Letter Shuffle Animation for a Menu

import { preloadFonts } from './utils';
import { Menu } from './menu';

// Initialize Menu instance
new Menu(document.querySelector('.menu'));
// Preloading webkit font
preloadFonts('zhn4ifz').then(() => document.body.classList.remove('loading'));

import { gsap } from 'gsap';
import "splitting/dist/splitting.css";
import "splitting/dist/splitting-cells.css";
import Splitting from 'splitting';
import { menuConfig } from './menuConfig';
import { MenuItem } from './menuItem';

// initialize Splitting
Splitting();

/**
 * Class representing the menu element (.menu)
 */
 export class Menu {
    // DOM elements
    DOM = {
        // Main element (.menu)
        el: null,
        // Menu items (.menu__item)
        items: null,
        // Menu button control
        menuCtrl: {
            el: null,
            lines: null,
            cross: null
        },
        // (.menu__bg)
        bg: null,
        // (.menu__tagline)
        tagline: null,
    }
    // The Menu Items instances array
    menuItems = [];
    // Checks if the menu is open or is currently animating
    menuStatus = {
        isOpen: false,
        isAnimating: false
    };
    
    /**
     * Constructor.
     * @param {Element} DOM_el - the .menu element
     */
    constructor(DOM_el) {
        this.DOM = {el: DOM_el};
        this.DOM.items = [...this.DOM.el.querySelectorAll('.menu__item')];
        this.DOM.menuCtrl = {el: this.DOM.el.querySelector('.menu__button')};
        this.DOM.menuCtrl.lines = this.DOM.menuCtrl.el.querySelector('path.menu__button-lines')
        this.DOM.menuCtrl.cross = this.DOM.menuCtrl.el.querySelector('path.menu__button-cross')
        this.DOM.bg = this.DOM.el.querySelector('.menu__bg');
        this.DOM.tagline = this.DOM.el.querySelector('.menu__tagline');

        // Create the MenuItem instances
        this.DOM.items.forEach(item => this.menuItems.push(new MenuItem(item)));

        this.initEvents();
    }
    /**
     * Initializes some events.
     */
    initEvents() {
        this.DOM.menuCtrl.el.addEventListener('click', () => {
            if ( this.menuStatus.isAnimating ) return;

            if ( !this.menuStatus.isOpen ) {
                this.open();
            }
            else {
                this.close();
            }
        });
    }
    /**
     * Opens the menu
     */
    open() {
        if ( this.menuStatus.isAnimating || this.menuStatus.isOpen ) return;
        this.menuStatus.isAnimating = true;
        this.menuStatus.isOpen = true;
        
        const gradient = {value: 'linear-gradient(to bottom, #2b192c, #1a191c)'};

        this.menuTimeline = gsap.timeline({
            defaults: {
                duration: 1.7,
                ease: 'expo.inOut'
            },
            onComplete: () => this.menuStatus.isAnimating = false
        })
        .addLabel('start', 0)
        .add(() => {
            this.DOM.el.classList.add('menu--open');
        }, 'start')
        .to(this.DOM.bg, {
            startAt: {x: -1*this.DOM.bg.offsetWidth + .2*window.innerWidth + .11*window.innerHeight},
            x: 0
        }, 'start')
        .to(gradient, {
            value: 'linear-gradient(rgb(68, 37, 61), rgb(29 24 39))',
            //value: 'linear-gradient(to bottom, #9b498a, #9b7749)',
            onUpdate: () => this.DOM.bg.style.backgroundImage = gradient.value
        }, 'start')
        .to(this.DOM.tagline, {
            opacity: 0,
            x: '-50%'
        }, 'start')
        .to(this.DOM.menuCtrl.cross, {
            duration: 0.5,
            ease: 'power2.inOut',
            opacity: 1
        }, 'start')
        .to(this.DOM.menuCtrl.lines, {
            duration: 0.5,
            ease: 'power2.inOut',
            opacity: 0
        }, 'start')
        .to(this.menuItems.map(item => item.DOM.slotMachine), {
            //ease: 'power3.inOut',
            y: `${100/menuConfig.slotMachineTotalLetters*(menuConfig.slotMachineTotalLetters-1)}%`,
            stagger: 0.03
        }, 'start')

        this.menuItems.forEach(item => {
            this.menuTimeline.to(item.DOM.chars, {
                startAt: {x: '100%', rotation: 10, opacity: 1},
                x: '0%',
                opacity: 1,
                rotation: 0,
                stagger: 0.04
            }, 'start');
        });
    }
    /**
     * Closes the menu
     */
    close() {
        if ( this.menuStatus.isAnimating || !this.menuStatus.isOpen ) return;
        this.menuStatus.isAnimating = true;
        this.menuStatus.isOpen = false;

        const gradient = {value: 'linear-gradient(rgb(68, 37, 61), rgb(29 24 39))'};
        
        this.menuTimeline = gsap.timeline({
            defaults: {
                duration: 1.3,
                ease: 'expo.inOut'
            },
            onComplete: () => this.menuStatus.isAnimating = false
        })
        .addLabel('start', 0)
        .add(() => {
            this.DOM.el.classList.remove('menu--open');
        }, 'start')
        .to(this.DOM.menuCtrl.cross, {
            duration: 0.5,
            ease: 'power2.inOut',
            opacity: 0
        }, 'start')
        .to(this.DOM.menuCtrl.lines, {
            duration: 0.5,
            ease: 'power2.inOut',
            opacity: 1
        }, 'start')
        .to(this.menuItems.map(item => item.DOM.slotMachine), {
            duration: 1.5,
            y: '0%',
            stagger: -0.01
        }, 'start')

