/**
     * Update the scrollbar
     */
    update(): void
    {
        if ( !this.isInitialized )
        {
            return;
        }

        // Update the perfect-scrollbar
        this.ps.update();
    }

    // -----------------------------------------------------------------------------------------------------
    // @ Public methods
    // -----------------------------------------------------------------------------------------------------

    /**
     * Document click
     *
     * @param {Event} event
     */
    @HostListener('document:click', ['$event'])
    documentClick(event: Event): void
    {
        if ( !this.isInitialized || !this.ps )
        {
            return;
        }

        // Update the scrollbar on document click..
        // This isn't the most elegant solution but there is no other way
        // of knowing when the contents of the scrollable container changes.
        // Therefore, we update scrollbars on every document click.
        this.ps.update();
    }

import * as Ps from 'perfect-scrollbar'
const container = document.body

// To initialise the plugin, `Ps.initialize` is used.
Ps.initialize(container)

// It can be initialised with optional parameters.
Ps.initialize(container, {
  wheelSpeed: 2,
  wheelPropagation: true,
  minScrollbarLength: 20
})

// If the size of your container or content changes, call `update`.
Ps.update(container)

// If you want to destroy the scrollbar, use `destroy`.
Ps.destroy(container)

// If you want to scroll to somewhere, just use a `scrollTop` property and update.
container.scrollTop = 0
Ps.update(container)

/**
 * https://github.com/noraesae/perfect-scrollbar#jquery
 */

import mountJQuery = require('perfect-scrollbar/jquery')
mountJQuery($)

 update() {
   PS.update(this.$element);
 }

 private updateScrollbar(): void {
     const container = this.elementRef.nativeElement.querySelector('md-nav-list');
     Ps.update(container);
 }