throttle.js

var wrapperFactory = function (wrapperContext) {
    var resetCancelToken = function () {
        wrapperContext.cancelToken = false;
    };
    var wrapper = function (cbThis, cb) {
        var args = [];
        for (var _i = 2; _i < arguments.length; _i++) {
            args[_i - 2] = arguments[_i];
        }
        wrapperContext.callbackThis = cbThis;
        wrapperContext.args = args;
        if (wrapperContext.cancelToken) {
            return;
        }
        if ('requestAnimationFrame' in window) {
            wrapperContext.cancelToken = window.requestAnimationFrame(function () {
                cb.apply(wrapperContext.callbackThis, wrapperContext.args);
                resetCancelToken();
            });
        }
        else {
            cb.apply(wrapperContext.callbackThis, wrapperContext.args);
            wrapperContext.cancelToken = window.setTimeout(resetCancelToken, 1000 / 60); // 60 fps
        }
    };
    wrapper.cancel = function () {
        if ('requestAnimationFrame' in window) {
            window.cancelAnimationFrame(wrapperContext.cancelToken);
        }
        window.clearTimeout(wrapperContext.cancelToken);
        resetCancelToken();
    };
    return wrapper;
};
var throttleFactory = function (callback, thisArg) {
    var argArray = [];
    for (var _i = 2; _i < arguments.length; _i++) {
        argArray[_i - 2] = arguments[_i];
    }
    var wrapper = wrapperFactory({});
    var argCount = arguments.length;
    var throttledCallback = function () {
        var args = [];
        for (var _i = 0; _i < arguments.length; _i++) {
            args[_i] = arguments[_i];
        }
        wrapper.apply(void 0, [argCount > 1 ? thisArg : this, callback].concat(argArray, args));
    };
    throttledCallback.cancel = function () { return wrapper.cancel(); };
    return throttledCallback;
};
/**
 * Returns a throttled function which runs once per rendered frame using
 * requestAnimationFrame. If window.requestAnimationFrame does not exist,
 * the behavior will be approximated using setTimeout.
 *
 * @param callback the function to be throttled
 */
window.throttle = function (callback) {
    var throttledCallback = throttleFactory(callback);
    // Override `bind()` to create a new throttled callback, otherwise both
    // the unbound and bound callbacks will have the same scope.
    throttledCallback.bind = throttleFactory.bind(null, callback);
    return throttledCallback;
};