
__Framer Motion makes it super easy to create great looking animations, but what if you want to have different animations for different screen sizes? In pure css you can just use a media query but did you know that by utilising the Window.matchMedia API you can use media queries in javascript too? This way we can write responsive animations for javascript animation libraries like Framer Motion & React Spring.__

## Using media queries in javascript

The easiest way to get started with the [window.matchMedia API](https://developer.mozilla.org/en-US/docs/Web/API/Window/matchMedia) in React is to create a custom hook. A lot of UI frameworks like [Material UI](https://material-ui.com/components/use-media-query/) and [Chakra UI](https://chakra-ui.com/docs/hooks/use-media-query) already exposes such a hook, but here's what it could look like if you would write your own:

```jsx
export function useMediaQuery(query) {
  const [matches, setMatches] = useState(false);

  useEffect(() => {
    const media = window.matchMedia(query);
    if (media.matches !== matches) {
      setMatches(media.matches);
    }
    const listener = () => {
      setMatches(media.matches);
    };
    media.addListener(listener);
    return () => media.removeListener(listener);
  }, [matches, query]);

  return matches;
}
```

It takes a media query string (the same way you would write it in css) and returns `true` if the query matches the current screen. If the screen is resized the value will update. Use it in code like this:

```jsx
 const isSmall = useMediaQuery('(min-width: 480px)');
```

A good idea is to set up custom hooks matching the media queries you already use in your css so you don't have to remember the pixel values (was it 479 or 480?):

```jsx
export const useIsSmall = () => useMediaQuery('(min-width: 480px)');
export const useIsMedium = () => useMediaQuery('(min-width: 768px)');

/* etc.. /*
```

## Responsive Animation with Variants

Now that we have our hooks setup lets put it all together by making an example using variants to conditionally change based on the media query.

```jsx
import { motion } from 'framer-motion'
import { useIsSmall } from 'src/hooks/utils'

const Component = () => {
	const isSmall = useIsSmall() /* or useMediaQuery('(min-width: 480px)'); */
 
	const variants = isSmall
	? {
	    animate: {
	      opacity: 1,
	      scale: 1,
				y: 0,
	    },
	    exit: {
	      opacity: 1,
	      scale: 1,
				y: 500,
	    },
	  }
	: {
	    animate: {
	      opacity: 1,
	      scale: 1,
	      y: 0,
	    },
	    exit: {
	      opacity: 0,
	      scale: 0.9,
	      y: -10,
	    },
	  };
	
	return (
		<motion.div initial="exit" animate="animate" exit="exit">Animated</div>
	);
}
```

That's it 🙌. You can also use the variable inline `<motion.div animate={isSmall ? { y: 500} : { y: 1000}} />` but I find that using it together with variants is the cleanest way most of the time.




Parallax scrolling has gotten a bad rap, but I believe that's in part because of the very poor implementations out there. As with everything, if we're mindful and make it subtle it can help convey our message more clearly. There's a simple thing you can do to greatly improve the effect: Use a spring-based easing.

Let's take a look at the [Epic React course](https://epicreact.dev) landing page:

<video playsInline autoPlay loop muted width="710" style={{ width: '100%', maxWidth: 710, marginBottom: 20}}>
    <source src="/blog/spring-parallax-framer-motion-guide/epicreact.mp4" type="video/mp4" />
    Sorry, your browser doesn't support embedded videos.
</video>

This is an example of a parallax transition implemented the right way. If you scroll super-quickly you will still see the animation, and if you use a mouse-wheel it never stutters. This is because the animation is eased and not mapped 1:1 to the actual scroll. This way the effect looks super nice! (And most importantly, it makes sense on this landing page and helps deliver the message).

Another website that does this right is [Quill.chat](http://quill.chat), notice how when you scroll through the site you get a sense of joy when the elements smoothly slide into view with just the right velocity. Had they not eased the movement if wouldn't have felt as good.

