[Vala] returning async func from a callback

[MohanR <mohan43u gmail com>]

Hi,

I'm not able to find a way to finish a async function from a signal's
lambda callback, something like this,

public async bool init(string[] args) {
        Gtk.init_check(ref args);
        /* do some gtk and webkit setup stuff */
        window.delete_event.connect((event) => {
                if(this.access_token == null) {
                        /* user closed the window
                        * without providing authorization.
                        * so, trying to return the "init"
                        * instead, below return applied
                        * to the "delete_event" callback,
                        * not to the async "init" func.
                        */
                        return false; //failed
                }
        });
        webview.load_changed.connect((event)=> {
                if(event == WebKit.LoadEvent.REDIRECTED) {
                        /*get "code" and do
                        * some other stuff
                        */
                }
        })
}

I'm new to vala, so experts help needed. In IRC, I got suggestion to use
"Cancellable" and do "Cancellable.cancel()" to interrupt the async flow,
but I'm trying to find a better way because people don't care about
providing a cancellable object most of the time.

Thanks,
Mohan R

Thanks,
Mohan R