A Tailwind never-ending carousel (ticker)

I recently wanted a never-ending carousel (I'm not sure of the correct terminology and ticker maybe more correct).

I'm making a side project Wedding Photo Collector and I wanted this for my hero section.

So here is a quick tutorial mostly inspired by this video.

I'm writing this in React but it should be easily convertible to other frameworks or just plain html.

First I start by defining the input Props of the component, which in this case are an array of images which have a url and an alt tag.

type TickerProps = {
    images: { url: string; alt: string }[];
};

Now the next thing was to create the React component and create a <ul> filled with the images.

type TickerProps = {
    images: { url: string; alt: string }[];
};

const Ticker = ({ images }: TickerProps) => {

    return (
        <ul className="">
            {images.map((image) => (
                <li key={image.url} className="">
                    <img
                        src={image.url}
                        alt={image.alt}
                        className=""
                    />
                </li>
            ))}
        </ul>
    );
};

export default Ticker;

Next thing to do is create the animation and to do this we need to edit the tailwind.config.ts we need to add the code below.

keyframes: {
    'image-scroll': {
        '0%': { transform: 'translateX(0)' },
        '100%': { transform: 'translateX(-100%)' },
    },
},
animation: {
    'image-scroll': 'image-scroll 20s linear infinite',
},

You can tweak the 20s value so that the speed makes sense with the amount of images or content you have.

We will now add a few tailwind classes to the ul. animate-image-scroll to apply the animation we just made above. We also want to pop it in a flex container with shrink-0 so the container won't shrink to fit the available size. We also want to add gap-8 and pr-8 to add spacing between the images, tweak the 8 to whatever value looks good for you.

For the <li> we want to add shrink-0 and on the <img> we add h-full to make the images fill the container height, object-cover to make the image fill the container.

At this stage I found a discrepancy in the way Chrome, Firefox and Safari treated this and the fix was to apply a fixed width (otherwise in Firefox and Safari the width would be set by the width of the image file even though the image is scaled down with object-cover) so I add w-[180px].

This should give us...

type TickerProps = {
    images: { url: string; alt: string }[];
};

const Ticker = ({ images }: TickerProps) => {

    return (
        <ul className="animate-image-scroll flex shrink-0 gap-8 pr-8">
            {images.map((image) => (
                <li key={image.url} className="shrink-0">
                    <img
                        src={image.url}
                        alt={image.alt}
                        className="h-full w-[180px] object-cover opacity-85"
                    />
                </li>
            ))}
        </ul>
    );
};

export default Ticker;

If you run this you will notice that it's not never ending it will simply slide off the page.

So here is where the trick comes in. We actually have two <ul> and when the animation finishes the second <ul> will be in the starting position and when the animation starts again it will seamlessly switch out!

There is a small gotcha that we want to put aria-hidden="true" on the second ul for accessibility and so that it doesn't look like duplicate content.

To do this I created an array and mapped over it.

type TickerProps = {
    images: { url: string; alt: string }[];
};

const Ticker = ({ images }: TickerProps) => {
    const ariaHidden = [false, true];

    return (
        <div className="flex h-64">
            {ariaHidden.map((hidden, idx) => (
                <ul className="animate-image-scroll flex shrink-0 gap-8 pr-8" aria-hidden={hidden} key={idx}>
                    {images.map((image) => (
                        <li key={image.url + idx} className="shrink-0">
                            <img
                                src={image.url}
                                alt={image.alt}
                                className="h-full w-[180px] object-cover opacity-85"
                            />
                        </li>
                    ))}
                </ul>
            ))}
        </div>
    );
};

export default Ticker;

Now we are getting there and it should be fully functional there is just one more thing I wanted to add.

As my page is not full width I wanted a fade out at either side so that the images do not get cut off abruptly.

This could be done using absolute positioning but I opted to use grid

So I wrapped it all in a <div> container with a grid class and added two extra <div> elements. All the child <div> where given a col-start-1 and a row-start-1 so they overlay each other.

I then added bg-gradient-to-r from-white via-transparent to-20% to the two extra divs making one to-l you can also change out your background colour here, mine is just white. I also increased the z-index with z-10

I also added overflow-hidden and a rotation with -rotate-3 which you can tweak or omit.

Here is the final component...

type TickerProps = {
    images: { url: string; alt: string }[];
};

const Ticker = ({ images }: TickerProps) => {
    const ariaHidden = [false, true];

    return (
        <div className="grid">
            <div className="col-start-1 row-start-1 flex h-64 -rotate-3 overflow-hidden">
                {ariaHidden.map((hidden, idx) => (
                    <ul className="animate-image-scroll flex shrink-0 gap-8 pr-8" aria-hidden={hidden} key={idx}>
                        {images.map((image) => (
                            <li key={image.url + idx} className="shrink-0">
                                <img
                                    src={image.url}
                                    alt={image.alt}
                                    className="h-full w-[180px] object-cover opacity-85"
                                />
                            </li>
                        ))}
                    </ul>
                ))}
            </div>
            <div className="z-10 col-start-1 row-start-1 -m-1 -rotate-3 bg-gradient-to-r from-white via-transparent to-20%" />
            <div className="z-10 col-start-1 row-start-1 -m-1 -rotate-3 bg-gradient-to-l from-white via-transparent to-20%" />
        </div>
    );
};

export default Ticker;