<video playsInline autoPlay loop muted width="710" style={{ width: '100%', maxWidth: 710, marginBottom: 20}}>
    <source src="/blog/spring-parallax-framer-motion-guide/quill.mp4" type="video/mp4" />
    Sorry, your browser doesn't support embedded videos.
</video>

## I'm convinced - How to implement parallax spring easing with react?

You can implement parallax scrolling in a lot of different ways, for this example I'm using my favourite animation framework Framer Motion to create a reusable `<Parallax />` component. You can do similar things with other frameworks like react-spring or as descibed [here](https://developers.google.com/web/updates/2016/12/performant-parallaxing) by Paul Lewis & Robert Flack on the google developer blog. If you already know the basics of parallax scrolling feel free to skip to the section adding the spring easing.

Let's start by creating a component that accept children as a prop.

```tsx
import { ReactNode } from 'react'

type ParallaxProps = {
  children: ReactNode
}

const Parallax = ({ children }: ParallaxProps): JSX.Element => {
  return children
})

export default Parallax
```

Next up we'll import `useViewportScroll` from framer-motion in order to get how far on the page we have scrolled. We'll use this as the input to another framer-motion hook called `useTransform` in order to calculate our parallax values which we'll add to a `motion.div`.

## Using Framer Motion useTransform

[useTransform](https://www.framer.com/api/motion/motionvalue/#usetransform) takes an input value and a transformer, and outputs a new value. For example:

```tsx
  // The output value will always be double that of `x`.
  const y = useTransform(x, value => value * 2)
```

Lets start by using some random values to see that it's working:

```tsx{2,9-12}
import { ReactNode } from 'react'
import { motion, useViewportScroll, useTransform } from 'framer-motion'

type ParallaxProps = {
  children: ReactNode
}

const Parallax = ({ children }: ParallaxProps): JSX.Element => {
  const { scrollY } = useViewportScroll()
  const y = useTransform(scrollY, [100, 200], [0, 500])

  return <motion.div style={{ y }}>{children}</motion.div>
})

export default Parallax
```

In order to find out the correct values we need to add some calculations. The idea is that the component should be centered in it's container when we've scrolled to the middle of the screen, but offset by x pixels when scrolled in either direction.

In order to do this we need two values: what the offsetTop of our element is and the height of the screen. Let's add a ref to our element and use `useLayoutEffect` to save those values when the component is about to mount.

```tsx{1,6,9-12,16-36,39}
import { useState, useRef, useLayoutEffect, ReactNode } from 'react'
import { motion, useViewportScroll, useTransform } from 'framer-motion'

type ParallaxProps = {
  children: ReactNode
  offset?: number
}

const Parallax = ({ children, offset = 50 }: ParallaxProps): JSX.Element => {
  const [elementTop, setElementTop] = useState(0)
  const [clientHeight, setClientHeight] = useState(0)
  const ref = useRef(null)

  const { scrollY } = useViewportScroll()

  // start animating our element when we've scrolled it into view
  const initial = elementTop - clientHeight
  // end our animation when we've scrolled the offset specified
  const final = elementTop + offset

  const y = useTransform(scrollY, [initial, final], [offset, -offset])

  useLayoutEffect(() => {
    const element = ref.current
    // save our layout measurements in a function in order to trigger
    // it both on mount and on resize
    const onResize = () => {
      // use getBoundingClientRect instead of offsetTop in order to
      // get the offset relative to the viewport
      setElementTop(element.getBoundingClientRect().top + window.scrollY || window.pageYOffset)
      setClientHeight(window.innerHeight)
    }
    onResize()
    window.addEventListener('resize', onResize)
    return () => window.removeEventListener('resize', onResize)
  }, [ref])

  return (
    <motion.div ref={ref} style={{ y }}>
      {children}
    </motion.div>
  )
})

export default Parallax
```

There's a lot going on here so let's break it down.

