src/main/javascript/scroll/floatz.scroll.scroller.js
/**
	 * Scroll backward handler.
	 *
	 * @param {Function} handler Custom handler
	 * @returns {Scroller} Scroller for chaining
	 */
Scroll backward handler.
@param {Function} handler Custom handler
@returns {Scroller} Scroller for chaining
Scroll backward handler . @param { Function } handler Custom handler @returns { Scroller } Scroller for chaining
onScrollBackward(handler) {
		this._handlers.push(() => {
			if (this._prevScrollPos > this.scrollPos()) {
				handler(this);
			}
		});
		return this;
	}
onScrollBackward ( handler ) { this . _handlers . push ( ( ) => { if ( this . _prevScrollPos > this . scrollPos ( ) ) { handler ( this ) ; } } ) ; return this ; }
Scroll backward handler.
Scroll backward handler .