inhibit type is only a wrapper over the bool type. It is used to indicate whether we should  stop propagating the event to the default handler or not. To see what this means, let's add an event handler for the window:

window.connect_delete_event(|_, _| {
    Inhibit(true)
});

If you run it, you'll note that we cannot close the window anymore. That's because we returned Inhibit(true) to indicate that we want to prevent the default behavior of the delete_event signal, which is to close the window.

Now let's try a slight variant of the previous code:

window.connect_delete_event(|_, _| {
    Inhibit(false)
});

In this case, we do not prevent the default handler from being run, so the window will be closed. ...