<ol>
  <li>We've added an <em>offset</em> prop to specify how strong we want our effect to be.</li>

  <li>We create a ref that we'll use to measure our element</li>

  <li>We setup our state where we'll save elementTop and clientHeight.</li>

  <li>We add a useLayoutEffect where we set those values so we can calculate the start and end for our transformer.</li>

  <li>Finally we put it all together in the useTransform function to get our new <em>y</em> value.</li>
</ol>

## Adding spring easing with useSpring

In order to get the smooth easing we talked about earlier we need to transform our new `y` value with a spring. We can do it with the useSpring hook.

```tsx{2,21-23}
import { useState, useRef, useLayoutEffect, ReactNode } from 'react'
import { motion, useViewportScroll, useTransform, useSpring } from 'framer-motion'

type ParallaxProps = {
  children: ReactNode
  offset?: number
}

const Parallax = ({ children, offset = 50 }: ParallaxProps): JSX.Element => {
  const [elementTop, setElementTop] = useState(0)
  const [clientHeight, setClientHeight] = useState(0)
  const ref = useRef(null)

  const { scrollY } = useViewportScroll()

  // start animating our element when we've scrolled it into view
  const initial = elementTop - clientHeight
  // end our animation when we've scrolled the offset specified
  const final = elementTop + offset

  const yRange = useTransform(scrollY, [initial, final], [offset, -offset])
  // apply a spring to ease the result
  const y = useSpring(yRange, { stiffness: 400, damping: 90 })

  useLayoutEffect(() => {
    const element = ref.current
    // save our layout measurements in a function in order to trigger
    // it both on mount and on resize
    const onResize = () => {
      // use getBoundingClientRect instead of offsetTop in order to
      // get the offset relative to the viewport
      setElementTop(element.getBoundingClientRect().top + window.scrollY || window.pageYOffset)
      setClientHeight(window.innerHeight)
    }
    onResize()
    window.addEventListener('resize', onResize)
    return () => window.removeEventListener('resize', onResize)
  }, [ref])

  return (
    <motion.div ref={ref} style={{ y }}>
      {children}
    </motion.div>
  )
})

export default Parallax
```

## Parallax accessibility: useReducedMotion

When designing products with motion we have to be careful and think about people who might have problems viewing things that move around. Some people can get dizzy or nauseous. You can specify this by a setting in you operating system, for example on MacOS the setting is in "Accessibility > Reduce Motion".

Luckily there's a Media Query for this called `prefers-reduced-motion`, and a useful hook exported by framer motion called `useReducedMotion`.

If the user prefers reduced motion we will render the children directly without our parallax container:

```tsx{2,10,34-37}
import { useState, useRef, useLayoutEffect, ReactNode } from 'react'
import { motion, useViewportScroll, useTransform, useSpring, useReducedMotion } from 'framer-motion'

type ParallaxProps = {
  children: ReactNode
  offset?: number
}

const Parallax = ({ children, offset = 50 }: ParallaxProps): JSX.Element => {
  const prefersReducedMotion = useReducedMotion()
  const [elementTop, setElementTop] = useState(0)
  const [clientHeight, setClientHeight] = useState(0)
  const ref = useRef(null)

  const { scrollY } = useViewportScroll()

  const initial = elementTop - clientHeight
  const final = elementTop + offset

  const yRange = useTransform(scrollY, [initial, final], [offset, -offset])
  const y = useSpring(yRange, { stiffness: 400, damping: 90 })

  useLayoutEffect(() => {
    const element = ref.current
    const onResize = () => {
      setElementTop(element.getBoundingClientRect().top + window.scrollY || window.pageYOffset)
      setClientHeight(window.innerHeight)
    }
    onResize()
    window.addEventListener('resize', onResize)
    return () => window.removeEventListener('resize', onResize)
  }, [ref])

  // Don't parallax if the user has "reduced motion" enabled
  if (prefersReducedMotion) {
    return <>{children}</>
  }

  return (
    <motion.div ref={ref} style={{ y }}>
      {children}
    </motion.div>
  )
}

export default Parallax
```

## Wrapping up

Our finished component:

<div style={{ background: 'var(--boxBg)', padding: 100 }}>
  <Parallax>
    <p style={{background: 'var(--brand)', color: 'white', padding: 10, textAlign: 'center', borderRadius: 5, fontWeight: 700}}>Parallax</p>
  </Parallax>
</div>

We've learned how we can create a parallax effect with Framer Motion, improve it by applying a spring easing and taking care of the accesibility aspect with useReducedMotion. Check out the full source code of our Framer Motion example in my [git repo](https://github.com/samuelkraft/samuelkraft-next/blob/master/components/parallax.tsx), and make sure to ❤️ the post below if you liked it, or reach out to me on [twitter](https://twitter.com/samuelkraft) for any comments or questions!