        this.menuItems.forEach(item => {
            this.menuTimeline.to(item.DOM.chars, {
                x: '100%', 
                rotation: 10, 
                stagger: -0.04
            }, 'start');
        });

        this.menuTimeline
        .to(this.DOM.bg, {
            x: -1*this.DOM.bg.offsetWidth + .2*window.innerWidth + .11*window.innerHeight,
            onComplete: () => {
                this.DOM.bg.style.transform = 'translateX(-100%) translateX(20vw) translateX(11vh)';
            }
        }, 'start+=0.2')
        .to(gradient, {
            value: 'linear-gradient(to bottom, #2b192c, #1a191c)',
            onUpdate: () => this.DOM.bg.style.backgroundImage = gradient.value
        }, 'start+=0.2')
        .to(this.DOM.tagline, {
            opacity: 1,
            x: '0%'
        }, 'start+=0.2')
    }
 }

/**
 * exports some default options.
 */
 export let menuConfig = {
    slotMachineTotalLetters: 8,
    displayVerticalTitle: 'HAPUKU'
};

import { menuConfig } from './menuConfig';

/**
 * Class representing the menu item (.menu__item)
 */
 export class MenuItem {
    // DOM elements
    DOM = {
        // Main element (.menu__item)
        el: null,
        // The span.char created by calling Splitting
        chars: null,
        // the element that stores all the vertical letters (.letter-wrap__inner) and that will animate up/down before revealing the menu item tex
        slotMachine: null,
    }
    // The position of this item in the menu
    itemPosition;
    
    /**
     * Constructor.
     * @param {Element} DOM_el - the .menu__item element
     */
    constructor(DOM_el) {
        this.DOM = {el: DOM_el};
        this.DOM.chars = [...this.DOM.el.querySelectorAll('span.char')];
        this.itemPosition = [...this.DOM.el.parentNode.children].indexOf(this.DOM.el);

        // Creates the necessary DOM elements to store all the letters and the extra random letters for the slot machine effect
        this.layout();
    }
    /**
     * This DOM modification will happen for every menu item e.g. <a data-splitting href="#" class="menu__item">ABOUT</a>
     * 
     * The a.menu__item will get transformed into:
     * 
     * <a href="#" class="menu__item">
     *   <span class="letter-wrap">
     *     <span class="letter-wrap__inner">
     *       <span>A</span> // first letter in "ABOUT"
     *       <span>H</span> // random letter
     *       <span>W</span> // random letter
     *       <span>P</span> // random letter
     *       ...            // random letters
     *       <span>P</span> // first letter in "HAPUKU"
     *     </span>
     *   </span>
     *   <span class="letter-wrap"><span>B</span></span>
     *   <span class="letter-wrap"><span>O</span></span>
     *   <span class="letter-wrap"><span>U</span></span>
     *   <span class="letter-wrap"><span>T</span></span>
     * </a>
     */
    layout() {
        // We need slotMachineTotalLetters-2 random letters. 
        // The first span inside the .letter-wrap__inner is the first letter in the original link name 
        // The last span inside the .letter-wrap__inner is the nth letter (this menu item'position) in the menuConfig.displayVerticalTitle 
        const totalRandomChars = menuConfig.slotMachineTotalLetters-2;
        const allChars = 'ABCDEFGHIJKLMNOPRSTUVWXYZ';
        
        this.DOM.chars.forEach((char, charPosition) => {
            const wrapEl = document.createElement('span');
            wrapEl.classList = 'letter-wrap';
            char.parentNode.appendChild(wrapEl);
            wrapEl.appendChild(char);
            
            // First char needs a vertical structure (slot machine)
            if ( charPosition === 0 ) {
                this.DOM.slotMachine = document.createElement('span');
                this.DOM.slotMachine.classList = 'letter-wrap__inner';
                wrapEl.appendChild(this.DOM.slotMachine);
                
                const randomCharsArray = Array.from({ length: totalRandomChars }, _ => allChars.charAt(Math.floor(Math.random() * allChars.length)));
                let htmlStr = `<span>${char.innerHTML}</span>`;
                for (let i = 0; i <= totalRandomChars-1; ++i ) {
                    htmlStr += i === totalRandomChars-1 ? `<span>${randomCharsArray[i]}</span><span>${menuConfig.displayVerticalTitle.charAt(this.itemPosition)}</span>` : `<span>${randomCharsArray[i]}</span>`
                };
                this.DOM.slotMachine.innerHTML = htmlStr;
                wrapEl.removeChild(char);
            }
        });
    }
 }

// Preload images
const preloadFonts = id => {
    return new Promise((resolve) => {
        WebFont.load({
            typekit: {
                id: id
            },
            active: resolve
        });
    });
};

export {
    preloadFonts
};

README.md
## Credits

- Images from [Unsplash](https://unsplash.com/)


## License
[MIT](LICENSE)

Made with :blue_heart:  by [Codrops](http://www.codrops.com)

MIT License

Copyright (c) 2009 - 2021 [Codrops](https://tympanus.net/codrops)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

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Source: https://gsap.com/community/standard-license/
Retrieved: 2026-09-22T04:22:49.089Z
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 Effective date: April 30, 2025

 Last modified date: May 30, 2025

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splitting@1.1.0 — LICENSE.md
MIT License

Copyright (c) 2018 Stephen Shaw

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.