ADHD module

ADHDHelpers.js

const ADHDHelpers = (function () {

    let module = {

        scrollTop: 0,

        isDisabled: false,

        shouldDisplayScrollbar: false,

        disablePageScroll: function () {
            if (this.isDisabled) {
                return;
            }

            let $body = document.body;

            this.isDisabled = true;
            this.shouldDisplayScrollbar = $body.scrollHeight > window.innerHeight;

            window.requestAnimationFrame(() => {
                this.scrollTop = $body.scrollTop;
                $body.style.position = 'fixed';
                $body.style.top = `-${this.scrollTop}px`;
                $body.style.width = '100%';

                if (this.shouldDisplayScrollbar) {
                    $body.style.overflowY = 'scroll';
                }
            });
        },

        enablePageScroll: function () {
            if (!this.isDisabled) {
                return;
            }

            this.isDisabled = false;
            let $body = document.body;

            window.requestAnimationFrame(() => {
                $body.style.position = '';
                $body.style.top = '';
                $body.style.width = '';
                $body.scrollTop = this.scrollTop;
                this.scrollTop = 0;

                if(this.shouldDisplayScrollbar) {
                    $body.style.overflowY = '';
                }
            });
        }
    };

    return {
        disablePageScroll: module.disablePageScroll.bind(module),
        enablePageScroll: module.enablePageScroll.bind(module)
    };

})();