Despite its funny name, If you’ve ever used an iOS device you’ll recognise the [UISegmentedControl](https://developer.apple.com/documentation/uikit/uisegmentedcontrol):

<div style={{ padding: '20px', border: '1px solid var(--border)', borderRadius: '5px', textAlign: 'center' }}>
  <video playsInline autoPlay loop muted width="375" style={{ width: '100%', maxWidth: 375, marginBottom: 20}}>
      <source src="/blog/segmented-control-framer-motion/segmented-control-ios-two.mp4" type="video/mp4" />
      Sorry, your browser doesn't support embedded videos.
  </video>
  <video playsInline autoPlay loop muted width="375" style={{ width: '100%', maxWidth: 375}}>
      <source src="/blog/segmented-control-framer-motion/segmented-control-ios-five.mp4" type="video/mp4" />
      Sorry, your browser doesn't support embedded videos.
  </video>
</div>

In this post I’ll show how to recreate it for web using React and Framer Motion resulting in this (try it out by clicking below!):

<div style={{ padding: '80px 7px 50px', border: '1px solid var(--border)', borderRadius: '5px', textAlign: 'center' }}>
  <SegmentedControl items={["Upcoming", "Past"]} />
  <br />
  <SegmentedControl items={["H", "D", "W", "M", "Y"]} />
</div>

## Our stack

I’m using a Next.js/React/Typescript/SASS/CSS Modules stack but any react project works fine, as we are use Framer Motion for the animations.

## Our finished component

```tsx
import { useState } from 'react'
import { motion, AnimateSharedLayout } from 'framer-motion'
import styles from './segmentedcontrol.module.scss'

type SegmentedControlProps = {
  items: Array<string>
}

const SegmentedControl = ({ items }: SegmentedControlProps): JSX.Element => {
  const [activeItem, setActiveitem] = useState(0)
  return (
    <AnimateSharedLayout>
      <ol className={styles.list}>
        {items.map((item, i) => {
          const isActive = i === activeItem
          return (
            <motion.li
              className={isActive || i === activeItem - 1 ? styles.itemNoDivider : styles.item}
              whileTap={isActive ? { scale: 0.95 } : { opacity: 0.6 }}
              key={item}
            >
              <button onClick={() => setActiveitem(i)} type="button" className={styles.button}>
                {isActive && <motion.div layoutId="SegmentedControlActive" className={styles.active} />}
                <span className={styles.label}>{item}</span>
              </button>
            </motion.li>
          )
        })}
      </ol>
    </AnimateSharedLayout>
  )
}

export default SegmentedControl
```

```scss
/* CSS variables from my global config */
:root {
  --boxBg: #f3f3f3;
  --activeBg: #292929;
  --text: #000;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

[data-theme='dark'] {
  --boxBg: #1f1e1d;
  --activeBg: #292929;
  --text: #fff;
}
```

```scss
.list {
  display: inline-flex;
  margin: 0;
  padding: 3px;
  list-style: none;
  background-color: var(--boxBg);
  border-radius: 10px;
}

.item {
  position: relative;
  margin-bottom: 0;
  line-height: 1;

  &:after {
    position: absolute;
    top: 15%;
    right: -0.5px;
    display: block;
    width: 1px;
    height: 70%;
    background-color: var(--border);
    transition: opacity 200ms ease-out;
    content: '';
  }

  &:last-of-type {
    &:after {
      display: none;
    }
  }
}

.itemNoDivider {
  composes: item;

  &:after {
    opacity: 0;
  }
}

.button {
  position: relative;
  margin: 0;
  padding: 7px 30px;
  color: var(--text);
  line-height: 1;
  background: transparent;
  border: none;
  outline: none;

  &:hover,
  &:focus {
    cursor: pointer;
  }
}

.label {
  position: relative;
  z-index: 2;
}

.active {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1;
  background-color: var(--inputBg);
  border-radius: 7px;
  box-shadow: var(--shadow);
  content: '';
}
```

There are a few things happening here so let’s walk it through.

