Function throttle

src/utils/index.ts:49–93

(
    this: C,
    func: (...args: T) => R,
    wait: number,
    options?: Partial<TrottleParams>
)

// but if you'd like to disable the execution on the leading edge, pass
// `{leading: false}`. To disable execution on the trailing edge, ditto.
export function throttle<T extends any[], R, C>(
    this: C,
    func: (...args: T) => R,
    wait: number,
    options?: Partial<TrottleParams>
): (...args: T) => R {
    let call: { context: C; args: T } | null;
    let result: R;
    let timeout: number | null = null;
    let previous = 0;
    const definedOptions: TrottleParams = Object.assign(
        {
            trailing: true,
            leading: true,
        },
        options
    );

    const later = function () {
        previous = definedOptions.leading === false ? 0 : Date.now();
        timeout = null;
        assert(call !== null, 'unreachable');
        result = func.apply(call.context, call.args);
        if (!timeout) call = null;
        return false;
    };
    return function (this: C, ...params: T) {
        const now = Date.now();
        if (!previous && definedOptions.leading === false) previous = now;
        const remaining = wait - (now - previous);
        call = { context: this, args: params };
        if (remaining <= 0 || remaining > wait) {
            if (timeout !== null) {
                Async.clearTimeoutId(timeout);
                timeout = null;
            }
            previous = now;
            result = func.apply(call.context, call.args);
            if (!timeout) call = null;
        } else if (!timeout && definedOptions.trailing !== false) {
            timeout = Async.addTimeout(GLib.PRIORITY_DEFAULT, remaining, later);
        }
        return result;
    };
}

export const isParentOfActor = (
    parent: Clutter.Actor | null,