svelte-motion/src/utils/subscription-manager.js

Svelte animation library based on the React library framer-motion.

/** 
based on framer-motion@4.0.3,
Copyright (c) 2018 Framer B.V.
*/
import { addUniqueItem, removeItem } from './array.js';

var SubscriptionManager = /** @class */ (function () {
    function SubscriptionManager() {
        this.subscriptions = [];
    }
    SubscriptionManager.prototype.add = function (handler) {
        var _this = this;
        addUniqueItem(this.subscriptions, handler);
        return function () { return removeItem(_this.subscriptions, handler); };
    };
    SubscriptionManager.prototype.notify = function (a, b, c) {
        var numSubscriptions = this.subscriptions.length;
        if (!numSubscriptions)
            return;
        if (numSubscriptions === 1) {
            /**
             * If there's only a single handler we can just call it without invoking a loop.
             */
            this.subscriptions[0](a, b, c);
        }
        else {
            for (var i = 0; i < numSubscriptions; i++) {
                /**
                 * Check whether the handler exists before firing as it's possible
                 * the subscriptions were modified during this loop running.
                 */
                var handler = this.subscriptions[i];
                handler && handler(a, b, c);
            }
        }
    };
    SubscriptionManager.prototype.getSize = function () {
        return this.subscriptions.length;
    };
    SubscriptionManager.prototype.clear = function () {
        this.subscriptions.length = 0;
    };
    return SubscriptionManager;
}());

export { SubscriptionManager };