First we make sure our component accepts an array of items as props, then we initialise our state to keep track of which item is selected with react `useState`.

```tsx
import { useState } from 'react'

type SegmentedControlProps = {
  items: Array<string>
}

const SegmentedControl = ({ items }: SegmentedControlProps): JSX.Element => {
  const [activeItem, setActiveitem] = useState(0)
  return ()
}

```

<Warning type="info">
In a real-world use case you might opt to keep track of the active item by the page pathname so that you can link to a specific page, in that case you'd get the current pathname with your respective routing solution and then compare it to your items. For Next.js something like:


```tsx
/* example.com/two */

import { useRouter } from 'next/router'

const { pathname } = useRouter()

const items = ['one', 'two', 'three']
{items.map(item => {
  const activeItem = pathname.contains(item)
})}

```
</Warning>

Moving on we wrap our component with `AnimateSharedLayout` from [Framer Motion](https://www.framer.com/motion/), it’s a dead simple way of animating between different elements or components. If you’ve used keynote you can think of it like the “Magic Move” transition. In this example we’re using it to animate our active background state when switching items.

We'll map over our items, get the current active tab by comparing the item index to our state, and for each item return a `motion.li`. [Motion components](https://www.framer.com/api/motion/component/) are used to specify how we want our animation to look like by passing props like `animate` (how the animation will finish), `initial` (our initial state of the animation), `exit` (how our animation looks like when the component dismounts) etc. There are also helper props for things like hover and taps like `whileHover` and `whileTap`. In this example we're using the `whileTap` prop for two things depending on if the item is active or not. If it's active, scale the active state down slightly so the user sees that the UI responds otherwise change the opacity slightly.

If showing more than 2 items, we want to show dividers between the items. We can do this in CSS by using an :after psuedo element. That way we don't need to add any extra elements to the original DOM. Let's change classNames for our motion.li depending on if the divider should be visible or not. There are two scenarios where it should not be visible: 1: when the current item is selected and 2: it's the item before the current selected one. This is because we're positioning the divider to the right of each item (`right: -0.5px`). Our last item does not need any divider so we can remove it with the `:last-of-type` selector. Let's also add an opacity transition so that the dividers fade smootly when switching items.

```tsx
return (
  <AnimateSharedLayout>
    <ol className={styles.list}>
      {items.map((item, i) => {
        const isActive = i === activeItem
        return (
          <motion.li
            className={isActive || i === activeItem - 1 ? styles.itemNoDivider : styles.item}
            whileTap={isActive ? { scale: 0.95 } : { opacity: 0.6 }}
            key={item}
          >
            …
          </motion.li>
        )
      })}
    </ol>
  </AnimateSharedLayout>
)
```
```scss
.item {
  position: relative;
  margin-bottom: 0;
  line-height: 1;

  &:after {
    position: absolute;
    top: 15%;
    right: -0.5px;
    display: block;
    width: 1px;
    height: 70%;
    background-color: var(--border);
    transition: opacity 200ms ease-out;
    content: '';
  }

  &:last-of-type {
    &:after {
      display: none;
    }
  }
}

.itemNoDivider {
  composes: item; /* css modules syntax, compiles to something like "class="item itemNoDivider" */

  &:after {
    opacity: 0;
  }
}
```



