Class SignalHandle

src/utils/signal.ts:17–53

 * An error will be logged if you try to disconnect the signal more than once.
 */
export class SignalHandle {
    private constructor(target: CanDisconnect, id: number) {
        this.target = target;
        if (target instanceof Clutter.Actor) {
            target.connect('destroy', () => {
                this.disconnect();
            });
        }
        this.id = id;
    }

    /** Creates a new signal handle by subscribing to the `signal` on `to` */
    static connect<F>(
        to: CanSendSignal<F>,
        signal: string,
        callback: F
    ): SignalHandle {
        return new SignalHandle(to, to.connect(signal, callback));
    }

    private target: CanDisconnect | null;
    private id: number;

    /** Disconnects the signal.
     * The callback function will not be called again after this.
     *
     * An error will be logged if you try to disconnect the signal more than once.
     */
    disconnect() {
        if (this.target == null) {
            log('Signal is already disconnected');
        } else {
            this.target.disconnect(this.id);
            this.target = null;
        }
    }
}

export class SignalObserver {
    signalObservedList: SignalHandle[];