We'll add a button inside each item in order to change item on click. If the current item is the active item we add a `motion.div` for rendering the active background styles. This is where we are telling AnimatePresence which element to animate by passing a `layoutId`. It can be any string but needs to match for all elements that should share the same transition. Let's add some styling to the active div and put our item text inside a span in order to position it above the background div with CSS.

```tsx
<button onClick={() => setActiveitem(i)} type="button" className={styles.button}>
  {isActive && <motion.div layoutId="SegmentedControlActive" className={styles.active} />}
  <span className={styles.label}>{item}</span>
</button>
```

```scss
.button {
  position: relative;
  margin: 0;
  padding: 7px 30px;
  color: var(--text);
  line-height: 1;
  background: transparent;
  border: none;
  outline: none;

  &:hover,
  &:focus {
    cursor: pointer;
  }
}

.label {
  position: relative;
  z-index: 2;
}

.active {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 1;
  background-color: var(--activeBg);
  border-radius: 7px;
  box-shadow: var(--shadow);
  content: '';
}
```

When clicking to change items our background will now animate magically 🪄. If you try to click the same item that's already active it will scale down slightly. If there are more than 2 items, we'll have dividers between the items that are not siblings to the active one. When switching items the dividers will fade smoothly.

## Our complete component

<div style={{ padding: '80px 7px 50px', border: '1px solid var(--border)', borderRadius: '5px', textAlign: 'center' }}>
  <SegmentedControl items={["One", "Two", "Three"]} />
</div>

The full source code is [available on my GitHub](https://github.com/samuelkraft/samuelkraft-next/blob/master/components/segmentedcontrol.tsx).

Creating transitions is super fun with Framer Motion and I am especially excited for the possibilities around AnimatedSharedLayout. It makes it extremely easy to create fluid interfaces and I'll be showing more examples of this in the future!

If this helped press the ❤️ below or let me know on [Twitter](https://twitter.com/samuelkraft)



Click around on this webpage and you'll notice a small transition between each page. In this post I'll show you how to create this page transition using Framer Motion.

## Let's get started

We'll start by installing framer motion

```bash
yarn add framer-motion
```

Then create a new component, PageTransition.tsx to house our transition. We want to animate any children of this component so we'll pass children as a prop.

```tsx
import { ReactNode } from 'react'

const PageTransition = ({ children }: { children: ReactNode }): JSX.Element => <div>{children}</div>

export default PageTransition
```

Use this component as a wrapper to any pages you want to animate. In my case I'll add it to my [Page component](https://github.com/samuelkraft/samuelkraft-next/blob/master/components/page.tsx#L29), which sets the layout and shows my footer on all pages.

```tsx{5}
const Page = ({ children }: PageProps): JSX.Element => (
  <div className={styles.container}>
    <Header />
    <main className={styles.main}>
      <PageTransition>{children}</PageTransition>
    </main>
    <Footer />
  </div>
)
```

Framer motion have a couple of different apis to use, and since we want to animate the entry of our children we'll use [AnimatePresence](https://www.framer.com/api/motion/animate-presence/) and [motion components](https://www.framer.com/api/motion/component/). AnimatePresence will animate components when they are added or removed from the React tree. Let's replace our placeholder div with AnimatePresence and nest a motion component that will contain our animation logic.

```tsx
import { ReactNode } from 'react'
import { AnimatePresence, motion } from 'framer-motion'

const PageTransition = ({ children }: { children: ReactNode }): JSX.Element => (
  <AnimatePresence>
    <motion.div>
      {children}
    </motion.div>
  </AnimatePresence>
)

export default PageTransition
```

[Motion components](https://www.framer.com/api/motion/component/) are used to specify how we want our animation to look like by passing props like animate (how the animation will finish), initial (our initial state of the animation), exit (how our animation looks like when the component dismounts) etc.

As an example, passing these values we can animate our component from hidden to visible:

```tsx
<motion.div initial={{ opacity: 0 }} animate={{ opacity: 1 }} />
```

In our specific case we want to animate the entry of the page as if it was sliding up. We can do this by changing our initial prop's y value, and then resetting it in animate.

```tsx
<motion.div initial={{opacity: 0, y: 8 }} animate={{ opacity: 1, y: 0 }}>
```

Navigate to a different page and our animation is working! However the transition needs some love. Framer motion automatically applies a transition based on what you're animating, as an example if you're just animating opacity it's automatically an easing and in the case of transforms it uses a spring. Let's change our transition by applying our own custom easing function. I recommend [cubic-bezier.com](http://cubic-bezier.com) as a great interactive website where you can create your own easings. We want our transition to start fast and then ease out so let's add a transition property with a duration and our custom easing:

```tsx
<motion.div
  initial={{opacity: 0, y: 8 }}
  animate={{
    opacity: 1,
    y: 0,
    transition: {
      duration: 0.4,
      ease: [0.61, 1, 0.88, 1],
    }
  }}
>
```

Now the transition feels a lot better ✌️.

## Improving organisation

We can improve this code further by using framer [variants](https://www.framer.com/api/motion/component/#animationprops.variants), it allows us to keep our animation logic outside out render function in an object organised by name.

Let's create a variable and add our logic. We can name our variants whatever we want, in this case I'll call them 'initial' and 'enter'.

```tsx
const variants = {
  initial: {
    opacity: 0,
    y: 8,
  },
  enter: {
    opacity: 1,
    y: 0,
    transition: {
      duration: 0.4,
      ease: [0.61, 1, 0.88, 1],
    },
  },
}
```

In our motion component we'll then pass our variant variable and can then simply reference our variant names in intial & animate:

```tsx
<motion.div initial="initial" animate="enter" variants={variants}>
  {children}
</motion.div>
```

Our complete final example now looks like this:
```tsx
import { ReactNode } from 'react'
import { AnimatePresence, motion } from 'framer-motion'

const variants = {
  initial: {
    opacity: 0,
    y: 8,
  },
  enter: {
    opacity: 1,
    y: 0,
    transition: {
      duration: 0.4,
      ease: [0.61, 1, 0.88, 1],
    },
  },
}

const PageTransition = ({ children }: { children: ReactNode }): JSX.Element => (
  <AnimatePresence>
    <motion.div initial="initial" animate="enter" variants={variants}>
      {children}
    </motion.div>
  </AnimatePresence>
)

export default PageTransition
```

Feel free to play with transitions and easings, maybe add an exit animation as well? As you've noticed framer motion makes it super easy to create fun and performant transitions. 👌



My site is a place to learn and try new tech, so after seeing Lee Robinsons post on [Using the Spotify API with Next.js](https://leerob.io/blog/spotify-api-nextjs) this was definitely something I wanted to try out. The goal was to add a "Now playing" widget to the footer showing what I'm currently listening to on Spotify.

A few years back I purchased the first version of  Apple Watch, and I remember that the "Now playing" complication had a very pleasant animation with "bars" jumping up and down. This tutorial shows how to create a similar animation perfect for visualizing music. This is what we're building: (psst, if I'm listening to music right now you can watch a live example in the footer…)

<div style={{ padding: '50px', backgroundColor: 'var(--boxBg)', borderRadius: '5px', textAlign: 'center' }}>
  <NowPlayingIcon />
</div>

## Let's get started

This animation is written in css modules with sass in a Next.js/Typescript project but can easily be adjusted to pure css by not using nesting & creating unique classes.

Let's start by creating a wrapper div that will contain our bars, then we'll add a span tag for every bar:

```tsx
import styles from './nowplaying.module.scss'

<div className={styles.icon}>
  <span />
  <span />
  <span />
</div>
```

We'll add some containing styles to our wrapper element and style each bar:

```scss
.icon {
  position: relative;
  display: flex;
  justify-content: space-between;
  width: 13px;
  height: 13px;

  span {
    width: 3px;
    height: 100%;
    background-color: orange;
    border-radius: 3px;
    content: '';
  }
}
```
Which renders:
<div style={{ padding: '50px', backgroundColor: 'var(--boxBg)', borderRadius: '5px', textAlign: 'center' }}>
  <div style={{ position: 'relative', display: 'inline-flex', justifyContent: 'space-between', width: 13, height: 13 }}>
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3 }} />
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3 }} />
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3 }} />
  </div>
</div>

To make our bars jump we'll create a keyframe animation, transforming each bar's scaleY up and down indefinitely and apply it to our bars.

<Warning>Because our bars have border-radius set, the radius will scale as well. This isn't ideal but I feel like it's a fair trade-off instead of animating the height in order to keep our animation at 60fps. <Link href="https://www.html5rocks.com/en/tutorials/speed/high-performance-animations/">Read more about high performance animations</Link></Warning>
<br />

```scss
@keyframes bounce {
  10% {
    transform: scaleY(0.3); /* start by scaling to 30% */
  }

  30% {
    transform: scaleY(1); /* scale up to 100% */
  }

  60% {
    transform: scaleY(0.5); /* scale down to 50% */
  }

  80% {
    transform: scaleY(0.75); /* scale up to 75% */
  }

  100% {
    transform: scaleY(0.6); /* scale down to 60% */
  }
}

span {
  width: 3px;
  height: 100%;
  background-color: orange;
  border-radius: 3px;
  animation: bounce 2.2s ease infinite alternate;
  content: '';
}
```

The infinite property basically tells our animation to keep going forever, and alternate is the short-hand for [animation-direction](https://developer.mozilla.org/en-US/docs/Web/CSS/animation-direction) saying that the animation should be played forwards first, then backwards keeping our animation smooth.

<div style={{ padding: '50px', backgroundColor: 'var(--boxBg)', borderRadius: '5px', textAlign: 'center' }}>
  <div style={{ position: 'relative', display: 'inline-flex', justifyContent: 'space-between', width: 13, height: 13 }}>
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3, animation: 'bounce 2.2s ease infinite alternate' }} />
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3, animation: 'bounce 2.2s ease infinite alternate'  }} />
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3, animation: 'bounce 2.2s ease infinite alternate'  }} />
  </div>
</div>

We have a few problems though. First, the bars are scaling from the center instead of the bottom. We can solve this by adding a transform-origin of bottom:

```scss
span {
  width: 3px;
  height: 100%;
  background-color: orange;
  border-radius: 3px;
  transform-origin: bottom;
  animation: bounce 2.2s ease infinite alternate;
  content: '';
}
```

<div style={{ padding: '50px', backgroundColor: 'var(--boxBg)', borderRadius: '5px', textAlign: 'center' }}>
  <div style={{ position: 'relative', display: 'inline-flex', justifyContent: 'space-between', width: 13, height: 13 }}>
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3, animation: 'bounce 2.2s ease infinite alternate', transformOrigin: 'bottom' }} />
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3, animation: 'bounce 2.2s ease infinite alternate', transformOrigin: 'bottom' }} />
    <span style={{width: 3, height: '100%', backgroundColor: 'var(--brand)', content: '', borderRadius: 3, animation: 'bounce 2.2s ease infinite alternate', transformOrigin: 'bottom' }} />
  </div>
</div>

Now our bars are animating in height but aligned to the bottom! The last thing we need to do is change so that they are not animating at the same time. We want each bar to start animating at a different time so we'll reach for the animation-delay property. But we can't simply delay each bar, because then the animation would't look good the first few seconds. If we add a negative value to animation-delay, the animation will begin immediately but partway through its cycle. From [MDN Docs](https://developer.mozilla.org/en-US/docs/Web/CSS/animation-delay):

> For example, if you specify -1s as the animation delay time, the animation will begin immediately but will start 1 second into the animation sequence.

Let's add different animation-delays to our bars with the :nth-of-type() selector:

```scss
span {
  &:nth-of-type(2) {
    animation-delay: -2.2s; /* Start at the end of animation */
  }

  &:nth-of-type(3) {
    animation-delay: -3.7s; /* Start mid-way of return of animation */
  }
}
```

<div style={{ padding: '50px', backgroundColor: 'var(--boxBg)', borderRadius: '5px', textAlign: 'center' }}>
  <NowPlayingIcon />
</div>

Voila! We now have a smooth working animation, perfect for building a music widget like the one on this website or similar! Check out the [full source code on GitHub](https://github.com/samuelkraft/samuelkraft-next/blob/master/components/nowplaying.module.scss).
